anatomy and physiology
TRANSCRIPT
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MS T102Anatomy and Physiology
Swami Vivekananda Yoga Anusandana Samsthana
(A Yoga University, established under Section 3 of the UGC Act, 1956)
Block - 1
Introduction to Human Anatomy & Physiology
Each Soulis potentially Divine. The goalof life is to manifest that Divinity within by controlling
nature internaland external. Do it by Work or Worship or Philosophy or Psychic control, by one
or more or allof these and be FREE….”
Swami Vivekananda
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EXPERT ADVICE AND
COURSE PREPARATION TEAM
Dr H R Nagendra
Vice chancellor,
SVYASA University
Dr Shirley Telles
Joint Director – Research,
SVYASA University
Dr Ramachandra G Bhat
Dean, Division of Yoga & Spirituality,
SVYASA University
Prof N V C Swamy
Dean, Yoga & PhysicalSciences, SVYASA
University
Dr Nagarathna R
Dean, Division of yoga & Life Sciences,
SVYASA University
Prof R N Iyengar
Dean, Division of Yoga & Humanities,
SVYASA
Dr N C B Nath
Dean, Yoga & Management,
SVYASA University
Prof R Venkatram
Directorate, Distance Education,
SVYASA University
BLOCK PREPARATION TEAM
Ms Karuna Nagarajan
Lecture , SVYASA University
Swami Vivekananda Yoga Anusandana Samasthana (A Yoga University)
Allrights are reserved. No part of this work may ereproduced in any form, by mimeograph or any
other means, without permission in writing from the
Swami Vivekananda yoga Anusandana Samsthana, University.
Printed & Published by
Swami Vivekananda Yoga Prakashana (SVYP),
Bangalore
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UNIT 1 HUMAN BODY STRUCTURE
Structure
1.0 Introduction
1.1 Objectives
1.2 About Human anatomy & physiology terminology
1.3 The Cell & Tissue
1.4 The Different systems of the body
1.5 Biological Basis of Human Behaviour
1.6 Summary
1.7 Questions
1.0 Introduction
Human beings are arguably the most complex organisms on this planet. Imagine billions of
microscopic parts, each with its own identity, working together in an organized manner for
the benefit of the total being. The human body is a single structure but it is made up of
billions of smaller structures of four major kinds: cell, tissue, organ & system.
Human beings are arguably the most complex organisms on this planet. Imagine billions of
microscopic parts, each with its own identity, working together in an organized manner for
the benefit of the total being. The human body is a single structure but it is made up of
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billions of smaller structures of four major kinds:
Cells
Cells have long been recognized as the simplest units of living matter that can maintain life
and reproduce themselves. The human body, which is made up of numerous cells, begins as a
single, newly fertilized cell.
Tissues
Tissues are somewhat more complex units than cells. By definition, a tissue is an organization
of great many similar cells with varying amounts and kinds of nonliving, intercellular
substance between them
Organs
Organs are more complex units than tissues. An organ is an organization of several different
kinds of tissues so arranged that together they can perform a special function. For example,
the stomach is an organization of muscle, connective, epithelial, and nervous tissues. Muscle
and connective tissues form its wall, epithelial and connective tissues form its lining, and
nervous tissue extends throughout both its wall and its lining.
Systems
Systems are the most complex of the component units of the human body. A system is an
organization of varying numbers and kinds of organs so arranged that together they can
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perform complex functions for the body. Ten major systems compose the human body:
• Skeletal
• Muscular
• Nervous
• Endocrine
• Cardiovascular
• Lymphatic
• Respiratory
• Digestive
• Urinary
• Reproductive
1.1 OBJECTIVES
In this unit you will be introduced to the terminologies of Anatomy & Physiology, Cell
structure, Cell functions, Body functions & planes of the body and body cavities, Tissues and
their types, different system of the human system and also the Biological basis of the human
behaviour.
1.2 ABOUT HUMAN ANATOMY & PHYSIOLOGY TERMINOLOGY
a. Anatomy is the study of the structure of the body. Often, you may be more interested in
functions of the body. Functions include digestion, respiration, circulation, and reproduction.
Physiology is the study of the functions of the body.
b. The body is a chemical and physical machine. As such, it is subject to certain laws. These
are sometimes called natural laws. Each part of the body is engineered to do a particular job.
These jobs are functions. For each job or body function, there is a particular structure
engineered to do it.
c. In the laboratory, anatomy is studied by dissection (SECT = cut, DIS = apart).
Physiology is the study of the functions of the body at the cellular level.
The individual cell is the basis of the structure and function of the human body. The
individual human body consists of great numbers of these cells working together as a total
organism. Groups of like cells performing a common function are called tissues. Different
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tissues collected together form individual organs. Groups of organs performing an overall
function are called organ systems, for example, the digestive system, the respiratory system,
etc. When these systems are together in a single individual, we refer to that individual as an
organism. The cellular level of function is the primary subject matter of physiology.
ANATOMY ===> structure
Always involves the question "What is it?"
PHYSIOLOGY ===> function
Always involves the question "How does it work?"
Involves process.
There is an inseparable relationship between structure and function in the human body.
Every structure is designed to perform a particular function or functions. Likewise, every
function has structures designed to perform it.
with the study of all living things in the subjects of biology; as well as this three is the work
of the cytologist, interested in details of the structure of cells, and that of the biochemist,
dealing with the chemical changes and activities of cells and investigating the complex
chemistry of life, and three is physics, the study of the physical reactions and movements
taking place in the body.
The body is made up of many tissues and organs, each having its own particular function to
perform. The cell is the unit or the smallest element of the body of which all parts are
comprised. The cells are adapted to perform the special functions of the organ or tissue they
are in. some cells, such as those in the nervous system and muscle, are very specialized
indeed; others, such as those in the connective tissues, are less highly developed. As a general
rule the most highly specialized cells are the least able to withstand damage and also are the
most difficult to repair or replace.
ANATOMICAL TERMINOLOGY
Before we get into the following learning units, which will provide more detailed discussion
of topics on different human body systems, it is necessary to learn some useful terms for
describing body structure. Knowing these terms will make it much easier for us to understand
the content of the following learning units. Three groups of terms are introduced here:
directional terms, terms describing planes of the body, and terms describing body cavities.
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Directional Terms
Planes of the Body
Body Cavities
Directional terms describe the positions of structures relative to other structures or
locations in the body.
Superior or cranial - toward the head end of the body; upper (example, the hand is part of the
superior extremity).
Inferior or caudal - away from the head; lower (example, the foot is part of the inferior
extremity). Anterior or ventral -front (example, the kneecap is located on the anterior side of
the leg).
Posterior or dorsal - back (example, the shoulder blades are located on the posterior side of
the body). Medial - toward the mid line of the body (example, the middle toe is located at the
medial side of the foot).
Lateral - away from the midline of the body (example, the little toe is located at the lateral
side of the foot).
Proximal - toward or nearest to the trunk or the point of origin of a part (example, the
proximal end of the femur joins with the pelvic bone).
Distal - away from or farthest from the trunk or the point or origin of a part (example, the
hand is located at the distal end of the forearm).
Planes of the body
Medical professionals often refer to sections of the body in terms of anatomical planes (flat
surfaces). These planes are imaginary lines - vertical or horizontal - drawn through an upright
body. The terms are used to describe a specific body part.
Coronal Plane (Frontal Plane)
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A vertical plane running from side to side; divides the body or any of its parts into anterior
and posterior portions.
Sagittal Plane (Lateral Plane)
A vertical plane running from front to back; divides the body or any of its parts into right and
left sides.
Axial Plane (Transverse Plane)
A horizontal plane; divides the body or any of its parts into upper and lower parts.
Median plane
Sagittal plane through the midline of the body; divides the body or any of its parts into right
and left halves.
Body Cavities
The cavities, or spaces, of the body contain the internal organs, or viscera. The two main
cavities are called the ventral and dorsal cavities. The ventral is the larger cavity and is
subdivided into two parts (thoracic and abdomino-pelvic cavities) by the diaphragm, a dome-
shaped respiratory muscle.
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Thoracic cavity
The upper ventral, thoracic, or chest cavity contains the heart, lungs, trachea, esophagus,
large blood vessels, and nerves. The thoracic cavity is bound laterally by the ribs (covered by
costal pleura) and the diaphragm caudally (covered by diaphragmatic pleura
Abdominal and pelvic cavity
The lower part of the ventral (abdominopelvic) cavity can be further divided into two
portions: abdominal portion and pelvic portion. The abdominal cavity contains most of the
gastrointestinal tract as well as the kidneys and adrenal glands. The abdominal cavity is
bound cranially by the diaphragm, laterally by the body wall, and caudally by the pelvic
cavity. The pelvic cavity contains most of the uro-genital system as well as the rectum. The
pelvic cavity is bounded cranially by the abdominal cavity, dorsally by the sacrum, and
laterally by the pelvis.
Dorsal cavity
The smaller of the two main cavities is called the dorsal cavity. As its name implies, it
contains organs lying more posterior in the body. The dorsal cavity, again, can be divided into
two portions. The upper portion, or the cranial cavity, houses the brain, and the lower portion,
or vertebral canal houses the spinal cord.
PHYSIOLOGICAL TERMINOLOGY
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Body functions
The living human being performs many functions as a part of daily life.
a. Nutrition. The body takes in materials for energy, growth, and repair. Since the body
cannot produce its own energy, it must continually take in foods to supply that energy to carry
on the life processes. This food also provides materials for growth and repair of the cells and
tissues.
b. Motion and Locomotion. Being an erect, standing organism, the body requires special
supporting structures. At the same time, it needs a mechanical arrangement to allow the parts
to move (motion) and to move from place to place (locomotion).
c. Reproduction. For the species to continue, there must be reproduction, the formation of
new human beings belonging to subsequent generations.
d. Control. All of this activity is controlled by three major systems of the body--
heredity/environment, hormones, and the nervous system. Hormones provide a chemical
control system. The nervous system works much like circuitry in a computer. In the final
analysis, however, all of the structures and functions of the body are determined by special
units called genes, the study of which is genetics and the transmission of which is heredity.
Heredity determines the potential range of an organism's characteristics. The environment
determines which potential characteristics are developed and to what degree.
Life Process
All living organisms have certain characteristics that distinguish them from non-living forms.
The basic processes of life include organization, metabolism, responsiveness, movements,
and reproduction. In humans, who represent the most complex from of life, there are
additional requirements such as growth, differentiation, respiration, digestion, and excretion.
All of these processes are interrelated. No part of the body, from the smallest cell to a
complete body system, works in isolation. All function together, in fine-tuned balance, for the
well being of the individual and to maintain life. Disease such as cancer and death represent a
disruption of the balance in these processes.
The following is a brief description of the life process:
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Organization
At all levels of the organizational scheme, there is a division of labor. Each component has its
own job to perform in cooperation with others. Even a single cell, if it loses its integrity or
organization, will die.
Metabolism
Metabolism is a broad term that includes all the chemical reactions that occur in the body.
One phase of metabolism is catabolism in which complex substances are broken down into
simpler building blocks and energy is released.
Responsiveness
Responsiveness or irritability is concerned with detecting changes in the internal or external
environments and reacting to that change. It is the act of sensing a stimulus and responding to
it.
Movement
There are many types of movement within the body. On the cellular level, molecules move
from one place to another. Blood moves from one part of the body to another. The diaphragm
moves with every breath. The ability of muscle fibers to shorten and thus to produce
movement is called contractility.
Reproduction
For most people, reproduction refers to the formation of a new person, the birth of a baby. In
this way, life is transmitted from one generation to the next through reproduction of the
organism. In a broader sense, reproduction also refers to the formation of new cells for the
replacement and repair of old cells as well as for growth. This is cellular reproduction. Both
are essential to the survival of the human race.
Growth
Growth refers to an increase in size either through an increase in the number of cells or
through an increase in the size of each individual cell. In order for growth to occur, anabolic
processes must occur at a faster rate than catabolic processes.
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Differentiation
Differentiation is a developmental process by which unspecialized cells change into
specialized cells with distinctive structural and functional characteristics. Through
differentiation, cells develop into tissues and organs.
Respiration
Respiration refers to all the processes involved in the exchange of oxygen and carbon dioxide
between the cells and the external environment. It includes ventilation, the diffusion of
oxygen and carbon dioxide, and the transport of the gases in the blood. Cellular respiration
deals with the cell's utilization of oxygen and release of carbon dioxide in its metabolism.
Digestion
Digestion is the process of breaking down complex ingested foods into simple molecules that
can be absorbed into the blood and utilized by the body.
Excretion
Excretion is the process that removes the waste products of digestion and metabolism from
the body. It gets rid of by-products that the body is unable to use, many of which are toxic
and incompatible with life.
The ten life processes described above are not enough to ensure the survival of the
individual. In addition to these processes, life depends on certain physical factors from the
environment. These include water, oxygen, nutrients, heat, and pressure.
Metabolism is a broad term that includes all the chemical reactions that occur in the body.
One phase of metabolism is catabolism in which complex substances are broken down into
simpler building blocks and energy is released.
Variations Among Human Organisms
The human organism is known scientifically as Homo sapiens, meaning the intelligent human
being. There is a more or less common form for human beings. This common form includes
one head, two upper members, two lower members, etc., but there are no two individuals
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exactly alike in detail. (This even includes identical twins. One tends to be left-oriented and
the other right-oriented.) As a result, there is a tremendous variation among humans which
has been further complicated by selection and propagation of specific traits by humans
themselves.
Energy
As we have previously mentioned, energy is required to carry on the life processes of each
individual human being.
a. One of the laws of nature is conservation of energy. This means that energy cannot be
created or destroyed but only transformed. For example, electricity can be
transformed into heat. The human body cannot produce energy on its own and must,
therefore, continuously take in a fresh supply of energy.
b. Except for a few special situations, all of the energy for living matter on Earth is received
from the Sun through solar radiation. Green plants trap and bind this solar energy in
molecules of glucose by the process of photosynthesis.
c. Humans take this glucose into their bodies directly by eating green plants or indirectly by
eating the flesh of plant-eating animals. The human body releases the trapped energy from
glucose by a process known as metabolic oxidation.
d. The released energy is used to form the compound ATP (adenosine triphosphate) from
ADP (adenosine diphosphate). ATP is like a charged battery; the "discharged battery" is
called ADP. Molecules of ATP are present in all of the living cells of the body. Within
each cell, molecules of ATP are "discharged" to release a large quantity of energy to drive
the various life processes. Through further metabolic oxidation, the resulting ADP
molecules are "recharged" to form ATP molecules once again.
which lies nearer to the median plane of the body then another is said to be medial to that to
that other. For e.g., the hamstring muscles which lie on the inner side of the thigh are nearer
the median therefore medial to the other group which are described as lateral. Similarly the
inner side of the thigh is described as the medial aspect and the outer as the lateral aspect.
The terms internal and external are used to describe the relative distance of an organ or
structure from the centre of a cavity. The ribs for e.g., have an internal surface which is near
the chest cavity and an external surface which is on the outer side, farther away from the
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cavity. The internal carotid artery is within the cranial cavity and the external is outside the
cavity.
1.3 THE CELL & TISSUE
A cell is a minute (jelly-like) mass of protoplasm containing a nucleus held together by a cell
membrane. In considering the structure of a cell its component parts may usefully be related
to its function.
Cell possess the qualities of all living matter, including those of self-preservation and
reproduction.
Ingestion and assimilation cells select from the intracellular or interstitial fluid which
surrounds them chemical substances such as amino-acids, which the cell builds up into the
very complicated substances, e.g., proteins, which make up protoplasm. Thus a cell is a very
active unit in which the nourishing food materials eaten by man absorbed and assimilated.
Growth and repair these materials brought to the cell may be used by the cell to synthesize
new protoplasm, in which case the cell increases in size, that is, it grows. They may also be
used to replace worn-out parts of the cell. These constructive activities, growth and cell
repair, are spoken of as the anabolic functions of the cell or anabolism.
Metabolism on the other hand, the cell needs a supply of energy for its activation and it will
use some absorbed food materials as a fuel. The food is broken down (catabolism) and the
energy stored in it is released and used by the cell to provide heat, glandular secretion,
movement and nervous activity. Anabolism and catabolism make up the total activities of the
cell or metabolism.
Respiration O2 brought from the lungs by the blood and the removal of the gaseous waste-
product, CO2, are essential for the functions and survival of the cell.
Excretion the waste materials resulting from the catabolic processes are eliminated from the
cell into the interstitial fluid, and thence carried away by the blood. The blood transports the
carbonic acid waste to the lungs where it is removed from the body as CO2. The other waste
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substances are eliminated, via the kidneys, in the urine.
Irritability and Conductive mention has been made of some of these cells characteristic
functional properties, their metabolic activities and power of growth.
By these two properties the cell is active. When a cell is stimulated either by chemical,
physical, mechanical or nervous means the cell responds; it may contract as does a muscle
cell; it may produce a secretion, as do the cells of the stomach, pancreas and other organs and
glands or it may conduct an impulse, as in the case of the nerve cell. This last is the best
example of cell conductivity as a nerve impulse generated by the stimulation of a nerve cell
may be conducted for a considerable distance, a yard or more according to the length of the
nerve fibre. But in all case, a stimulus which excites a cell to action is conducted along the
entire length from end to end of the cell.
CELL STRUCTURE
The structure of the cell it is essential to relate its part to its function.
The protoplasm of the cell is composed of a centrally placed body, the nucleus and the
cytoplasm or reminder of the protoplasm, which surrounds the nucleus.
Cytoplasm this contains the following essential requirements:
1. Mitochondria, small rod-like structure which are closely connected with the
catabolic or respiratory processes of the cell body.
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2. Golgi apparatus, a canal-like structure lying next to the nucleus and involved in
the secretory activities of the cell.
3. Ground cytoplasm, a highly complex colloidal material in which the other
structures are embedded. It is largely concerned with the anabolic or synthetic
activities of the cell.
4. Centrosome, a minute dense part of the cytoplasm, lying close to the nucleus. It
plays an important part during cell division.
5. Cell membrane, the cell boundary is no static envelope. Many important functions
are connected with it, but in particular it acts as selective sieve through which
certain substances are allowed to pass into the cell or which prevents other
substances from gaining access to it. Thus it is most important in maintaining the
correct chemical composition of protoplasm.
Nucleus the nucleus consists of a more compact mass of protoplasm, separates from the
cytoplasm by the nuclear membrane which is also selectively porous, allowing substances to
escape from the nucleus into the cytoplasm or substances to pass into it. The nucleus controls
the cell and all its activities. Without a nucleus the cell would die.
The nucleus contains many protein-rich threads lying in a nuclear sap. In the ‘resting cell’ the
threads are collectively spoken of as chromatin. These threads or chromosomes are vital to
the everyday activities of the cell and are responsible for determining the hereditary
characteristics of the human body. On the chromosomes in linear arrangement sit the genetic
or hereditary determinants the genes. The number of chromosomes in a body cell is constant
for a particular species of organism. In man there are 23 pairs of 46 chromosomes.
Reproduction a cell does not go on growing indefinitely in size but at a certain optimum
point divides into two daughter cells. Further, certain cells will undergo divisions to replace
worn-out cells or those destroyed by disease. This kind of cell division is called mitosis or
karyokinesis.
Activity begins in the nucleus, the nuclear membrane disappears and the chromatin changes
character and becomes long filaments called chromosomes. The centrosome divides and the
two new centrosome move away from each other to reach end of the nucleus called the poles.
The chromosomes are then attracted to the poles and lie near the new centrosomes. The
chromatin of which the nucleus is formed now comes to rest and two new nuclei exist.
Finally the protoplasm of the cell constricts and divides and the two new cells are complete.
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Each new daughter cell resulting from mitosis contains 46 chromosomes, so that during
mitosis each chromosome must duplicate itself. The process of chromosomal duplication is
one of the least understood of the cell’s activities.
However, mitosis is not the only kind of cell division. In the sex organs, the ovary and testis,
another kind of cell division occurs called meiosis. During mitosis each chromosome must
duplicate itself. The process of chromosomal duplication is one of the least understood of the
cell’s activities.
However, mitosis is not the only kind of cell division. In the sex organs the ovary and testis,
another kind of cell division occurs called meiosis. During the formation of the sex cells. Or
gamates, the number of chromosomes is halved, so that the spermatozoa contains only 23
chromosomes and the egg-cell or ovum 23.
When fertilization occurs that is when spermatozoon and ovum fuse to form the cell (zygote)
which develops into a new individual, the normal chromosomal complement of 46 is
restored. By this means a mixing of the hereditary determinants or genes from male and
female is achieved.
TISSUES
Four groups of tissue in the body are known as the elementary tissues. These are
epithelial tissue
muscular tissue
nervous tissue
connective tissue.
Types of Epithelial Tissue an epithelium consists of cells which cover surfaces of the body,
e.g., blood vessels and the air cells. There are two main classes of epithelial tissue, each
containing several verities. All epithelial cells lie on and are held together by a homogenous
substance called a basement membrane.
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Simple Epithelium this class consists of a single layer of cells, and is subdivided into three
verities.
Pavement or Squamous Epithelium. Pavement epithelial cells are fine thin plates placed edge
to edge like the particles in a mosaic pattern or the stone of a pavement. These cells form the
alveoli of the lungs. They are found whenever a very smooth surface is essential as in the
lining of the heart, lining of blood vessels and lymphatics. When lining these structures the
epithelial covering or lining is called endothelium.
Columnar Epithelium forms a single layer of cells which line the duct of most glands the gall-
bladder, nearly the whole of the digestive tract, in which goblet cells are interspersed and
parts of the genitor-urinary tract. Columnar cells from intestine; these have a slightly striated
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border. In some situations as when lining the alveoli of secreting glands, the cells of columnar
epithelium are short and have a cubical appearance-they are then described as cubical cells.
Ciliated Epithelium is found lining the air-passage and their ramification such as the frontal
and maxillary sinuses. It also lines the uterine tubes or oviducts and parts of the uterus and
the ventricles of the brain. These cells are like columnar cells in shape, but they have in
addition fine hair-like processes attached to their free edge. These processes are called cilia.
The ciliary processes keep up a continual movement directed towards the external opening.
This movement has been likened to the movement seen in a field or corn, blown in one
direction by the wind. In the respiratory passages the constant movements prevents ducts,
mucus etc., entering the lungs and in the uterine tubes the movements conveys the ovum into
the uterus.
Goblet cells are mucus-secreting cells which lie in the walls of glands and ducts lined by
columnar cells, either plain or ciliated. Goblet cells secret mucus or mucin and express it on
to the surface; they act as mucus-secreting glands and are most numerous where a
considerable amount of mucus covers the surface as in the stomach, colon and trachea.
Compound Epithelium consists of more then one layer of cells. Stratified Epithelium forms
the epidermal layers of the skin.
It also lines the mouth, pharynx, esophagus, the lower part of the urethra, the anal canal and
the vagina, and covers the surface of the cornea. In these areas it does not become cornified.
The outer layers of cells near the surface comprise the horny layer of the skin; these cells are
flattened and resemble scales. The deepest layer of cells is columnar in shape. These form the
germinative layer and hence the cells multiply by karyokinesis, pushing those above them
nearer the surface until the superficial ones are cast off.
The cells between the basal layer and the horny zone are called ‘prickle cells’, they are
connected to each other by fine tendrils which give them a prickly appearance when
examined under the microscope.
Transitional Epithelium is a compound stratified epithelium consisting of three layers of cells.
It lines the urinary bladder, the pelvis of the kidney, the ureters and the upper part of the
urethra. The deeper layers of cells in transitional epithelium are of the columnar type of cell
with rounded ends which make them pyriform or pear-shaped. As the cells in the deeper
layers multiply by dividing, the superficial layers of cells are cast off. The superficial cell
layers in transitional epithelium are less scale-like than those of stratified epithelium.
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Functions of Epithelial Tissue. The epithelial tissue which forms the covering of the body,
the skin and the lining of the cavities which open on to the surface is mainly protective. It
prevents injury to the underlying tissues, prevents the loss of fluid from these tissues and also
prevents the passage of fluid into the structure which are covered by skin. Micro-organisms
cannot pass through healthy skin but they can and do pass through abraded skin.
Secretory. Most of the secreting glands and their ducts are composed of columnar
epithelium. Very often the epithelium lining the gland and its duct is continuous with that of
the surface in which the glands lie. Simple tubular and simple saccular glands are just
involutions from the surface such as the simple tubular glands of the intestine. When these
involutions branch, the structure becomes more complicated, as in the formation of
compound tubular glands such as those of the kidneys, and compound racemose or saccular
glands such as the salivary glands and the pancreas.
The endocrine glands are also composed of epithelial cells which may be massed together or
may line hollow vesicles as occurs in the thyroid gland where vesicles are lined by columnar
epithelial cells, cubical in shape. These cells produce their secretion-colloid-but there is no
duct from these glands and therefore the secretion reaches the blood stream either directly or
though the lymphatics.
Glands a gland is a secretory organ which may exist as a separate organ such as liver,
pancreas and spleen; or may be simply a layer of cells as the simple tubular glands of the
alimentary canal, body cavities, etc. All glands have a rich blood supply. Their special
function is to select from the blood stream certain substances, which they then elaborate into
their important juices or secretions. There is a tremendous variety of glands, each with its
different function, making a collective description and classification difficult. A simple
classification as follows:
Glands which pour their secretion directly on to the surface include the sweat glands,
sebaceous glands and the gastric and intestinal glands.
Glands which pour their secretion indirectly, by means of ducts, on to the surface include the
salivary glands, pancreas and liver.
Ductless glands. These are the glands of internal secretion. A great deal of the well-being of
the body depends on these glands, which through their secretions exert an important chemical
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control on the functions of the body.
Membranes layers of specialized cells which line the cavities of the body are described as
membrane. The three principal membranes are: Mucous, Synovial and Serous membrane.
All these membranes secrete a fluid to lubricator moisten the cavity they line.
Mucous membrane is found lining the alimentary tract, the respiratory tract, and parts of the
genitor-urinary tract. It varies in character in the different areas. In the digestive tract it
consists of columnar epithelial cells closely packed together. Some of them called goblet
cells. The cell becomes more and more distended and finally ruptures and discharges its
secretion on to the surface.
Mucus is the secretion of the membrane and consists of water, salts and a protein, mucin
which gives the sticky or viscid character to the secretion.
Synovial membrane lines the cavities of joints. It consists of fine connective tissue, with a
layer of Squamous endothelial cells of the surface. The secretion of Synovial membrane is
thick and glairy in character.
Serous membranes are found in the chest and abdomen, covering the organs contained
therein and lining these cavities.
The pleura covers the lungs and lines the thorax.
The pericardium covers the abdominal organs and lines the abdomen.
The characteristics which are common to all three serous membranes are that each consists of
a double layer of membrane having an intervening potential cavity which receives the fluid
secreted by the membrane. This serous fluid is very similar to blood serum or lymph. It acts
as a lubricant, and in addition it contains protective substances and removes harmful
products, passing these on to the lymphatic system to be dealt with.
Muscular-Nervous-Connective Tissue
Muscular Tissue muscle is a tissue which is specialized for contraction and by means of this,
movements are performed. It is composed of cylindrical fibres which correspond to the cells
of other tissues. These are bound together into little bundles of fibres by a form of connective
tissue which contains a highly specialized contractile element.
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There are three types of muscles:
Striped (striated, skeletal or voluntary muscle). The individual muscle fibres are transversely
striated by alternate light and dark makings. Each fibres is made up of a number of myofibrils
and enclosed in a fine membrane-the sarolemma (muscle sheath). A number of fibres are
massed together to form bundles, many of these bundles are boun together by connective
tissue to form large and small muscle. When a muscle contracts it shortens and each
individual fibres part in the movement by contracting. This type only contracts when
stimulated to do so by the nervous system.
Unstriped (unstriated, smooth or involuntary muscle). This type will contract without
nervous stimulation although in most parts of the body its activity is under the control of the
autonomic (involuntary) nervous system. This variety is composed of elongated spindle-
shaped muscle cells which retain the appearance of a cell.
Involuntary muscle is found in the coats of blood and lymphatic vessels, in the walls of the
digestive tract and the hollow viscera, trachea and bronchi in the iris and ciliary muscle of the
eye and in the involuntary muscles in the skin.
A sphincter muscle is composed of a circular band of muscle fibres situated at the internal or
external openings of a canal or at the mouth of an orifice, tightly closing it when contracted.
Examples include the cardiac and pyloric sphincters at the openings of the stomach, the ileo-
colic sphincter or valve, the internal and external sphincters of the anus and urethra.
Cardiac muscle is found only in the muscle of the heart. It is striated like involuntary
muscle. But it differs in that its fibres branch and anastomose with each other; they are
arranged longitudinally as in striated muscle, are characteristically red in color and not
controlled by the wall. Cardiac muscle possesses the special property of automatic rhythmical
contraction independent of its nerve supply. This function is described as myogenic as
distinct from neurogenic. Normally the action of the heart is controlled by its nerve supply.
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Muscular contraction. When a muscle is stimulated a short latent period follows, during
which it is taking up the stimulus. It then contracts, when it becomes short and thick and
finally it relaxes and elongates.
In the case of a striped (voluntary) muscle fibre the contraction lasts only a fraction of a
second and each contraction occurs in response to a single nerve impulse. Each single
contraction is of the same force. The force with which a whole muscle contracts is adjusted
by varying the number of fibres contracting and the frequency with which each fibres
contracts. When contracting vigorously the individual fibres may contract more then 50 times
each second.
Certain factors influence the force with which a muscle fibre contracts. It contracts more
forcibly when it is stretched and cold weaken the power to contract.
Unstriped muscle fibres contract mush more slowly and are not dependent on nervous
impulses, although these alter the force of their contraction.
Muscle tone. Muscle is never completely at rest; it may appear to be but it is always in a
condition of tone, which means ready to respond to stimuli. For instance, the knee-jerk
obtained by sharply tapping the patellar tendon results in contraction of the quadriceps
extensors of the thigh and slight extension of the knee joint. This is a reflex produced by
stimulation of the nerves.
Posture is determined by the degree of muscle tone.
The energy of the muscular contraction is provided by the conversion of adenosine
triphosphate (ATP) into adenosine into ATP by energy provided by the breakdown of
glycogen. In the presence of adequate supplies of oxygen, this break down is aerobic and
produces CO2 and water. If there is not enough O2, the glycogen is only broken down to
lactic acid (anaerobic glycogen) and the content of lactic vigorous in the blood increases. This
is a normal occurrence in vigorous athletes, but occurs too readily in patients whose heart or
circulation does not supply the working muscles with enough blood.
Nervous Tissue. The nervous tissue consists of three kinds of matter, (a) grey matter,
forming the nerve cells, (b) white matter, the nerve fibres and (c) neuralgia, a special kind of
supporting cell, found only in the nervous system, which holds together and supports nerve
cells and fibres. Each nerve cell with its processes is called a neuron.
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Nerve cells are composed of highly specialized granular protoplasm, with large nuclei and
cells and fibres. Each nerve cell. Various processes arise from the nerve cells; these processes
carry the nerve impulses to and from the nerve cells.
Connective Tissues. This tissue provides the framework of the body. There are several
varieties of connective tissue.
Areolar tissue. This consists of loosely woven tissue which is distributed widely throughout
the body. It is placed immediately beneath the skin and mucous surfaces forming the
subcutaneous and sub-mucous tissue, and it also forms the sheaths of fascia which supports
and bind and connects together muscles, nerves, blood vessels and other organs.Areolar tissue
consists of a matrix of intracellular substance in in which lie connective tissue cells and into
which are woven bundles of fine fibres, composed of wavy strands, running through the
matrix in every direction and so arranged that they form a network. These fibres consists of
collagen, a gelatinous substances, and they are held together by mucin.
Elastic fibres which are yellow in appearance and composed of elastin also from part of the
structure. These fibres are fine.
The tissues spaces in which lymph collects are large, and it is from the lymph contained in
them that most of the nourishment of areolar tissue is derived. These lymph
spacescommunicate with each other and it is here in these that many of the immunizing
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substances which protect the body from disease are formed.
Retiform (reticular) lymphoid or adenoid tissue is similar to areolar, but a particular kind of
cell, the lymphocyte, is present in very large numbers and forms the bulk of the tissue. The
lymphocytes are held together by fine connective tissue fibres, called reticular fibres. These
are like immature collagen fibres.
Mucoid tissue is found in the umbilical cord, at birth, in the jelly of Wharton. It is also found
in the adult in the vitreous humour of the eye.
Adipose tissue. Adipose or fatty tissue is deposited inmost parts of the body. It is associated
with areolar tissue by the deposition of fat cells specially adapted for storing droplets of fat
and is present in all subcutaneous tissue except that of the eyelids and the penis and inside the
cranial cavity.
Functions. To help support and retain in position the organs of the body. The kidneys, for
e.g., are deeply embedded in fat.
To form a protective covering for the body.
To act as a store water and of fat which when required can be re-absorbed and by combustion
in the tissue during metabolism, provide a source of heat and energy for the use of the body.
Elastic tissue. This form of connective tissue contains a large proportion of elastic fibres. It is
found in the walls of arteries and in the air tubes of the respiratory tract and assists in keeping
these vessels and passages open. It is also present in certain ligaments, as in the ligamentum
sub-flava of the qualities it materially assists in the performance of sustained muscular effort,
as in maintaining the erect position of the spine.
Fibrous tissue is often spoken of as a white fibrous tissue because it is composed mainly of
white collagen fibres arranged in definite lines. This arrangement gives great strength and
fibrous tissue is found where resistance is required. Between the definite bundles of white
fibres some areolar tissue lies, which contains the nerves, lymphatics, and blood vessels
supplying the structure.
Fibrous tissue is tough and strong. It forms ligaments, except the elastic ones, and tendons.
The dura matter lining the skull and neural canal, the peritoneum covering bone, the strongest
layers of fascia separating muscular sheaths, the fibrous layer of the pericardium and the
sclerotic coat of the eye, are examples of fibrous tissue.
Cartilage or gristle is a dense, clear blue-white substance very firm less firm then bone. It is
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principally at joints and between bones. The bones of the embryo are first cartilages, then the
growing centers persist as cartilage and when adult age is reached cartilage is found covering
the bone ends. Cartilage does not contain blood vessels but is covered by a membrane, the
perichondrium, from which it derives its blood supply.
There are three main varieties of cartilage which demonstrate the characteristic of this
substance-firmness, flexibility and rigidity.
Hyaline cartilage consists of collagen fibres embedded in a clear, glassy, tough ground
substance or matrix. It is firm and elastic and is found covering the ends of the long bones as
articular cartilage, in the costal cartilages, in the nose, larynx, trachea and bronchial tubes
where it keeps open the orifices. It is also the temporary cartilages from which bone is
formed. In the developing embryo and fetus it acts as temporary scaffolding supporting the
other tissues until bone is laid down to replace it. The cells of hyaline are arranged principally
in small groups set in a tough matrix.
White fibro-cartilage which is composed of bundles of fibres having the cartilage cells
arranged between the bundles of fibres is found where great strength is required. Fibro-
cartilage deepens the cavities of bony sockets, as in the acetabulum of the innominate bone,
and the inter-articular cartilages, as in the semilunaar cartilages of the knee, and the
connecting cartilages as in the intervertebral discs of the vertebral column and in the pad of
cartilage at the symphysis pubis.
Elastic cartilage is often called yellow elastic cartilage because it contains a great many
elastic fibres which are yellow. It is found in the lining of the ear, the epiglottis and the
Eustachian tubes, when compressed or bent it is vary flexible and readily springs back into
sharp.
Bone Structure and Growth. Bone is the hardest of the connective tissues of the body. It is
composed of nearly 50% water; the remaining solid parts are divided into a composition of
mineral matter, principally calcium salts 67% and cellular matter 33%.
The structure of bone may be examined by the naked eye when the gross structure is seen and
with the aid of a micro-scope, when the minute structure is examined.
Bone consists of two kinds of tissue; compact and cancellous tissue.
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Compact bone tissue is hard and dense, it is found in flat bones and in the shaft of the long
bones, and as a thin covering over all bones.
Cancellous bone tissue is spongy in structure. It is found principally in the end of the ling
bones, in the short bones, and as a layer in between two layers of compact tissue in the flat
bones such as the scapula, cranium, sternum and ribs.
The Gross Structure of a Long Bone. A long bone such as those of the limbs shows both
varieties of bone tissue. When sawn through longitudinally, the distribution of compact and
cancellous tissue can be seen. It is divided into a shaft, the central part and two extremities or
ends of the bone. In the shaft is cut across, dense bone tissue will be seen and a hollow centre
called the medullary cavities, containing yellow bone marrow. If the end of a long bone is
cut, the spaces in the cancellous tissue will be seen containing red bone marrow. In the yellow
marrow fat cells predominate; in the red marrow red blood cells very numerous. The red bone
marrow is the birthplace of both red and white blood cells.
Minute Structure. A transverse section of compact shows a wonderful design mapped out in
circles. In the centre of each circle is a Haversian canal. The plates of bone or lamellae are
arranged concentrically around the central canal, in between these plates are minute spaces
called lacunae, these spaces contain bone cells and the spaces are concerted to each other and
to the central Haversian canl by minute canals called canaliculi. Each pattern so formed is a
complete Haversian system composed of: A central Haversian canal containing nerves, blood
vessels and lymphatics, Lamellae arranged concentrically, Lacunae containing bone cells and
Canaliculi radiating between and liking up the lacunne and the haversian canals.
The areas between these Haversian systems are composed of interstitial lamellae and
canaliculi arranged somewhat differently. In cancellous bone tissue the lamellae are rather
irregularly arranged, there are no Haversian canals, the blood vessels ramify in the interstitial
spaces which are filled with marrow to support the minute blood vessels. Bone is covered by
a vascular membrane, the periosteum, but at the articular surface it is covered by hyaline
cartilage.
Periosteum is a fibrous vascular membrane covering bone. It is rich in blood vessels and
invests the bone closely. The blood vessels from the periosteum ramify in the bone substance
and in this way help to supply the bone with blood. In growing bone a layer of bone-forming
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cells lies between the periosteum and the bone, and form multiplication of these cells the
bone grows in circumference.
In addition to blood derived from the periosteum the long bones are supplied with blood by a
special nutrient artery, which pierces the bone obliquely at a protected part of it-in the case of
the long bones of the upper extremity, in a direction towards the elbow and those of the lower
extremity, in a direction away from the knee. The nutrient foramina are well marked in the
long bones.
The Development and Growth of Bone. Bone develops either in cartilage or in a membrane
of connective tissue fibres. The flat bones ossify in membrane and are called membrane
bones and the long bones in cartilage, called cartilage bones.
Membranous ossification. The connective tissue membrane, from which the flat bones
develop, such as those of the skull, is very richly supplied with blood.
Ossification begins at defined centers, and proceeds by the multiplication of cells within the
membrane until a delicate network of bone is formed. Eventually a flat bone is produced
which consists of two layers of hard compact bone covered by periosteum, separated by an
interstitial layer of bone resembling cancellous bone tissue.
Cartilaginous ossification. In the developing embryo all the long bones are first represented
by rods of cartilage covered by perichondrium. A primary centre of ossification called the
diaphysis appears at the middle of what will eventually be the shaft of a long bone. Calcium
is laid diwn in the mtrix, and bone cells develop. The perichondrium becomes periosteum and
from it bone cells are laid down so that the bone increases in circumference as well as in
length. It is because of this function of the periosteum that surgeon are careful, when
removing bone, to replace the periosteum in position, for the formation of new bone from it.
The growing bone now consists of a shaft, the diaphysis and two extremities, the epiphysis.
Later in the process of development, a secondary centre of ossification appears at each
extremity or epiphysis and ossification begins three and extends towards the shaft and also
towards the end of each epiphysis. The ends of the bone remain covered by hyaline cartilage
which becomes the articular cartilage. A layer of cartilage remains between the shaft or
diaphysis and each extremity or epiphysis, and this layer is called the epiphyseal cartilage
which persists until the bone is fully grown.
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If acromegaly occurs, which is brought about by disorder of the function of the anterior lobe
of the pituitary gland before the epiphyseal cartilages have disappeared the condition of
gigantism results; but when acromegaly occurs after the ossification of the epiphyseal
cartilages then only certain bones are affected-those of the hands and jaw.
Two types of bone cells are involved in the building of bone; osteoblasts which build bone,
and osteoclasts which destroy bone. In this way the solid parts are formed and the spaces
cavities and canal also are constructed.
THE BODY FLUIDS
Water with its solvent needed for the health of the cells is termed body fluid, and this fluid is
partly inside and partly outside the cells.
Intracellular fluid forms 50% of the body-weight; it lies within the cells and contains
electrolytes including potassium and phosphate and food materials like glucose and amino-
acids. Enzymes action is constant within the cells, breaking down and building up as in all
metabolism to maintain a balance.
Extracellular or interstitial fluid represents 30% of the water in the body. It is the medium in
which the cells live, obtaining from it salts, food and oxygen and passing into it their waste
products.
Blood plasma forms 5% of body-weight and it is the transport system which serves the cells
through the medium of the Extracellular fluid.
Tissue Fluid Exchange the fluid of the plasma is under greater mechanical hydrostatic
pressure than the interstitial pressure and therefore fluid tends to leave the capillaries.
However, there are proteins in the plasma but not in the interstitial fluid; these are proteins
exert an osmotic pressure which tends to suck fluid into the capillaries.
At the arterial end of the capillaries the mechanical, hydrostatic pressure is greater than the
osmotic pressure so the balance of the forces sends fluids out into the tissues. At the venous
end the hydrostatic pressure is less; the osmotic pressure over comes it and draws fluid
leaving the capillaries. Normally there is more fluid leaving the capillaries than there is fluid
coming into them. This excess is removed by the lymphatic.
Exchange between the Extracellular and intracellular fluids is also dependent on osmotic
pressure, but the cell membrane too has a selective permeability, allowing some substances,
such as oxygen, CO2 and urea to cross freely, but pumping others either in or out to maintain
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different concentrations in the intra-and extracellular fluids. For e.g., potassium is
concentrated in the intracellular fluid, whilst sodium is pumped out.
1. 4 THE DIFFERENT SYSTEMS OF THE BODY
The Systems of the Body
Systematic anatomy or the division of the body into systems is arranged (a) according to the
functions they perform and (b) under the heading of the different terms employed to indicate
the knowledge of certain parts.
Osteology is knowledge of bones.
Arthrology ” ” ” joints.
Mycology ” ” ” muscles.
Splanchnology ” ” ” organs of viscera.
Neurology ” ” ” nerves and nerve structure.
When grouped according t function the general arrangement is as follows.
The Locomotor System. This includes the parts concerned in the movements of the body:
the skeletal system which is composed of the bones, and certain cartilages and membranes,
the articulatory system which deals with the joints or articulations and the muscular system
which includes muscles, fascia and tendon sheaths.
The Blood-Vascular System includes the circulatory system and lymphatic system. Blood is
the principal transport system; it is pumped round the body by the heart, oxygen is brought
from the lungs and carbon dioxide collect from the tissues. Food passes to the liver and
thence to the general circulation. Waste products are passed to the kidneys.
The Digestive System consists of the alimentary canal and the glands organs associated with
it. Food is broken down by enzymes in the digestive tract and taken by the blood to the liver
and finally to the tissues.
The Respiratory System contains the passages and organs concerned with breathing.
Oxygen from the air is taken into the blood and carried to the tissues; the waste product,
carbon dioxide (CO2), is carried by the blood from the body tissues to the lungs and breathed
out in the expired air.
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The Ductless Glands are group together because of the internal secretions they produce. The
spleen is sometimes including in this group because it also had no duct, though as far as is
known it does not produce and internal secretion; it is concerned with the formation of red
blood cells.
The Urogenital System includes the organs of the urinary system and the reproductive
system. The waste products of the body, except carbon dioxide are excreted by the kidneys.
The Nervous System is composed of the central nervous system which includes the brain
and spinal cord, the peripheral nervous system consisting of the nerves given off brain and
cord and the autonomic nervous system. The central and peripheral systems are often grouped
together and described as the cerebrospinal nervous system. The autonomic nervous system
includes the sympathetic and parasympathetic nerves. It is also described as the involuntary
nervous system.
The Special Sense organs include taste, smell, sight and hearing and also the tactile function
of the skin. It is through these organs that the individual is kept aware of external forces and
thus enables to protect himself. A chicken aware of the sound of traffic runs or flies to safety.
The Excretory System is the term sometimes employed to describe collectively the organs
that deal with the excretion of waste products from the body. These organs include the urinary
system, the lungs in their function of eliminating CO2, and the colon which excretes certain
insoluble substances in the faeces.
1.5 BIOLOGICAL BASIS OF HUMAN BEHAVIOUR
Behaviour = a product of nature & nurture.
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This brings us to the next issue- can we change our brain?
It is well known that we inherit several characteristics from our parents through genes. The
brain has the a way the brain develops is rigidly fixed, depending on what the way the brain
has a large number of regulating genes, it is now known that these are not enough to specify
the large number of connections between nerve cells. In fact, the brain is one of the most
‘plastic’ structures in Nature, with infinite possibilities for change. Hence the brain is a
product of nature and nurture. Nature has a specially strong influence on the developing brain
during specific periods of our life time. The most important period occurs during the
development of the baby in the uterus of the mother, particularly the last three months of
pregnancy. This period continues after birth, for the next two years. This is known as the
growth spurt period during which the growth of the brain is very rapid. It is now known that
changes in the environment have maximum effect during this time. Let us examine the factors
which can cause change.
Brain growth spurt period
Nutrition.
A well known saying states that ‘we are that we eat’. Indeed, our diet can radically modify
our brain and hence our behaviour. While all the chief constitutes of the diet are important,
deficiency of proteins has the most marked effect on the brain. If a pregnant woman has a diet
deficiency in the necessary protein, then the brain of the developing baby is affected. In case
the deficiency occurs around the 26the week of pregnancy, then the total number of brain of
the brain cells would probably be less than normal. In case the deficiency occurs in the last
few weeks of pregnancy or two years after birth the number of cells may be normal, but the
cells have less processes than normal. Some reports say that these children are not as quick
thinking as those who have normal nourishment. It is very important to remember that any
measures to correct the deficiency should be taken as early as possible- preferably, feed the
mother! Apart from this, even in adults specific food can influence our moods.
BEHAVIOURBrain Function
NatureGenes
NurtureExperience
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Social Contact
Contact with others of the same species, particularly with the mother, has been demonstrated
to be of great importance in the normal development of an infant. Elaborate experiments were
conducted by Harry & Margaret Harlowe in the 1960s. Their detailed observations showed
that if a baby monkey was separated from its mother soon after birth, this has profound
influences on the monkey which can persist till adult life. A female baby is deprived of
contact with the mother in infancy grows up unable to fulfill normal functions as a mother, &
neglects her own infants. To some extent this can be prevented by allowing the infant to have
contact with a foster mother. In man also, social contact during infancy was shown to be
necessary for normal intellectual & social development. In the 1640s, Rene Spitz observed
babies who were being brought up in an orphanage. Extra care was taken to ensure that
hygienic conditions prevailed. The babies were not handled more than necessary. Practice
such as hugging were avoided, as they were believed to be unhygienic. Another group of
babies were being brought up in a nursing home attached to a prison. Their mothers were
prisoners they were allowed frequent contact with their babies. At 4 months of age the babies
in the orphanage were much healthier than those in the prison nursing home. They seemed to
be developing sooner as well. However, when they were 2 years old, this situation had
reversed-the orphanage group was now found to be very dull, not interested in anything, and
even much more likely to get infections-in spite of the precautions to regulate hygiene!
Sensory Experience
Stimulation keeps a system active, and functioning well. Athletes have well developed and
efficient muscles. Sedentary workers have poorly developed muscles which do not work
efficiently. The brain functions in the same way. Experiments have shown that if new born
rats are reached in a cage with interesting toys, they have definite changes in the brain,
compared to new born rats which are reared in a cage without toys. The main changes is a
significant proliferation of the short processes. The experience increases the dendritic zone,
hence increasing the ‘receiving area’ of a nerve cell. This makes it much more sensitive.
From this it is easy to understand why children should be given stimulating and thought
provoking toys.
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Learning
It is a process which brings about change throughout life. These changes occur in the
dendritic zone. As with sensory experience, learning includes proliferation of the dendrites.
1.6 SUMMARY
Here is what we have learned from this unit:
The human body is a single structure but it is made up of billions of smaller structures
of four major kinds: cells, tissues, organs, and systems.
An organ is an organization of several different kinds of tissues so arranged that
together they can perform a special function.
A system is an organization of varying numbers and kinds of organs so arranged that
together they can perform complex functions for the body.
Ten major systems include the skeletal, muscular, nervous, endocrine, cardiovascular,
lymphatic, respiratory, digestive, urinary, and the reproductive system.
Body functions are the physiological or psychological functions of body systems.
Survival of the body depends on the body's maintaining or restoring homeostasis, a
state of relative constancy, of its internal environment.
Human life process includes organization, metabolism, responsiveness, movements,
reproduction, growth, differentiation, respiration, digestion, and excretion. All these
processes work together, in fine-tuned balance, for the well-being of the individual
and to maintain life.
Life depends on certain physical factors from the environment, which include water,
oxygen, nutrients, heat, and pressure.
Useful terms for describing body parts and activities include:
o Directional terms
o Terms describing planes of the body
o Terms describing body cavities
o A brief introduction to biological basis of human behaviour.
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1.7 QUESTIONS
1. ________ do not belong to the four basic human body structure units.
A. Cells.
B. Differentiation
C. Tissues
D. Systems
2. An American physiologist, Walter B. Cannon suggested the name ________ for the
relatively constant states maintained by the body.
A. homosapien
B. homogenization
C. homology
D. homeostasis
3. The word homeostasis is derived from ________.
A. Greek
B. Latin
C. Sanskrit
D. German
4. One of the additional requirements specific to the basic processes of human life is
________.
A. organization
B. differentiation
C. metabolism
D. responsiveness
5. One phase of metabolism is ________ in which complex substances are broken down
into simpler building blocks and energy is released.
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A. organization
B. responsiveness
C. catabolism
D. growth
6. Responsiveness or ________ is concerned with detecting changes in the internal or
external environments and reacting to that change.
A. flexibility
B. contractility
C. irritability
D. responsibility
7. The word caudal is a directional term that indicates "________".
A. toward the head end of the body
B. away from the head
C. toward the midline of the body
D. away from the midline of the body
8. The hand is located at the ________ end of the forearm.
A. proximal
B. medial
C. interior
D. distal
9. Coronal plane runs ________, dividing the body or any of its parts into anterior and
posterior portions.
A. crosswise
B. from front to back
C. from side to side
D. through midline
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10. The ________ cavity contains the heart, lungs, trachea, esophagus, large blood
vessels, and nerves.
A. dorsal
B. abdomino-pelvic
C. cranial
D. thoracic
Choose the correct - True or False
1. A human life begins as a single, newly fertilized cell.
A. True
B. False
2. One average-sized adult body may consist of 100 million cells.
A. True
B. False
3. Intricate arrangements of fine fibers and thousands of organelles exist within the cell
nucleus.
A. True
B. False
4. The nucleus determines how the cell will function, as well as the basic structure of that
cell.
38
A. True
B. False
5. All of the functions for cell expansion, growth and replication are carried out in the
cytoplasm of a cell.
A. True
B. False
6. Epithelial tissue consists of tightly packed cells with little intercellular matrix, having
one free surface.
A. True
B. False
7. Connective tissue cells are able to reproduce twice as rapidly as epithelial cells.
A. True
B. False
8. The cells in muscle tissue that generate and conduct impulses are called neurons.
A. True
B. False
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9. Mucous membranes line the body cavities that open to the outside.
A. True
B. False
10. Synovial fluid lubricates the membrane and reduces friction and abrasion when organs
in the thoracic or abdominopelvic cavity move against each other or the cavity wall.
A. True
B. False
Write a brief note on :
a. Cell & its structure.
b. Tissues
c. Different systems of the body
d. Biological basis of human behaviour.