NOTES: CH 40 – Introduction to

Human Anatomy & Physiology

THE HUMAN BODY

Anatomy Physiology

(= structures) (= functions

or processes)

Characteristics of LIFE:

1) Made up of 1 or more

CELLS.

2) Obtain and use energy.

3) Reproduction.

Characteristics of LIFE:

4) Growth /

development - -

life cycle.

5) Ability to

RESPOND to

environment.

Living Things are ORGANIZED:

molecules organelles

CELLS tissues

organs organ systems

organism!

Structure & Function

● at every level of organization,

we see that “form fits function”

EXAMPLES:

● RIBCAGE: shape fits the

function of support &

protection of the organs in the

thoracic cavity

● SMALL INTESTINE: structure

fits the function of digestion &

absorption of nutrients

• What is a TISSUE?

Tissues are groups of cells with

specialized structural and functional roles.

Intercellular materials, varying from solid

to liquid, separate cells.

(also known as MATRIX)

• Four Main Kinds of Tissue:

-Epithelial

-Connective

-Muscle

-Nervous

EPITHELIAL TISSUE:

*General Characteristics:

• covers all

free body surfaces

(outer and inner

surfaces of organs)

• major tissue of glands

EPITHELIAL TISSUE:

• anchored to connective tissue by a

BASEMENT MEMBRANE

• lack blood vessels

EPITHELIAL TISSUE:

• nutrients get to the epithelial tissue by

diffusion from the connective tissue below

EPITHELIAL TISSUE:• readily divide; so injured areas heal quickly

as new cells replace lost or damaged ones

EPITHELIAL TISSUE:

• cells are tightly packed – form effective

protective barriers

EPITHELIAL TISSUE:

• functions include:

protection

secretion

absorption

excretion

EPITHELIAL TISSUE:

• cells are classified according to shape and number of layers of cells

-simple = single layer of cells

-stratified = two or more layers of cells

-squamous = thin, flattened cells

-cuboidal = cube-shaped cells

-columnar = elongated cells

EPITHELIAL TISSUE:

• free surface cells may have modifications

suited to their function

(i.e. cilia, microvilli, mucus-secreting cells)

• General Characteristics of

CONNECTIVE TISSUE:

Functions include:

Support Provide framework

Protect Fill space

Store fat Produce blood cells

Connect Protect against infection

Repair damaged tissue

Connective Tissue:

Considerable amount of intercellular

material (MATRIX) between cells

*Matrix consists of fibers and ground

substance

Connective Tissue: Major Cell Types:

1) Fibroblasts: produce collagenous & elastic

fibers

2) Macrophages: phagocytes (engulf

pathogens)

3) Mast cells: usually near blood vessels;

release heparin and histamine

Connective Tissue Fibers may be:

1) Collagenous fibers: composed of

collagen; have great tensile strength

2) Elastic Fibers: composed of microfibrils

embedded in elastin; are very elastic

3) Reticular fibers: very fine, collagenous

fibers

• Categories of connective tissue:

Loose (Areolar)

Connective Tissue:

-forms thin membranes between

organs and binds them

-beneath the skin and between

muscles

Adipose tissue:

-stores fat

-found beneath the skin, around

kidneys, heart and joints

• Categories of connective tissue:

Dense connective tissue:

-composed of strong, collagenous fibers

-found in tendons, ligaments, white portion

of eyes, deep layer of skin

• Categories of connective tissue:

Cartilage:

-provides a supportive framework for various

structures

-cartilage lacks a direct blood supply and is

slow to heal

Elastic cartilage

Hyaline cartilage

Fibrocartilage

• Categories of connective tissue:

Bone:

-intercellular matrix contains mineral salts and

collagen

-an active tissue that heals rapidly

• Categories of connective tissue:

-transports substances; helps maintain a stable

internal environment

-composed of: red blood cells (RBCs), WBCs,

and platelets in plasma.

-blood develops in red marrow in the hollow

parts of long bones.

MUSCLE TISSUES

General Characteristics:

• muscle tissues contract, moving structures

that are attached to them

• three types are: SKELETAL, SMOOTH,

and CARDIAC

Skeletal Muscle Tissue:• usually attached to

BONES and controlled

by conscious effort

• cells, or muscle fibers,

are long and threadlike

• muscle fibers contract

when stimulated by

nerve impulses, then

immediately relax

Smooth Muscle Tissue:

• in the walls of hollow internal organs and

blood vessels

• usually it is involuntarily controlled

Cardiac Muscle Tissue:

• found only in the heart

• cells are joined by intercalated discs and

form branched networks

NERVOUS TISSUES

• in the brain, spinal cord, and peripheral

nerves

Neurons (Nerve Cells):

• sense changes and

respond by transmitting

nerve impulses to other

neurons or muscles or

glands

• coordinate, regulate, and

integrate body activities

(Nervous Tissue)

Supporting Cells:

• functions include:

-bind and support

nervous tissue

-phagocytosis

-connect neurons

to blood vessels

Organizationmolecules organelles CELLS tissues

organs organ systems organism!

• Organ: structure made of 2 or

more tissues

• Organ system: group of

organs which are concerned

with the performance of one or

more general physiologic goals

together

Anatomical Terms

DISTAL

PROXIMAL

Body Planes:

(FRONTAL)

Body Plan

CAVITIES

Dorsal Ventral

cranial spinal thoracic abdominal-surrounds -surrounds -heart, -digestive,

brain spine & lungs, excretory

spinal cord trachea,

(a.k.a. esophagus

vertebral cav.) pelvic

reproductive

BODY CAVITIES:

Overview of Organ Systems:

System Major

Structures

Function(s)

Skeletal Bones structure, support,

movement

Muscular Muscles structure, support,

movement

Integumentary Skin, hair, nails protection,

excretion

Skeletal

System

Muscular

System

Integumentary

System

Overview of Organ Systems:

System Major

Structures

Function(s)

Circulatory Heart, blood

vessels

transport

Respiratory Lungs, air

passages

gas exchange

Immune Lymph nodes,

B & T cells

fight disease

Circulatory System

Immune

System

Respiratory

System

Overview of Organ Systems:

System Major

Structures

Function(s)

Digestive Stomach,

intestines,

esophagus

digestion,

absorption

Excretory /

Urinary

Kidneys, skin removal of waste

Nervous Brain, spinal cord,

nerves

sense,

coordination,

control

Digestive

System

Excretory

System

Nervous

System

Overview of Organ Systems:

System Major

Structures

Function(s)

Endocrine Glands,

hypothalamus

control &

regulation of

homeostasis

Reproductive Gonads production of

offspring

Endocrine

System

Female

Reproductive

System

Male

Reproductive

System

Homeostasis

• In general, organ systems participate in

FEEDBACK LOOPS designed to maintain

the status quo of internal environment

(= HOMEOSTASIS)

3 Components of a feedback

system:

• Receptor:

detects a change

in some variable

of the animal’s

internal

environment

(e.g. body temp.)

3 Components of a feedback

system:

• Control center:

processes

information it

receives from

the receptor

(brain,

hypothalamus)

3 Components of a feedback

system:

• Effector: receives

a message from

the control center

and responds

appropriately

(muscles

shivering,

goosebumps)

NEGATIVE FEEDBACK

• Example

Negative feedback: body temperature

(needs to stay around 37°C)

rise in brain message to body temp.

temp. “thermostat” sweat glands lowers

to produce

sweat

**Negative feedback maintains HOMEOSTASIS!

POSITIVE FEEDBACK

• Example

Positive feedback:

childbirth (body needs

to achieve a heightened

state of exertion…

LABOR!)

pressure uterine more more

of baby’s contractions pressure contractions…..

head