chapter 4 lecture notes

Chapter 4: Body StructureChapter Overview

Levels of Organization(Cell, Tissue, Organ, System, Organism)

Anatomical positionPlanes of the bodyBody cavitiesAbdominopelvic divisionsQuadrantsRegionsSpineDirectional termsPathology

This chapter presents the basic structure and functions in the body, the terms used to describe planes of the body, it’s cavities, the quadrants & regions of the abdominal cavity, and the divisions of the spinal column; to provide a greater understand of the general concepts of pathology (the study of the nature of diseases, their causes, development, and consequences).

Levels of OrganizationOur bodies are made up of many different levels of structure and function, some are more complex than others. Listed below, from least to most complex, are the levels of organization that make up our body systems.

1.) Cell2.) Tissue3.) Organ4.) System5.) Organism

1.) Cell: The structural and functional unit of life. The study of the body at the cellular level is called cytology. A cell consist of the following:

– Cell membrane: acts as a barrier that encloses the entire cell. It controls the transport of many substances to and from the cell.

– Cytoplasm: a jellylike matrix of proteins, salts, water, dissolved gases, and nutrients. Inside the cytoplasm are various structures called organelles that provide socialized functions for the cell.

– Nucleus: is the largest cell organelle and it is responsible for metabolism, growth, and reproduction. It carries the genetic blueprint of the organism and is found in a complex molecule called DNA that is organized into a threadlike structure called chromatin. When a cell prepares to divide, chromatin forms chromosomes, which carry thousands of genes that become our genetic blueprint.

Genes pass biological information from one generation to the next. This biological info. includes traits like hair color, body structure, and metabolic activity. All cells in the human body, except sperm cells and egg cells contain 23 pairs, or 46 chromosomes. Sperm and egg cells each have 23 unpaired chromosomes. After fertilization, each cell of the embryo then has all 46 chromosomes.

Deoxyribonucleic acid

2.) Tissue: Groups of cells that perform a specialized activity. The study of tissues is called histology. More than 200 cell types make up four major tissues of the body; they are as follows:– Epithelial tissue: is composed of cells arranged in a continuous sheet consisting of

one or more layers.

– Connective tissue: supports and connects other tissues and organs.

– Muscle tissue: provides the contractile tissue of the body, which is responsible for movement.

– Nervous tissue: transmits electrical impulses as it relays information throughout the entire body.

This type of tissue covers surfaces of organs, lines cavities and canals, forms tubes and ducts, provides the secreting portions of glands, and makes up the epidermis of the skin.

This type of tissue is made up of diverse cell types, including fibroblasts, fat cells, and blood.

This type of tissue transmits information throughout the body that allows us to move, think, taste, see and experience all functions associated with being alive.

3.) Organ: Organs are the body structures that perform specialized functions. They are composed of at least two or more tissue types.

The stomach is made up of connective tissue, muscle tissue, epithelial tissue, and nervous tissue. •Muscle and connective tissue form the wall of the stomach.•Epithelial and connective tissue cover the inner and outer surfaces of the stomach. •Nervous tissue penetrates the epithelial lining of the stomach and its muscular wall to stimulate the release chemicals for digestion and contraction for peristalsis (the rhythmic contraction and relaxation of the walls of a tubular organ to propel its contents onward).

An example:

4.) System: A body system is composed of different numbers of organs and accessory structures that have similar or related functions.

An example:

The organs of the gastrointestinal system include the esophagus, stomach, small intestine, and bowel.

The accessory structures of the GI system would be the liver, gallbladder, and pancreas. The purpose of this system is to digest food, remove and use its nutrients, and expel wastes.

5.) Organism: The highest level of organization is the organism. An organism is a complete living entity capable of independent existence. All complex organisms, including humans, are made up of several body systems that work together to sustain life. The human body is an organism. The systems that keep us

functioning are complex and must maintain a proper balance to continue to perform successfully.

There are 10 different body systems including the special senses that keep our bodies going. These systems are:1.) Integumentary system2.) Digestive system3.) Respiratory system4.) Cardiovascular system5.) Blood, Lymph, and Immune systems6.) Musculoskeletal systems7.) Genitourinary systems8.) Female Reproductive systems9.) Endocrine systems10.)Nervous systemsSpecial senses

Anatomical Position: is a body posture used to locate anatomical parts in relation to each other.

Anatomical Position

The body is erect and the eyes are looking forward. The upper limbs hang to the sides, with the palms facing forward. The lower limbs are parallel, with toes pointing straight ahead.

No matter how the body is actually positioned– standing or lying down, facing forward or backward– or how the limbs are actually placed, the positions and relationships of a structure are always described as if the body were in anatomical position.

Planes of the body: are identified by anatomists by the use of an imaginary flat surface called a plane. The most commonly used planes are midsagittal (median), coronal (frontal), and transverse (horizontal).

Planes of the body

Because of the advancement in imaging techniques; we have current imaging procedures, such as magnetic resonance imaging (MRI) and computed tomography (CT). These procedures can produce three-dimensional images on more than one plane. Making it easier to find and identify structural abnormalities in the body.

Body Cavities: Medical professionals locate structures or abnormalities by referring to the body cavity in which they are found. The body has two major cavities.

1.) Dorsal (posterior), including the cranial and spinal cavities.2.) Ventral (anterior), including the thoracic and abdominopelvic cavities.

Body Cavities

Abdominopelvic divisionsAbdominopelvic divisions: The abdominopelvic area of the body lies beneath the

diaphragm. It holds the organs of digestion (abdominal area) and the organs of reproduction and excretion (pelvic area). Two anatomical methods are used to divide this area of the body for medical purposes: Quadrants and Regions.

• Quadrants: Four divisions of the lower torso used to show topographical location.• Regions: Primarily used to identify the location of underlying body structures and visceral organs. (p.46-text)

Quadrants: are four divisions of the lower torso used to show topographical location. They provide a means of locating specific sites for descriptive and diagnostic purposes. The divisions of quadrants are used in clinical examinations and medical reports.

Quadrants

An imaginary cross passing through the navel identifies the four quadrants.

Right upper

QuadrantLeft upper Quadrant

Right lower

Quadrant

Left lower Quadrant

*Remember: Quadrants are primarily used to identify topical sites.

Abdominopelvic Regions: are primarily used to identify the location of underlying body structures and visceral organs.

Regions

An example: the stomach is located in the left hypochondriac and epigastric region.

Right hypochondriac

regionRight

lumbar region

Right inguinal (iliac) region

Epigastric region

Umbilical region

Hypogastric region

Left hypochondriac

region

Left inguinal (iliac) region

Left lumbar region

Another example: the appendix is located in the hypogastric region of the body.

Spine: The spine is divided into sections corresponding to the vertebrae located in the spinal column. These divisions are:

• Cervical (neck)• Thoracic (chest)• Lumbar (loin)• Sacral (lower back)• Coccyx (tailbone)

• (p. 275-text)

Spine

Directional terms: are used to show the position of a structure in relation to another structure.

Directional terms

For example, the kidneys are superior to the urinary bladder. The directional phrase superior to denotes above.

Terms DefinitionsAbduction Movement away from the midsagittal (median) plane of the

body or one of its parts.

Adduction Movement toward the midsagittal (median) plane of the body.

Medial Pertaining to the midline of the body or structure.

Lateral Pertaining to a side.

Superior (cephalad) Toward the head or upper portion of a structure.

Inferior (caudal) Away from the head or toward the tail or lower part of a structure.

Terms DefinitionsProximal Nearer to the center (trunk of the body) or

to the point of attachment.

Distal Further from the center (trunk of the body) or from the point of attachment.

Anterior (ventral) Front of the body.

Posterior (dorsal) Back of the body.

Parietal Pertaining to the outer wall of the body cavity.

Visceral Pertaining to the viscera, or internal organs, especially the abdominal organs.

Prone Lying on the abdomen, face down.

Supine Lying horizontally on the back, face up.

Terms Definitions

Inversion Turning inward or inside out.

Eversion Turning outward.

Palmar Pertaining to the palm of the hand.

Plantar Pertaining to the sole of the foot.

Superficial Toward the surface of the body (external).

Deep Away from the surface of the body (internal).

Pathology: as a branch of medicine includes the use of laboratory methods rather than clinical examination of signs and symptoms to study the causes, nature, and development of diseases.

Pathology

Besides oxygen and nutrients, all body cells need a stable internal

environment that provides a narrow range of temperature, water,

acidity, and salt concentration.

This stable internal

environment is called

homeostasis.

A disruption in homeostasis causes

cells, tissues, organs or systems to become non-functional or work less effectively. Once this

happens, the condition is then called a disease.

• Signs: are objective indicators that are observable.• Symptoms: are subjective and are experienced only by the patient.• Clinical findings: are the results of radiographic, laboratory, and other medical

procedures performed on the patient or their specimens.

Possible causes of diseases include:Metabolic (diabetes) Infectious (measles or mumps)Congenital (cleft lip) Hereditary (hemophilia)Environmental (burns or trauma) Neoplastic (cancer)

Pathology

Disease is a pathological or morbid condition that presents a group of signs, symptoms, and clinical findings.

Etiology is the study of the cause or origin of a disease or disorder.

• Diagnosis (Dx): is establishing the cause and nature of a disease.• Prognosis: is the prediction of the course of a disease and its probable outcome.• Idiopathic: is a disease with no known cause.

Pathology

Diagnostic procedures are used to identify diseases and determine their extent or involvement.

Diagnostic procedures can be simple or complex and many procedures can be categorized as surgical, clinical, endoscopic, laboratory, and radiological.

Terms Definitions

adhesion Abnormal fibrous band that holds or binds together tissues that are normally separated

Analyte Substance analyzed or tested, generally by means of laboratory methods.

Contrast medium Substance injected into the body, introduced via catheter, or swallowed to facilitate radiographic images of internal structures that otherwise are difficult to visualize on x-ray films.

Dehiscence Bursting open of a wound, especially a surgical abdominal wound.

Febrile Feverish; pertaining to a fever.

Homeostasis Relative constancy or balance in the internal environment of the body, maintained by processes of feedback and adjustment in response to external or internal changes.

Inflammation Body defense against injury, infection, or allergy that is marked by redness, swelling, heat, pain, and sometimes, loss of function.

Diagnostic, Symptomatic, and Related Terms


Terms Definitions

Morbid Diseased; pertaining to a disease.

Nuclear medicine Branch of medicine concerned with the use of radioactive substances for diagnosis, treatment, and research.

Radiology Medical specialty concerned with the use of electromagnetic radiation, ultrasound, and imaging techniques for diagnosis and treatment of disease and injury.

•Interventional Radiological practice that employs fluoroscopy, CT, and ultrasound in nonsurgical treatment of various disorders.

•Therapeutic Use of ionizing radiation in the treatment of cancer; also called radiation oncology.

Radionuclides Substances that emit radiation spontaneously, also called tracers.

Radiopharmaceutical Radionuclide attached to a protein, sugar, or other substance used to visualize an organ or area of the body that will be scanned.


Terms Definitions

Scan Term used to describe a computerized image by modality (such as CT, MRI, and nuclear imaging) or by structure (such as thyroid and bone).

Sepsis Pathological state, usually febrile, resulting from the presence of microorganisms or their products in the bloodstream.

Suppurative Producing or associated with generation of pus.

Procedure Description

Diagnostic Procedures

Endoscopic Medical device consisting of a camera mounted on a flexible tube.

Endoscopy Visual examination of a body cavity or canal using a specialized lighted instrument called an endoscope.

Laparoscopy Visual examination of the organs of the pelvis and abdomen through very small incisions in the abdominal wall.

Thoracoscopy Examination of the lungs, pleura, and pleural space with a scope inserted through a small incision between the ribs.

Laboratory

Complete blood count (CBC)

Common blood test that enumerates red blood cells , white blood cells, and platelets; measures hemoglobin (the oxygen-carrying molecule in red blood cells); estimates red cell volume; and sorts white blood cells into five subtypes with their percentages.

Urinalysis (UA) Common urine screening test that evaluates the physical, chemical, and microscopic properties of urine.

Diagnostic and Therapeutic Procedures



Radiographic

Computed tomography (CT)

Imaging technique achieved by rotating an x-ray emitter around the area to be scanned and measuring the intensity of transmitted rays from different angles; formerly called computerized axial tomography.

Doppler Ultrasound technique used to detect and measure blood-flow velocity and direction through the cardiac chambers, valves, and peripheral vessels by reflecting sound waves off moving blood cells.

Fluoroscopy Radiographic technique in which x-rays are directed through the body to a fluorescent screen the displays continuous motion images of internal structures.

Magnetic resonance imaging (MRI)

Noninvasive imaging technique that uses radiowaves and a strong magnetic field rather than an x-ray beam to produce multiplanar cross-sectional images.



Nuclear scan Diagnostic technique that uses a radioactive material (radiopharmaceutical) called a tracer that is introduced into the body (inhaled, ingested, or injected) and a specialized camera to produce images of organs and structures.

Positron emission tomography

Scanning technique using computed tomography to record the positrons (positive charged particles) emitted from a radiopharmaceutical, that produces a cross-sectional image of metabolic activity in the body tissues to determine the presence of disease.

Radiography Imaging technique that uses x-rays passed through the body or area and captured on a film; also called x-ray.

Single photon emission computed tomography (SPECT)

Radiological technique that integrates computed tomography (CT) and a radioactive material (tacer) injected into the bloodstream to visualize blood flow to tissues and organs.



Tomography Radiographic technique that produces an image representing a detailed cross-section, or slice, of an area, tissue, or organ at a predetermined depth.

Ultrasonography (US) Imaging procedure using high-frequency sound waves (ultrasound) that display the reflected “echoes” on a monitor; also called ultrasound, sonography, echo, and echography.

Surgical

Biopsy (bx) Representative tissue sample removed from a body site for microscopic examination, usually to establish a diagnosis.

•Frozen section (FS) Ultra-thin slice of tissue cut from a frozen specimen for immediate pathological examination.

Diagnostic and Therapeutic ProceduresProcedure Description

•Needle Removal of a small tissue sample for examination using a hollow needle, usually attached to a syringe.

•punch Removal of a small core of tissue using a hollow instrument (punch).

•Shave Removal of tissue using a surgical blade to shave elevated lesions.

Therapeutic ProceduresSurgicalablation Removal of a part, pathway, or function by surgery, chemical destruction,

electrocautery, or radio frequency.

Anastomosis Surgical joining of two ducts, vessels, or bowel segments to allow flow from one to another.

Diagnostic and Therapeutic ProceduresProcedure Description

Therapeutic Procedures

Surgical

Cauterize Destroy tissue by electricity, freezing, application of heat, or corrosive chemicals.

Curettage Scraping of a body cavity with a spoon-shaped instrument called a curette (curet).

Incision and drainage (I&D)

Incision made to allow the free flow or withdrawal of fluids from a wound or cavity.

Laser surgery Surgical technique employing a device that emits intense heat and power at close range to cut, burn, vaporize, or destroy tissues.

Radical dissection Surgical removal of tissue in an extensive area surrounding the surgical site in an attempt to excise all tissue that may be malignant and decrease the chance of recurrence.

Resection Partial excision of a bone, organ, or other structure.

Medical Word Elements

Element Meaning Word AnalysisCombining Forms

Cellular StructuresCyt/o Cell Cyt /o/logist: specialist in study of cells –logist;

specialist in the study of

Hist/o Tissue Hist /o/logy: study of tissues.Kary/oNucle/o

Nucleus Kary /o/lysis: destruction of the nucleus.Nucle/ar: pertaining to the nucleus.

Position and Direction

Anter/o Anterior, front anter/ior: pertaining to the front.

caud/o Tail Caud/ad: toward the tail.

Crani/o Cranium (skull) Crani/al: Pertaining to the cranium.

Dist/o Far, farthest Dist/al: pertaining to the farthest (point of attachment).

Dors/o back Dors/al: pertaining to the back (of the body).



Position and DirectionInfer/o Lower, back Infer/ior: pertaining to a lower (structure or

surface).

Later/o Side, to one side

Later/al: pertaining to a side.

Medi/o Middle medi/ad: toward the middle.

Poster/o Back (of the body), behind, posterior

Poster/ior: pertaining to the back (of the body)

Proxim/o Near, nearest Proxim/al: pertaining to the nearest (point of attachment).

Ventr/o Belly, belly side ventr/al: pertaining to the belly side (front of the body)



Regions of the bodyAbdomin/o Abdomen Abdomin/al: pertaining to the abdomen.Cervic/o Neck; cervix uteri (neck

of the uterus)Cervic/al: pertaining to the neck.

Crani/o Cranium (skull) Crani/al: pertaining to the cranium.

Gastr/o Stomach Hypo/gastr/ic: pertaining to (the area) below the stomach.

Ili/o Ilium (lateral, flaring portion of the hip bone)

Ili/al: pertaining to the ilium.

Inguin/o Groin Inguin/al: pertaining to the groin.

Lumb/o Loins (lower back) Lumb/ar: pertaining to the loins (lower back).

Pelv/IPelv/o

Pelvis Pelv/i/meter: instrument for measuring the pelvis. Pelv/ic: pertaining to the pelvis



Regions of the bodyspin/o Spine spin/al: pertaining to the spine.Thorac/o Chest Thorac/ic: pertaining to the chest.

Umbilic/o Umbilicus, navel Umbilic/al: pertaining to the navel.

ColorAlbin/oLeuk/o

White Albin/ism: condition of whiteness.Leuk/o/cyte: white cell.

Chlor/o Green Chlor/opia: green vision.

Chrom/o Color Heter/chrom/ic: pertaining to different colors.

Cirrh/oJaund/oXanth/o

Yellow Cirrh/osis: abnormal yellowing.Janund/ice: yellowing.Xantho/o/cyte: yellow celll

Medical Word ElementsElement Meaning Word Analysis

Combining FormsColorsCyan/o Blue Cyan/o/tic: pertaining to blueness.erythro/o Red Erythr/o/cyte: red cell.

Melan/o Black Melan/oma: black tumor.

Poli/o Gray; gray matter (of the brain or spinal cord.

poli/o/myel/it is: inflammation of the gray matter of the spinal cord.

OtherAcr/o Extremity Acr/o/cyan/osisi: abnormal condition in which the

extremities turn blue.

Eti/o Cause Eti/o/logy: study of the causes of disease.

Idi/o Unknown, peculiar Idi/o/path/ic: pertaining to an unknown (cause of) disease.

Morph/o Form, shape, structure.

Morph/o/logy: study of form, shape, or structure.



OtherPath/o Disease Path/o/logist: specialist in the study of disease.Radi/o Radiations, x-

ray; radius (lower arm bone on thumb side).

Radi/o/logist: specialist in the study of radiation.

Somat/o Body Somat/ic: pertaining to the body.

Son/o Sound Son/o/graphy: process of recording sound; also called ultrasonography.

Viscer/o Internal organs

Viscer/al: pertaining to internal organs.

Xer/o Dry Xer/osis: abnormal condition of dryness.



Suffixes-genesis Forming,

producing, originpath/o/genesis: origin of disease.

-gnosis Knowing Pro/gnosis: knowing before.

-gram Record, writing Arteri/o/gram: record of an artery.

-graph Instrument for recording

Radi/o/graph: instrument for recording x-rays.

-graphy Process of recording

Arthr/o/graphy: process of recording a joint.

-logist Specialist in the study of

Dermat/o/logist: specialist in the study of the skin.

-logy Study of hemat/o/logy: study of blood.



Suffixes-meter Intrument for

measuringTherm/o/meter: instrument for measuring heat.

-metry Act of measuring Ventricul/o/metry: act of measuring the ventricles.

-pathy Disease Gastr/o/pathy: disease of the stomach.

PrefixesAb- From, away from Ab/duction: act of bringing away from (midline of the

body).Ad- Toward Ad/duction: act of bringing toward (midline of the body).

Hetero- Different Hetero/morph/ous: different form or shape.

Homeo- Same, alike Homeo/plasia: formation of same (tissue).

Infra- Below, under Infra/cost/al: pertaining to (the area) below the ribs.



PrefixesPeri- Around Peri/cardi/al: pertaining to (the area) around the

heart.Super- Upper, above Super/ior: pertaining to the upper (area).

Trans- Across, through Trans/abdomin/al: pertaining to (a direction) across or through the abdomen.

Ultra- Excess, beyond Ultra/son/ic: pertaining to beyond (audible) sound.

Abbreviations

Abbreviation Meaning

ant Anterior

AP Anteroposterior

Bx, bx Biopsy

CBC Complete blood count

CT Computed tomography

DNA Deoxyribonucleic acid

DSA Digital subtraction angiography

Dx Diagnosis

FS Frozen section

I&D Incision and drainage

Abbreviations


LAT, lat Lateral

LLQ Left lower quadrant

LUQ Left upper quadrant

MRI Magnetic resonance imaging

PET Postitron emission tomography

Post Posterior

RF Rheumatoid factor; radio frequency

RLQ Right lower quadrant

RUQ Right upper quadrant

Sono sonogram

Abbreviations


SPECT Single photon emission computed tomography

Sx Symptom

Tx Treatment

UA Urinalysis

U&L, U/L Upper and lower

US Ultrasound, ultrasonography