INTRODUCTION TO THE BODY

HUMAN ANATOMY & PHYSIOLOGY

Anatomy/Physiology

ANATOMY - study of the structure of an organism and the relationships of its parts Anatomists learn about the human body by dissection

PHYSIOLOGY – study of the function of living organisms and their parts Requires active experimentation

Anatomical structures are designed for their specific functions FORM FITS FUNCTION! “Struc-Func”

History of Anatomical Studies

Andreas Vesalius 1514-1564 Obtained bodies of executed criminals for dissection Founder of modern human anatomy Published the first true anatomy textbook

De humani corporis fabrica (On the Workings of the Human Body)

Henry Gray 1827-1861 Published Gray’s Anatomy Recent editions still used by medical students today

“Muscle Man” as seen in De Humani Corporis Fabrica

by Andreas Vesalius

Hand-colored diagram of blood vessels in the neck as seen in Gray’s Anatomy (2nd ed.)

by Henry Gray

Structural Levels of Organization The body is a single structure, but it is made

up of trillions of smaller structures working together to make a functioning organism

Atoms combine to form molecules Molecules combine to form organelles Organelles combine to form cells (smallest “living” unit) Cells that work together combine to form tissues Tissues that work together to form organs Organs that work together form an organ system Organ Systems that work together form an organism

Structural Levels of Organization

Balance of Body Functions

All living organisms have mechanisms that ensure survival of the body by keeping consistent internal conditions Homeostasis – regulation of the living

environment – “biological balance” Every organism must have some sort of

self-regulation to maintain homeostasis Known as FEEDBACK LOOPS

Negative Feedback Loop Negates or opposes a change in a condition

By reversing the change, it returns to normal

Positive Feedback Loop

Not as common Amplify or reinforce a change that is occurring Causes increase in rate of occurrence of

events until something stops the process Examples: Uterine contractions in the

birthing process; increasingly rapid sticking together of platelets to cuts

System – Group of organs that perform a more complex function than any organ alone

Integument Skeletal Muscular Nervous Endocrine Circulatory Respiratory Digestive Lymphatic Urinary

Listing of the 10 organ systems (the human body’s largest and most complex structural unit)

Human Organ Systems Poster & Peer-Teaching Project

INTEGUMENTARY Skin – 20 lbs-(16%) body

weight (largest and most important organ of integumentary system)

Appendages –hair, nails, sweat / oil glands

Sense Organs – respond to pain, pressure, touch and changes in temperature

Function: Primary is protection Regulates body temperature

SKELETAL 206 bones, cartilage,

ligaments, joints Function:

Support and protection

Storage for minerals (Ca, P)

Formation of blood cells in red marrow of certain bones

MUSCULAR Voluntary (STRIATED)

Skeletal Muscle – under conscious control

Involuntary Smooth Muscle (Stomach,

Small Intestine) Cardiac Muscle - Heartbeat

Function : Movement, body posture,

shape, generate heat Tendon – attaches

muscle to bone

NERVOUS Sense organs: Brain, spinal cord, nerves

Nerves extend from brain and spinal cord to every area of body

Functions: 1. Communication between body functions

2. Integration of body functions

3. Control of body functions

4. Recognition and response to stimuli

5. Rapid, precise control of body functions Functions are done by specialized signals -

nerve impulses

ENDOCRINE

Glands that secrete hormones: pituitary, pineal, hypothalamus, thyroid, parathyroid, thymus, adrenal, pancreas

Functions: Produce and secrete

hormones; communication; control growth; regulate metabolism, fluid and electrolyte balance, acid-base balance and reproduction

CIRCULATORY

Heart, arteries, veins, capillaries

Cardiovascular refers to heart and blood vessels

Functions: Transportation of O2, CO2,

nutrients, hormones Regulate body temp. Defense or immunity

RESPIRATORY Nose, pharynx,

larynx, trachea, bronchi, lungs, alveoli (air sacs)

Function: O2 – CO2 exchange

in alveoli (air sacs) Warming air Irritants removed Regulates acid-

base balances

DIGESTIVE Primary (GI TRACT) – mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum, anus

Secondary – teeth, salivary glands, tongue, liver, gallbladder, pancreas, appendix

Functions: Proper digestion of food,

absorb nutrients, eliminate waste (feces)

LYMPHATIC Lymph nodes, lymphatic

vessels, tonsils, thymus, spleen Functions:

Movement of large molecules from tissue spaces around cells

Movement of fat-related nutrients form digestive tract to blood

Also is involved in functioning of the immune system

Lymphatic vessels are filled with lymph, a whitish watery fluid composed of lymphocytes, proteins and some fatty molecules

URINARY

Kidneys, ureters, bladder, urethra

Functions: Clean blood Maintain acid-base,

electrolytes, and water balances

Produces and releases urine