Anatomy & Physiology: Chapter 1

Anatomy

study of structures (gross/microscopic)

Physiology

study of function

Principle of Complementarity of structure & function

Function is dependent on structure, & the form of a structure relates to its function

Hierarchy of Structural Organization

Chemical, Cellular, Tissue, Organ, Organ System, Organismal

Chemical

atoms combine to form molecules

Cellular

molecules combine to make cells (muscle cell)

Tissue

Similar types of cells make up tissues (muscle tissue)

Organ

different types of tissues make up organs (blood vessels)

Organ system

different organs work closely together to make up organ systems (cardiovascular system)

Organismal

many organ systems make up an organism (human body)

Integumentary system

covers & protects external body (hair, skin, nails)

Skeletal system

protects & supports organs; movement (bones, joints)

Muscular system

body movement; produces heat (skeletal muscles)

Nervous system

control system of body; maintains homeostasis (brain, spinal cord, nerves)

Endocrine system

glands secrete hormones that regulate body cell functions (thyroid gland, adrenal gland, pancreas)

Cardiovascular system

pumps & transports blood (heart, blood vessels)

Lymphatic system

returns fluid that has leaked from blood vessels; immunity (lymph nodes, lymphatics, spleen, bone marrow, thymus)

Respiratory system

keeps blood supplied with O2 & removes CO2 (trachea, lungs)

Digestive system

breaks down & absorbs food/water; eliminates indigestible substances (stomach, liver, intestines)

Urinary system

eliminates nitrogenous wastes; regulates water balance (kidney, ureter, bladder, urethra)

Reproductive system

production of offspring (penis, testes, uterus, ovaries)

Homeostasis

Body's ability to maintain relatively stable internal conditions despite continuous changes in environment (dynamic state of equilibrium: all organ systems are involved)

Control mechanism components

3 components: Receptor (thermometer), Control center (thermostat), Effector (AC - unit)

Negative Feedback Mechanism

most common in body; opposes (REDUCES) stimulus & returns body to original state (maintains homeostasis): body temp., blood sugar, diff.

Positive Feedback Mechanism

ENHANCES original stimulus & brings body further away from original state (amplifies effect): labor contractions, blood clotting.

Homeostatic imbalance

Any disturbance of homeostasis, often results in diseases.

Anatomical Position

Body erect, feet slightly apart, palms facing forward (thumbs away from body).

Superior (cranial)

Toward the head or upper part of body (ABOVE).

Example of Superior

Head is superior to the abdomen.

Inferior (caudal)

Away from head or toward lower part of body (BELOW).

Example of Inferior

Navel is inferior to the chin.

Anterior or Ventral

Toward or at front of body (IN FRONT OF).

Example of Anterior

Breastbone is anterior to the spine.

Posterior or Dorsal

Toward or at back of body (BEHIND).

Example of Posterior

Heart is posterior to breastbone.

Medial

Toward or at midline of body (INNER SIDE OF).

Example of Medial

Heart is medial to arm.

Lateral

Away from midline of body (OUTER SIDE OF).

Example of Lateral

Arm is lateral to chest.

Intermediate

Between a more medial & a more lateral structure.

Example of Intermediate

Collarbone is intermediate between breastbone and shoulder.

Proximal

Closer to origin or point of attachment of body.

Example of Proximal

Elbow is proximal to wrist.

Distal

Farther from origin or point of attachment of body.

Example of Distal

Knee is distal to thigh.

Superficial

Toward or at body surface.

Example of Superficial

Lungs are deep to skin.

Deep

Away from body surface; internal.

Two major body divisions

Axial - head, neck, trunk; Appendicular - limbs (appendages).

Body planes

Flat surfaces that lie at right angles to each other.

Sagittal

Divides body vertically (L & R).

Midsagittal

Divides vertically R & L on midline.

Parasagittal

Divides vertically R & L parallel to midline.

Frontal (coronal)

Divides vertically into anterior & posterior.

Transverse (axial)

Cross section - divides horizontally into superior & inferior.

Oblique

Cuts made at an angle between horizontal and vertical planes.

Dorsal Body Cavity

Includes cranial (within skull - brain) and vertebral (within vertebral column - spinal cord).

Ventral Body Cavity

Includes thoracic (above diaphragm - heart, lungs, & space above heart) and abdominopelvic (below diaphragm).

Serosa

Thin, double-layered serous membrane that produces serous fluid (reduces friction).

Parietal serosa

Lines wall of body cavity; visceral serosa = covers internal organs.

Serous cavity

Slit-like cavity between parietal & visceral layer - filled with serous fluid.

Serous Membrane (lungs)

Pleural (with pleural cavity between layers).

Serous Membrane (heart)

Pericardium (with pericardial cavity between layers).

Serous membrane (abdominal cavity)

Peritoneum (with peritoneal cavity between layers).