HSC0003 Ch 6

1. What is homeostasis?
Homeostasis is the tendency of a cell or the whole organism to maintain a state of balance.
2. What are the levels in the structural organization of the body?
The levels of the body are organized from the smallest to the largest. They are:

body systems (two or more organs)
the human body as a whole
3. What are the components of the cell, and what are their functions?
The cell consists of:

cell membrane—the outer covering that controls the substances entering and leaving the cell
cytoplasm—the gel-like liquid inside the cell consisting of water, proteins, carbohydrates, lipids (fats), and salts
organelles—structures with specialized functions ranging from the nucleus, which controls cell activity including reproduction, to ribosomes, which produce protein for the cell structures
4. What are the four primary types of tissues?
The four primary types of tissues are:

epithelial—covers the internal and external organs of the body
connective—holds parts of the body in place
nervous—transmits electrical impulses throughout the body to activate function
muscular—contracts and relaxes to cause or allow skeletal, smooth cardiac muscle function
5. What is the anatomical position?
The anatomical position is a view of the human body as it stands in a full upright position with the arms relaxed at the sides of the body, palms facing foreword, feet pointed foreword, and eyes looking straight ahead.
6. What are the three body planes and how do they divide the body?
The three body planes are the:

midsagittal plane—passes from the top to the bottom through the center, dividing the body into equal right and left halves
frontal plane—divides top to bottom through the center, and divides the body into front and back portions
transverse plane—divides the body horizontally into top and bottom portions
7. What are the main directional terms used for medical descriptions?
There are several directional terms used in medicine, none of which correspond to earth surface directions like north or west. Medical directions include:

lateral—away from the center of the body
medial—toward the center of the body
anterior—toward the front of the body
posterior—toward the back of the body
caudal—closer to the lower back
cephalic—closer to the head
deep—farther from the body surface
superficial—close to the body surface
distal—farther from a reference point
peripheral—away from the center
proximal—closer to a reference point
apex—at the highest point
base—at the lowest point
8. What are the primary body cavities and what structures are in each one?
The primary body cavities are the:

cranial—skull, containing the brain
spinal—spinal column, containing the spinal cord
thoracic cavity—chest, containing the heart, lungs, and major blood vessels, and separated from the abdominal cavity by the diaphragm
abdominal cavity—in the abdomen, containing the stomach, intestines, liver, gallbladder, pancreas, and spleen
pelvic cavity—in the lower abdomen, containing the urinary bladder, rectum, and reproductive organs
9. What are the two methods used for describing the abdominal area?
The abdominal area can be described in the following ways.

Divide the area into nine regions to describe specific areas with greater precision and clarity: epigastric (over the stomach); right and left hypochondriac regions (below ribs); umbilical (navel); right and left lumbar (either side of umbilical); hypogastric (below the stomach); right and left iliac regions (hip bone)
Describe the abdomen in quadrants: upper quadrant (liver, gallbladder); right quadrant (appendix, female reproductive organs); left quadrant (pancreas, stomach, spleen); left lower quadrant (some female reproductive organs)