4) Organ (extremely complex functions become possible)
5) Organ System (organs that work together to accomplish common purpose)
6) Organismal (highest level.... living human being)
Necessary Life Functions
1) Maintaining Boundaries
-- ability to sense and respond to stimuli
-- breaking down ingested food to simple molecules
-- chemical reactions that occur in body cells
(Greek kata= downward; ballein= to throw)
(Greek ana= upward; ballein= to throw)
-- process of removing waste, or excreta
-- occurs at cellular and organismal level. In cellular reproduction, the original cell divides
-- increase in size of a body part or organism as whole
4) Normal Body Temperature
5) Appropriate Atmospheric Pressure
Homeostasis is a dynamic equilibrium of the internal environment. All body systems contribute to homeostasis, but the nervous and endocrine systems are most important. It is necessary for health.
"wisdom of the body" -Walter Cannon (American physiologist of early 20th century)
Name the three body planes
Frontal = lie vertically and divide body into anterior and posterior (aka coronal plane)
Sagittal = vertical plane that divides body into right and left parts. When it lies directly in the middle, it is called median plane or midsagittal plane. When it's offset from midline, it is called parasagittal plane (para=near)
Transverse = runs horizontally from left to right, dividing body into superior and inferior parts. Also called cross section.
Oblique sections = cuts made on diagonal
1) What 3 elements work together?
2) What are negative feedback mechanisms?
3) What are positive feedback mechanisms?
1) Control mechanisms of the body contain at least 3 elements that work together: receptor (sensory neurons), control center (brain), and effector (provides means to respond output from control center)
2) Negative feedback mechanisms reduce the effect of the original stimulus, and are essential for maintaining homeostasis. Body temp, heart rate, breathing rate/depth, and blood levels of glucose are regulated by negative feedback mechanisms.
3) Positive feedback mechanisms intensify the initial stimulus, leading to an enhancement of the response. They rarely contribute to homeostasis, but blood clotting and labor contractions are regulated by them.
With age, the efficiency of negative feedback mechanisms declines, and positive feedback mechanisms occur more frequently. These changes underlie certain disease conditions.
Studies the structure of body parts and their relationships to one another.
Body structures can be seen, felt, and examined closely. You don't need to imagine what they look like.
1) Gross (macroscopic) = study of large body structures visible to naked eye... heart, lungs, kidneys, ect
a - Regional anatomy= all structures in particular region of body studied at same time, eg leg
b - Systemic anatomy= body structure studied system by system
c - Surface anatomy= study of internal structures as they relate to the overlying skin structures
2) Microscopic anatomy = deals with structures too small to be seen with the naked eye
a - cytology= considers cells of body
b - histology= study of tissues
3) Developmental anatomy = traces structural changes that occur in body throughout life span
a - embryology= concerns developmental changes that occur before birth