Body Orientation and Organizational Levels Flashcards
(83 cards)
Anatomy
The science of structure and the relationship among structures
Physiology
the science of body functions - how the parts of the body work
Why are anatomy and physiology taught together?
Structure often determines function and vice versa. Structure and function are easiest to understand when observed together
6 Levels of Organization from smallest to largest
Chemical Cellular Tissue Organ System Organismal
Chemical
atoms and molecules
Cellular
basic structural and functional units of an organism
Tissue
groups of cells and the materials surrounding them that work together to perform a particular function
Organ
different kinds of tissues come together to form body structures
System
consists of related organs that have a common function
Organismal
all systems of the body combine to make up an organism
Muscular System
Components: skeletal, smooth, and cardiac muscle tissue
Functions: brings about body movement, maintains, posture, produces heat
Skeletal System
Components: bones and joints of the body and their associated cartilages
Functions: supports and protects, muscle attachment, produce blood cells, store minerals and
lipids
Nervous System
Components: brain, spinal cord, nerves, and special sense organs
Functions: regulates body activities
Metabolism
the sum of all the chemical processes that occur in the body (sum of all the building up
and breaking down)
Homeostasis
The maintenance of relatively stable conditions necessary for effective functioning and
survival
Ensures that the body’s internal environment remains constant despite changes inside and outside
the body
Maintained by means of many feedback loops
Each body system contributes to homeostasis in some way
It is dynamic – it can change over a narrow range that is compatible with maintaining cellular
life processes
Homeostatic mechanisms are mainly under the control of two systems: the nervous system and
the endocrine system
Nerve impulses cause quick, immediate corrections
Hormones secreted by the endocrine system cause slow, long acting corrections
Feedback Loops
a cycle of events in which a condition in
the body in continually monitored, evaluated, changed, remonitored, reevaluated, and so on
Controlled conditions
body temperature, blood pressure, blood glucose level, etc.
Stimulus
anything that disrupts the controlled condition
Three components of a feedback system
Receptor
Control Center
Effector
Receptor
a body structure that monitors changes in a controlled condition and sends
information called the input to a control center
Control Center
the brain sets the ranges of values within which a controlled condition
should be maintained, evaluates the input it receives from receptors, and generates output
commands when they are needed
Effector
a body structure that receives output from the control center and produces a
response that changes the controlled condition
Negative Feedback loop
reverses a change in a controlled condition; the activity of the effector
produces a result that reverses the effect of the stimulus; tend to regulate conditions that are held
fairly stable over long periods; works like the thermostat in your house
Positive feedback loop
strengthens a change in a controlled condition; reinforces conditions that
don’t happen very often (childbirth or blood-clotting); must be shut off by some event outside
the system so it can’t “run away” and produce life-threatening changes
