Major themes of anatomy, physiology & anatomical terminology

Question 1

Define Physiology

Answer 1

Physiology is the study of the function of the body’s structural machinery often at a cellular or molecular level.

Question 2

Define Anatomy

Answer 2

Anatomy is the study of the structure of body parts and their relationships to one another.

Question 3

Define Pathophysiology

Answer 3

Pathophysiology is the study of structural and functional changes in tissues and organs that lead to disease.

Question 4

List the levels of human structure from the simplest to most complex.

Answer 4

Atoms -combine to form
Molecules - connect to form 
Organelles - work together to form
Cells - may function individually or group together to form
Tissues- different tissues come together to form
Organs - working together form
Organ systems 
Living organism

Question 5

Name the eleven organ systems of the human body

Answer 5

1. Digestive system
2. Muscular system
3. Integumentory system
4. Lymphatic system
5. Endocrine system
6. Nervous system
7. Skeletal system
8. Reproductive (female & male)
9. Respiratory system
10. Circulatory system
11. Urinary system

Question 6

Define Anatomical variation and give examples

Answer 6

Anatomical variation is the variation in number, position or structure of a particular organ or body part

• variable number of lumbar vertebrae (4,5,or 6)
• horseshoe shapes kidneys or pelvic kidneys
• Aortic branch structural differences

Question 7

Define homeostasis and explain why this concept is central to physiology

Answer 7

Homeostasis is the ability to maintain a relatively stable internal environment in an ever changing outside world. with a predetermined temperature set point for dynamic state of equilibrium

Loss of homeostatic control disrupts all balance and can cause illness or death

Question 8

State three basic components of a feedback loop

Answer 8

The following and homeostatic control mechanisms aid in preventing homeostatic imbalances

1. Receptor
   Sensors that maintain the environment by responding to stimuli that create imbalance I.e hormones, free nerve endings
2. Control centre
   Determines the set point the variable is maintained at. Analysis input from the receptor and determines response I.e brain,spinal cord.
3. Effector
   Provides the means for the control centers response I.e muscle, glands.

Question 9

Provide an example of a negative feedback loop & describe it’s role in maintaining homeostasis and normal body functions

Answer 9

Feedback is ‘Negative’ because it proceeds in the opposite direction of the initial disturbance. The output shuts off the the original stimulus or reduces its intensity.

Example of Negative Feedback Loop
Human Thermoregulation

Receptor- Sensory receptors (thermoreceptors) in the skin and blood monitor body temperature.

Control Center - hypothalamus (small region of the brain) receives nerve signals from receptors and compares actual body temperature with ‘built in’ set point and sends outgoing nerve signal to effectors.

Effectors - Skeletal muscles ( shivering) and vasoconstriction- blood vessels constrict, decreasing blood flow to the skin, preventing heat loss if to cold and vasodilation - skin blood vessels (sweating and evaporate) if too hot.

Question 10

Provide an example of a positive feedback loop and describe its role in normal body functions.

Answer 10

in positive feedback the output enhances or exaggerates the original stimulus. Feedback is ‘positive’ because the change that occurs proceeds in the same direction as the initial disturbance. can create out of control situations as controlled variables deviate further from the set point. ( abnormally high fever)

Positive feedback example
Blood Clotting

Receptor
1. Break or tear in blood vessel wall (feedback cycle is initiated)

Control Center

2. Clotting occurs as platelets adhere to site and released chemicals.
3. released chemicals attract more platelets.

Effector

4. Clotting proceeds; newly forming clot grows
5. feedback cycle ends after clot seal breaks.