Module 1- Midterm-Physiology

Question 1

What is the Internal Environment?

Answer 1

• Fluid in which the cells of our body are bathed in

- Contains interstitial fluid and blood plasma

Question 2

What is the ExternaL Environment?

Answer 2

-Region outside the body
Includes:
          -Respiratory Tract
          -Digestive Tract
          -Urogenital Tract

Question 3

What is Homeostasis?

Answer 3

Maintenance of stable conditions within the internal environment, regardless of the conditions of the external environment. Maintains this environment through positive and negative feedback loops

Question 4

What is a negative feedback loop?

Answer 4

• Contains a set point, control center, effector, controlled variable, sensor
• Where controlled variable eventually shuts off its own production

Question 5

Give an example of a negative feedback loop?

Answer 5

-A house has a set point of 20 degrees, the sensor detects that the house is below 20 degrees and sends a message to the effector. The effector (furnace) produces heat which is the controlled variable. When the temperature reaches the setpoint, the thermostat stops.

Question 6

The nervous system

Answer 6

• used in feedback loops
• rapid communication through nerves and neurons
• spinal cord, brain and nerves

Question 6

What is a positive feedback loop?

Answer 6

• controlled variable stimulates its own production
• self-amplifying
• can produce a very rapid change in system
• generation of action potentials in nerve cells
• surge of LH hormone causing ovulation

Question 7

The endocrine system

Answer 7

• slowly

- through the release of hormones into the blood

Question 8

Body’s Structural Hierarchy

Answer 8

• atoms
• molecules
• macromolecules
• cellular organelles
• tissues
• organ
• organ systems
• organism