Session 5 - Control Of The Internal Environment

Question 1

What is negative feedback mechanism?

Answer 1

A regulatory mechanism in which a stimulus (controlled variable) causes the opposite output in order to maintain homeostatic conditions.

Question 2

What is the partial pressure of carbon dioxide in atmospheric air?

Answer 2

0.3 mmHg

Question 3

What is the partial pressure of carbon dioxide in alveolar air?

Answer 3

40 mmHg

Question 4

What is the partial pressure of carbon dioxide in arterial blood?

Answer 4

40 mmHg

Question 5

What is the partial pressure of carbon dioxide in venous blood?

Answer 5

45 mmHg

Question 6

What is the formula for calculating ABP?

Answer 6

ABP = CO x TPR

Question 7

What does ABP stand for?

Answer 7

Arterial Blood Pressure

Question 8

What is positive feedback mechanism?

Answer 8

A regulatory mechanism in which a stimulus (controlled variable) causes a response that is further away from he normal and in the same direction as the stimulus.

Question 9

Explain the positive feedback mechanism of contraction of the uterus during childbirth.

Answer 9

1. Head of baby pushes against cervix
2. Nerve impulses from cervix are transmitted to brain
3. Brian stimulates pituitary gland to secrete oxytocin
4. Oxytocin carried in bloodstream to uterus
5. Oxytocin stimulates uterine contractions and pushes baby towards cervix