Homeostasis and Blood pH

Question 1

What is the main stimulus affecting the breathing rate?

Answer 1

The level of carbon dioxide in blood.

Question 2

Explain how exercising stimulates our breathing rate

Answer 2

1. during exercise, cell metabolism increases and produces more CO2
2. More CO2 dissolves in blood, lowering blood pH slightly.
3. Receptors sense the drop and send nerve signals to increase breathing rate.
4. increased breathing rate quickly removes more CO2 from blood, causing pH to rise slightly, returning it to normal.

Question 3

Explain how holding your breath stimulates our breathing rate

Answer 3

1. holding breath causes levels of CO2 to rise in blood.
2. CO2 combines with water to form carbonic acid.
3. carbonic acid dissociates to form bicarbonate ion and H+
4. pH sensors detect drop and send signal to brain, forcing person to breathe.

Question 4

What is the respiratory center of the brain?

Answer 4

The Medulla Oblongata

Question 5

What stimulates the Medulla Oblongata to regulate our breathing?

Answer 5

Change is detected in an imbalance and sent to receptor - input sent to control centre - output sent to effector - it then responds to the change, balancing the homeostasis.

Question 6

The path of respiratory gases in circulatory system

Answer 6

inhaled air - alveolar spaces - pulmonary veins - systemic capillaries - body tissue - systemic veins - pulmonary arteries - exhaled air.

Question 7

Weddell seals in Antartica can remain underwater for how long?

Answer 7

20 min to 1 hour

Question 8

Elephant seals can dive to hour many meters? how long can they remain underwater?

Answer 8

1500 meters

2 hrs

Question 9

Marine mammals have a ____ blood: body volume ratio

Answer 9

high