Lecture 19

Question 1

What are the two forms of oxygen transport in the blood?

Answer 1

Dissolved and bound to haemoglobin

Question 2

Why does oxygen dissolve poorly in blood?

Answer 2

Because of its warm temperature

Question 3

How is oxygen carried in haemoglobin?

Answer 3

Bound to the iron

Question 4

How many O2 molecules can haemoglobin carry?

Answer 4

Four as there are 4x haem structures with 1x iron on each

Question 5

What is the binding curve relationship of O2 and haemoglobin?

Answer 5

Sigmoidal

Question 6

Why is the binding curve relationship sigmoidal?

Answer 6

Because of the co-operative binding properties of haemoglobin

Question 7

Describe the co-operative nature of haemoglobin

Answer 7

Binding affinity increases as more O2 binds, 1st is hardest to bind and 4th is easiest

Question 8

What are the two jobs of haemoglobin?

Answer 8

To move oxygen from air in the alveolus to blood in the capillaries and to move oxygen from the blood in the capillaries to the surrounding tissues

Question 9

How is haemoglobin able to preform both its jobs effectively?

Answer 9

Because of its co-operative nature

Question 10

What are the two reasons for the relationship of the haem binding curve not being linear?

Answer 10

To allow the body to store O2 in reserve and adjust the distribution of O2 depending on the tissues metabolic needs

Question 11

Is the haemoglobin binding curve static or dynamic?

Answer 11

Dynamic

Question 12

What are the two ways the haemoglobin binding curve can be shifted?

Answer 12

Changing the pH and temperature of the blood

Question 13

What has to happen to the pH and temp of blood to reduce O2 affinity?

Answer 13

Lowing pH and increasing temperature

Question 14

What has to happen to the pH and temp of blood to increase O2 affinity?

Answer 14

Increase pH and decrease temperature

Question 15

What does affinity mean?

Answer 15

How tightly the molecules are bound to each other. Lower O2 affinity for haemoglobin means it lets it go easier

Question 16

What are the three forms of transportation for carbon dioxide in the blood?

Answer 16

Dissolved in plasma, bound to haemoglobin and converted into bicarbonate

Question 17

How does bicarbonate form?

Answer 17

CO2 and H2O combine to form carbonic acid, which dissociates into bicarbonate and hydrogen ion, lowering the pH

Question 18

Is O2 usage and CO2 production variable or static?

Answer 18

Variable

Question 19

What are the four sensors that control breathing?

Answer 19

Chemoreceptors, baroreceptors, lung stretch receptors and protective reflexes

Question 20

Is the information from sensors that control breathing afferent or efferent

Answer 20

Afferent

Question 21

What area of the brain is the central controller of breathing?

Answer 21

Pons, medulla and some other parts

Question 22

What are chemoreceptors?

Answer 22

Receptors that detect changes in O2 and CO2 levels in the blood

Question 23

If O2 is up or CO2 is down what will the chemoreceptors do?

Answer 23

Send afferent input to the brain, resulting in increased breathing frequency and tidal volume

Question 24

What are the primary chemoreceptors that control breathing?

Answer 24

CO2 receptors

Question 25

What are the secondary chemoreceptors that control breathing?

Answer 25

O2 receptors

Question 26

What are baroreceptors?

Answer 26

Blood pressure sensors

Question 27

How does baroreception affect respiratory function?

Answer 27

If arterial BP decreases, less O2 is being delivered to tissues so the baroreceptors will send afferent signals to inform the brain and the brain will increase respiratory minute volume and the uptake of air

Question 28

What is the function of the lung stretch receptors?

Answer 28

As the lungs inflate or deflate, afferent input is sent to the brain. Brain sends efferent output to prevent over stretch or deflation

Question 29

What is the function of the protective reflexes?

Answer 29

To detect irritation and send efferent signals from brain to trigger coughing or sneezing