chapter 15 quiz #2

Question 1

What is the respiratory control centre?

Answer 1

The medulla oblongata

Question 2

What is the role of the respiratory control centre?

Answer 2

Send signals to muscles that cause breathing to occur.

Question 3

What are the two regions in the medulla that control breathing?

Answer 3

The ventral respiratory group and the dorsal respiratory group.

Question 4

What does the ventral respiratory group control?

Answer 4

Expiratory breathing movements

Question 5

What does the dorsal respiratory group control?

Answer 5

Inspiratory breathing movements.

Question 6

Other than expiration and inhalation, what air movements does the medulla oblongata control?

Answer 6

• Coughing
• Sneezing
• Swallowing
• Vomiting

Question 7

What controls the respiratory rate?

Answer 7

The pons, under the medulla oblongata

Question 8

Why does inspiration occur?

Answer 8

Increased firing in inspiratory nerves (phrenic and intercostal) and an increase of motor units to intercostal and diaphragm muscles causing contraction.

Question 9

Why does expiration occur?

Answer 9

Impulses along inspiratory nerves cease.

Question 10

What is the pleura?

Answer 10

The thin membrane between the rib cage and the lungs which helps the two slide against each other.

Question 11

Where are the lungs located?

Answer 11

Within the sealed thoracic cavity.

Question 12

In the respiratory system, where is there a continuous column of air?

Answer 12

From the pharynx to the alveoli in the lungs.

Question 13

What sends signals via the vagus nerve for the respiratory centre to stop inhalation impulses?

Answer 13

Stretch receptors in the alveoli walls.

Question 14

What does the respiration centre detect?

Answer 14

Whether lungs are full or empty, to activate phrenic nerve to stimulate diaphragm .

Question 15

What elements stimulate activity in the respiratory centre?

Answer 15

CO2 and H+, not oxygen

Question 16

What is a carotid?

Answer 16

In arteries that carry blood to head and neck.

Question 17

What is the carotid sensitive to?

Answer 17

H+, CO2 and O2 levels in blood.

Question 18

What are the aortic bodies sensitive to?

Answer 18

Blood O2 and CO2 levels, pH of blood.

Question 19

What is a chemoreceptor?

Answer 19

A sensitive cell responsive to chemical stimuli.

Question 20

What are the two types of chemoreceptors?

Answer 20

Central: in medulla oblongata. Peripheral: carotid and aortic bodies.

Question 21

What is the role of the central chemoreceptors?

Answer 21

Sensitive to pH of environment.

Question 22

If the aortic bodies sense low oxygen concentration, what happens?

Answer 22

Breathing becomes faster and deeper.

Question 23

What happens when there are higher concentrations of CO2 and H+ in blood?

Answer 23

Breathing becomes faster and deeper.

Question 24

What cells influence respiration rate?

Answer 24

Carotid and aortic bodies.

Question 25

What is the order of nerves from respiratory centre to throat?

Answer 25

Respiratory centre (medulla oblongata), phrenic nerve, intercostal muscle/diaphragm, alveoli stretch receptors, vagus nerve.

Question 26

What directions do the phrenic and vagus nerves go?

Answer 26

Phrenic: from brain, vagus: to the brain.

Question 27

What is the role of the phrenic nerve?

Answer 27

Contracts muscles for breathing.

Question 28

What is the role of the vagus nerve?

Answer 28

Relaxes muscles for breathing.

Question 29

What is the formula for Carbaminohemoglobin?

Answer 29

HbCO2

Question 30

What is the role of HbCO2 and percentage CO2?

Answer 30

Carrier of CO2 in blood, 10%

Question 31

What is the formula for oxyhemoglobin?

Answer 31

HbO2

Question 32

What is the role of HbO2 and percentage O2

Answer 32

Main carrier of O2 in blood, 2.95%

Question 33

What is the formula for reduced hemoglobin?

Answer 33

HbH

Question 34

What is the role of HbH?

Answer 34

Formed when Hb picks up excess H+ ions in blood.

Question 35

What is the formula for bicarbonate ion?

Answer 35

HCO3

Question 36

What is the role of HCO3 cand percentage of CO2

Answer 36

Main carrier of CO2, 85%

Question 37

5% of CO2 and 5% of O2 in blood is found where?

Answer 37

plasma

Question 38

Where does H+ in blood come from?

Answer 38

Dissociation of H2CO3 (carbonic acid).

Question 39

What do you call the exchange of gases between air in alveoli and blood in pulmonary capillaries?

Answer 39

External respiration.

Question 40

Describe external respiration in lungs?

Answer 40

CO2 leaves blood, O2 enters blood.

Question 41

What are the 4 chemical equations for external respiration?

Answer 41

Hb + O2 → HbO2 HbCO2 → Hb + CO2 HCO3- + H+ → H2CO3 →(carbonic anhydrase)→ H2O + CO2 HbH → Hb + H+

Question 42

What is the role of carbonic anhydrase?

Answer 42

Speeds up breakdown of carbonic acid.

Question 43

When do hemoglobin have a higher affinity for O2?

Answer 43

In lower temp

Question 44

How does CO2 leave blood?

Answer 44

carried in plasma as HCO3, diffuses into lungs

Question 45

How does O2 enter blood?

Answer 45

O2 diffuses from lungs to plasma and then to RBC

Question 46

What do you call the exchange of gas between blood in systemic capillaries and the tissue fluid?

Answer 46

Internal respiration

Question 47

What happens in the internal respiration of the tissue?

Answer 47

O2 leaves blood, CO2 enters blood.

Question 48

What are the 4 chemical equations for internal respiration?

Answer 48

1. HbO2 → Hb + O2 2. Hb + CO2 → HbCO2 3. CO2 + H2O →(carbonic anhydrase)→ H2C03 → HCO3- + H+ 4. Hb + H+ → HbH

Question 49

How does CO2 enter blood in the tissues?

Answer 49

Combines with hemoglobin or combines with water in plasma to form carbonic acid H2C03 which dissociates to H+ and HCO3

Question 50

Why does O2 enter tissues?

Answer 50

Because they have a higher temperature so Hb connects to it less