Physiology

Question 1

What structure covers the larynx when we are eating?

Answer 1

Epiglottis

Question 2

What is the point on division of the trachea into right and left called?

Answer 2

Carina of the trachea

Question 3

How many lobes does the right lung have?

Answer 3

3 - Superior, middle, inferior

Question 4

How many lobes does the left lobe have?

Answer 4

2 - Superior and Inferior

Question 5

What does the pulmonary artery contain?

Answer 5

Deoxygenated blood

Question 6

What happens at the alveoli?

Answer 6

Blood from the pulmonary artery is oxygenated and taken back to the heart via the pulmonary vein.

Question 7

What is a type 1 alveoli?

Answer 7

Simple squamous alveoli which is used for gas exchange

Question 8

What is a type 2 alveoli?

Answer 8

Alveoli that produces surfactant

Question 9

Where are the respiratory control centres in the brain?

Answer 9

Medulla

Question 10

What two groups make up the medullary respiratory centre?

Answer 10

Ventral and Dorsal groups

Question 11

What is the ventral group of the respiratory centre responsible for?

Answer 11

Rhythmicity of breathing

Question 12

What is the dorsal group of the respiratory centre responsible for?

Answer 12

Inspiration

Question 13

What does the pontine respiratory centre do?

Answer 13

Provides tonic input to the medulla to provide smooth respiration

Question 14

What is boyle’s law?

Answer 14

At any constant temperature the pressure exerted by a gas varies inversely with the volume of the gas

Question 15

How is the volume of the thorax increased?

Answer 15

Vertical contraction of the diaphragm causing it to flatten. External intercostal muscle contraction

Question 16

How is inspiration brought about?

Answer 16

Respiratory centres cause contraction of the diaphragm and external intercostal muscles. This increases volume of the thorax and causes the intra alveolar pressure to fall. This then causes air to enter the lungs to equal the pressure gradient.

Question 17

Is expiration an active or a passive process?

Answer 17

Passive

Question 18

What is FVC?

Answer 18

Forced vital capacity. The maximum volume that can be forcibly expelled from the lungs following maximum inspiration

Question 19

What is FEV1?

Answer 19

Forced expiratory volume in one second

Question 20

What FEV1/FVC pattern would you see in obstructive lung disease?

Answer 20

Normal FVC
Low FEV1
Low FEV1/FVC ration

Question 21

What FEV1/FVC pattern would you see in restrictive lung disease?

Answer 21

Low FVC
Low FEV1
Normal FEV1/FVC

Question 22

What effect does parasympathetic stimulation have on the lungs?

Answer 22

Bronchoconstriction

Question 23

What effect does sympathetic stimulation have on the lungs?

Answer 23

Bronchodilation

Question 24

What is pulmonary compliance?

Answer 24

A measure of effort that has to go into stretching or distending the lungs

Question 25

What is anatomical dead space?

Answer 25

Inspored air that is not available for gas exchange as it is lying in the airways

Question 26

Why is alveolar ventilation lower than pulmonary ventilation?

Answer 26

Anatomical dead space.

Question 27

Where are the peripheral chemoreceptors?

Answer 27

Carotid bodies | Aortic bodies

Question 28

Where are the central chemoreceptors?

Answer 28

Near the medulla of the brainstem

Question 29

What do central chemoreceptors respond to?

Answer 29

The H+ concentration of the CSF

Question 30

What is the most potent stimulator of respiration in normal people?

Answer 30

Carbon dioxide causing stimulation of the central chemoreceptors

Question 31

Which chemoreceptors mediate the hypoxic drive?

Answer 31

Peripheral chemorecpetors

Question 32

What is the cardiac output?

Answer 32

The volume of blood pumped by each ventricle per minute

Question 33

What is the resting CO in a healthy adult?

Answer 33

5L per minute

Question 34

What is stroke volume?

Answer 34

The volume of blood ejected by each ventricle per heart beat

Question 35

What is the frank starling curve?

Answer 35

The more the ventricle is filled with blood during diastole (the end diastolic volume) the greater the volume of ejected blood will be during the resulting systolic contraction (stroke volume)

Question 36

How does heart failure change the frank starling curve?

Answer 36

Shifts it to the right. Reduces the stroke volume of the heart and impairs its pumping ability.

Question 37

What is the significance of the sigmoid curve in haemoglobin saturation?

Answer 37

The steep lower part means that the peripheral tissues get a lot of oxygen for only a small drop in capillary PO2. The flat upper portion means that a moderate fall in alveolar Po2 will not much affect oxygen loading.