Respiratory Physiology

Question 1

What is respiration?

Answer 1

The production of ATP from organic molecules - not breathing!

Question 2

What is aerobic respiration?

Answer 2

Taking of oxygen in and combining it with glucose to produce ATP and produce CO2 and water as byproducts

Question 3

What are the byproducts of aerobic respiration?

Answer 3

CO2 and Water

Question 4

Where does breathing and gas exchange come in?

Answer 4

Oxygen and CO2

Question 5

Where does unoxygenated blood enter the heart via? and in which atrium?

Answer 5

Vena cava in the right atrium

Question 6

What is the pulmonary circuit?

Answer 6

The process of blood being oxygenated via leaving the right pulmonary artery and returning via the left atrium and left ventricle, being returned via the aortic artery.

Question 7

What is ‘bulk flow’?

Answer 7

Flow due to a pressure gradient and this pressure occurs when we breathe. To move a large number of molecules at one time.

Question 8

Where are motor sensors for up or downregulating your breathing?

Answer 8

Cerebellum, coming off the pons and medulla

Question 9

What are chemoreceptors?

Answer 9

Detect different gases in the blood
Hypoxia (low O2)
Hypercapnia (High CO2)
High protons/hydrogen ions (Acidosis)

Question 10

Where are chemoreceptors located?

Answer 10

In the aortic arch and carotid bodies (arteries going to the neck)

Question 11

Which lung has an extra fissure (3 lobes instead of 2)?

Answer 11

Right; the Transverse Fissure

Question 12

Whats the role of the epiglottis?

Answer 12

Trapdoor; dual chamber for food vs. air
When we swallow we push tongue up and the chamber moves, the epiglottis closes over the trachea and shuts airway

Question 13

What divides the upper and lower respiratory tract?

Answer 13

The vocal cords (laryngeal folds)

Question 14

What the ‘jacket of the lungs’?

Answer 14

The Pleural

Question 15

What’s the deep to superficial pleural order?

Answer 15

Visceral, pleural space and Parietal

Question 16

Describe the visceral pleural

Answer 16

Sits like a 2nd skin on top of the lungs, it’s wet, thin and fragile

Question 17

Describe the Parietal pleural

Answer 17

Outer membrane that attaches to and lines the thoracic cavity

Question 18

When we breathe what happens to the lungs, diaphragm, pleural space and the intercostal muscles?

Answer 18

Lungs go up Diaphragm goes down and Pleural Space gets bigger. External intercostal contract, internal relax

Question 19

What happens to the diaphragm when breathing in?

Answer 19

It contracts and goes down

Question 20

What happens to the external intercostal muscles when we breathe in?

Answer 20

They contract and move the ribcage upwards to allow expansion of the thoracic cavity(the internal relax)

Question 21

What do the intercostal muscles do?

Answer 21

They’re between the ribs and manipulate the width of the rib cage

Question 22

Where does gas exchange occur?

Answer 22

In the alveoli

Question 23

What is Boyle’s Law?

Answer 23

The inverse relationship between volume and pressure. When volume decreases, pressure increases. Lungs use this to compress oxygen and force it into the capillaries.

Question 24

How many layers are there of alveolar diffusion? What are they?

Answer 24

Oxygen has 4 layers to diffuse across. Oxygen dissolves into the surfactant lining the alveoli –> alveoli epithelium –> epithelial basement membrane –> capillary basement and capillary endothelial cells

Question 25

How many binding sites for oxygen do the red blood cells (haemoglobin) carry?

Answer 25

4

Question 26

Fick’s Law - what is rate of diffusion inversely proportional to?

Answer 26

Rate of diffusion is inversely proportional to membrane thickness

Question 27

Fick’s Law - what is rate of diffusion directly proportional to?

Answer 27

1) Difference in partial pressure of gas in alveoli and capillary blood
2) Difference in surface area of the membrane

Question 28

What is the apneustic centre?

Answer 28

The apneustic centre is located in the lower pons and stimulates neurons in the medulla (dorsal root ganglia) to facilitate inhaling. Additionally, it regulates the intensity of respiration/depth of inhalation. Stimulates the DRG whereas pneumotaxic inhibit the DRG.

Question 29

What is the pontine respiratory group?

Answer 29

Located in the pons consists of apneustic and pneumatic centre

Question 30

What does the ventral respiratory group do?

Answer 30

In the Medulla, resulting in forced inspiration but mainly in forced expiration. Neurons in ventral root ganglia stimulate accessory muscles in forced breathing to contract.

Question 31

What is a pneumothorax?

Answer 31

Collapsed lung. Build up between pleura layers.

Question 32

Where is the respiratory centre found within the brainstem?

Answer 32

Medulla

Question 33

What is the pneumotaxic centre?

Answer 33

Inhibit neurons in the apneustic centre and thus relax after inspiration and thus control heart rate.

Question 34

What is the dorsal root ganglia involved in?

Answer 34

Maintaining a constant breathing rhythm. DRG stops it no longer stimulates the diaphragm in expiration.