respiratory systems

Question 1

what is the main function of the lungs ?

Answer 1

is gas exchange , oxygen enters the body and carbon dioxide is removed.

Question 2

what occurs during an inhale ?

Answer 2

the diaphragm contract and pulls down so that the chest muscles can pull outwards and the chest expands. This causes the lungs to have a lower pressure than the area outside in the air and air flows into the lungs.

Question 3

what occurs during an exhale ?

Answer 3

the muscles relax and the lungs return to their normal size which pushes air out as the pressure inside the lungs is higher than the outside air.

Question 4

how many lobes are in the right lung ?

Answer 4

3

Question 5

lobes in the left lungs ?

Answer 5

2

Question 6

what are the sites of gas exchange in the lungs ?

Answer 6

tiny air- containing sacs called alveoli

Question 7

what does the trachea branch into ?

Answer 7

2 bronchi / singular bronchus

Question 8

what gives the trachea and bronchi their cylindrical shape and structure ?

Answer 8

cartridge rings

Question 9

what is the first airway branch that no longer cartlidge ?

Answer 9

bronchioles

Question 10

what are the alveoli surrounded by ?

Answer 10

capillaries allow gas exchange to occur

Question 11

what type of muscle does the bronchi contain and how are they controlled ?

Answer 11

smooth muscle and the ANS - involuntary

Question 12

how is flow calculated ?

Answer 12

change in pressure/resistance.

Pressure = (Palveoli - Patmosphere)

Question 13

what is partial pressure (P) ?

Answer 13

this is the pressure of a gas in a mixture

Question 14

what is it proportional to ?

Answer 14

concentration , so P02 is the conc of oxygen in the air

Question 15

the first stage of gas exchange is ventilation what is it ?

Answer 15

this is the exchange of air between the atmosphere and the alveoli by bulk flow.

Question 16

what is bulk flow ?

Answer 16

This is when large amounts of oxygen enters the body from the air.

Question 17

then there is what ?

Answer 17

Exchange of oxygen and carbon dioxide between the alveolar air and blood in the lung capillaries by diffusion. Oxygen flows into blood from area of high concentration to an area of lower concentration. While the carbon dioxide flows from the blood into the alveolar air , to be expelled from the body.

Question 18

next stage ?

Answer 18

transport of oxygen and carbon dioxide through the pulmonary and systemic circulation by bulk flow.

Question 19

then ?

Answer 19

Exchange of oxygen and carbon dioxide between blood in tissue capillaries and cells in tissue by diffusion.

Question 20

last stage ?

Answer 20

Cellular utilisation of oxygen and production of carbon dioxide.

Question 21

what is diffusion ?

Answer 21

allows the flow of small molecules across capillaries such as glucose and oxygen from the blood into the tissues and carbon dioxide from the tissue into the blood.

Question 22

what carries the oxygen in the blood ?

Answer 22

iron in the heme from haemoglobin that carries oxygen which is found in RBC ( erthyrocytes).

Question 23

how many heme groups in haemoglobin ?

Answer 23

4 groups of heme and can therefore carry four oxygen molecules.

Question 24

when is there a 100% oxygen saturation of haemoglobin ?

Answer 24

when the P02 is at 100mmHg for systemic arterial.

Question 25

in terms of comparison to control what does graph look like for foetal saturation ?

Answer 25

shifted to the left

Question 26

higher temperature , acidic ?

Answer 26

shifted to the right

Question 27

where does the oxygen load into the haemoglobin and how ?

Answer 27

in the alveoli as it moves down it’s concentration from an area of higher concentration outside the alveoli into the alveoli and hence to the haemoglobin.

Question 28

why does the oxygen unload from the haemoglobin to the tissue ?

Answer 28

it moves from an area of high concentration in the haemoglobin to the lower area of concentration in the tissue.

Question 29

why does C02 move from tissue to blood ?

Answer 29

moves from an area of high concentration in the tissue to the area of lower concentration , the blood. Also it moves from the blood to the alveoli down it’s concentration gradient.

Question 30

where is carbonic anhydrase found and function ?

Answer 30

erthrocyets and it catalyses the conversion of:
CO2 + H20 → HCO3 + H+

Hc03 is bicarbonate ion

Question 31

what is insipration and what occurs ?

Answer 31

diaphragm contracts and the external intercostal muscles pull the ribs up and out

Question 32

what occurs during expiration ?

Answer 32

diaphragm relaxes and the abdominal organs press upwards while the lung elasticity recoils inwards.

Question 33

what do the carotid chemoreceptors do ?

Answer 33

detect a fall in the ‘set levels’ and this causes an excitatory input to the medulla inspiratory neurons which causes the intercoastal muscles and diaphragm to contract/relax.