Gas Exchange- Humans and Lung disease

Question 1

what is the epiglottis

Answer 1

flap of cartilage

closes over the entrance to the trachea

Question 2

What is the trachea

Answer 2

has a cilitated liningto beat upwards are sweap mucuos out.

has rings of cartilage to keep the airway open

Question 3

name the other compenents of the gas exchange

Answer 3

broncuhs
ribs
sternum
plerual membrane
lungs
bronchioles
intercostal muscles
diaphragm 
abdomen

Question 4

How does air flow in?

Answer 4

diaphragm contracts and is flat
external intercostal muscles contract
ribs move up and out
ribcage pulls on the pleural membrane
reduces the pressure in the alveoli
air rushes in

Question 5

How does air flow out?

Answer 5

Diaphragm relaxes
Internal intercostal muscles contract
ribs move in and down
volume of the thoratic cavity decreases
increased pressure in the thoratic cavity and lungs
air flows out

Question 6

What is a spirometer?

Answer 6

used to measure and record volumes of inspired and expired air.

Question 7

How does oxygen get into the blood?

Answer 7

diffusion

Question 8

How is the alveoli adapted for diffusion?

Answer 8

short diffusion distance- one flattened epithelial cell thick

Folds- increase surface area

Has its own capillary network to maintain a gradient as new blood is always flowing through.

Question 9

Advantages to humans of an internal gas exchange surface

Answer 9

reduces water loss

maintains a moist gas exchange surface.

Question 10

What is the diaphragm?

Answer 10

a tough membrane attached by muscles to inner wall of the chest.

when muscles of the diaphragm contract, the domoe flattens.

Question 11

Breathing in

Answer 11

as volume of chest increases, the air pressue inside the lungs decreases and becomes slightly lower than air pressure outside, air moves down the presure gradient.

Question 12

Breathing out

Answer 12

Lungs rocoil from being stretched (at rest)
as external intercostal muscles relax, the elastic fibres recoil and squeeze air out.
Internal intercostal muscles contract and pull ribs back down.

Question 13

Deep breathing

Answer 13

internal intercostal muscles pull ribcage down as far as possible to empty the lungs of more air than when at rest.

Question 14

What is residual volume?

Answer 14

air that is not expired.

Question 15

Which artery takes blood to the alveoli?

Answer 15

pulmonary artery

Question 16

which vein takes blood away from the alveoli?

Answer 16

pulmonary vein

Question 17

What happens at the alveoli?

Answer 17

CO2 diffuses into the alevoli out of the blood.

02 diffuses out of the alevoli into the blood.

Question 18

Why is there never a 0% CO2 concentration in the alveoli?

Answer 18

Because diffusion requires a gradient, so an equilibrium is found.

Question 19

Why does oxygen bind to haemoglobin?

Answer 19

because haemoglobin has a high affinity for oxygen.

Question 20

What does tobacco smoke contain?

Answer 20

nicotine and carbin monoxide.

Question 21

What is a retrospective study?

Answer 21

collecting data from the past, it is unreliable because people may have forgotten details .

Question 22

What is a prospective study?

Answer 22

collecting data as it accumulates.

Takes a lot of time.

Question 23

What do you need to consider when analysing a health risk study?

Answer 23

1. the number of people investigated.
2. identify the different levels of exposure to the health risk.
3. asses whether the control group were matched.
4. asses whether the differences are sufficiently large to indicate a factor as a risk.
5. see if tests have been done to see if stat. sig.

Question 24

What does incidence mean?

Answer 24

The number of cases that occur in a particular group of people in a given time.

Question 25

What does mortality rate mean?

Answer 25

number of deaths per number of population per year from a cause.

Question 26

How is relative risk calucated?

Answer 26

finding the ratio between incidences with factor to incidences without factor.

Question 27

What are the risk factors of COPD?

Answer 27

Smoking

Air pollution

Genetics

Infections

Occupation