human gas exchange

Question 1

what is the definition of breathing?

Answer 1

= movement of air in and out of the lungs

Question 2

What is respiration?

Answer 2

= chemical reaction to release energy in the form of ATP

Question 3

What is gas exchange?

Answer 3

= diffusion of oxygen from the air in the alveoli to the blood and co2 from the blood into the air of alveoli

Question 4

What is the structure of the human gas exchange system?

Answer 4

= 2 lungs
= alveoli
= bronchioles
= bronchi
= trachea

Question 5

What is the trachea?

Answer 5

= wind pipe
= made from cartillage
= prevents walls from collapsing
= C-shaped: allows movement and flexibility- allows food through
= walls are lined with epithelial cells and goblet cells

Question 6

What does the trachea branch into?

Answer 6

= bronchi
= carries air into either lungs
= contains cartillage, goblet cells and epithelial cells

Question 7

What does the bronchi branch into?

Answer 7

= smallert tubes- bronchioles into each lung
= has air sacs- aveolilo

Question 8

What does ventillation involve?

Answer 8

= involves diagphram, and intercostal muscles and external
intercostal muscles - antagonistic

Question 9

What are the intercostal muscles?

Answer 9

= external: contraction leads to inspiration- pulls rib-cage up and outwards- provides more volume in thorax
= internal intercostal muscles: relaxing, leads

= internal intercosyal micles: exhale
= internal intercostal muscles contract and external relaxes, pulls rib-cage in and down decrease volume and higher pressure forcing air out

Question 10

When we breathe in what happens to the diagphram?

Answer 10

= contracts reduces the pressure, as volume increases, there is a higher atomospherical pressure, so air moves into the lungs

Question 11

What happens when we breathe out?

Answer 11

= diagprah- relaxes, dome shape
= volume decreases, so pressure increases and is higher than the atmospherical pressure, so air moves out the lungs

Question 12

When we breathe in what happens to the rib cage?

Answer 12

= pulled up and outwatds- external intercostal muscles are contracting

Question 13

when we breathe out what happens to the rib-cage?

Answer 13

= moves downwards and in
= internalinetrcostal muscles contracign

Question 14

What happens with the alveoli?

Answer 14

= lots of alveoli- surface area for diffusion of gases
= wall of the alveolous and wall of cappilar are one cell thick- short diffusion pathway between air in alveoli and red blood cells
= when oxygen diffuses into the blood it is rapildy carried away from the alveoli
=- allows steep concentration gradient
= also maintained by breathing brings fresh air- allows high concentration in alveoli and low co2

Question 15

What do goblet and celial epithelial cells do?

Answer 15

= goblet cells: secrete mucus, traps dust and pathogens
= celial epithelial cells: have hair like structure, cillia tosses mucus to the throat, where it is swallowed and dust and pathogens are digested

Question 16

Is breathing in active?

Answer 16

= yes, requires the contraction of muscles

Question 17

is breathing out passive?

Answer 17

=yes, alveoli has elastic fivres which revoil pushes the air out, unless these are damaged

Question 18

What are the lungs surrounded by?

Answer 18

= plural membranes
= between is plural fluid
= acts as a lubricant as the lung volume changes