Respiratory

Question 1

how is water breathing different to air

Answer 1

• less O2 available in water in same volume of air
• requires greater efficiency

Question 2

how does gas exchange occur

Answer 2

• passive diffusion
• from region of higher partial pressure to region of lower partial pressure

Question 3

what is partial pressure

Answer 3

the pressure the gas would have if it was alone in the volume

Question 4

what are some respiratory surfaces

Answer 4

• should be moist and large
• skin, gills, trachea, lungs

Question 5

what are gills

Answer 5

outfoldings of the body that create a large surface area for gas exchange

Question 6

how do gills work in aquatic environments

Answer 6

• ventilation moves water (resp medium) over resp suurface (gills)
• countercurrent exchange may be used where blood flows in different direction to create a concentration gradient of O2

Question 7

what does the operculum do

Answer 7

a gill cover than pumps water in mouth and over/out gills

Question 8

what are gill fillaments

Answer 8

layers of tissue contaning blood vessels, takes O2 from water

Question 9

what are lungs

Answer 9

an infolding of the body surface

Question 10

explain the respiratory system of an insect

Answer 10

• branched tubes (tracheae), enlarged portions of the tracheae are called air sacs.
• air enters tracheae via openings on insects body surface (spiracles)
• tracheoles (tubes to cells) contain fluid that disspates when active, so more O2 in contact with cells.

Question 11

what is the order of mammalian respiratory system sections

Answer 11

nostrils, pharynx, larynx (voice), trachea, bronchi, bronchioles, alveoli

Question 12

what is the conducting zone and what does it involve

Answer 12

all structures allowing passage of air to lungs

needed for cleansing, humidifying and warming air.

everything other than alveoli

Question 13

respiratory zone

Answer 13

where gas exchange actually occurs
alveoli

Question 14

explain bird respiratory system

Answer 14

• many air sacs throughout body (8 or 9)
• even when exhaling, body is receiving fresh air
• air moves one direction only
• nostrils -> trachea -> primary bronchi -> some air enters lungs for exchange, remaining enters posterior air sacs -> breathe out expells used air, posterior sac empties air into lungs whilst more air enters -> next exhale air enters anterior sac and so on…

Question 15

why are alveoli covered in surfactants

Answer 15

• to reduce surface tension (stop collapse of alveoli)

Question 16

how do amphibians breathe

Answer 16

• ventilate the lungs by positive pressure breathing, which forces air down the trachea

Question 17

explain how mammals bring air in

Answer 17

negative pressure
- diaphragm and rib muscles contract to increase volume of lungs = reduced pressure
- surface tension from pleura cause lungs to cling to wall of thorax = open
- air flows form high pressure outside to low pressure inside

Question 18

what is tidal volume

Answer 18

the volume of air inhaled in each breath