3.3.1 exchange surfaces.

Question 1

what does the trachea look like

Answer 1

C shaped ring of cartilage
smooth muscle only between cartilidge ends
biggest
Has ciliated colomnar epithelium

Question 2

What does a bronchus look like

Answer 2

a full ring of smooth bronchial muscle
has cartilage plates
has ciliated columnar epithelium
medium size

Question 3

What do the bronchioles look like

Answer 3

Lumen is star shaped
branches of pulmonary vessels are parralel
smallest

Question 4

what is tidal volume

Answer 4

volume of air breathed in and out at rest

Question 5

what is vital capacity

Answer 5

the volume of breathed in and out during exercise so the greatest volume of air that can be taken in by the lungs

Question 6

what is residual volume

Answer 6

the minimum amount of air always within the lungs to prevent collapse

Question 7

Chemoreceptors that change breathing patterns detect what?

Answer 7

CO2 ———-hydrogencarbonate ions

Question 8

Where are these chemoreceptors of breathing found

Answer 8

brain stem/medulla or aortic bodies

Question 9

what part of the body controls the breathing rate

Answer 9

brain stem/medulla

Question 10

Describe inspiration

Answer 10

External intercostal muscles contract
internal intercostal muscles relax
rib cage come up and out
diaphragm contracts
volume increases in the thorax
air enters due to pressure being less inside

Question 11

Why do organisms need respiratory surfaces

Answer 11

so they can absorb enough oxygen and get rid of enough co2 to support the amount of metabolic activity.

Question 12

features of a good exchange surface

Answer 12

moist- dissolve oxygen within it
good blood supply/ventillation- to keep conc gradient
thin- short diffusion distance

Question 13

how are mammals respiratory systems adapted

Answer 13

millions of alveoli so large S/A
lined with squamous epithelial tissue which is really thin
surrounded by dense capillary network 
moist so can dissolve oxygen
elastic so can adapt to ventillation

Question 14

How are insects respiratory systems adapted

Answer 14

insects carry out ventilation movements to maintain concentration gradient as they dont use vessels like mammals
have millions of tracheoles so increased surface area

Question 15

how are fishes respiratory systems adapted

Answer 15

Gills have filaments and lamellae which allow for large s/a
counter current flow maintains conc gradient
efficient ventilation so conc gradient is maintained with oxygen rich water
large blood supple and capillary network for conc gradient
gill filaments have thin walls

Question 16

how do fish ventilate

Answer 16

the mouth lowers
water enters
buccal cavity raised up increases pressure
forces water into operculum
operculum moves outwards 
water flows over gills

Question 17

what is counter current flow

Answer 17

blood flows in the opposite direction to the flow of water to the conc gradient is always at the max

Question 18

why are ciliated epithelial and goblet cells needed

Answer 18

goblets produce mucus
traps dust or pathogens
cilia use hair like projections to waft mucus to top of the throat
defence against infection and keep airways clean

Question 19

why is cartililage needed in the airways

Answer 19

keeps trachea and bronchus open during stages of ventilation
allows food to pass through the oesophagas
provides attachment for smooth muscle in trachea
Ring cartillage in the tracheo allows in to be flexible and bend

Question 20

why is smooth muscle needed in the airways

Answer 20

allows bronchi to constrict or dilate for air flow adjustment
allows the bronchioles to recoil and push every bit of air out
closure of air pipes eg asthma

Question 21

what is surfactant

Answer 21

it lines the alveoli and is used for oxygen to be dissolved and so that the alveoli dont collapse during low pressure conditions
reduces surface tension

Question 22

how is the alveoli adapted to ventilation movements

Answer 22

contains elastic fibres which allow for dimension changes during ventillation
elastic recoil helps expel air out

Question 23

how are paticles of dust removed from the alveoli

Answer 23

macrophages engulf them and the lysomal actions breaks them down

Question 24

how are alveoli adapted

Answer 24

thin- 1 cell thick
elastic- expel air
squamous epithelial
surfactant to prevent collapse
conc gradient maintained

Question 25

why do mammals need a transport system

Answer 25

low s/a to volume
cells deep within get nout
the metalbolism too fast so to get enough 02 and get rid enoiugh co2