exchange surfaces

Question 1

describe the sructure of the trachael system

Answer 1

-network of tubes called trachae
-have rings to keep airways open
-trachae divide into tracheoles

Question 2

what are the adaptations of the trachael system?

Answer 2

1. tracheoles have thin walls= short difusion pathway
   2.tracheoles highly branched = larger SA many
   3.tubes of air. gas exchange is quicker in a gas not a liquid
   4.abdominal contracts
   =moves air so maintains a conc grad

Question 3

how do insects reduce water loss?

Answer 3

-small SA:vol ratio
-waterproof covering. chitin cuticle
-spiracles close at rest and open when active

Question 4

how do gases etc travel through the trachael system?

Answer 4

1. diffuse down a conc grad
   O2 higher in trachae and lower at tissure during aerobic respiration
2. abdominal muscles contract= squeezes trachae so air moves in and out of spiracles creatin g a pressure gradient
   3.loss of water by osmosis

Question 5

what does anerobic respiration produce? problem?

Answer 5

lactate
insoluble so lowers water potential in respiring cells

Question 6

describe the structure of the gill

Answer 6

-each gill is made of gill filaments=large surface area
-covered with lots of lamellae with lots of capillaries so thin surface layer

Question 7

describe the counter current system

Answer 7

-water flows over the lamellae
-blood flows opposite towards the water
-so water with a relatively high o2 conc will always flow next to blood with a larger conc of O2 this ensures a steep concentration gradient is maintained

Question 8

gwhy is diffusion slower in multicellular organisms?

Answer 8

1.some cells are deep within the body so long distance
2.lower SA:V so need a specialised transport exchange organs

Question 9

how are plants adapted for gas exchange?

Answer 9

-short diffusion pathway-many smallpores so close to stoma
-many interconnecting air spaces
-large SA to v ratio

Question 10

where are the stomata?

Answer 10

in the epidermis

Question 11

how do stomata open?

Answer 11

water enters the guard cells making them turgid which opens the stomatal pore

Question 12

where is the main gas exchange surface in a plant?

Answer 12

mesophyll cells

Question 13

adaptations to prevent waterloss

Answer 13

-stomata sunk n pits=traps vapor,reduce conc grad
-hairs on epidermis=traps water vapor
-curled leaves so stomata on inside=protects from wind
-thicker waxy cuticle
-reduced stomata

Question 14

describe inspiration

Answer 14

-external intercostal muscles contract
-diaphragm flattens ribs move up and out
-thorax volume cavity increases
-pressure in lungs is lower than atmospheric pressure
-air moves in down a pressure gradient

Question 15

describe expiration

Answer 15

-internal intercostal muscle contacts
-diaphragm relaxes
and becomes a dome shape
-volume of thorax cavity decrease
-pressure in lungs is grater than atmospheric pressure
-air moves down a pressure gradient

Question 16

explain the need for a ventilation system

Answer 16

-draws o2 into the lungs
-removal / excretion of co2
-mintains conc grad

Question 17

describe alveoli

Answer 17

small air sacs at ends of bronchioles

Question 18

difference between ventilation and gas exchange system?

Answer 18

ventilation:
-movement of air
-muscles so active process
-involves mass flow
gas exchange:
-movement pf o2 and co2
-o2 moves from lungs to alveoli to red bood cells to tissue
-passive = diffusion
-takes place across a surface

Question 19

alveoli adaptations

Answer 19

-large total surface area = 300 million
-thin permeable walls = single layer of flattened cells
-moist linings = surfactant reduces surface tension stopping walls sticking to each other
-elastic walls
-large network of capillaries

Question 20

how is the trachae adapted?

Answer 20

-flexible
-rings of cartillage prevents collapsing

Question 21

define forced vital capacity?

Answer 21

max vol of air to breathe forcfully out after a deep breath

Question 22

how do you obtain a vital capacity?

Answer 22

person needs to breath out as much as possible and in as much as possible

Question 23

define pulmonary ventilation rate

Answer 23

total vol of air moved into the lungs in one minute

Question 24

whats the formula for pulmonary ventilation rate

Answer 24

tidal volume x breathing rate

Question 25

define residual volume

Answer 25

the vol of air that remains in the lungs after a deep breath out

Question 26

define forced expiratory volume

Answer 26

max vol of air that can be breathed forcfully out of the lungs in 1 second

Question 27

why does forced expiraroty volume reduce with age

Answer 27

loss of elasticity of internal intercostal muscles

Question 28

how do you calculate breating rate of a graph/trace?

Answer 28

1.how many peaks
2. 60 divide seconds taken
3. x by how many peaks

Question 29

define breathing rate

Answer 29

number of breaths taken in or out per minute

Question 30

what is a degenerate disease?

Answer 30

symptoms get worse over time

Question 31

define acute disease

Answer 31

symptoms last a short time

Question 32

define chronic disease

Answer 32

symptoms last a long time-incurable

Question 33

what are risk factors of lung disease?

Answer 33

-genetic makeup
-occupation
-frequent chest infections