gas exchange in mammals

Question 1

how can small organisms have direct diffusion

Answer 1

diffusion distances very small
surface area to volume ratio large
metabolic demands low

Question 2

factors that effect diffusion

Answer 2

surface area
concentration gradient of particles coming in- more there are quicker they diffuse
distance of diffusion is taking place

Question 3

things needed for efficient gas exchange

Answer 3

large surface area
-thin layers
-rich blood supply
-moist surfaces
-permeable surfaces

Question 4

how does rich blood supply increase efficiency

Answer 4

blood involved in transporting molecules to and from gas exchange site
maintains steep conc gradient

Question 5

how does moist surfaces help efficiency

Answer 5

most diffusion takes place in solutions

Question 6

features of nasal cavity

Answer 6

large surface area
good blood supply
thin walls
hairs as filters

Question 7

how air entering has smallest effect possible

Answer 7

moist surfaces increase levels of water vapour in air and rich blood supply raises temp of air

Question 8

function of nasal cavity

Answer 8

main route by which gas enters gas exchange system

Question 9

function of mouth

Answer 9

air can enter respiratory system but misses out on filtering through nasal cavity

Question 10

epiglottis

Answer 10

flap of tissue that closes over glottis in reflex action when food is swallowed. prevents food from entering gas system

Question 11

larynx

Answer 11

voice box uses flow of air to produce sounds

Question 12

trachea

Answer 12

major airway to bronchi.
lined with cells including mucus secreting cells
cilia on surface move mucus and dust away from lung s

Question 13

incomplete rings of cartilage

Answer 13

prevents trachea and bronchi from collapsing but allow food to swallowed

Question 14

left and right bronchus

Answer 14

tubes leading to lungs are similar in structure to trachea but narrower and divide to form bronchiles

Question 15

lung

Answer 15

organ where lung exchange takes place

Question 16

bronchioles

Answer 16

small tubes that spread through lungs and end in alveoli.

Question 17

structure of bronchioles

Answer 17

small diameter
small cartilage
collapse quite easily

Question 18

function of bronchioles

Answer 18

main function still as airway but little gas exchange occurs

Question 19

alveoli

Answer 19

main site of gas exchange in the lungs

Question 20

ribs

Answer 20

protective bony cage around gas exchange system

Question 21

intercostal muscles

Answer 21

found between ribs and important for breathing

Question 22

pleural membrane

Answer 22

surround lungs and line chest cavity

Question 23

pleural cavity

Answer 23

spaces between pleural membranes

Question 24

structure of pleural cavity

Answer 24

filled with thin layer of lubricating fluids that allow membranes to slide easily with breathing movements

Question 25

diaphragm

Answer 25

broad sheet of tissue that forms floor of chest cavity important for breathing movements

Question 26

whats an alveolus made of

Answer 26

single layer of flattened epithelial cells

Question 27

features of capillaries that run close to alveoli

Answer 27

have a wall that is one cell thick

Question 28

what is between the alveoli and capillaries

Answer 28

elastic connective tissue holding everything together

Question 29

whats elastic recoil of the lungs

Answer 29

when elastic connective tissue help to force air out of lungs which are stretched when you breath in

Question 30

what prevents alveolis from collapsing

Answer 30

special phospholipid known as lung surfactant

Question 31

lung surfactant

Answer 31

phospholipid that coats alveoli and makes breathing easier

Question 32

gaseous exchange between alveoli and deox blood

Answer 32

process by simple diffusion between alveolar air and deox blood in capillaries

Question 33

features of blood when involved in alveoli simple diffusion via capillaries

Answer 33

low in oxygen and high in carbon dioxide

Question 34

how does alveoli give large surface area

Answer 34

folded membrane

Question 35

conc of oxygen in alveoli

Answer 35

high

Question 36

adaptations of alveoli

Answer 36

short distance thin capillaries good blood supply high SA with folded membrane

Question 37

short distance diffusion alveoli

Answer 37

walls of alveoli one cell thick and wall of capillaries next to them

Question 38

steep conc gradient of alveoli

Answer 38

blood always flowing through capillaries so constant exchange of gases

Question 39

how alveoli maintain steep con gradient

Answer 39

continious flow of blood making gas exchange constantly happen

Question 40

method of movement of gases into and out of alveoli

Answer 40

by diffusion

Question 41

movement of air in and out of lungs

Answer 41

mass transport system

Question 42

structure of alveoli in order

Answer 42

alveolar duct thin squamous epithelium tidal air diffusion of co2 up and o2 down alveolar air macrophage liquid surfactant on inner surface

Question 43

role of macrophage in alveoli

Answer 43

white blood cell engulf bacteria coming inside alveoli

Question 44

process of moving air between lungs and external enviormnent

Answer 44

active process of ventilation

Question 45

2 parts of breathing

Answer 45

inhilation and exhalation

Question 46

feature of chest cavity

Answer 46

sealed unit for air one way in or out through trachea

Question 47

what does breathing involve

Answer 47

a series of pressure changed in the chest cavity that bring movement of air

Question 48

what type of process is inhalation

Answer 48

active energy using process

Question 49

muscles of diaphgram when inhaling

Answer 49

contract and result in it being lowered and flattened

Question 50

intercostal muscles when inhaling

Answer 50

muscles between ribs also contract raising rib cage upwards and outwards

Question 51

movement of disgphram and intercostal muscles when inhaling

Answer 51

result in volume of chest cavity increasing which reduces pressure in cavity.

Question 52

how does pressure change help inhaling

Answer 52

pressure within chest cavity lowered than pressure of atmospheric air outside so air moves inside through trachea bronchi and bronchioles into lungs to equalise pressure inside and out

Question 53

what type of process is normal exhalation

Answer 53

passive process

Question 54

muscles of diagphram when exhaling

Answer 54

relax so it moves up into resting domed shape

Question 55

intercostal muscles when exhaling

Answer 55

relax so ribs move down

Question 56

elastic fibres around alveoli when exhaling

Answer 56

elastic fibres around alveoli return to their normal length

Question 57

result of elastic fibres turning back to normal shape

Answer 57

volume of chest decreases causing an increase in pressure

Question 58

how is air released

Answer 58

pressure of chest cavity greater than that of outside air so air moves out via the trachea bronchi and bronchioles

Question 59

process of forced exhalation

Answer 59

internal intercostal muscles contract pulling ribs down and in abdominal muscles contract forcing diaphgram upwards increase in pressure in chest cavity so causes exhalation

Question 60

protection of lungs from outside bad things

Answer 60

mucus that lines airways and traps bacteria cillia move runny mucus upward to airway acid in stomach and digestive enzymes in mucus carry it away