Module 3: Section 1 - Exchange and Transport

Question 1

alveoli?

Answer 1

tiny air sacs that consist of
epithelial cell layer
elastic fibres
collagen

Question 2

bronchi?

Answer 2

divisions of trachea that consist of small tubes
suppoted by incomplete rings of cartilage

Question 3

cartilage?

Answer 3

rings are incomplete to bend
strong & flexible to stop organs from collapsing
connective tissue
provide support

Question 4

smooth muscle?

Answer 4

involuntary muscle
found in walls of trachea and bronchi
controls organs diameter in tubes so when relaxed they widen

Question 5

cilliated epithelium (cillia)?

Answer 5

beats bacteria containing mucus upwards away from alveoli towards throat (swallowed) to prevent infection
tiny-hair like cillia

Question 6

goblet cells?

Answer 6

secrete mucus into trachea lining
mucus traps harmful microorganisms and dust particles preventing enter to lungs

Question 7

elastic fibres?

Answer 7

allow alveoli to stretch as air is inhaled + recoil as air is exhaled
found in trachea, bronchi, brochioles

Question 8

bronchioles?

Answer 8

small divisions of bronchi

Question 9

trachea?

Answer 9

primary airway which carries air from nasal cavity to the chest

Question 10

ventilation?

Answer 10

movement of fresh air into lungs and stale out via expiration/inpiration

Question 11

what does trachea contain?

Answer 11

C cartilage
smooth muscle
elastic fibres
goblet cells
cilliated epithelium

Question 12

what does bronchi contain?

Answer 12

Small cartilage
smooth muscle
elastic fibres
goblet cells
cilliated epithelium

Question 13

what does alveoli contain?

Answer 13

elastic fibres
squamous epithelium

Question 14

what does bronchioles contain?

Answer 14

smooth muscle
elastic fibres
goblet cells
cillia

Question 15

why do we need exchange surfaces?

Answer 15

to exchange mats such as urea water and oxygen ACROSS PLASMA MEMBRANES

Question 16

squamous epithelium?

Answer 16

Flat, scale-like epithelial cells
thin walls for quick diffusion pathway

Question 17

diffusion is quick when? why?

Answer 17

the SA:V is greater

Question 18

diffusion is slow when? why?

Answer 18

the SA:V is smaller
as larger organisms cells have no direct contact with external environment so diffusion distance is larger

Question 19

why do larger organisms have specialised exchange surfaces?

Answer 19

as they have higher metabolic rate and smaller SA:V so require more oxygen and glucose

Question 20

adaptations for alveoli?

Answer 20

layer of squamous epithelium cells for quick diffusion pathway
partially permeable to allow certain gases across
ventiliation of air for a steep diffusion gradient
large SA to increase rate of gas exchange
good blood supply so gas exchange can be transported

Question 21

ribcage?

Answer 21

consist of ribs that enclose the thorax (chest)

Question 22

diaphragm?

Answer 22

sheet of muscle that moves the ribcage up and out when it contracts

Question 23

external intercostal muscles?

Answer 23

found between the ribs
pull the ribcage up and out when they contract

Question 24

internal intercostal muscles?

Answer 24

found between the ribs pull the ribcage down and in when they contract

Question 25

pleural cavity?

Answer 25

found in thoracic cavity double membrane filled with pleural fluid that lubricates lungs adheres to thoracic cavity and lungs via water cohesion so lungs expands whilst breathing

Question 26

inspiration?

Answer 26

active process requiring energy for muscle contraction

Question 27

expiration?

Answer 27

a passive process

Question 28

events of inspiration?

Answer 28

1. external intercostal muscles contract while internal intercostal muscles relax, moving the ribcage up and out 2. The volume of the thoracic cavity increases 3. diaphragm contracts and flattens, further increasing the volume of the thoracic cavity 4. lung pressure decreases below atmospheric pressure 5. Air flows into the lungs down the pressure gradient

Question 29

events of expiration?

Answer 29

1. external intercostal muscles relax, moving ribcage down and in 2. The volume of the thoracic cavity decreases 3. diaphragm relaxes and unflattens, further decreasing the volume of the thoracic cavity 4. lung pressure increases above atmospheric pressure. 5. Air is forced out of the lungs down the pressure gradient.

Question 30

What is tidal volume

Answer 30

The air inhaled and exhaled when at rest

Question 31

What is breathing rate

Answer 31

How many breaths are take (usually in a minute)

Question 32

What is oxygen consumption

Answer 32

the rate at which an organism uses up oxygen

Question 33

What is a spirometer

Answer 33

its a machine that can give readings of tidal volume, vital capacity, breathing rate and oxygen uptake

Question 34

How does a spirometer work

Answer 34

1) It has an oxygen-filled chamber with a moveable lid 2)The person breaths through a tube connected to the oxygen chamber 3) as the person breathes in and out , the lid of the chamber moves up and down 4) These movements are recorded by a pen attached to the lid of the chamber and this writes on the rotating drum

Question 35

What is residual volume

Answer 35

Volume that remains in the lungs so they don't collapse

Question 36

Why do fish have special adaptations

Answer 36

there is a lower concentration of oxygen in water than in air

Question 37

how are fish gills ventilated

Answer 37

1) fish opens its mouth, lowering the floor of the buccal cavity and the volume of the buccal cavity increases decreasing the pressure in the cavity 2) When the fish closes its mouth the floor of the buccal cavity raises again and the volume inside the cavity decreases and the pressure increases and the water is forced out across the gill filaments 3) Each gill is covered by a bony flap called operculum, the increase in pressure forces the operculum on each side of the head to open

Question 38

what is ventilation?

Answer 38

the total volume of air inhaled in 1 minute

Question 39

describe insects structure

Answer 39

rigid exo-skeleton with waxy coating that is impermeable to gases small openings called spiracles along the thorax and abdomen

Question 40

what are spiracles?

Answer 40

small pores that allow gases to diffuse into the body these lead into the tracheae can open/close via sphincters

Question 41

spiracles pathway? aka structure in insects cant afford diagrams ;(

Answer 41

exo-skeleton/spiracle -> tracheae -> tracheole

Question 42

what are tracheae?

Answer 42

air filled tubes that carry O2 in the body these have rigid rings of chitin to keep tracheae open

Question 43

what are tracheoles?

Answer 43

smaller versions (NO CHITIN) of tracheae that have thin permeable walls that delive O2 directly to exchange surface contain tracheal fluid (dissolves O2)

Question 44

what happens during activity in an insect?

Answer 44

-lactic acids builds -this loers water potential in cells -water leaves the tracheoles into the cells via osmosis -this allows more SA to be exposed for gass exchange

Question 45

what are the ventilation mechanisms in insects? mininum 2

Answer 45

-Mechanical active ventilation -Collapsible air sacs -Wing movement -Thoracic muscle vibration

Question 46

describe - Mechanical active ventilation

Answer 46

muscles around tracheae contract and relax to change the volume of the thorax and abdomen, causing the tracheae to push air in and out of the spiracles.

Question 47

describe - Collapsible air sacs

Answer 47

inflate and deflate to ventilate the tracheal system and can increase the volume of air moved through the system.

Question 48

describe - Wing movement

Answer 48

pumps air to ventilate the tracheal system.

Question 49

describe - Thoracic muscle vibration

Answer 49

pumps air to ventilate the tracheal system.

Question 50

Bony fish - Structure?

Answer 50

large, active so higherlevels of O2 needed low SA:V

Question 51

Bony fish - Gills - Structure?

Answer 51

Covered by the operculum (bony flap) - maintains flow of water over gills Gills consist of stacked filaments called gill lamellae Gill lamellae surrounded by good blood supply

Question 52

what are the adaptations of gills?

Answer 52

The lamellae provide a large surface area. The lamellae membranes are thin to minimise diffusion distance. The gills have a good blood supply to maintain steep diffusion gradients. The countercurrent flow of blood and water creates even steeper concentration gradients.

Question 53

what is the counter-current system?

Answer 53

the flow of blood and water in opposite directions

Question 54

how does the counter-current system function?

Answer 54

O2-rich blood meets H2o across gills maximising diffusion of O2 to blood (H2O flowing away = O2 weak H2O) O2-poor blood meets O2-reduces H2O allowing for diffusion into the blood (H2O flowing towards = O2 H2O)