Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology > 4.2 > Flashcards

4.2 Flashcards

gas exchange

1
Q

why do very small organisms not need a gas exchange or transport system

A

diffusion distance from the outside to the inner most areas in very small
large sa:vol
metabolic demands are low

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the 3 main factors that affect rate of diffusion

A

surface area
concentration gradient
diffusion distance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

give 5 ways lungs are adapted for gas exchange

A

large surface area
thin walls (small diffusion distance)
rich blood supply (maintain conc gradient)
most surfaces (gases dissolve)
permeable surfaces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

why are the airways covered in hairs and have a lining that secrete mucus

A

filter out dust, small particles and pathogens that you breathe in

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how does your body raise the temperature if the air that you breathe in

A

rich blood supply

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

why are moist surfaces needed in gas passages

A

increase level of water vapor in the air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the epiglottis

A

flap of tissue that prevents food entering gas exchange system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is the name for the voice box

A

larynx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are the incomplete rings of cartilage needed for

A

prevent trachea and bronchi from collapsing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

describe bronchioles

A

small tubes that spread through lungs & end in alveoli
(no cartilage so can collapse)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

where are the intercostal muscles found

A

between the ribs and are important in breathing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are the pleural membranes and cavity

A

pleural membranes:
surround lungs & line chest
cavity:
space between pleural membranes, allows easy breathing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the diaphragm

A

broad sheet of tissue that form the floor of the chest cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is the electrostatic recoil of the lungs

A

elastic connective tissue forces air out of lungs as they stretch when you breathe in

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the use of the lung surfactant

A

coast alveoli
stops collapsing alveoli
makes breathing easier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how are alveoli adapted for gas exchange

A

single layer of flattened epithelial cells
capillaries one cell thick so short diffusion distance
folded surface increases surface area
constant blood supply maintains concentration gradient
moist so gasses dissolve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

define breathing/ventilation

A

physical movements of the chest change the pressure so that air is moved in or out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is the mass transport system

A

an arrangement of structures by which substances are transported in the flow of a fluid with a mechanism moving it around the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

where are the intercostal muscles

A

between the ribs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Is inhalation an active or passive process

21
Q

explain inhalation

A

muscles around the diaphragm contract so it is lowered and flattened
the intercostal muscles contract raising the rib cage upwards and outwards
this increases the volume chest cavity so the pressure is lower and air moves in

22
Q

explain exhalation

A

muscles surrounding the diaphragm relax so it moves into the resting domed shape
intercostal muscles relax so ribs move down and in
volume of chest cavity decreases causing an increase in pressure so air moves out of the lungs

23
Q

how can exhalation be forced

A

contraction of abdominal muscles forcing the diaphragm upwards increasing pressure in the chest cavity causing exhalation

24
Q

how does the airways prevent infection

A

produce a lot of mucus lining the airways which traps tiny particles and organisms which is moved upwards to the back of your throat by cilia and digested by the acid in your stomach

25
describe insects gas exchange system
spiracles on the exoskeleton lead to the trachea which becomes tracheoles that lead to muscle fibers
26
what are spiracles
openings along the side of the thorax and abdomen for the entry and exit of respiratory gases which are opened and closed by sphincters
27
why do spiracles need to be controlled by sphincters
to control water loss
28
what is the trachea in insects
large tubes supported by chitin in the insect respiratory system carrying air directly into the body for gas exchange running alongside and and into the insect dividing into tracheoles
29
what are tracheoles
minute tubes of elongated cells with no chitin lining so are fully permeable for gas exchange spread throughout the tissue and penetrating into some individual cells
30
how does the insect respiratory system work
air enters through spiracles moves along trachea to tracheoles where the large surface area allows gas exchange to take place
31
how do insects increase rate of gas exchange when they are active
tracheoles contain water which reduces gas exchange however when the insect is very active lactic acid builds up which affects the osmotic concentration of cells and causes water to move out of the tracheoles to the cells exposing additional surface area for gas exchange
32
how is the opening and closing of spiracles coordinated
controlled by sphincters stimulated by respiratory centers in the nervous center which respond to levels of CO2 & O2 as well as lactic acid build up
33
how do very active insects supply extra oxygen
mechanical ventilation - air is actively pumped into the tracheal system through muscular pumping movements of the thorax and abdomen which changes the pressure causing air to be drawn in or out collapsible trachea - air sacs act as air reservoirs and increase the volume of air moved through the respiratory system via ventilating movements of the thorax and abdomen inflating and deflating them
34
what is the outer structure of the gills
gills are contained in a gill cavity which is covered by a protective bony flap called the operculum
35
why is the operculum important
it maintains the flow of water over the gills even when the fish is stationary
36
explain gas exchange in fish
water flows in through the mouth over the gills and the lamellae where gas exchange occurs then out through the operculum `
37
how is a fish gas exchange well adapted for gas exchange
gill filaments have a large surface area the lamella has a rich blood supply to maintain a concentration gradient they do counter current exchange to maximize gas exchange along the entire length of the lamella thin walls for short diffusion distance overlapping of gill filaments slows down the flow of water therefor allowing more time for gas exchange
38
what is the countercurrent exchange system
water moving over the gills moves in the opposite direction to the blood in the blood vessels maintaining a concentration gradient as it ensures equilibrium of oxygen is not met allowing diffusion to occur across the entire length of the lamella
39
describe the structure of a leaf
waxy cuticle on the surface of the leaf then the upper layer of epidermis then the palisade mesophyll then the spongy mesophyll which also contains xylem vessels, phloem tissue and air spaces then the lower epidermis which has guard cells and stomata
40
how is the spongy mesophyll adapted for gas exchange
irregularly shaped to increase surface area arranged with large air spaces between them and are moist so gasses can dissolve and gas exchange can occur more freely between cells
41
why is the waxy cuticle needed
it is impermeable therefor acts as a barrier to diffusion through the surface of the leaf
42
what are stomata
specialized pores found mainly in the epidermis on the underside of the leaf through which gases diffuse into and out of the cell
43
describe the structure of a guard cell
border a stomata specialized epidermal cell sausage-shaped contain chloroplasts cellulose in their cell walls is unevenly distributed
44
how are stomata closed
when conditions are not in favor of photosynthesis turgor pressure is low as the potassium ions are excreted therefor due to the unsymmetrical thickness of cellulose in the cell wall the guard cells become flaccid and close the stomata
45
how are stomata opened
when conditions are favorable for photosynthesis solutes are moved into the guard cells by active transport therefor water moves into the guard cells by osmosis causing them to swell and increase turgor pressure this opens the stomata due to the uneven bending as the spiral thickenings of cellulose means that only the outer walls stretch creating semicircular pore openings
46
what solutes are most commonly moved into the stomata
potassium ions
47
describe the structure of guard cells
contains nucleus, vacuole and chloroplasts thickened inner wall thin outer wall
48
what are lenticels and why are they needed
loosely arranged cells with many air spaces link the inner tissue of the trunk and the air so gas exchange can take place

Biology (33 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions