Exchange Surfaces And Breathing Chapter 3.1

Question 1

What factors effect the need for an exchange systems ?

3

Answer 1

1-size
2-SA:V
3-level of activity

Question 2

What’s the formula for a)surface area of cylinder

B) volume of cylinder

Answer 2

A) (piDxheight )x 2pi ^2

B) pi r^2 x height

Question 3

SA of sphere ?

Volume of sphere ?

Answer 3

SA: 4pi r squared

Volume : 4/3 pi r ^3

Question 4

How should you write SA:V ratio

Answer 4

X:1

Question 5

What are the features if s good exchange system ?

4

Answer 5

1-large SA
2-thin barrier ( reduce Diffusion distance )
3-Good Blood supply( maintain Concentration gradient )
4-Good ventilation

Question 6

Outline the mammalian has exchange order ?

4

Answer 6

Trachea —> bronchi —> Bronchioles —> Alveoli

Question 7

How are alveoli good exchange surfaces ?

4

Answer 7

• large SA:V ratio
• layer of moisture ( surfactant ) stops them sticking together
• alveolus wall is thin ( squamous epithelium )
• good blood supply ( may capillaries )

Question 8

What makes the lungs a good exchange surface ?

4

Answer 8

• large SA:V
• good blood supply
• constantly ventilated so concentration gradient in air is maintained
• many alveoli increases SA

Question 9

What happens in inhalation ?

• diaphragm
• ext int Costel muscles
• v
• air

Answer 9

• diaphragm moves DOWN and contracts
• Ext intercostal muscles = ribs rises
• Volume increases
• pressure decreases
• Air moves in

Question 10

What happens in exhalation? (6)

• diaphragm
• ext intercostal muscles
• interval intercostal muscles
• v
• p
• air

Answer 10

• diaphragm moves up
• ext intercostal muscles lOWERS RIBS
• Internal intercostal muscles push out Air forcefully
• volume decreases
• pressure increases
• air moves out

Question 11

Why do humans need lungs ?

3

Answer 11

• large organism ( diffusion distance is too big )
• High metabolic activity
• small SA:V

Question 12

Why do active organisms need a specialised exchange system ?
( 3)

Answer 12

• respiration ( energy )
• aerobic respiration works best
• NEED O2 from Lungs

Question 13

What are the physiological changes that occur during Excersize ?
(4)

Answer 13

1- volume of air breathed out rises
2-breath rate increases
3-concentration gradient maintained at higher level
4-muscle repaired more

Question 14

What are the properties of the airways ?

3

Answer 14

• large enough to allow airflow
• supported = prevent collapse
• Flexible = movement

Question 15

What do the trachea and bronchi both have (tissues ) ?

5

Answer 15

• cartilage
• smooth muscle
• elastic fibres
• goblet cells
• epithelium

Question 16

What does a bronchiole not have ?

1

Answer 16

• cartilage

Question 17

What do alveoli have ?

1

Answer 17

• elastic fibres

Question 18

What are the main cells and tissues that work together in lungs ?

Answer 18

• goblet cells
• ciliates cells
• elastic fibres
• smooth muscle
• cartilage

Question 19

What does :
A) ciliates epithelium do ?
B) glandular tissue do ?
C)smooth muscle do ?

Answer 19

A-cilia wafts mucus
B-produces mucus
C-supports airway

Question 20

What does :
A) elastic tissue do ? 
B) blood do ?
C) nervous tissue do ?
D) connective tissue do ?

Answer 20

A-elastic tissue recoils and dilates airway ( expels Air )
B-blood transports gases
C-nervous tissue carries messages to coordinate actions
D-connective tissue holds other tissues together

Question 21

What’s the Oxygen uptake?

Answer 21

Volume of O2 absorbed by lungs in 1min

Question 22

What’s tidal volume ?

Answer 22

Volume of air inhaled and exhaled in one breath , usually measured at rest

Question 23

What vital capacity

Answer 23

• greatest volume of air that can be expelled after taking the deepest breath

Question 24

What does vital capacity depend on ?

3

Answer 24

1-size of person
2-age / gender
3-level of exercise

Question 25

How do you investigate breathing.

Answer 25

SPIROMETER

Question 26

How does a spirometer work?
2 points
- breath in
-breath out

Answer 26

1-Oxygen filled chamber with moveable lid with Pen attached ( recorded on rotating drum ) 
-person breathe out via tube
-person breaths IN ( lid goes down ) 
-person breaths out ( kid goes up )
2- results = spirometer trace

Question 27

What’s soda like for in spirometer?

Answer 27

Absorb CO2

Question 28

What are precaution to take when using a spirometer ?

5

Answer 28

• subject is healthy - no asthma
• soda like is fresh and functioning
• no air leak
• mouth piece sterilised
• water chamber isn’t tooo high

Question 29

Why does total volume of air decrease in chamber ?

3

Answer 29

• Air Breathed our by Person is O2 and CO2
• CO2 is absorbed by soda lime so only O2 left
• O2 used up by respiration

Question 30

How do you calculate ventilation rate ?

Answer 30

Tidal volume x breathing rate

Question 31

How do fish breathe ?

2

Answer 31

• water enters mouth and passes through gills

- countercurrent flow

Question 32

Outline the gill structure.

Answer 32

• gills made of gill filaments or primary lamellae( increase SA)
• Gill plates
• each gill supported by gill arch
• lots of capillaries on gill plates p

Question 33

How are fish ventilated?

9

Answer 33

• mouth opens
• Buccal cavity is lowered
• v increases
• p decreases
• water sucked in

Mouth closes

• floor of buccal cavity raised
• v decreases
• p increases
• water forced out of gill filaments

Each gill has a bony flap ( OPERCULUM)
When p increases this opens and water leaves the

Question 34

How are insects ventilated?
Structure ?
(4)

Answer 34

O2 in via spiracle  
-trachea 
-tracheole 
-tracheal fluid 
Oxygen travels down conc gradient to cells ! (High—> low)

Question 35

How do insects pump gases ?

2

Answer 35

• rhythmic body movements

- movement of wings

Question 36

Why are so many blood vessels important in lungs?

3

Answer 36

• many small blood vessels = larger SA than 1 or 2
• CO2 carried to lungs
• O2 constantly carried away ( gradient )