Module 3 Section 1 - Exchange and Transport

Question 1

Describe the difference in the appearance of microvilli and cilia.

Answer 1

There’s none - it’s a trick question.
Microvilli and cilia look the same under a microscope

Question 2

What five things do organisms need to survive? Explain why.

I need to learn two in particular which I’m weaker at.

Answer 2

• Minerals to maintain water potential gradient (osmoregulation) and enzyme action
• Fats to synthesise membranes & as an energy store
• Proteins for growth and repair (and enzymes)
• Oxygen for aerobic respiration
• Glucose for respiration as a source of energy

Question 3

How do fish gills have a good blood supply?

Answer 3

They have a good network of capillaries

Question 4

Explain three reasons why diffusion is too slow in multicellular organisms for them to absorb and excrete substances in this way.

Answer 4

• Low surface area to volume ratio - it’s hard for all the substances needed for the organism to survive to diffuse across this smaller space
• High metabolic rate, so oxygen and glucose are used more quickly
• Many cells are deep within the body - large diffusion pathway

Question 5

How do gills maintain a large concentration gradient?

Answer 5

• Large capillary network
• Well-ventillated - fresh water constantly passes over them

Question 6

How does good ventillation/blood supply maintain a steep concentration gradient?

Answer 6

There is fast substance removal on the other side, so there’s a high concentration on the outside and low on the inside.

Question 7

People with emphysema have ____ alveoli in their lungs compared to healthy people.

Answer 7

bigger

Question 8

Alveoli are covered in ____.

Answer 8

capillaries

Question 9

How do plants ensure a steep concentration gradient in root hair cells?

Answer 9

The xylem and phloem remove substances from root hair cells and take them up the plant.

Question 10

How does the small intestine have a large surface area?

Answer 10

There are villi and microvilli which cover these villi - both increase the surface area for nutrient absorption.

Question 11

What do elastic fibres do in the respiratory system?

Answer 11

They stretch and recoil, allowing expiration to occur (the process of pushing air out of the lungs is passive because of this)

Question 12

What does smooth muscle do in the respiratory system?

Answer 12

Controls the diameter of tubes (e.g. the trachea, bronchi and bronchioles) regulating the resistance to airflow and so how easily air can move in or out of the lungs

Question 13

What does cartilage do in the respiratory system?

Answer 13

Connective tissue that is strong but flexible, preventing the trachea from collapsing in on itself when breathing i.e. the tracheal rings provide support

Question 14

The trachea and bronchi are similar in structure. T/F and why?

Answer 14

True - they have basically the same structure (although the trachea has larger, C-shaped cartillage rings vs. the bronchi having smaller cartillage pieces)

Question 15

The cartilage in the bronchi is interspersed with what?

Answer 15

smooth muscle (to control the bronchi’s diameter)

Question 16

Compare the structures of the trachea and bronchi.

Answer 16

The trachea has larger, C-shaped cartillage while the bronchi having smaller cartillage pieces.

Both the trachea and bronchi have goblet cells, elastic fibres, smooth muscle and ciliated epithelium.

Question 17

How do the alveoli compare in structure to other parts of the respiratory system?

Answer 17

They don’t have goblet cells, ciliated epithelium, cartilage or smooth muscle - they ONLY have elastic fibres (to stretch for efficient fas exchange).

They are very similar in structure to the smallest bronchioles.

They’re stretchy like balloons !

Question 18

What is the structure of the largest bronchiole like?

Answer 18

Very similar to the trachea/bronchi, except they don’t have any cartilage.

Question 19

What is the structure of the smaller bronchiole like?

Answer 19

Very similar to the largest bronchiole, but doesn’t have any goblet cells (or cartilage).

Question 20

What is the structure of the smallest bronchiole like?

Answer 20

Similar to the smaller bronchiole, but doesn’t have any smooth muscle or ciliated epithelium (or cartillage or goblet cells).

Question 21

Explain the shape of the cartillage in the trachea.

Answer 21

C-shaped so it doesn’t rub against the neighbouring oesophagus

Question 22

What do the larger bronchioles possess that the smaller bronchioles don’t? Explain why.

Answer 22

Elastic fibres and smooth muscle - these help change the size of the airway to change the airflow

Question 23

Describe the parts of the lung where you would find elastic fibres.

Answer 23

Trachea, bronchi, larger bronchioles, smaller bronchioles and alveoli (i.e. all of them)

Question 24

Describe the parts of the lung where you would find smooth muscle.

Answer 24

Trachea, bronchi, larger bronchioles and smaller bronchioles

Question 25

Describe the parts of the lung where you would find cartilage, and what this looks like.

Answer 25

Trachea (C-shaped) and bronchi (smaller pieces)

Question 26

Describe the parts of the lung where you would find goblet cells.

Answer 26

Trachea, bronchi and larger bronchioles

Question 27

Describe the parts of the lung where you would find ciliated epithelium.

Answer 27

Trachea, bronchi, larger bronchioles and smaller bronchioles

Question 28

Where are the intercostal muscles located?

Don’t think you need to know?

Answer 28

Between the ribs surrounding the lungs
(inter = among/between, costal = ribs)

Question 29

Where is the sternum located?

Don’t think you need to know?

Answer 29

In the centre of the chest, underneath the heart

Question 30

What does the sternum do?

Don’t think you need to know?

Answer 30

Protects the heart & lungs and connects bones and muscles together with cartilage

Question 31

What do the pleural membranes do?

Don’t think you need to know?

Answer 31

Cushions the lung, reducing friction between the lungs, ribcage and chest cavity, and makes breathing easier.

Question 32

Where are the pleural membranes located?

Don’t think you need to know?

Answer 32

The pleura is a watery tissue that coats the outside of the lungs and walls of the chest/thorax.

Question 33

breathing in

Answer 33

inspiration

Question 34

How does passive expiration work?

Answer 34

• Diaphragm relaxes, becomes a curve again
• External intercostal muscles relax, causing the ribcage to move down and in
• The thoracic volume decreases, increasing the pressure in the chest cavity
• This forces air to flow out of the lungs

Question 35

How does forced expiration occur?

Answer 35

The internal intercostal muscles contract, pulling the ribcage down and in

Question 36

Cilia beat mucus ____.

Answer 36

away from the alveoli

Question 37

1dm³ = ?

Answer 37

1 litre

Question 38

Explain how the volume of gas in a spirometer changes over time.

Answer 38

The soda lime in the spirometer absorbs/reacts with carbon dioxide produced in respiration. Oxygen is used up in respiration, so the total volume of gas in the spirometer decreases over time.

Question 39

tidal volume

Answer 39

The volume of air in each breath.

Question 40

vital capacity

Answer 40

The maximum volume of air that can be inhaled/exhaled at once.

Question 41

counter current system

Answer 41

Blood flows one way through the gills, while water flows in the opposite direction

Question 42

gill filament

Answer 42

A thin plate that makes up fish gills; primary lamellae

Question 43

gill plate

Answer 43

Small structures that cover the gill filaments in fish gills; secondary lamellae

Question 44

gill arch

Answer 44

Bone/cartilage joined to a gill, holding it in place