Exchange surfaces and breathing

Question 1

Large multicellular organisms have evolved specialised systems for the exchange of substances, they have large and effective?

Answer 1

Exchange surfaces

Question 2

Increased surface area for exchange surfaces (benefits) and what does this overcome -

Answer 2

• Overcomes the limitation of SA:V ratio of larger organisms, like root hair cells

Question 3

Benefit of thin layers for exchange surfaces -

Answer 3

• Result in short diffusion distances, making it fast and efficient, like alveoli

Question 4

Benefit of good blood supply for exchange surfaces how does it effect the concentration gradient -

Answer 4

• steeper concentration gradient, the faster the diffusion takes place.
• Means substances are constantly delivered and removed.

Question 5

Benefits of ventilation to maintain diffusion gradient on exchange surfaces -

Answer 5

• Maintain concentration gradients making it more efficient like the alveoli and the gills of the fish.

Question 6

Mammals are relatively meaning they have small what with what what rates of activities -

Answer 6

SA:V ratio with high metabolic activities

Question 7

The flow of breathing can follow these key structures in order -

Answer 7

Nasal cavity, trachea, bronchus, bronchioles and alveoli

Question 8

Nasal cavity features -

Answer 8

• Large surface area, with a good blood supply which warms the air
• Hairy lining, which secretes mucous to trap dust and bacteria and protects delicate lung tissue
• Moist surfaces, increase the humidity and reduce evaporation from the exchange surfaces.

Question 9

Trachea function -

Answer 9

Carries warm, clean moist air from the nose down to the chest.

Question 10

Trachea structure -

Answer 10

It is a wide tube supported by incomplete rings of cartilage, stops the trachea from collapsing.

Question 11

Why are the cartilage rings incomplete in the trachea?

Answer 11

Allows food to easily move down the esophagus behind the trachea .

Question 12

The trachea and its branches are lined and with types of specialised cells - state

Answer 12

Ciliated epithelium with goblet cells present inside of them.

Question 13

Goblet cells functions -

Answer 13

Secrete mucous onto the lining of the trachea to trap dust and microorganism that have escaped the nose lining (cavity)

Question 14

Cilia function (Ciliated epithelium cell) -

Answer 14

Beat and move the mucous along with the trapped microorganisms and dirt. Most goes to the throat to be swallowed and digested. Effected by cigarette smoke.

Question 15

The dividing of the trachea in the chest cavity, what happens?

Answer 15

The trachea divides to form a left and right bronchus which both lead to there corresponding lungs.

Question 16

Bronchus structure can be deemed similar to trachea because?

Answer 16

They have the same supporting rings of cartilage, but are smaller.

Question 17

In the lungs the bronchus (bronchi) divide to form?

Answer 17

Bronchioles

Question 18

Bronchioles structure -

Answer 18

• No cartilage rings
• The walls contain smooth muscle, when the smooth muscle contracts the bronchioles constrict and when it relaxes they dilate.
• Lined with some flattened epithelium making some gaseous exchange possible.

Question 19

The main gas exchange surfaces are the?

Answer 19

Alveoli

Question 20

Alveoli structure and movement -

Answer 20

• Large diameter
• Consists of a thin layer of flattened epithelial cells
• Composed of collagen and elastic fibres (composed of elastin)
• Elastic tissues allow the alveoli to stretch as the air is drawn in.

Question 21

When alveoli return to their resting size, they help squeeze the air out this is called?

Answer 21

Elastic recoil of the lungs

Question 22

Pressure changes are located in?

Answer 22

The throrax (chest cavity)

Question 23

Inspiration process -

Answer 23

• Diaphragm contracts. Flattens and lowers, external muscles contracts . Moves the rib cage upwards and outwards. The volume of the thorax increases so the pressure is decreased inside the thorax.

Question 24

Expiration process -

Answer 24

Diaphragm relaxes, the external intercostal muscles relax. Ribcage moves downwards and inwards. Now the pressure is higher inside the thorax is greater, so air moves out of the lungs.

Question 25

Measuring the capacity of the lungs - (peak flow meter) -

Answer 25

Device that measures the rate at which air is expelled from the lungs.

Question 26

Measuring the capacity of the lungs - (More common)

Answer 26

Spirometer

Question 27

Tidal volume -

Answer 27

Amount of air that moves in and out of the lungs with each resting breath.

Question 28

Vital capacity -

Answer 28

Amount of air that can be breathed in when the strongest possible exhalation is followed, by the deepest possible intake of breath.

Question 29

Inspiratory reserve volume -

Answer 29

The maximum volume of air you can breathe in, over normal inhalation.

Question 30

Expiratory reserve volume -

Answer 30

Extra amount of air you can force out of your lungs over above the normal tidal volume.

Question 31

Residual volume -

Answer 31

The amount of air left in your lungs after the deepest level of exhalation.

Question 32

Total lung capacity =

Answer 32

Residual volume + the total vital capacity

Question 33

Ventilation rates =

Answer 33

TV + breathing rate.

Question 34

In an insect what is it called within the region where no gaseous exchange can take place?

Answer 34

Exoskeleton

Question 35

Along the thorax and abdomen in insects what are the small openings and what do they do?

Answer 35

Spiracles - Air enters and leaves through the spiracles, these spiracles are kept closed to avoid water loss.

Question 36

Spiracles in insects open when?

Answer 36

Oxygen demand is needed or carbon dioxide builds up.

Question 37

What leads away from the spiracles in insects?

Answer 37

Trachea

Question 38

Trachea (insect) characteristics -

Answer 38

Lined with spirals of chitin, keeping them open if pressed and bent, relatively impermeable to gases so little gaseous exchange takes place.

Question 39

The trachea in insects further divide to form?

Answer 39

Tracheoles

Question 40

Tracheoles are free of what which is present in trachea and what does the absence of this allow?

Answer 40

Chitin and allow them to be freely permeable to gases. Small in size so spread between individual cells. This is where most gaseous exchange takes place between the air and respiring cells.

Question 41

Towards the end of the tracheoles there is?

Answer 41

Tracheal fluid

Question 42

Tracheal fluid in insects?

Answer 42

Limits the penetration of air for diffusion, when oxygen demand builds up, it exposes more surface area for gaseous exchange.

Question 43

Animals that get their oxygen from water do not need to prevent water loss becuase?

Answer 43

They are in water.

Question 44

Fish maintain a flow of water in one direction over the what?

Answer 44

Gills

Question 45

Gills characteristics -

Answer 45

• Large surface area
• Good blood supply
• Thin layers needed for gaseous exchange

Question 46

Gill Lamellae -

Answer 46

Main site of gaseous exchange in fish from their rich blood supply and large surface area.

Question 47

Gill filaments -

Answer 47

• Occur in large stacks and need a flow of water to keep them apart, exposing the large surface area needed for gaseous exchange.