Exchange Surfaces

Question 1

Tidal Volume

Answer 1

The volume of air inspired or expired in a normal (resting) breath.

Question 2

Pulmonary Ventilation

Answer 2

Volume of air inspired or expired in a minute (at normal breath)

Question 3

Ventilation Rate

Answer 3

Number of breaths taken per minute

Question 4

difference between endothelium vs epithelium?

Answer 4

Endothelium in blood vessels, Epithelium in alveoli.

Question 5

Inspiration…

Answer 5

• Diaphragm contracts, external intercostal muscles contract
• thorax volume increases
• air moves into lungs down air pressure gradient

Question 6

Expiration

Answer 6

• Diaphragm relaxes, internal intercostal muscles contract
• volume of thorax decrease
• air moves out of lungs.

Question 7

How to find oxygen usage?

Answer 7

Gradient of trace on spirometer graph.

Question 8

How do we maintain a steep concentration gradient across the alveoli and capillaries?

Answer 8

Constant inhalation replaces CO2 in alveoli with O2, so the concentration of O2 in alveoli is always higher than that of the blood.

Question 9

What does the spirometer draw with?

Answer 9

A kymograph

Question 10

Volume of air breathed in per min

Answer 10

Pulmonary ventilation

Question 11

Pulmonary ventilation equation

Answer 11

Tidal vol x ventilation rate

Question 12

why do fish need such adapted exchange surfaces?

Answer 12

Less oxygen dissolved in water than thre is in air.

Question 13

Process of ventilation in FISH?

Answer 13

• mouth opens
• buccal cavity floor drops
  Water rushes into fishes mouth
• opercular cavity expands
• mouth closes
• buccal cavity floor rises
• water rushes into opercular cavity and across gills.
• water flows out of operculum

Question 14

Why is countercurrent used across gill lamellae?

Answer 14

Maintains a favourable concentration gradient across the entire diffusion surface.

Question 15

Explain the movement of fluid in ventilation system of insects?

Answer 15

Fluid moves into tracheoles when at rest. when muscles are not at rest, fluid is drawn into muscle.

Question 16

Movement of oxygen between cells and tracheoles?

Answer 16

Cells use oxygen for respiration.
Oxygen concentration is low in cells.
Oxygen diffuses into cells.

Question 17

How are spiacles adapted to reduce water loss?

Answer 17

• Close in non-optimal conditions
• hairs that trap humid air

Question 18

what are trachea lined with?

Answer 18

CHITIN

Question 19

what are the tracheoles not made of?

Answer 19

CHITIN

Question 20

How does oxygen get to cells?

Answer 20

Diffuses into a fluid medium

Question 21

Why is tracheal fluid in tracheoles not ideal in times of high oxygen demand?

Answer 21

It limits the surface area of the tracheoles.

Question 22

explain how tracheal fluid moves into muscle cells?

Answer 22

Lactic acid builds up in muscle cells, reduces water potential, tissue fluid moves into muscle cells.

Question 23

explain mechanical ventilation of tracheal system?

Answer 23

Muscles of the abdomen and thorax change the volume of the body of the insect. This changes the pressure inside the trachea, forcing air in and out.

Question 24

what is used as a resevoir of air in insects?

Answer 24

air sacs or collapsable enlarged trachea.

Question 25

How do air sacs in insects store air?

Answer 25

Thorax and abdomen created ventilating movement that inflates these air-resevoirs! now the insect can close its spiracles, yay !

Question 26

What does DGC stand for?

Answer 26

Discontinuous gas exchange cycles

Question 27

Name the 3 stages of DGC

Answer 27

Closed spiracles Fluttering spiracles Open spiracles

Question 28

what happens at "closed spiracles" DGC?

Answer 28

oxygen moves into cells, CO² moves out and is held in tissue fluid (buffering).

Question 29

What happens at "spiracles fluttering" DGC?

Answer 29

Spiracles open and close rapidly. moves oxygen into trachea whilst minimising water loss.

Question 30

What happens at "open spiracles" DGC?

Answer 30

CO² build up in tissue fluid leads to rapid flush of CO² out of trachea

Question 31

Give the safety precautions for using a spirometer...

Answer 31

- sterilised mouthpiece - refreshed soda lime - no asthmatics - no air leaks in the apparatus.

Question 32

What does smooth muscle in bronchioles do?

Answer 32

conract to restrict airways. relax to dilate airways

Question 33

What is the shape of the cartilage in the trachea and why?

Answer 33

C shaped It allows food to pass down an esophagus

Question 34

Define residual volume...

Answer 34

The air that remains in the lungs even after forced expiration.

Question 35

define vital capacity..

Answer 35

The maximum volume of air that can be exhaled.

Question 36

Usual range for vital capacity...

Answer 36

2.5 to 5.0

Question 37

Adaptations of nasal cavity

Answer 37

- large surface area, good blood supply. warms air to body temperature. - moist surfaces increase humidity and reduce evaporation from exchange surfaces. - hairy lining that produces and secretes mucus to trap pathogens.

Question 38

Residual volume

Answer 38

volume of air left in the lungs after forced expiration.

Question 39

what are tracheoles?...

Answer 39

single elongated cells with no chitin.

Question 40

Total lung capacity calculation

Answer 40

Vital capacity + residual volume

Question 41

Where is smooth muscle found in the lungs...

Answer 41

in the trachea, bronvhi abd brinchioles up to the bronvhioles ending.

Question 42

Why do larger organisms need a circulatory system?

Answer 42

- high metabolic demand - low surface area to volume ratio - longer diffusion pathway - a slow rate of diffusion - slow rate of respiration

Question 43

how can insects control ventilation rate? 3 ways

Answer 43

A. wing movements to control vol and pressure in thorax B. Expand and contract tracheal walls C. opening and closing spiracles

Question 44

Lines both capiliaries and alveolus

Answer 44

squamus epithelium