respiration 2

Question 1

how do 4 models of respiration differ

Answer 1

• small relies only on diffusion
• embrace circulates the external medium through the body entirely, using bulk flow
• skin uses cutaneous respiration along with circulatory transport
• mass transit uses special respiratory surface which uses bulk flow along with a circulatory transport

Question 2

identify where diffusion, dissolution, and bulk flow occur in systems

Answer 2

diffusion: into cells
dissolution: from air to water
bulk flow: to lungs, through spiracles, through circulatory transport,

Question 3

How does countercurrent blood flow differ from concurrent blood flow?

Answer 3

countercurrent has an equal exchange gradient across the entire respiratory surface
-concurrent flow decreases going down the flow

Question 4

What is non-directional ventilation, and what are the benefits and drawbacks of such a system?

Answer 4

nondirectional: medium flows past the respiratory surface in an unpredictable pattern

Question 5

What are the limits to cutaneous respiration?

Answer 5

.-requires moist/aquatic environ.

-requires small surface area

Question 6

How do the physical differences between water and air determine the types of ventilation used?

Answer 6

O con in air is 30x greater than Ocon in water

• 30 times more water must then be ventilated
• water is more dense and viscous, so it is also more difficult to ventilate
• unidirectional usually aquatic and allows for countercurrent exchange
• tidal is airbreathers, as it allows air to flow and requires too much work in water
• air-filled tubes are used by insects for high diffusion rates in air

Question 7

circulatory system function

Answer 7

links external and internal respiration, lying between respiratory surface and tissues

Question 8

cutaneous respiration downsides

Answer 8

found in aquatic and a few vertebrates

• conflict between respiration and protection
• generally confined to moist/aquatic environ
• have to be small, have low surface area

Question 9

specialized respiratory surfaces

Answer 9

allows rest of skin to be protected/thick
higher effective SA, highly vascularized, lower diffusion distance
-protected in body cavity and can be kept moist
-highly ventilated
-sync’d with circulatory system
-can either be evaginations (gills) for increased area, or invaginations (lungs), that hold external environ
-found in vertebrates

Question 10

lungs adv/dis

Answer 10

adv: high SA can be protected, thin membrane/low diffusion distance
dis: only good in water since they lack support, easily damaged
- requires ventilation

Question 11

gills adv/dis

Answer 11

adv: high SA, protected, can be kept moist when on land, suitable for breathing air
dis: only good in air (at the cost of ventilation)

Question 12

Ventilation

Answer 12

movement of medium across respiratory surfaces by BULK FLOW

• either nondirectional, unidirectional, or tidal
• anatomy of resp surface determines ventilation type
• pattern, not direction can change with environmental and metabolic conditions

Question 13

nondirectional

Answer 13

medium flows past the repiratory surface in an unpredictable pattern

Question 14

unidirectional

Answer 14

medium enters the chamber at one point and exits at another

Question 15

tidal

Answer 15

medium moves in and out of chamber

Question 16

eupnea

Answer 16

normal breathing

Question 17

apnea

Answer 17

no breathing

Question 18

blood flow and medium

Answer 18

movement of blood through respiratory surface affects efficiency of gas exchange

• saturation of blood increases with increased CONTACT TIME btw blood and surface
• saturation decreases with decreased DIFFUSION DISTANCE btw blood and respiratory surface

Question 19

increased boundary layer and blood saturation

Answer 19

decreases diffusion distance which decreases blood saturation of oxygen

Question 20

tidal ventilation

Answer 20

allows medium to move in and out at the same time, so PO2 can increase while PCO2 decreases

Question 21

concurrent flow

Answer 21

PO2 of medium and blood will equilibrate, both flow in same direction

Question 22

countercurrent flow

Answer 22

PO2 of blood approaches that of inhalant medium

-medium and blood move in opposite directions

Question 23

cross current flow

Answer 23

foudn in birds, vessels cross the respiratory surface

-PO2 increases with more rapid medium flow, so get better exchange the fast the circ and vent