Gas Exchange And Circulation

Front 1

Cells need oxygen. Why?

1. Critical for:

-O2 critical for:

-anaerobic only:

- aerobic:

2. Most multicell. life requires:

Back 1

1. Cell respiration

-electron acceptor in electron transport chain

-anaerobic repsiration (fermentation) prodcues 2 ATP per glucose

- produces 30 ATP per glucose

2. lots of ATP energy, thus lots of oxygen

Front 2

Cells need to void CO2

1. CO2 produced during:

- can't be used b/c essentially:

- build up of CO2:

-b/c

2. Solution:

Back 2

1. oxidation of glucose (respiration)

- a waste product (can't be used)

- is toxic, b/c decreases pH inside cell (not at set point), and decrease loss of protein function (denaturation)

2. cooperation b/w respiratory and circulatory systems

Front 3

Partial Pressure of Gases

1. Partial pressure:

ex:

2. Concentration of ox remains

3. but levels of oxygen

4. with increasing elevation, PO2:

Back 3

1. pressure that a component of a gas mixture wold have if it occupied the volume alone

ex: atm pressure (sea level) = 760 mm Hg

O2 = 21%

PO2 = 760 x 0.21 = 160mm Hg

2. constant

3. changes

4. falls

Front 4

Gas exchange:

1. Ventilation:

2. Gas Exchange:

3. Circulation:

4. Cellular respiration:

continuous cycle

Back 4

1. environemntal :air or water in/out of respiratory system, allows oxygen into blood

2. circulatory system - as ox in, CO2 out. Must do both at roughly same time

3. allows body to deliver ox to cell for respiraiton, carries CO2 away from cell for elimination

4. in mitochondria

Front 5

What effect does water have on Partial Pressure?

1. water contains:

2. Challenges for aquatic animals:

3. Water temperature have on partial press?

4. problem for trop. vs cold water fish?

Back 5

1. much less oxygen than air

2. work harder to get enough O2 from water to support phys. processes. (must adapt)

2. increase = lower oxygen levels

4. must adapt to lower levels of oxygen

- osmoconformers sensitive to temp, harder time adjusting to temp changes and less O2

Front 6

Gas Diffusion

1. Gases flow along:

2. CO2 in soda =

3. CO2 moves from -

Back 6

1. partial pressure gradient (high pressure to low pressure)

2. higher pressure than in air

3. CO2, to liquid, to air

Front 7

Ficks law of Diffusion= rate of diffusion

1. Exchange of O2 and CO2 depends on 5 traits:

2. larger surface area of tissue =

3. increase thickness =

4. difference in partial pressure =

Back 7

1. diffusion constant, area for gas exchange, difference of partial pressure on either side of barrier, distance (thickness of barrier to diffusion)

2. more space for molecule to pass through (faster diffusion)

3. hinderance, thicker is harder to pass through (slower diffusion)

4. p1 = lower pressure, p2 = higher pressure

- larger difference of pressure = faster rate of diffusion

Front 8

Practice:

O2 will diffuse form blood to tissue faster in response to which of the following?

1. increase PO2 of tissue

2. decrease PO2 of tissue

3. increase thickness cap. wall

4. decrease in surface area of cap. wall.

Back 8

1. decrease of PO2 in tissue.

O2 wants to move from high to low. Larger difference of partial pressures = faster rater of diffusion so further decreasing tissue PO2 creates a larger gradient from blood to tissue.

Front 9

Gas exchange via diffusion

1. some animals, adaptation for animals w/o "breathing" organs=

-usually live in:

2. O2 and CO2 diffuse:

3. water flow does what:

-very important

-stagnant pool=

4. however, in order to "breathe"

Ex:

Back 9

1. air diffuses directly across skin

-aquatic environments

2. into and out of skin cells individually

3. removes CO2 and brings in fresh O2 - body movements also help (wash CO2 away from animal so they aren't swimming in pool of CO2

-very bad - low O2, high CO2

4. animals must stay wet = trade-off

-have to remain in aquatic environment for whole life

Ex: sponges, cnidaria, ctenophores, rotifers, platyhelminthes, nematodes

Front 10

Larger animals

1. Bodies get bigger, why diffusion not enough?

2 solution:

3. ventilation:

Back 10

1. volume increase relative to surface area = cells can't take up as much O2 as need to support resp. and other metab. activity

- can't rid CO2 fast enough

2. ventilation to move gases thru body

3. bulk flow of O2 (or CO2) in air or water

- bring or give off a lot of molecules all at once

Front 11

Ventilation: Arthropods

1. Adaptation to desiccation issues:

- excretion:

- exposure:

- gas exchange

Back 11

1. water conservation adaptations

-uric acid

-minimize exposure to water loss conditions

- specialized struct. minimize H2O loss during exchange

Front 12

ventilation: arthropods

system to conserve H2O during gas exchange

1. tracheal system:

2. spiracles:

3. open in some parts to allow:

4. closed in other places to allow:

5. open at different times

Back 12

1. branching system of narrowing canals from spiracles to cells

2. openings to enviro, closed when don't need to exchange gases (like stomata)

3. O2 to enter

4. CO2 to exit

Front 13

Gills for ventilation

1. structures that exchange gases with:

2. special adaptations:

3. Function:

4. high PO2, low CO2:

5. low PO2, high CO2:

6. allows:

Back 13

1. aquatic surroundings

2. high surface area=high gas exchange

highly vascularized=efficient gass exchange (intersection with blood vessels)

3. diffusion of gasses down part. press. gradient

4. in water

5. in gills

6. O2 to flow into cell, CO2 to flow out of cell down gradient

Front 14

Counter-current exchange in fish gills (bony fish/cart. fish)

1. blood flow moves:

-process:

2. maximizes:

3. prevents:

Back 14

1. opposite direction to that of water flow

-water comes in across gills, high vascularized

- blood vessels running under gills, countercurrent

-H2O high in O2, so blood takes O2 to body

-veins take CO2 to gills to eliminate

2. O2 uptake and CO2 output

3. "early equilibrium"

Front 15

Counter Current cont'd

1. blood flow moves:

2. PO2 H2O

3. Why not concurrent?

Back 15

1. opposite to that of water flow

2. always higher than that of blood in gills

3. diffusion eventually stops

Front 16

Gas exchange in tetrapods

Amphibia

1. May use multiple structures:

-gills:

-skin:

-lungs:

Back 16

1. depending on enviro, development, species

-gills on larvae (some adults retain)

-skin (cutaneous respiration)

.why they must stay moist

-lungs used by terrest. adults (usually fairly simple)

Front 17

reptilia (aves)

1. Have:

2. Path of air during inhalation:

3. path during exhalation:

4. Efficient:

Back 17

1. lungs and air sacs

2. during inhalation - inhaled through trachea into posterior air sacs, while previous air is pulled further into anterior airs sacs

3. posterior air sacs collapse, push air into lungs, lungs pass to rest of body

-Oxygen, CO2 out. Maximizes

4. Very! perfect for flight