Gas Exchange

Question 1

respiratory medium

Answer 1

water or air. both use diffusion

Question 2

respiratory exchange surface

Answer 2

border between respiratory medium and body

highly branched, large SA, highly vascularized, and thin.

Question 3

respiratory organ

Answer 3

bodily organ where gas exchange occurs

gills skin or lungs

Question 4

ventilation

Answer 4

bring air or water past respiratory surface/gas exchange membrane

Question 5

perfusion

Answer 5

move blood or circulatory fluid over other side of hte gas exchange membrane

Question 6

gases diffuse

Answer 6

along a concentration gradient of partial pressure

high to low

Question 7

oxygen and CO2 diffusion in body

Answer 7

diffuses from alveoli to blood, from blood to body’s tissues

CO2 diffuses from body tissues to blood stream to alveoli

Question 8

Fick’s law of diffusion

Answer 8

Q=DA((p1-p2)/L)
q= rate of diffusion
a=cross sectional area
p1-p2 difference in partial pressure
l=path length
d- constant depending on diffusing medium.

Question 9

diffusion greatest when

Answer 9

larger difference in partial pressure
larger cross sectional area
short diffusion distance (blood vessels close to surface of gas exchanger)
greatest in air

Question 10

water vs. air

Answer 10

O2 diffuses faster in air, less dense less thick, less viscous. holds more oxygen
veinilation takes more energy in water

Question 11

gills

Answer 11

outfoldings to increase body surface
ventilation is unidirectional
can be internal or external gills
ventilation via swimming, pushign with cilia, or appendages

Question 12

endotherms respiratory surfaces

Answer 12

require more oxygen for metabolism, larger surface area, more complex
respiratory structures inside to aboid dessication

Question 13

fish gill componenets

Answer 13

folded into secondary lamellae
increase SA
finger like projections
capillaries come close to contact 
very small path length
made of lamellae that contain capillaries

Question 14

fish gas exchange utilizes

Answer 14

countercurrent exchange
blood flows opposite oxygen, becomes more oxygenated. little energy cost.
concentration gradient for entire length of flow- not one end reaching equilibrium
max transfer of oxygen to blood

Question 15

why arent gills used on land

Answer 15

water loss

collapse of respiatory organ

Question 16

cutaneous respiration

Answer 16

amphibians, earthworms, mollusks
in both air and water
skin must be kept moist
gas exchange across body surface
capillaries run right next to skin surface to maximize rate of exchange

Question 17

tracheal system

Answer 17

insects
system of branched tubes that infiltrate the body and carry oxygen directly to the cells of insects. elaborate open ducts. no circulatory system for gas exchange, gills, or lungs.

efficient in small insects
spiracles where meet outside environment

individual cells exchange gasses with environment

Question 18

Titdal ventilation

Answer 18

breathe in air and exhale in the same path it was inhaled

birds are the exception

Question 19

amphibians

Answer 19

ventilation occurs by positive pressure- air gulping. air forced into lungs. relaxes to exhale

closes off mouth and contracts

Question 20

mammals

Answer 20

use negative pressure breathing- lowers pressure inside lung causing air to rush in. expanding lungs decreases pressure

Question 21

diaphragm

Answer 21

musculular sheet at bottom of thoracic cabity. alllows lungs to expand and contract

contracts causing the the diaphragm to drop and ribcage to expand with intercostal muscles. creates negative pressure sucking air in.

Exhale- diaphragm relaxes. passive

Question 22

pleural membranes

Answer 22

lubricate and keep lungs stuck to thoracic cavity

Question 23

inhalation

Answer 23

diaphragm contracts, lungs expand, active.
Ribs expand, increase volume of thoracic cavity, lungs stuck to walls of thoracic cavity. decreases pressure with the bigger volume.
air rushes in.
Exhalation is passive, diaphragm relaxes, lungs recoil

Question 24

branching in lungs (end of branchioles)

Answer 24

alveoli, increase surface area for absorption

here blood is oxygenated and CO2 unlaods from the blood

Question 25

capillaries

Answer 25

surround hte alveoli, small path length

Question 26

tidal volume

Answer 26

volume an animal inhales and exhales with each normal breath

Question 27

vital capacity

Answer 27

maximum volume of air that can inhale and exhale

Question 28

residual volume

Answer 28

amount of stale air that remains in dead space after lungs exhale. never devoid of air- collapse

Question 29

stale air

Answer 29

remains in lungs, mixes with fresh air during inhale. never full oxygen content of air

Question 30

Birds

Answer 30

``` unidirectional air flow air sacs. extract more oxygen from air so can fly at high altitiudes witout rest more efficient no mixing with stale air ```

Question 31

bird air sacs

Answer 31

2 cycles of inhalation and exhalation Bird inhales, air flow into posterior air sacs Exhales, moves air to lungs Inhales moves air from lungs to anterior air sacs Bird exhales moves air from anterior air sacs out of the body through the trachea

Question 32

O2 in blood and transport moleclues

Answer 32

does not dissolve in blood, needs transport molecules hemocyanin in arthropods and mollusks, blue hemoglobin- iron-red- carries 4. reversible, can unload and pick up oxygen

Question 33

4 affinity of oxygen of hemoglovin

Answer 33

Partial pressure of oxygen in blood (decrease, reduces affinity) type of hemoglobin subuint PH of blood (decrease in ph reduces affinity) concentration of BPG- blood oxygen levels of low, produces a metabolite that increases rate of glycolysis to lower affinity

Question 34

bohr shift dissociation curve

Answer 34

amount of oxygen bound to hemoglobin when the pigment is at different pp of oxygen exercise requires more oxygen, partial pressure falls as oxygen is consumed, left on curve, exercise forms CO@ which forms carbonic acid and lowers blood ph. ph affinity falls, unloads more oxygen from hemoglobin. blood delivers more oxygen than usual- bohr shift

Question 35

myoblobin

Answer 35

higher affinity for oxygen than hemoglovin. when metabolic demand is highest and pressure is very low

Question 36

brain parts controlling breathing

Answer 36

medulla oblangata. controls breathing rhythm and tempo. | stretch receptors in lungs provide feedback