Gas Exchange

Question 1

Gas exchange

Answer 1

Intake of oxygen and release of carbon dioxide

Question 2

How does gas diffuse?

Answer 2

They diffuse down a concentration gradient (high to low)

Question 3

Partial pressure

Answer 3

Part of atmospheric pressure caused by one gas

Question 4

There is more gas at the surface of the Earth than at the top. T or F?

Answer 4

True

Question 5

Which holds more oxygen at sea level, water or air?

Answer 5

Water holds 30x less oxygen than air

Question 6

Respiratory surfaces

Answer 6

Sites of gas exchange

Question 7

What allows for fast gas diffusion?

Answer 7

Wide, thin surface

Question 8

What are the types of exchange surfaces?

Answer 8

Epidermis, trachea, gills, and lungs

Question 9

Epidermis

Answer 9

Skin; is a respiratory site for smaller animals allowing them to breathe through skin; Ex: amphibians, annelids, lophotrochozoans

Question 10

Trachea

Answer 10

System of tubes and sacs that distribute air, from external openings, throughout the body; does not require linkage w/ circulatory system; Ex: arthropods

Question 11

Gills

Answer 11

Type of respiratory surface that allows for ventilation; large, highly vascularized area that water moves over to transfer oxygen; Ex: salamander, crayfish, fish

Question 12

Ventilation

Answer 12

Movement of respiratory medium over the respiratory surface

Question 13

How do gills use countercurrent exchange to extract oxygen?

Answer 13

Water moves over gills. As water gets close to the blood vessels, O2 diffuses from water to blood. The vessel containing the O2 rich blood sends oxygenated blood to the rest of the body, while the deoxygenated blood that is carried from the heart to the gradient (due to fish only exhibiting single circulation) where it can be oxygenated via countercurrent exchange.

Question 14

Lungs

Answer 14

Internal respiratory exchange surface; bronchus branches into bronchioles and then into alveoli covered w/ capillaries; pulmonary artery brings deoxygenated blood from the heart to the lungs where it gets oxygenated and sent back to the heart and later to the rest of the body via the pulmonary vein

Question 15

Capillaries

Answer 15

Small blood vessels that cover alveoli

Question 16

Alveoli

Answer 16

Tiny air sacs do the lungs that allow for rapid gas exchange

Question 17

What are the three modes of ventilation?

Answer 17

Buccal pump, tidal respiration, and flow through respiration

Question 18

Buccal pump

Answer 18

Forces air over gills/lungs via positive pressure (our heart operates like this but not our lungs); essentially pumping to another chamber by muscle contractions; squeeze throat=force lungs into air, squeeze lungs=expels air; Ex: amphibians and sharks

Question 19

Tidal respiration

Answer 19

Muscle contractions draw in air via negative pressure (we do this); reduce pressure by expanding the volume of lungs (using diaphragm) forces air into lungs

Question 20

Flow through respiration

Answer 20

Inhale air and travels to posterior air sacs then then inhale again to go to lungs and inhale again to go to anterior air sacs; air travels in one direction; lungs only encounter fresh, oxygen-rich air; 2 cycles of inhaling and exhaling to oxygenate the body; most efficient among vertebrates, almost as efficient as fish; Ex: birds

Question 21

Partial pressure gradients

Answer 21

Cause gases to diffuse into and out of the circulatory system; uses approx. 40 mm Hg of O2 from air

Question 22

Which is not an example of a respiratory exchange surface?

Gills
Lungs
Skin
Air sacs

Answer 22

Air sacs

Question 23

Respiratory pigments

Answer 23

Reversible bind oxygen; hemoglobin in vertebrates is red due to iron; hemocyanin in arthropods and molluscs is blue due to copper (used to see if vaccines are safe); annelids have hemerythrin (purple) and chlorocruorin (green)

Question 24

Can animals survive w/ no hemoglobin?

Answer 24

Yes, icefish do not have red blood cells or hemoglobin. They are able to survive due to have large hearts, blood volumes
and more mitochondria. More importantly, they live in cold water which holds more oxygen than warm water.