lesson 15

Question 1

gas exchange involves diffusion across membranes

Answer 1

-ficks law of diffusion

Question 2

gills

Answer 2

-specialized extensions of tissue that project into water
-increase surface area for diffusion of oxygen
-external gills
-found in immature fish and amphibians
-must be constantly moved
-easily damaged

Question 3

transition to land

Answer 3

gills are poorly adapted to terrestrial environment
-air is less supportive
-water evaporates
-lungs minimize evaporation
-amphibians use positive pressure breathing

Question 4

human respiratory system

Answer 4

lungs increase surface area
-300 million alveoli each lung
-80 square meters surface area
-42 times the surface area of skin in adult

Question 5

breathing in humans

Answer 5

inhale: greater volume; lower pressure; air moves in
exhale: lower volume; greater pressure; air forced out

Question 6

respiratory diseases

Answer 6

chronic obstructive pulmonary disease (COPD)
-refers to any disorder that obstructs airflow on a long-term basis
-asthma
-bronchitis
-emphysema
-Lung cancer
-accounts for more deaths that any form of cancer
-caused mainly by cigarette smoking

Question 7

transport of gases

Answer 7

hemoglobin
-oxyhemoglobin-oxygen bound to iron atom
-deoxyhemoglobin

some invertebrates
-hemocyanin

Question 8

transport of CO2

Answer 8

1. dissolved in plasma
2. bound to hemoglobin
3. bicarbonate