BIO 132 – Anatomy and Physiology II

LECTURE 10: PHYSIOLGY OF THE RESPIRATORY SYSTEM: GAS EXCHANGE, TRANSPORT, AND CONTROL OF BREATHING

Study Outline

Answers

10.1. Dalton’s Law of Partial Pressures:

a. oxygen; nitrogen

b. pressures exerted independently by each gas in the mixture

c. partial pressure; fractional concentration of that gas

d. 47 mmHg

e. decreases; the same; lower

10.2. Composition of Alveolar Air:

a. inspired fresh air mixes with air already in the alveoli

b. of mixing with air in the anatomic deadspace.

c. 40 mmHg; pulmonary veins

d. 100 mmHg; 40 mmHg

e. 40 mmHg; 45 mmHg

10.3. Henry’s Law and Pulmonary Diffusion:

a. solubility of the gas in the liquid; partial pressure

b. 20; negligible

c. surface area; diffusion coefficient; partial pressure gradient; thickness

d. the molecular weight

e. decrease

f. 0.2 to 0.5 microns; decrease

g. increase

h. a relatively higher solubility

i. 0.75; 0.25

j. of a lower partial pressure gradient for diffusion

10.4. Transport of O₂ in Blood:

a. chemically bound to hemoglobin

b. 4; Fe²⁺

c. P_O2

d. half saturated with O₂

e. sigmoidal

f. 97.4%; 75%

10.5. Factors that Affect the Oxy-hemoglobin Dissociation Curve:

a. right

b. right

c. left

d. right

e. increased

f. right; increased P_CO2; decreased pH; decreased

10.6. Transport of CO₂ in Blood:

a. bicarbonate; plasma; physically dissolved; proteins

b. carbonic anhydrase; red blood cells (RBCs)

c. hemoglobin

d. right; left

e. RBCs; bicarbonate; into the RBC

f. bicarbonate; out of the RBC

10.7. Control of Breathing:

a. phrenic; external intercostal

b. frequency of action potentials; duration of inspiratory impulses; duration of expiratory impulses

c. dorsal respiratory group; ventral respiratory group

d. pneumotaxic; apneustic

e. stretch receptors in the lungs; irritant receptors; cerebral input; hypothalamus; muscle receptors; chemoreceptors

f. cerebral cortex

g. hypothalamus

h. P_O2; P_CO2; pH; P_CO2

i. hypercapnia; increase; medulla

j. hypoxia; 60 mmHg; P_CO2