Body Systems: Respiratory System (Gas Exchange And Regulation)

Question 1

Pneumothorax:

Answer 1

-Collapsed lung.
-Air leaks into the space between your lung and chest wall.
-This air pushes on the outside of your lung and makes it collapse.
-Chest tube inserted to release air and equalize pressure.

Question 2

Dalton’s law:

Answer 2

Each gas in a mixture exerts its own pressure (partial pressure).

Question 3

Gas laws:

Answer 3

Gasses will diffuse from areas of higher partial pressures to areas of lower partial pressures (like concentration gradients, but for a gas dissolved in a liquid).

Question 4

External respiration—O2:

Answer 4

-External respiration enriches the blood with O2.
-Air breathed into the lungs has a higher PO2 (partial pressure of O2) than the blood in the pulmonary capillaries.
-Therefore, O2 diffuses out of air in the lungs and into the bloodstream.

Question 5

External respiration—CO2:

Answer 5

-External respiration cleanses the blood of CO2.
-Blood flowing into pulmonary capillaries has a higher PCO2 (partial pressure of CO2) than the air in the lungs.
-Therefore, CO2 diffuses out of blood into alveoli.
-The waste carbon dioxide can be breathed out and is removed from the body.

Question 6

External respiration—O2 and CO2 (full):

Answer 6

-External respiration enriches the blood with O2.
-Air breathed into the lungs has a higher PO2 (partial pressure of O2) than the blood in the pulmonary capillaries.
-Therefore, O2 diffuses out of air in the lungs and into the bloodstream.
-External respiration cleanses the blood of CO2.
-Blood flowing into pulmonary capillaries has a higher PCO2 (partial pressure of CO2) than the air in the lungs.
-Therefore, CO2 diffuses out of blood into alveoli.
-The waste carbon dioxide can be breathed out and is removed from the body.

Question 7

Internal respiration (CO2 and O2):

Answer 7

-CO2 and O2 are exchanged between capillaries and alveoli (external respiration).
-Blood in the capillaries then goes back to the heart and is circulated to the tissue cells.
-There it undergoes internal respiration and CO2 and O2 is exchanged again.

Question 8

O2 transport in the blood:

Answer 8

-99% of O2 is transported on a molecule called hemoglobin, which is only in red blood cells.
-The rest is dissolved in blood plasma.

Question 9

CO2 Transport in the blood:

Answer 9

-23% of CO2 is carried by hemoglobin.
-7% is carried in plasma.
-70% combines with water and forms carbonic acid.
-Carbonic acid is very unstable and almost immediately dissociates into bicarbonate (HCO3-) and hydrogen ions (H+).

Question 10

CO2 and pH:

Answer 10

-High [H+] = low pH = acidic.
-Therefore, high [CO2] in blood = acidic.

Question 11

Regulation of breathing:

Answer 11

-Breathing movements are controlled by nerves from the medulla oblongata in the brain.
-High CO2 —> chemoreceptors are activated —> medulla oblongata sends a message to intercostal muscles and diaphragm —> increases breathing movements/rate.
-As CO2 levels fall, chemoreceptors become inactive.

Question 12

Response to exercise:

Answer 12

-Ventilation (breathing rate) can increase up to 20x with heavy exercise.
-3 important factors that increase ventilation:
•Decreased O2.
•Increased CO2.
•Increased H+.

Question 13

Blood Doping:

Answer 13

-Blood doping increases the amount of hemoglobin in the bloodstream.
-Hemoglobin is an oxygen-carrying protein in the blood.
-Increasing hemoglobin allows higher amounts of oxygen to reach and fuel an athletes muscles.
-This can improve stamina and performance, particularly in long-distance events, such as running and cycling.

Question 14

Training and altitude:

Answer 14

-At higher altitudes lower atmospheric pressure makes it more difficult for O2 to enter our lungs.
-The blood produces more red blood cells to counter the lower oxygen saturation in the blood.