Respiratory Physiology & Breathing

Question 1

What is respiratory physiology?

Answer 1

The functions of the respiratory system

Question 2

Name and briefly describe the 4 distinct events that collectively occur for respiratory physiology. (4)

Answer 2

1. Pulmonary ventilation → air must move into and out of the lungs so that the gases in the air sacs or the lungs are continuously refreshed → breathing
2. External respiration → gas exchange between pulmonary blood and alveoli must take place between the blood and the exterior of the body
3. Respiratory gas transport → Oxygen and carbon dioxide must be transported to and from the lungs and tissue cells of the body through the bloodstream
4. Internal respiration → at systemic capillaries, gas exchange must be made between the blood and tissue cells

Question 3

When volume changes, pressure changes. What important function does this result in?

Answer 3

Gas flow

Question 4

State the 2 phases of breathing. (2)

Answer 4

1. Inspiratory

2. Expiratory

Question 5

Describe inspiration/inhalation. (5)

Answer 5

1. When air is flowing into the lungs
2. The diaphragm contracts and the size of the thoracic cavity increases
3. Diaphragm moves inferiorly and flattens out
4. As a result, the lungs are stretched to the larger thoracic cavity causing intrapulmonary pressure to fall and allow air into the lungs
5. When the diaphragm relaxes it moves superiorly decreasing the size of the thoracic cavity, allowing air to flow out of the lungs

Question 6

Describe expiration/ exhalation (5)

Answer 6

1. When air leaves the lungs
2. Passive process
3. As the inspiration both the thoracic and intrapulmonary volumes decrease
4. The gases inside the lungs are forced more closely together, and the intrapulmonary pressure rises to a point higher than atmospheric pressure
5. Expiration becomes an active process in cases of asthma, chronic bronchitis, and pneumonia

Question 7

What is non-respiratory air movement mainly a result of?

Answer 7

Mainly the result of reflex activity

Question 8

Define: oxyhemoglobin

Answer 8

Bright red substance formed by the combination of hemoglobin with oxygen → oxygenated blood

Question 9

How is most carbon dioxide transported in the plasma?

Answer 9

As bicarbonate ions

Question 10

Define hypoxia and how it appears based on skin tone. (3)

Answer 10

1. Hypoxia: condition resulting from inadequate oxygen delivery to the blood tissue
2. In fair-skinned people, this can usually be seen as a bluish cast to their skin and mucosae
3. In dark-skinned people, it is difficult to see on the skin and usually observed only in the mucosae and the nailbeds

Question 11

Briefly describe carbon monoxide

Answer 11

Odourless, colourless gas