Exam 3 - Respiratory System

Question 1

Eupnea

Answer 1

Normal, quiet breathing

Question 2

Hyperpnea

Answer 2

Increase in the amount of air moving in and out of the lungs. Aka hyperventilation

Question 3

Hypopnea

Answer 3

Decrease in amount of air moved into and out of the lungs. Aka hypoventilation.

Question 4

Apnea

Answer 4

Absence of breathing

Question 5

Dyspnea

Answer 5

Labored breathing (a sensation of breathlessness).

Question 6

What are the inspiratory muscles?

Answer 6

The diaphragm and the external intercostals.

Question 7

What are the expiratory muscles?

Answer 7

Internal intercostals and abdominals.

Question 8

What is surface tension? Why is it a problem for our respiratory system?

Answer 8

A. Surface tension is the tension of the surface film of a liquid caused by the attraction of the particles in the surface layer by the bulk of the liquid, which tends to minimize surface area.
B. The problem with surface tension is that surface tension (1) resists expansion and (2) diminishes elastic recoil which is what you would want in your lungs.

Question 9

What is surfactant and how does this help with the problem that surface tension causes?

Answer 9

1. Surfactant is the fluid that lines the respiratory parts of the lungs. About 70% phospholipids + some proteins.
2. Surfactant has a much lower surface tension than does water. Water, with it’s high surface tension (due to polar molecules) would keep us from being able to properly inhale - it would resist expansion of inspiratory muscles.

Question 10

What is unique about the pulmonary circulation?

Answer 10

1. Brings in deoxygenated blood.
2. Comes from the right side of the heart (atrium and ventricle).
3. Only circuit in the body that receives 100% of cardiac output.
4. Perfusion pressure is lower - about 25/10 (causes blood to move slower in order to allow necessary time for gas exchange).
5. Transit time that is the same as in the systemic circuit

Question 11

***What are the autonomic inputs to the arterioles and bronchioles of the lungs?

Answer 11

• Both sympathetic and parasympathetic innervation of arterioles and bronchioles.
• Arterioles in the pulmonary circuit are not as responsive to pressure changes as they are in the systemic circuit, because there is lower pressure.
• Arterioles:

Question 12

What kinds of things influence the rate and depth of breathing

Answer 12

1. Changes in O2, CO2, and pH. (aortic bodies and carotid bodies)
2. Exercise
3. Emotions
4. Sleep
5. Temperature
6. Requirements for speech
7. Stretch of the lungs

Question 13

What is Hering-Breuer Reflex? How is the vagus nerve involved?

Answer 13

• Stretch of lungs inhibits inspiration (only with stretch greater than during eupnea)
•It is a reflex to help prevent overinflation of the lung. If the vagus nerve is cut then this reflex will be eliminated.
•

Question 14

What is Hering-Breuer Reflex? How is the vagus nerve involved?

Answer 14

• Stretch of lungs inhibits inspiration (only with stretch greater than during eupnea)
• It is a reflex to help prevent overinflation of the lung. If the vagus nerve is cut then this reflex will be eliminated.
• Other interacting responses: Decrease in O2 levels will cause an increase in rate and depth of breathing.

Question 15

What conditions would override the Hering-Breuer Reflex?

Answer 15

• Lower O2 levels (altitude)
• If CO2 gets too high, which would mean that pH wold be too low (more oxygen needs to be let into the lungs, so deeper breaths are requried).

Question 16

What conditions would override the Hering-Breuer Reflex?

Answer 16

• Lower O2 levels (altitude)
• If CO2 gets too high, which would mean that pH wold be too low (more oxygen needs to be let into the lungs, so deeper breaths are required).

Question 17

What happens to our breathing when we go to high altitude?

Answer 17

Decrease in rate and depth of breathing.

Question 18

What factors influence respiratory changes when we exercise?

Answer 18

• During exercise the muscles produce more CO2 and metabolites.
• Cardia output increases to match the needs of the tissues.

Question 19

What input do proprioceptors have? Why is this efficient?

Answer 19

• Feed info to respiratory centers.

* Movement of joints = increased respiration

Question 20

What is Asthma?

Answer 20

• Muscle spasms in walls of bronchioles resulting in decreased oxygen due to dyspnea.
• May be hereditary tendency
• May have allergic inputs
• May have emotional inputs

Question 21

Emphysema

Answer 21

• Lungs lose elasticity
• Results in decreased oxygen
• Fewer alveoli (less surface area)
• Alveolar walls thickened (decreased diffusion)
• Capillaries can become obstructed: overstretched lungs-decreased tidal volume and decreased vital capacity.
• Frequently associated with heart disease
• Increased peripheral resistance = right side heart tissues

Question 22

Pneumonia

Answer 22

Many types, but most common is bronchopneumonia: patches of lung tissues are cut off from air supply; fine bronchioles clogged with mucus; group of alveoli filled with exudate - effects of surface tension. Bacterial or viral origins.

Question 23

Where are the pattern generators for breathing?

Answer 23

Respiratory centers of the medulla and pons.

Question 24

What do chemoreceptors in the carotid bodies and aortic bodies monitor and what do they do to breathing?

Answer 24

• Chemoreceptors in the carotid bodies and aortic bodies monitor the pH levels in the blood.
• They have inputs to the respiratory center so if there is a high level of CO2 low level of oxygen, respirations will increase.
• If there is a low level of CO2 and a high level of oxygen, respirations will decrease.

Question 25

Chemoreceptors are also found in a part of the brain. Where are they and what do they monitor?

Answer 25

Chemoreceptors are found in the fourth ventricle of the brain and they monitor the pH levels in the cerebrospinal fluid.