3.6.3. Respiratory System Regulation

Question 1

Hyperpnea? I believe this is usually called tachypnea…

Answer 1

Hyperpnea - increased breathing that matches metabolic needs (i.e. during exercise)

Question 2

Brachypnea

Answer 2

Brachypnea - shortness of breath (dyspnea)

Question 3

Hypoxia vs. Hypoxemia

Answer 3

Hypoxia vs. Hypoxemia - low tissue oxygenation vs. low blood oxygen (low paO2)

Question 4

What and where is the CPG?

Answer 4

“central pattern generator” creates breathing cycle, with input from central chemoreceptors and sensory integrators; the specific site of the CPG is unknown

Question 5

What are the 3 parameters that influence breathing?

Answer 5

Arterial levels of blood gases

position and stress on structural components

measured at the CNS and in peripheral positions via
central/peripheral chemoreceptors and mechanical (stretch) receptors

Question 6

In 1812, the _____ was identified as essential for breathing

Answer 6

In 1812, the medulla was identified as essential for breathing

Question 7

In 1923, the _____ was identified as necessary for breathing

Answer 7

In 1923, the pons was identified as necessary for breathing

Question 8

2 parts to the Pons

Answer 8

Apneustic Center

Pneumotaxic center

Question 9

Discuss the apneustic center of the pons

Answer 9

located in the lower pons

stimulates inspiration, producing a deep and prolonged inspiratory gasp (apneusis)

Question 10

Discuss the pneumotaxic center of the Pons

Answer 10

located in the upper pons

inhibits inspiration, regulates respiratory volume and rate

Question 11

2 parts of the medulla

Answer 11

Dorsal respiratory group (containing the nucleus of the solitary tract)

Ventral Respiratory group:

Question 12

Discuss the signaling involved in the dorsal respiratory group of the medulla and the end result

Answer 12

recieves input from the thorax and abdomen regarding pO2 and pCO2 [via the vagus and glossopharyngeal n.]
communicate with pre motor neurons [via the phrenic n.]

Is primarily responsible for inspiration, generates the basic rhythm for breatihing

Question 13

What is the ventral respiratory group responsible for and when is it active?

Answer 13

primarily responsible for expiration
not active during normal, quiet breathing; expiration is passive

is activated during exercise OR when expiration becomes and active process

Question 14

What part of our breathing do we control and how?

Answer 14

voluntary control of breathing (i.e. breath holding)

Question 15

In regards to CO2 or H+ responses by receptors, what types recognize these changes and which one is most important?

Answer 15

The response of peripheral chemoreceptors to CO2 is less important that the response of the central chemoreceptors for CO2 (or H+)

Question 16

What does our body due in response to Hypercapnia, or increased paCO2?

Answer 16

activates the central medullary chemoreceptors and increases breathing rate (not as important as pH)
activates peripheral carotid and aortic bodies to increase breathing rate (more important than pH, but less than O2)

Question 17

What is acidosis?

Answer 17

decreased pH

Question 18

What is our body’s response to acidosis?

Answer 18

activates the central medullary chemoreceptors and increases breathing rate
activates peripheral carotid and aortic bodies to increase breathing rate (least important stimulus)

Question 19

What happens during hypoxia?

Answer 19

Only activates the peripheral carotid and aortic bodies; most important stimulus in peripheral system (if <60mmHg)

Question 20

Discuss central control of breathing

Answer 20

sensitive to the pH of the CSF

decreased pH increases the breathing rate

CO2 diffuses from arterial blood across the BBB and causes the drop in pH (via carbonic anhydrase which yields H+ and HCO3-) which is measured directly by the medullary chemoreceptors

Question 21

Where are the carotid bodies and what system of breathing control are they a part of?

Answer 21

Peripheral control and they are located at the bifurcation of the common carotid arteries

Question 22

Where are the aortic bodies?

Answer 22

aortic bodies are located above and below the aortic arch

Question 23

How do arotic bodies respond?

Answer 23

decreases in arterial O2 will stimulate the peripheral chemoreceptors to increase the breathing rate

this only occurs when pO2 is <60mmHg

increases in pCO2
stimulate chemoreceptors and increase breathing rate

Question 24

Where are lung stretch receptors and what do they do?

Answer 24

located in the smooth muscle of the airways

are stimulated by lung distension

decrease breathing frequency (Hering-Breuer reflex)

Question 25

Where are irritant receptors and what do they do?

Answer 25

located between airway epithelial cells

stimulated by foreign substances

Question 26

Where are juxtacapillary receptors and what do they do?

Answer 26

located in the alveolar walls, close to cappilaries

engorgement of the capillaries (as seen in left heart failure) stimulates and causes rapid shallow breathing

Question 27

What are joint and muscle receptors and what activates them?

Answer 27

activated by movement of the limbs

involved in the early stimulation of breathing during exercise