5.5 - Control of Ventilation

Question 1

TRUE OR FALSE

Skeletal muscles can contract spontaneously without being innervated by somatic motor neurons

Answer 1

FALSE

CANNOT CONTRACT SPONTANEOUSLY

Question 2

What initiates the contraction of the respiratory skeletal muscles?

Answer 2

medulla oblongata (brain)

Question 3

What is the central pattern generator and what do they do?

Answer 3

its a network of neurons in the medulla oblongata and they have intrinsic rhythmic activity, they fire signals at a rhythmic rate

Question 4

What is the function of the dorsal respiratory group?

Answer 4

control external intercostal muscles and diaphragm (muscles of inspiration)

Question 5

the dorsal respiratory group is also known as ____

Answer 5

inspiratory neurons (I neurons)

Question 6

the ventral respiratory group is also known as _____

Answer 6

active expiratory neurons (E neurons)

Question 7

Which muscles do the ventral respiratory group neurons control?

Answer 7

internal intercostals and abdominal muscles (active expiration)

Question 8

What is the function of chemoreceptors?

Answer 8

to modify or adjust the rhythm of the central pattern generator neurons

Question 9

Peripheral chemoreceptors are found in ____

Answer 9

carotid bodies, glomus cells

Question 10

Decreased PO2, decreased pH, or increase in PCO2 will lead to ____

Answer 10

increase in ventilation

Question 11

TRUE OR FALSE:

Peripheral chemoreceptors initiate signals when plasma PO2 changes slightly

Answer 11

FALSE

radical change in plasma PO2 must occur to get a signal

Question 12

What is the function of peripheral receptors?

Answer 12

sense changes in PO2 and pH of plasma or increase in PCO2

Question 13

Where are the central chemoreceptors located?

Answer 13

located in the medulla oblongata

Question 14

TRUE OR FALSE

Peripheral receptors are the most important chemical controller of ventillation

Answer 14

FALSE

central chemoreceptors are most important

Question 15

What happens if there is an increase in PCO2 in arterial blood?

Answer 15

increased ventilation

Question 16

What happens when CO2 crosses the blood brain barrier into the cerebrospinal fluid?

Answer 16

activation of central chemoreceptors via changes in pH caused by production of carbonic acid

Question 17

TRUE OR FALSE

Central chemoreceptors sense changes of H+ in both CSF and arterial blood

Answer 17

FALSE

only in CSF

Question 18

What is the function of mechanoreceptors?

Answer 18

to control ventilation to protect the lungs

Question 19

Where are irritant receptors found and what do they do?

Answer 19

located in airway mucosa

triggers parasympathetic neurons which innervate smooth muscles of bronchioles leading to bronchioconstriction

Question 20

Where are stretch receptors found and what do they do?

Answer 20

found in airway smooth muscle

terminates ventilation if lungs are over inflated (Hering-Breueur inflation reflex)