SF3 Exam 2 Control Of Respiration

Question 1

What are central chemoreceptors sensitive to?

Where are they located?

Answer 1

CO2 fluctuation

In the Brainstem on the other side of the blood brain barrier.

Question 2

Where are the peripheral chemoreceptors located?

What variables effect them?

Answer 2

Located in the neck and aortic arch

Arterial H+

PCO2

PO2

Question 3

What is the most important controller of ventilation in central chemoreceptors?

How does this variable cause this?

Answer 3

PaCO2

CO2 can enter the CSF. Here it binds with water and results in H+ and bicarb formation

CSF lacks hemoglobin, so the H+ causes an increased rate of breathing due to the initial lowering of pH.

Question 4

What does hypoxia activate?

Can hypoxia be adapted to through this mechanism?

Answer 4

Peripheral chemoreceptors

Adaptation cannot be achieved in peripheral receptors for hypoxia

Question 5

What is the most powerful stimulus of respiration? Which type of receptor is this?

Answer 5

Most powerful is pH

Peripheral

Question 6

How does hypercapnia effect hypoxia?

Answer 6

Hypercapnia is increased PCO2.

This causes an increased effect of hypoxia.

Since both of these are in effect, the PO2 being low and the CO2 being high, both the CENTRAL and PERIPHERAL chemoreceptors kick in, increasing ventilation.

Question 7

What sustains respiratory drive at high elevations?

Answer 7

Arterial PaO2

Question 8

You have a PaO2 of 45mmHg and a PaCO2 of 62mmHg. What receptor(s) is/are being activated and by which piece of information?

Answer 8

Peripheral—— O2 is below 60mmHg

Central—— CO2 is above 45mmHg

Question 9

What parameters activate peripheral and central chemoreceptors in terms of PaCO2 and PaO2

Answer 9

PaO2<60 activates peripheral

PaCO2>45 activates central

Question 10

The phrenic nerves effect?

Answer 10

Inhalation

Question 11

If a person damages C7, what would happen during respiration?

Answer 11

Chest wall function will be impaired

Intercostal muscles are innervated at this level

Question 12

Dorsal Respiratory Groups (DRGs) are made of what type of neuron?

What do DRGs control?

Answer 12

Inspiratory neurons

They control your basic rhythm of breathing.

Question 13

What do your Ventral Respiratory Groups (VRGs) control?

When are these used?

Answer 13

They control you upper airway muscles

They are recruited during exercise.

Question 14

Where are the DRG and VRG located?

Answer 14

Medulla

Question 15

Where is the Apneustic center?

Answer 15

Pons

Question 16

What is apneustic breathing?

When is this shown to occur?

Answer 16

Inspiration holds in the cycle

When the apneustic center, pneumotaxic center, and vagus nerve are removed

Question 17

What is wrong in Congenital Central Hypoventilation Syndrome (CCHS)?

What is required to treat this?

Answer 17

Central pattern generator is inoperative

Insensitivity to CO2, O2, and pH

Respiration is not automatically controlled.

They must use a mechanical ventilator.

Question 18

What effect does alcohol, opiates, barbiturates, and anesthetics have on breathing?

Answer 18

They dampen normal response to CO2 increased and cause respiratory failure.

Question 19

What do cocaine, amphetamine, and caffeine cause?

Answer 19

They cause an increase in respiratory drive

Question 20

How does mild hypothermia effect ventilation?

What about deep hypothermia?

Answer 20

Mild increases ventilation due to an increased sympathetic nervous system.

Deep causes depression of ventilation due to lowered neural activity

Question 21

What patients typically display the Cheyenne-Stokes Breathing pattern?

What appears first in the pattern?

Answer 21

cardiac failure or brain damage

PCO2 of pulmonary blood increases then the PCO2 of respiratory neurons.

Fast lines followed by apnea. (Hyperventilation occurs/ “waxing and waning of ventilation”

Question 22

Biot’s respiration occurs in which patients?

What is it characterized by?

Answer 22

Meningitis and cerebral circulation disorders

Hyperapnea where there is an increased depth of respiration amplitude followed by apnea.

Question 23

Central sleep apnea

Answer 23

Airflow matches thoracic effort.

This is a normal cycle with absent airflow of 10 second cycles inserted.

Question 24

Obstructive Sleep apnea

Answer 24

Thoracic effort constantly works, but an upper airway obstruction (by fat or other) causes pharyngeal muscles to not contract.

This leads to gaps in airflow

Question 25

Kussmaul’s respiration.

Answer 25

Hyperventilation
Deep and labored
Kidney failure/ diabetic coma/ high acidosis

repetitive quick sharp peaks

Question 26

If a person comes in with high PCO2 and low PO2 and they are in distress, what should you do?

Answer 26

The CO2 will fix itself.

You shouldn’t give 100% oxygen. The patient will stop breathing. You need to watch the patient and use a lower mixture of oxygen to start with them.