Control of Respiration

The peripheral chemoreceptors are activated only when the arterial PO2 falls below

60 mm Hg

Central chemoreceptors

7x more sensitive to CO2 compared to carotid/aortic bodies but much slower

If the Pneumotaxic center is destroyed, then ____ may occur.

Apneusis

This pons center inhibits inspiratory neurons from being switched off.

Apneustic center

____ can cross the blood brain barrier but ____ cannot cross.

CO2, H+

____ are sensitive to Plasma H+

Carotid bodies

The phrenic nerves innervate the ____

Diaphragm

Increase in plasma CO2 will cause CO2 to diffuse down its concentration gradient into the ___

ECF

(T/F) Central chemoreceptors are sensitive to Plasma H+

FALSE! Central chemoreceptors are only sensitive to H+ in the cerebral spinal fluid

(T/F) Plasma H+ has an effect on central chemoreceptors

False

(T/F) Apneusis is a breathing pattern characterized by quick inhales and prolonged exhales

False. Prolonged inhales and quick short exhales

(T/F) The Rostral VRG are composed of expiratory neurons

False. Rostral VRG neurons are inspiratory

(T/F) The VRG is active during quiet respiration.

False. The VRG is NOT active during quiet respiration.

(T/F) The body is much more sensitive to O2 than CO2.

False. more sensitive to CO2

The carotid bodies send fibers to the DRG via ___

Glossopharyngeal nerve (cranial nerve 9)

____ has little effect on central chemoreceptors

H+ in PLASMA

_____ prevents the lungs from over filling.

Hering- Breuer Reflex

A decrease in pH, results in an _____ in alveolar ventilation.

Increase

An increase in PCO2, results in an ____ in alveolar ventilation.

Increase

Aceto-acetate, B-hydroxy butyric Acid, and Acetone are examples of ___

Ketobodies

The DRG is most found in the ___

NTS (nucleus solitarius)

The VRG is mostly found in the ___

Nucleus ambiguus and the nucleus retro-ambiguus

____ plays a major role in respiration rate

PCO2

Under normal conditions, ____ plays a little role in normal respiration rate

PO2

During CO poisoning, the ____

PO2 remains unchanged (PaO2 = 100 mmHg)

If the plasma H+ increases and PCO2 is not changed, then ____ will increase respiration.

Peripheral chemoreceptors

The C 3,4,5 neurons in turn send out axons to form the ___

Phrenic Nerve

The Apneustic center is an antagonist to the ____

Pneumotaxic center

_____ sends fibers to the DRG that help switch off the inspiratory neurons

Pneumotaxic center

The Nucleus parabarchialis is located in the __

Pons

The rostral ventromedial medulla is also known as the ___

Pre-Botzinger complex

SIDS

Sudden infant death syndrome

(T/F) The aortic bodies are not very sensitive to plasma pH

True

Peripheral chemoreceptors mostly consists of ___ but also some ___

carotid bodies, aortic bodies

Ketoacids in the blood are a result of ___

fat metabolism

When PCO2 is ____ the respiratory center becomes depressed

greater than 80 mmHg

During exercise caudal VRG neurons activate motor neurons in the spinal cord that control the ____ and ____

abdominal and internal intercostal muscles

Ondine's curse (Hypoventilation syndrome)

because of brain stem lesion, the person must remember to breathe

Central chemoreceptors indirectly change pH of ECF (cerebral spinal fluid) by __

binding to H+

What happens if the Pneumotaxic center is destroyed?

breathing pattern consists of prolonged inspiration gasps abruptly interrupted by very quick expiration

Medullary respiratory center

neurons send efferent fibers to motor neurons in C 3,4,5

Hering- Breuer Reflex

stretch receptors in smooth muscle of bronchi and bronchioles send fibers via the vagus nerve to the DRG, which turns off these neurons

The aortic bodies send fibers to the DRG via ___

vagus nerve (cranial nerve 10)

3 things the body makes when using fat as an energy source

1) Aceto-acetate 2) B-hydroxy butyric Acid 3) Acetone

3 factors that affect nature of blood gas regulation

1) PO2 2) PCo2 3) H+

The Pons center has two parts

1) Pneumotaxic center 2) Apneustic center

The Pons respiratory centers are

1) Pneumotaxic center 2)Apneustic center

The respiratory control centers in the brain stem

1) Pons 2) Medulla

The VRG (ventral respiratory group) can be divided into two parts

1) Rostral VRG (inspiratory neurons) 2) Caudal VRG (expiratory neurons)

The Medulla respiratory centers are

1) Rostral ventromedial medulla 2)Dorsal respiratory group 3) ventral respiratory group

What keeps you breathing?

C 3,4,5

If the PO2 drops significantly below 60 mmHg, the chemoreceptors stimulate respiration to __

increase the levels of PO2

The reason you cannot hold your breath for so long is because of ___

increased CO2

The Dorsal respiratory group (DRG)

is mostly inspiratory neurons which are responsible for quiet respiration rhythm

The peripheral chemoreceptors compared to central chemoreceptors are ___

less sensitive to PCO2 but they are 5x faster

Diabetes mellitus may result in ____.

metabolic acidosis