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
