Physiology-Respiratory System Regulation Flashcards Preview

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Flashcards in Physiology-Respiratory System Regulation Deck (15):


Breathing faster to meet metabolic needs


Fast and slow breathing?

Tachypnea and bradypnea


What parts of the brain stem are responsible for respiratory control?

PONS (PRG), MEDULLA (DRG, Rostral and Caudal VRGs) and the spinal cord.


What component of the brainstem drives the inspiratory response? How does it help mobilize the diaphragm for inspiration?

The dorsal respiratory group (DRG) of the medulla. It works with the ventral respiratory group (VRG) and pre-motor neurons to mobilize the diaphragm. Axons descend from the DRG. The DRG + the VRG = Botzinger Complex.


What component of the brainstem plays a role in activation of powerful expiratory abdominal muscles during exercise?

Ventral respiratory group (VRG).


How do the phrenic, inspiratory and expiratory neurons coordinate during respiration?

Phrenic= on during inspiration and diaphragm contraction. Inspiratory neurons on during inspiration. Expiratory neurons inhibit inspiratory muscles during expiration.


Where is the major pacemaker for ventilation located? What are other locations for possible pacemakers?

Pre-Botzinger complex in the VRG. Other pacemakers may exist in the DRG and hormone secreting cells.


What component of the brainstem is involved in stopping inspiration and increasing respiratory rate? What component may control depth of breath?

The pneumotaxic center in the pons. Apneustic center may control depth of breath.


What bridges the gap between the brain stem and actual concentrations of O2, CO2 and H+ in the blood?

Central and peripheral chemo and stretch receptors.


Where are the central chemoreceptors located? What changes do they detect?

Just beneath the medulla. CO2 readily diffuses across the BBB. Once in the brain's ECF, carbonic anhydrase converts it to carbonic acid and H+. The chemoreceptor senses that increase in H+ and sends a signal to the DRG to increase ventilation and expel CO2.


If it takes the DRG 10 minutes to increase ventilation in response to increased CO2, how does your body account for increased ventilation during exercise?

Anxiety response and fast-reacting peripheral chemoreceptors (in the carotid body and aortic arch).


Who are the effector cells at the carotid body and aortic arch? How do they work?

Glomus cells. Presence of oxygen around them allows K+ entry into the cell and hyperpolarizes the cell. When oxygen is low, the cell depolarizes and sends signals to the brain telling it that you need to breath faster because O2 concentration is low. H+ and CO2 also cause depolarization and signal conduction to the CNS.


How do peripheral and central chemoreceptors differ in the molecules that they sense?

CNS = CO2 and mainly H+. Peripheral = mainly O2, but also H+ and CO2.


Where are the mechanoreceptors of the respiratory system found?

Slow adapting stretch receptors (smooth muscle of airways), rapidly adapting stretch receptors (epithelium of airways) and J receptors (juxtaposed to pulmonary capillaries).


How do the brain stem, chemoreceptors, lungs and active tissue all work together to regulate ventilation?