Neurochemical regulation of respiration Flashcards
Central nervous system and respiration
- The respiratory brain centers are in the pons and medulla at the base of the brain ( BRAIN STEM)
- connections between the medulla and the pons make it possible so influence breathing
- signals carried by the autonomic nervous system control breathing
Roles of respiratory centre
Ventilation is controlled by neurons in pons and medulla oblongata in the brain
What are the three groups of neurons
- pneumotaxic area in the pons
- apneustic area in the pons
- medullary rhythmicity area the medulla oblongata
Medullary rhythmicity area
- controls basic rhythm of respiration
- in normal quite breathing the expiratory rate area is inactive
- during forceful breathing the inspiratory area activates the expiratory area, which is active during high ventilation rates
Role of pneumotaxic area in the pons
sends impulses to the inspiratory area. these signals shorten the duration of inhalation
Role of apneustic area in the pons
sends stimulatory impulses to the inspiratory area. these signals prolong the duration of inhalation
Chemical regulation of respiration
- inspiratory area sets its own pace until CO2 accumulates and arterial partial CO2 rises to 40mm Hg.
- a slight increase in pCO2, a condition called hypercapnia stimulates central and peripheral chemoreceptors
- a response to increased pCO2 increased H+ and decreased pO2 the inspiratory area is activated and hyperventilation, rapid and deep breathing occurs
What is calmodulin ?
- helps calcium ions to become physiologically active
MLCK ( MYOSIN LIGHT CHAIN KINASE AND SMOOTH MUSCLE CONTRACTION )
MLCK is responsible for phosphorylating myosin’s
Phosphorylation of myosin by MLCK is responsible for muscle contraction.
Airflow obstruction
can occur as a result of :
- a reduction in airway diameter
- increased mucus secretion
- tissue inflammation
