Neural control of respiration (6) Flashcards
What is the major rhythm generator?
Medulla
What is the Pre-Botzinger complex and where is it found?
Network of neurons that generate breathing rhythm found near the upper end of the medullary respiratory centre
what does pre-botzinger complex stimulate?
Excites dorsal respirartory group neurones which fire and stimulate inspiration
What happens during “active” expiration during hyperventilation?
Increased firing of dorsal neurones excites ventral respiratory group neurons and this excites internal intercostals and abdominals for forceful expiration
How can the rhythm generated be modified?
Neurons in the pons , pneumotaxic centre (PC) stimulation terminates inspiration
What is Apneusis?
Without PC - Breathing is prolonged inspiratory gasps with brief expiration
What are involuntary modifications of breathing?
1) pulmonary stretch receptors hiring- Breuer reflex
2) joint receptors reflex in exercise
3) cough/sneeze reflex
What factors increase ventilation during exercise?
1) reflexes originating from the body movement
2) adrenaline release
3) impulses from the cerebral cortex
4) Increase in body temp
What is the function of cough reflex’s?
Helps clear airways of dust , dirt or excessive secretions
What happens during a cough reflex?
Afferent discharge stimulates, short intake of breath, followed by closure of the larynx, then contraction of abdominals and finally opening of the larynx and expulsion of air at high speed
What happens during a sneeze reflex?
Activated by irritation of mucosa of upper respiratory passages exspecially the nasal mucosa. Complex afferent discharge stimulating eyes, face, neck muscles,soft palate,uvula,abdominal muscles, diaphragm and chest muscles results in sudden forceful expulsion of air through the nose and mouth.
