2.02 Flashcards
(52 cards)
Role of adrenal medulla in sympathetic activity of respiratory system
Releases adrenaline and noradrenaline
- RELAXATION of smooth muscle in bronchioles
Role of parasympathetic division in respiratory system
CONSTRICTION of bronchioles
How are sympathetic impulses delivered in respiratory system?
sympathetic chain
How are parasympathetic impulses delivered in respiratory system?
Vagus nerve
What is the effect of the parasympathetic nervous system on the bronchioles?
Relaxation of smooth muscle in bronchioles
Which neurotransmitter is a key mediator of allergic reactions in the bronchioles?
Histamine
Which receptors on the bronchial smooth muscle are responsible for the cholinergic response?
M2 receptors
Where are the M1, M2, and M3 muscarinic receptors located?
M1 = parasympathetic ganglia
M2 = nerve terminals
M3 = airway smooth muscles.
Where are the dorsal respiratory group and the ventral respiratory group located?
Medullary Respiratory Centre
What are the functions of the dorsal respiratory group and the ventral respiratory group?
Dorsal respiratory group = controls normal breathing, sending impulses to the diaphragm and intercostals.
Ventral respiratory group = controls forceful breathing, activating accessory muscles of inhalation and exhalation
What complex controls respiratory rhythm?
Pre-Bötzinger
Where are the apneustic center and the pneumotaxic center located?
Pontine respiratory center
What are the functions of the apneustic center and the pneumotaxic center?
Apneustic center = promotes inhalation by stimulating the dorsal respiratory group
Pneumotaxic center = inhibits the apneustic center.
How do the dorsal respiratory group and the ventral respiratory group work together to control normal and forceful breathing?
Normal breathing =
dorsal respiratory group stimulates the diaphragm and intercostals.
Forceful breathing = ventral respiratory group activates accessory muscles of inhalation and exhalation.
Explain the differences in the neural pathways and functions of the sympathetic and parasympathetic control of the bronchioles.
The sympathetic nervous system, via the adrenal medulla, causes bronchodilation, while the parasympathetic nervous system, via the vagus nerve, causes bronchoconstriction. The pathways and effects are opposite between the two systems.
Function of M1 receptors
facilitate neurotransmission within the parasympathetic nervous system.
Function of M2 receptors
mediate the cholinergic response of bronchial smooth muscle, causing bronchoconstriction.
Function of M3 receptors
contribute to the cholinergic bronchoconstriction response.
primary neurotransmitter involved in the cholinergic response of bronchial smooth muscle?
ACh
Describe the mechanism by which the cholinergic response leads to constriction of the bronchioles.
binding of acetylcholine to M2 receptors on the bronchial smooth muscle activates a signaling cascade that leads to an increase in intracellular calcium, which ultimately causes contraction and constriction of the bronchioles.
What nerve mediates the cholinergic innervation and response of the bronchial smooth muscle?
The vagus nerve provides the parasympathetic innervation to the bronchial smooth muscle and mediates the cholinergic response
How do the M2 receptors on the nerve terminals differ in their function from the M3 receptors on the bronchial smooth muscle itself?
M2 receptors on the nerve terminals regulate the release of acetylcholine, while M3 receptors on the smooth muscle itself transduce the contractile response.
Muscles of passive inhalation
Diaphragm
External intercostals
Muscles of active inhalation
Sternocleidomastoid
Scalene
Serratus anterior
Pectoralis minor
