Autonomic nervous system Flashcards
(21 cards)
Is the autonomic nervous system voluntary or involuntary
involuntary
How does the ANS function
Fibres synapse once at a ganglion after they leave the CNS - 2/3 neuron chain
What does the ANS innervate
Smooth muscle, cardiac muscle, glands - can stimukate or inhibit
What does the somatic nervous system innervate
Skeletal muscle fibres - always stimulatory
Parasympathetic nerves use which CN to supply which parts of the body
CN 3,7,9,10
Head, thorax and abdomen
Which CN do parasympathetic fibres travel with to the thorax and abdomen
Vagus nerve
How are pelvic organs supplied
Sacral outflow ( S1 & 2) from spinal cord
Sympathetic nervous system uses CN for supply to where
The eye
Where does The sympathetic nerve supply to the thorax, abdommen and pelvis come from
Sympathetic chain
Functions of the ANS
Thermoregulation Adaption to exercise Digestion Competition Sexual function
Compare the parasympathetic & sympathetic nervous systemeffect on: heart, blood vessels, lungs, GIT
Sympathetic
- ^ HR, ^ force of contraction
- vasoconstriction
- bronchodilation
- decreased mobility of GIT, sphincter contraction & decreased secretions
- male ejaculation
Parasympathetic
- decreased HR and force of contraction
- vasodilation
- bronchoconstriction
- increased mobility of GIT, sphincter relaxation, ^ secretions
- male erection
What are neural connections in the sympathetic trunk called
Rami communications
How do preganglionic fibres differ from postganglionic fibres in PNS
Pre are myelinated
Post are unmyelinated so slower conducting
Pelvic innervations that comes from the sacral outflow of the spinal cord are called….
Pelvic splanchnic nerves
What is the enteric nervous system
Coordinates GI function and can work independently from ANS
How do the neurotransmitters differ in the SNS vs PNS
ACh pre then noradrenaline post in SNS
ACh pre then ACh post again in PNS
Noradrenaline synapse has alpha and beta receptors. Give the main subtypes of both
Alpha 1 & 2
Beta 1,2 & 3
When a -1 & 2, b-2 receptors are stimulated with noradrenaline, What is their effect on blood vessels
Alpha 1 & 2 = Vasoconstriction
Beta 2 = vasodilation
What is the predominant receptor in the heart and give its effect
Beta 1 Increased contractility ( faster and stronger )
What is the effect of beta 2 on the lungs
Relaxation of the bronchus
What receptors are in the platetelets to stimulate aggregation and clotting
Alpha 2
