Flashcards in Autonomic Nervous System Deck (29):
What system controls organs?
Autonomic Nervous System (ANS)
What are the two divisions of the ANS?
Sympathetic and Parasympathetic
What do the blood vessels control?
Nerves which determine blood pressure
Where does the sympathetic nervous system originate
Nerves coming out the spinal cord
Where do the parasympathetic nervous systems originate?
Nerves coming out of cranial (brain)
What is ganglion made of?
Swelling created by synapses
Where to ganglion cells congregate?
In a sympathetic chain, close to spinal cord
Where is there no parasympathetic nerves?
Describe parasympathetic activity
Causes a fall in heart rate- vessels relax (dilation)
Describe sympathetic activity
Causes a rise in heart rate- contraction makes diameter narrower making pressure go up
What causes blood pressure in terms of activity?
Cause by balance between sympathetic and parasympathetic vessels
What is the transmitter in all ANS processes?
What is the transmitter process for the Parasympathetic Nervous system?
Pre-ganglionic-> Long preganglionic fibre-> Postganglionic acetylcholine
Where does Acetylcholine act in the parasympathetic system?
What is the transmitter process for the Sympathetic Nervous system?
Preganglionic fibre-> acetylcholine-> postganglionic fibre-> noradrenaline
Where does Acetylcholine act in the sympathetic system?
Adrenergic receptors (norepinephrine)
What does the noradrenaline then act upon in the sympathetic system?
Noradrenaline-> adrenal medula-> Adrenaline
What is the process for arterial pressure?
Detector (Baroreceptors- stretch receptors, signal brain) -> afferent pathways -> Medulla (coordinating centre)-> efferent pathways ->effector -> heart and vessels -> means arterial pressure
Where and what are baroreceptors?
Above aortic arch and detect stretch
How is adrenaline produced in sympathetic system?
Preganglionic fibres release acetylcholine and postganglionic fibres produces noradrenaline to produce adrenaline
How does sympathetic nervous system have control?
Innervation of small areteries and surrounding per-vascular adipose tissue (PVAT)
What effect does noradrenaline have when it's next to cells?
Affects diameter of the cell
What transmitters comprise the sympathetic triad?
NA (noradrenaline), ATP and NPY (neuropeptide Y)
What transmitters comprise the parasympathetic triad?
Ach (acetylcholine), NO and VIP
What importance do sensory nerves have in ANS?
Blood from sensory nerve produce vasodilation receptors (allows more bloodflow)
What three steps are involved in the Lewis Triple Response?
1. Redness along scratch
2. Spreading flare
3. Local swelling along the scratch
What is varicosity?
Release site, which inside has thousands of vesicles
What are the steps for vesicles in the active zone?