ANS (Autonomic Nervous System)
Pre & Post Ganglionic Fibers for Parasympathetic
PAN AM ACh - Nicotinic ACh - Muscarinic
What are the divisions and functions of the ANS?
PNS - rest and digest ; slows things down SNS - fight or flight ; speeds things up
What is the difference between the pre and postganglionic fibers of the Sympathetic division (SNS) and Parasympathetic division (PNS) of the ANS?
PNS = are long then short SNS = short then long
Neurotransmitters/Receptors: Sympathetic
Receptors: Alpha and Beta NT: ACh, Nore,/epinephrine
Neurotransmitters/Receptors: Parasympathetic
Receptors: Muscarinic and nicotinic NT: ACh
Pre & Post Ganglionic Fibers for Sympathetic
SAN BEAN ACh - Nicotinic Beta- Epinephrine Alpha -Norepinehrine
What is the SNS also called?
Thoracolumbar
What are the effects of the PNS on target organs and tissues?
eye - constriction of pupil heart - decreased heart rate, force of contraction and blood pressure airways - decreased airway diameter sphincter - opens sphincter bladder - releasing of bladder reproductive - Ejaculation SHOOT
What is the difference between nuclei and ganglia?
nuclei - inside CNS ganglia - in PNS
What segments of the spinal cord are associated with the SNS?
thoracic to lumbar vertebrae
What are the postganglionic receptors and what are their functions? (SNS)
Alpha 1 (BV) - Excite/Contract Alpha 2 (BV) - Relax AND Dilate Beta 1 (<3) - E Beta 2 (Lungs) - RAD Beta 3 (Fat cells) - E
Organs affected by parasympathetic
(craniosacral division) - Decrease: metabolic rate, heart rate, blood pressure - Increase: saliva, digestive - Urination & defecation simulation
Organs affected by sympathetic
(thora-columbar division) - eyes (dilation), - heart (accelerates), - lungs (relax), - blood vessels - sweat glands, - digestive system, kidney (secretes nore/epinephrine) - penis
What about the adrenal medulla? Is it a part of the SNS or PNS?
- Part of SNS - Secretes hormones in blood stream Epinephrine (adrenaline) Norepinephrene (noradrenaline)
What segments of the spinal cord are associated with the PNS? Are there any other structures?
- Spinal cord segments S2-S4 - Cranial nerves 3,7,9,10
Nitric Oxide as Neurotransmitter
- The sympathetic division release NO as neurotransmitter - occur where neurons innervate smooth muscles in the walls of blood vessels in many regions
What are the effects of the SNS on target organs and tissues?
- eye: dilation of pupil - blood vessels: to skin, dilation and constriction - veins: constriction alpha 1 - heart: increased heart rate, force of contraction and blood pressure - airways: increased airway diameter - sphincter: closes sphincter - bladder: constriction of bladder - reproductive: erection POINT
What is the PNS also called?
Craniosacral
What is the system of the gastrointestinal tract?
Digestive System
