Exam 2: Nervous System/Synaptic Transmission Flashcards
What are the two main nervous systems of the CNS?
Afferent and Efferent
Sensory Information to the CNS is within the _______ system
Afferent
Motor commands from the .CNS. fall under the ______ system
Efferent
The motor system is split into two parts
Somatic (control ourselves)
Autonomic (brain controls)
What is a reflex arc?
When the spinal cord sends an efferent signal back to the skeletal muscle before the brain has processed it.
Autonomic System has what three subdivisions?
Sympathetic
Parasympathetic
Enteric
Sympathetic NS
^HR
^BP
Dilates Bronchioles
Shunts Blood to Muscles
“Fight or Flight”
Widespread Impact
Reaches organs and tissues throughout the body.
Parasympathetic
Conserves energy
Shunts blood to Endocrine, GI, and Urogenital systems
“Rest and Digest”
Innervates only specific visceral structures
Effects are shorter lived
Sympathetic nerves are located in the _____ parts of the CNS system
Thoracolumbar
Parasympathetic Nerves are located in the ______ parts of the CNS system
Craniosacral
Sympathetic system has _____ Preganglionic Fibers and _____ Postganglionic Fibers
Short
Long
Parasympathetic system has _____ Preganglionic Fibers and _____ Postganglionic Fibers
Long
Short
Sympathetic Preganglionic Fibers Terminate:
Spinal Cord (ganglia paravertebral chains)
Parasympathetic Preganglionic Fibers Terminate:
Close to the organ
No Chain Ganglion
The GI system is mainly under the control of:
The Parasympathetic System/Enteric System
GI system is inhibited by the:
Sympathetic System
Many neurons of the Enteric System are non-______?
Non-Adrenergic AND Non-Cholinergic
Preganglionic Nerves Release:
Acetylcholine (ACh)
Postganglionic Nerves Release:
Epinephrine
(or)
Acetylcholine
Somatic System Targets:
Skeletal Muscles
Autonomic NS Targets:
Cardiac Muscle
Smooth Muscle
Glands
Sympathomimetics - Direct
Epinephrine
Isoproterenol
Albuterol
Act directly on a specific receptor
Sympathomimetics Actions
-Constrict blood vessels
-Inotropic and Chronotropic Cardiac Effects
-Decrease Bronchiole Tone
-Decrease Uterine Muscle Tone
Sympathomimetics - Indirect
Ephedrine
Amphetamines
-Can Release NE
-Inhibits NET
-Poor agonists at adrenoreceptors
(confusion about the VMAT thing?)
Sympatholytic
Blocks SNS
Decrease BP
Block receptors: alpha, beta, or both
Cholinergic Receptors
Muscarinic
Nicotinic
Adrenergic Receptors
Alpha
Beta
Dopamine
Excitatory Muscarinic
1, 3, 5
Activates Gq / Phospholipase C
Inhibitory Muscarinic
2 & 5
Activates Gi / Inhibits cAMP
2 Nicotinic Types
Neuronal and Muscular
How many types of Alpha and Beta Receptors?
2 Alpha
3 Beta
Where are Dopamine Receptors Located?
Brain and Renal System
Alpha 1 Activate
Gq = Activates Phospholipase C
Alpha 2 Activate
Gi = Inhibits cAMP
Beta Receptors Activate
Gs = Stimulate cAMP
Alpha1
Gq
Smooth Muscle
Binds GPCR -> Phospholipase C -> IP3/DAG -> Myosin Activated
IP3 -> MLCK activation
DAG -> MLCP inactivation
MLCK
Myosin Light Chain Kinase
Phosphates Myosin to activate it
MLCP
Inactivates Myosin by Removing a Phosphate from Myosin
What interacts with Myosin to allow smooth muscle contraction?
Actin
Beta 1 (and B2) - Heart
Gs
Norepinephrine activation
cAMP second messenger
Activates PK-A (Protein Kinase A)
Ca Release & absorption
Contraction
Alpha 2
Presynaptic Receptor
Prevents release of NE when activated
Beta 2 - peripheral
Gs
cAMP still, but is INHIBITORY
Inhibits MLCK
Allows for relaxation of arterial blood vessels -> Increased blood flow
More for Skeletal/Cardiac blood vessels. (more O2/nutrients to these)
Sympathetic stimulation shunts blood from ______ to _______.
From Visceral Tissue to Skeletal Muscle.
NANC Neurons
Non-Adrenergic, Non-cholinergic
Neurons that release other things.
(A lot of these)
NOs, Substance P, Somatostatin
See in the gut ENS
Postganglionic ACh
Skeletal muscle = activation
Skeletal Blood Vessels = Dilation
Abdominal Blood Vessels = Constriction
