topic 19 Flashcards
Compare and contrast Sympathetic and Parasympathetic nervous systems
PANS:
Long preganglionic/short postganglionic
Ganglion normally in organ being innervated
Craniosacral origins
Cholinergic/Nicotinic (Ionotropic) receptor at ganglion
Cholinergic/Muscarinic (g protein coupled) receptor (M1, M2, M3) at effector site
SANS:
Short preganglionic/Long postganglionic
Multiple axons after ganglion
Thoracolumbar origins
Cholinergic/Nicotinic (Ionotropic) receptor at ganglion
Adrenergic(g protein coupled) receptor (A1, A2, B1, B2) at effector site
Compare and contrast the somatic and autonomic nervous systems
Somatic Nervous System-Anatomical
a) Ganglia outside CNS=None
b) Pathway from CNS- Effector Organ=Uninterrupted
c) Fibers=Myelinated
d) Peripheral plexus=None
e) Reflex Arc=Spinal cord and brain stem
Autonomic Nervous System
a) Ganglia outside CNS=YES: Paravertebral Prevertebral, Intramural
b) Pathway from CNS- Effector Organ=interrupted
c) Fibers=Preganglionic-myelinated; Postganglionic-unmyelinated
d) Peripheral plexus=Fibers branch and form a network
e) Reflex Arc=Spinal cord and brain stem
Functional-Somatic
a) Peripheral Effect-Excitation
b) After Denervation-Paralysis (atrophy)
c) Control Environment-Adjusts body to external environment
Functional-Autonomic
a) Peripheral Effect-Excitation or Inhibition
b) After Denervation-No Paralysis
c) Control Environment-Regulation of internal environment
Chemical-somatic
a) Neurotransmitter-Acetylcholine
b) Co-transmitters-None
Chemical-Autonomic
a) Neurotransmitter-Acetylcholine & norepinephrine
b) Co-transmitters-Vasoactive intestinal peptide (VIP-parasympathetic), Neuropeptide Y (Sympathetic), ATP (Sympathetic and Parasympathetic)
What are some exceptions to the rule in the sympathetic nervous system?
Eccrine Sweat Glands- The postganglionic neurons that are involved with stress related excretion release use NE. Those involved with thermoregulation release use ACh
Kidneys-Postganglionic neurons to the smooth muscle of the renal vascular bed release dopamine
Adrenal gland-Pregangl. neurons do not synapse in paravertebral symp ganglion. They synapse directly with adrenal gland which has nicotinic receptors. Adrenal glands release NE and epi into circulation (no postganglionic).
What are primary afferent nerves like? Enteric afferent nerves? Which ganglion do enteric afferents use that go to the spinal cord? and that go to cranial nerves?
Primary afferent-Bipolar, go all the way from organ into CNS.
Enteric afferent-Synapse in a ganglion before reaching CNS
Ganglions-Spinal (Dorsal Root), Cranial (Petrosal, Nodose, Geniculate)
Where is myenteric plexus located? What does it do? What is another name for it? What is it like? Same questions for submucosal plexus?
Myenteric-Large, between the two muscle layers in the gut. Found throughout GI tract. Auerbachs plexus. Peristalsis and Motility
Submucosal-Small, Located closer to lumen, not in stomach or esophagus. Stimulate secretion
What are the sensory neurons in the enteric nervous system? What are the effector systems? How is it connected with the CNS? How does it use interneurons and motor neurons w/o CNS? What are the Enteric Pacemakers?
Sensory neurons-Chemoreceptors, mechanoreceptors, thermoreceptors.
Not using the CNS, these sensory neurons relay information to interneurons (reflex circuits and motor programs) which send signals to motor neurons to either excite or inhibit the effector systems.
Also, the Sensory neurons can send signals to the CNS (Autonomic) which sends signals to the interneurons to cause the same actions.
Effector systems-Muscle, secretory epithelium, Inflammatory cells, endocrine cells, vasculature
Enteric Pacemakers-Interstitial cell of Cajal (ICC)-Not neural or glial but in between-mediates neurotransmission from nerves to bowel SM cells (pacemaker)
What are 4 inputs to the NTS? What is the output? What are 2 general options of what can happen once a visceral afferent signal reaches the Nucleus Tractus Solitarius (NTS)? What kinds of signals does the area postrema receive? What are two possible general responses of central integration?
Inputs to NTS-Autonomic Sensory nerves, Ascending spinal pathways, nuclei of the brain, area postrema
Output of NTS-Various nuclei in the brain that can carry out the correct response.
Signal to NTS can go down into a reflex pathway (autonomic output) or it can go up for central integration. With central integration, two possible options are the limbic system–>behavioral response and endocrine system–>hormonal response
Area postrema receives info concerning plasma electrolytes, hormones, and CSF chemicals
What are 3 examples of co-transmission and neuromodulation?
Presynaptic inhibition-signal sent, negative feedback sent to autoreceptors on same neuron
Heterotropic presynaptic inhibition-NT from nearby neuron gives negative feedback on heteroreceptor
Postsynaptic synergism-Two different NTs lead to a stronger signal.
What 3 things are autonomically effected in the eye? What is the sympathetic effect and the receptor type? What is the parasympathetic effect and the receptor type?
Radial Muscle (outer) and Sphincter/Circular Muscle (inner), iris
Symp: contraction radial muscle–>pupil dilation (mydriasis)++, A1
Parasymp: contraction of circular muscle–>smaller pupil (Miosis)+++, M3/M2
ciliary muscle
Symp: Relaxation for far vision, B2
Parasymp: contraction for near vision+++, M3/M2
Lacrimal glands
Symp: Secretion+, A
Parasymp: Secretion+++, M3/M2
What 5 things are autonomically effected in the heart? What is the sympathetic effect and the receptor type? What is the parasympathetic effect and the receptor type? What are some terms to know concerning the heart?
SA Node
Symp: Increase in heart rate (positive cronotropic)++, B1>B2
Parasymp: Decrease in heart rate+++, M2>>M3
Atria
Symp: Increase in contractility (Inotropic) and conduction velocity++, B1>B2
Parasymp: Decrease in contractility and contractility and shortened AP Duration++, M2>>M3
AV Node
Symp: Increase in automaticity and conduction velocity (dronotropic)++, B1>B2
Parasymp: Decrease in conduction velocity, AV block+++, M2>>M3
HIS Purkinje
Symp: Increase in automaticity and conduction velocity, B1>B2
Parasymp: Little effect, M2>>M3
Ventricle
Symp: Increase in contractility, conduction velocity, automaticity, and rate of idioventricular pacemakers+++, B1>B2
Parasymp: little effect
Dronotropic-conduction velocity, inotropic-contractility, chronotropic-heart rate, bradycardia (slow heart rate), tachycardia (fast heart rate), atrial flutter (even faster heart rate), fibrillation (lack of coordination of muscles), ventricular fibrillation leads to death.
What are 2 bold statements concerning autonomic nervous system and blood vessels? Are there parasympathetic (muscarinic receptors in blood vessels? Are they innervated? What are 2 examples of them being innervated? What does this mean concerning medications? Where are the muscarinic receptors located? What effect does it have when they are stimulated? How does NO prevent constriction? Which 7 arteries/arterioles are innervated by autonomic? What does symp do with which receptor? What does parasymp do with which receptor? Same with veins?
Every blood vessel has a sympathetic receptor; it is mainly just controlled by sympathetics. Also, every alpha receptor in a blood vessel will cause contraction of SM and thus vasoconstriction–>increase BP
There are parasymp receptors in blood vessels in the endothelium that oppose the symp but they are not innervated. however, they are able to be stimulated by medication. When this happens, they release NO which activates guanylate cyclase which creates cGMP which prevents myosin-P/actin binding which prevents muscle contraction leading to dilation. Vessels in erectile tissue and salivary gland are innervated by parasymp nerves leading to dilation.
Coronary, Viscera, Skin, and Brain
Symp:Constriction, A
Parasymp: No effect
Skeletal muscle
symp: dilation, B2
Parasymp: No effect
Erectile Tissue and salivary gland
Symp: Constriction, A
Parasymp: dilation, M3
Veins
symp: constriction, A; Dilation, B2
Parasymp: No effect
What 3 things are autonomically effected in the lung? What is the sympathetic effect and the receptor type? What is the parasympathetic effect and the receptor type?
Tracheal and bronchial SM
Symp: Relaxation (open airway), B2
Parasymp: contraction (constrict airway), M2=M3
Bronchial glands
Symp: not important
Parasymp: Stimulation, M3/M2
Mast cells–>bronchoconstriction
Symp: Inhibition, b2; stimulation, a1
parasymp: stimulation, M2/M3
What is the GI tract mainly controlled by? What 3 things are autonomically effected in the GI tract (both stomach and intestine? What is the sympathetic effect and the receptor type? What is the parasympathetic effect and the receptor type?
Mainly controlled by parasymp not symp
Motility and tone
Symp: decrease+, all of them
Parasymp: Increase+++, M2=M3
sphincters
Symp: contraction+, A1
Parasymp:Relaxation+, M3/M2
Secretion
Symp: Inhibition, A2
Parasymp: Stimulation++, M3/M2
What effect does the autonomic system have on gallbladder/ducts? What is the sympathetic effect and the receptor type? What is the parasympathetic effect and the receptor type?
Symp: Relaxation+, B2
Parasymp: contraction+, M
Which branch of ANS causes Renin secretion in kidney? Which receptor is used? How does the angiotensin pathway work?
JG cells are stimulated to secrete renin. Renin causes the conversion of Angiotensinogen to angiotensin I which is converted by ACE to angiotensin II which causes vasocontriction, release of aldosterone (prevents release of water and sodium–>increase BP), and increase release of NE (more vasoconstriction).
Renin Secretion
Symp: increase++, B1
Parasymp: no innervation
