Ch. 9: Autonomic NS Flashcards
Adrenal Medulla
- secrete epinephrine into blood for widespread distribution
- (bost ganglionic neuron very short)
- Adrenal medulla is ganglia
Control Neuron somas in_____. (PNS)
medulla and pons
Acetylcholine
Preganglionic: fast, quick response
Postganglionic: slow prolonged response
metabolism
Sympathetic: increase metabolism/uses energy
Parasymp: decrease metab/store energy
Mm Blood Flow
Symp: increase/decrease (capacitance/shunt)
Parasymp: N/A
Afferent Pathways
- Spinal Nerves (anterolateral column–visceral info)
- cranial Nn (VII, IX, X–from deep viscera)
Autonomic NT
Cholinergics (Ach)
Adrenergics (NE, Epi)
Control Areas
Cell Bodies in pons/medulla and send axons to spinal cord
Outlying ganglia
-ganglia out near target organs
abdominal and pelvic organs
Functions of sympathetic NS
- reg temp
- reg blood flow to Mm
- reg vision
- Salivary glands-thicker saliva
- Reg HR and contractility
- Reg Air exchange
- Reg GI, bowel, bladder
- Reg metab
different receptors on different tissues allow____
sympathetic NT to act differently
Synergistic Effects
SNS/PNS
- HR
- Bowel/Bladder
- Iris of eye
2 components of ANS
Sympathetic NS
Parasympathetic NS
Sympathetic NS
- thoracolumbar outflow
- fight/flight
- uses energy
4 receptors of ANS
- Mechanoreceptors (pressure/stretch)
- chemoreceptors (chemical environment)
- nociceptors (stretch/ischemia)
- thermoreceptors (hypothalamus/cutaneous temp)
central regulation of visceral function
- control areas (medulla/pons)
- modulatory areas (hypothal, thal, limbic)
Modulatory areas
- cell bodies in thal, hypothal, limbic
- send axons down to pons/medulla
Horner’s Syndrome
- Damage to cervical paravertebral ganglia
- -drooping eyelid, pupil constriction, flushing, abscense of sweating (no sympathetic work)
Cell bodies of preganglionic neurons in___
PNS
- Nuclei of cranial Nn (III, VII, IX, X)
- lateral horn of spinal cord from S2-S4
–Sympathetic NS–
Control cell bodies:
Control Axons:
Bodies: pons/medulla
Axons: descending spinal cord in lateral columns
HR/contractility
Symp: increase HR/contractility
Parasymp: decrease HR, no effect on contractility
Vision
Symp: dilate pupil, elevate eyelid, increase far vision
Parasymp: constrict pupil, increase convexity of lens, increase near vision
Cell bodies of postganglionic neurons in____
PNS
peripheral ganglia near organs they innervate
Damage to spinal region
only affect PNS if in S2-S4
Ant:
Post:
Lat:
Ant: motor
Post: Sensory
Lat: autonomic
Air Exchange
Symp: dilate airways
Parasymp: constrict airways
Cell bodies of preganlionic neurons in____
SNS
Lateral horn of spinal cord T1-L2
Salivary Glands
Symp: increase thickness
Parasymp: thin saliva (start of digestion)
Adrenergics
Preganglionic symp: (NE, to target organ)
Adrenal Medulla: (Epi, into bloodstream)
Post-ganglionic
- cell bodies in peripheral ganglion
- send axons from ganglion to visceral organ
Syncope
- Vasopressor Syncope
- —sudden emotion causes dilation of vessels and decreased BP
- Vasovagal syncope
- —Above plus PNS slows HR
- Postural (orthostatic) hypotension
- —ANS malfunction and doesn’t constrict venules upon rising
-Decreased CO–>decreased BP
If peripheral nerve damaged:
- only sympathetic system effected
- –>decreased tissue health, change in Mm strength and sensation
Autonomic NS: peripheral pathway
2 neurons
Autonomic NS: Termination
everything but Mm fibers
Autonomic NS: control
-unconscious
Autonomic NS: myelination and neuron size
preganglionic: myelinated
Postganglionic: not
Size: pregang=B, postgang=C
Cell bodies of postganglionic neurons in____
SNS
paravertebral ganglia
outlying ganglia
adrenal medulla
paravertebral ganglia
- string of pearls all up and down spinal cord
- symp neurons only exit at levels T1-L2
Preganglionic
- cell bodies in brain stem/spinal cord
- send axons outside to ganglion
tests of Autonomic function
-checking for orthostatic hypotension
GI, Bowel, Bladder
symp: decrease activity
Parasymp: empty bowel/bladder, increase peristalsis
body temp
Symp: increase/decrease (metab, shunt, sweat)
Parasymp: n/a
Unopposed effects
SNS/PNS
SNS: blood vessels, sweat glands, contractility of heart
PNS: lense of eye, external genitalia
Somatic NS: Peripheral Pathway
1 neuron
Somatic NS: termination
skeletal muscle fibers
Somatic NS: control
conscious control
Somatic NS: myelination and neuron size
thick myelin (A-alpha Size: large, A-Alpha
Parasympathetic NS
- craniosacral outflow
- rest, digest, feed, breed
- stores energy
Central axons for sacral segments____
PNS
descending in lateral column of spinal cord
Efferent pathways
- Sympathetic System (pre/postganglionic)
- Parasymp (pre/postganglionic)
Connections of visceral afferents in spinal Nn
- to brainstem, hypothal, thal (anterolat column; autoresponse to pain
- somatosensory nociception afferents (referred pain)
- visceral efferents (inhibit organ function to protect)
- Somatic efferents (muscle guarding to protect organ)
