Autonomics: Lecture 5 Flashcards
Autonomic Nervous System
Involuntary or unconscious control of two neuron pathway
Yes ganglia
Sensory input from general and visceral/Motor output to cardiac, smooth muscles, & glands
Excited with Ach & norepinephrine
Thin, sometimes myelinated axons
Somatic Nervous System
Voluntary or subconscious control of single neuron pathway
No ganglia
Sensory input/Motor output to skeletal muscles
Excites with Ach only
Thick, myelinated axons
Is White mater/rami or gray mater/rami myelinated?
White mater/rami
How does the cardiac plexus function?
Sympathetically- Increases HR and BP
Parasympathetically- Decreases HR
How does the pulmonary plexus function?
Sympathetically- Bronchodilation
Parasympathetically- Bronchoconstriction & increased secretion from mucous glands of bronchial tree
How does the Esophageal plexus function?
Parasympathetically- Controls swallowing reflex
How does the abdominal aortic plexus function?
Autonomic control of digestion
*Consists of celiac, superior mesenteric, and inferior mesenteric plexuses
How does the hypogastric plexus function?
Autonomic control of urinary and reproductive function
Describe the characteristics of the neural pathways of Parasympathetic neurons
Long preganglionic axon, Ach release only, short postganglionic axon
*No branching
Describe the characteristics of the neural pathways of Sympathetic neurons
Short preganglionic axon with branching, Ach & Norepinephrine release, long postganglionic axon with branching
What are the 4 areas of the CNS autonomic control area and what does each control?
Cerebrum- Conscious activities affect hypothalamus ANS control
Hypothalamus- Integration & command center for ANS (visceral) functions (emotions)
Brainstem- Contains major ANS reflex center
Spinal Cord- Contains ANS reflex centers for defecation & urination
What region of the spinal cord are the Sympathetic Preganglionic neuron cell bodies housed?
Lateral horn of T1-L2
Why does the sympathetic trunk look like a string of beads?
The “string” is composed of bundles of axons
The “beads” are the sympathetic trunk ganglion
What do white rami do and where are they located?
Carry preganglionic sympathetic axons from T1-L2 spinal nerves to the sympathetic trunk
Myelinated
What do gray rami do and where are they located?
Carry postganglionic sympathetic axons from the sympathetic trunk to the spinal nerve
Unmyelinated
Connect all spinal nerves to disperse sympathetic information to all parts of the body
What are the characteristics of the Splanchnic nerve?
Composed of preganglionic sympathetic axons
Run anteriorly to sympathetic trunk to most abdominal viscera
Terminate in prevertebral ganglia
Sympathetic postganglionic axons extend from these ganglia and innervate many abdominal organs
What are the routes a sympathetic signal can take?
Spinal nerve->White rami->A, B, C, or D A) Ascend then synapse B) Synapse at level of entry C) Descend then synapse D) Pass through without synapsing into abdominopelvic splanchnic nerve for innervation of abdominopelvic viscera only
The parasympathetic division is also termed the _____?
Craniosacral division
What are the cranial nerve contributions to the parasympathetic division?
Oculomotor, Facial, Glossopharyngeal, & Vagus
What ganglion does the oculomotor nerve go to and what parasympathetic activities does it control?
Ciliary ganglion
Controls pupil constriction & ciliary muscles of lens for accommodation (near vision)
What ganglion does the facial nerve go to and what parasympathetic activities does it control?
Pterygopalatine Ganglion
Controls lacrimal gland (tear activity), nasal cavity, & oral cavity
Submandibular Ganglion
Controls submandibular and sublingual glands (saliva)
What ganglion does the Glossopharyngeal nerve go to and what parasympathetic activities does it control?
Otic Ganglion
Controls Parotid gland (saliva)
What ganglion does the Vagus nerve go to and what parasympathetic activities does it control?
Multiple terminal and intramural ganglia
Heart- Decreases HR
Respiratory Organs- Decreases respiration
Bronchial Passages- Constricts, excites mucous production
Esophagus- Promotes swallowing and peristalsis
Abdominal Viscera- Promotes digestion
What are the caudal nerve contributions of the parasympathetic division?
Pelvic and Sacral Splanchnic Nerves from S2-S4
Preganglionic parasympathetic axons form superior and inferior hypogastric plexus, then travel to organs and synapse with ganglia close to, or in the walls of the organs
Areas of the body affected by Pelvic Splanchnic Nerve are _____?
Descending/sigmoid colon, rectum, most reproductive organs, urinary bladder, distal ureters, & erection
