NeuroAnatomy_Unit3_Lec2 Flashcards
Somatic nervous system
Under voluntary control
Sensory neurons- receptors from the body walls and limbs (exteroceptors)
Motor neurons- innervate skeletal muscles
Autonomic nervous system
Involuntary system
Sensory neurons- interoceptors
output- regulates cardiac activity, smooth muscle, glandular tissues, and visceral reflexes
Pain afferent autonomic neurons
- ) what do they monitor
- ) where are the cell bodies
- ) how do they get to the brain
respond to internal stimuli such as excessive stretching, distension of the wall of the GI tract, lack of Oxygen and nutrients to cardiac muscle
cell bodies are in the dorsal root ganglia
Their afferent fibers are distributed with sympathetic motor fibers and travel to the brain.
Non-Pain afferent autonomic neurons
- ) what do they monitor
- ) where are the cell bodies
- ) how do they get to the brain
continually send signals to the brain, motoring and integrating visceral activities
cell bodies are in special nuclei in the brain
They are distributed with parasympathetic motor fibers (Their processes travel either with cranial nerves or in specific tracts within the spinal cord)
Referred pain
When pain is felt at a site other than that of the actual anatomical location of the problem.
Due to the visceral afferent fiber cell bodies being located in the same area as the somatic afferent fibers (which supply the dermatomes)
Sympathetic nervous system
fight or flight
Parasympathetic nervous system
rest and digest
Areas that receive only sympathetic input (most receive both sympathetic and parasympathetic)
cutaneous blood vessels, sweat glands, and hair shafts
Preganglionic neuron
Myelinated
Cell body-in the brain or spinal cord
axon- exits the CNS as part of a spinal or cranial nerve
Postganglionic neuron
Un-myelinated
cell body- in the PNS (cell body located in a Ganglion)
axon- terminates in a visceral organ
2 types of sympathetic ganglia
Paravertebral ganglia (lie in a row on either side of the vertebral column)
Prevertebral ganglia (lie anterior to the vertebral column, cervical level)
Parasympathetic ganglia
most are located close or within the wall of a visceral organ
Preganglionic Sympathetic Neurons
form a column in the intermedio-lateral horn (T1-L2), send their axons through the anterior/ventral root of the spinal cord.
white ramus communicant
the pathway from the intervertebral foramina to the sympathetic ganglia
found at every level btw T1-L2
T1-T4 sympathetic preganglionic neurons synapse in
Synapse in the paravertebral ganglia, and their postganglionic neurons supply the heart, lungs and smooth muscles of the bronchi
T5-L2 sympathetic preganglionic nuerons synapse in
the prevertebral ganglia
T5-T9
greater thoracic splachnic nerve
- synapses in the the celiac ganglion
- stomach spleen liver, kidney and small intestine
T10-T11
lesser thoracic splachnic nerve
- synapses in the mesenteric ganglion
- innervates the small intestine and proximal colon
T12
least thoracic splachnic nerve
-innervates kidneys and ureter
L1-L4
lumbar splachnic nerve
- synapse in the inferior mesenteric ganglion
- innervates distal colon, rectum, urinary bladder, and genital organs
Cell bodies of the preganglionic parasympathetic neurons are found in
the nuclei in the brainstem
4 pairs of parasympathetic ganglia
ciliary ganglia
pterygopalatine ganglia
submandibular ganglia
otic ganglia
ciliary ganglia
postganglionic axons innervate smooth muscle fibers in the eye
pterygopalatine ganglia
postganglionic axons innervate the palate, pharynx, nasal mucosa and lacrimal glands
submandibular ganglia
postganglionic axons innervate salivary glands (submandibular and sublingual)
otic ganglia
postganglionic axons innervate salivary glands (parotid)
ganglia associated with the vagus nerve
carry 80% of the cranio-sacral outflow
pelvic splanchnic nerves
S2-S4, synapse in ganglia close to or within the organs they innervate (colon, ureters, urinary bladder, and reproductive organs)
