Lecture 18 Flashcards
The somatic nervous system is divided into what 2 groups
The visceral nervous system is divided into what 4 groups
Visceral afferent components- what are the 4 interoceptors?
Interoceptors
- chemoreceptors
- baroreceptors (blood pressure)
- visceral mechanoreceptors (bladder fullness)
- visceral nociceptors
Visceral afferent components- What do the sensory receptors associate with to transmit signals to the CNS
Peripheral processes of pseudounipolar sensory neurons
The anterior roots of spinal nerves carry what 2 things
Somatic multipolar motor neurons (skeletal muscle), autonomic multipolar motor neurons (cardiac/ smooth/ glands)
Pseudounipolar sensory neurons exit where
Posterior root ganglion
For visceral efferent (motor) neurons where is the synapse
Between CNS and target tissue
What is the somatic nervous system composed of
What is the visceral nervous system composed of
Somatic efferent (SE): always a___________ from the CNS to the target
Single neuron pathway
Autonomic efferent (VE): both SNS and PSNS utilize a _____________- to reach target
Two-neuron pathway with a ganglion
Somatic and visceral afferent (SA, VA): always a ___________
Single neuron pathway from the periphery to the CNS
What are the 2 divisions of the visceral motor system
Sympathetic/ parasympathetic
Parasympathetic nervous system- Length of preganglionic axons and postganglionic axons?
Pre- Long
Post- Short
PSNS- ganglia are located where
In or near wall of target organ
PSNS- low ratio of what
Post- to pre-ganglionic neurons (localized effects)
SNS- Length of preganglionic axons and postganglionic axons
Pre- short
Post- long
SNS- Where are the ganglia located
Close to CNS
SNS- high ratio of what
Post to preganglionic neurons
Which is which
Parasympathetic- where are preganglionic cell bodies
Brainstem nuclei and S2-S4 spinal cord segments
Parasympathetic- where are the postganglionic cell bodies
In intrinsic ganglia (in or near wall of target organ)
Sympathetic- Preganglionic cell bodies are located where
T1-L2 spinal cord segments
Sympathetic- Postganglionic cell bodies are located where
Paravertebral or prevertebral ganglia
Where is the only place we’ll ever have preganglionic sympathetic neurons
T1-L2
What is another term for the sympathetic division
Thoracolumbar system
What is another term for parasympathetic division
Craniosacral
Most organs receive _______ innervation from both SNS/PSNS (2 exceptions)
Dual
What are the structures that receive ONLY SNS innervation
-Visceral structures of the body wall (arrector pili, sweat/sebaceous glands, vascular smooth muscle)
- Suprarenal (adrenal) gland
PSNS- Cranial nerves 3/7/9 carry what and originate from where
Preganglionic parasympathetic axons, brainstem nuclei
PSNS- What are the targets of the postganglionic neuronal cell bodies
Pupillary constriction/ lens accommodation
Cranial nerve 10 (vagus)- Where are the preganglionic neuronal cell bodies & postganglionic neuronal cell bodies
Pregang: Brainstem nucleus
Postgang: intrinsic ganglia in or near the walls of the target organs
What are the target organs for CN 10
Visceral organs of the thoracic and abdominal cavities/ transverse colon
Identify arrow
Preganglionic parasympathetic neuronal cell bodies (sacral portion)
Where are the preganglionic parasympathetic neuronal cell bodies located in the sacral portion
S2-S4 within the intermediate zone of the spinal cord grey matter
Preganglionic axons originating from S2-S4 spinal cord segments travel as _______
Pelvic splanchnic nerves
Parasympathetic nervous system sacral portion- where are the postganglionic neuronal cell bodies/ what are the targets
Intrinsic ganglia in or near the walls of the target organs
Targets
- abdominal viscera beyond the distal 1/3 of the transverse colon (left colic flexure)
- pelvic viscera
Sympathetic nervous system- where are the preganglionic neuronal cell bodies
Sympathetic nervous system- what are the paravertebral ganglia
Sympathetic nervous system- where are the prevertebral ganglia
Sympathetic nervous system- what connect the paravertebral ganglia with anterior rami of spinal nerves
White and grey rami
Sympathetic nervous system- What is the entrance to the sympathetic chain
White rami
Sympathetic nervous system- What happens in the white rami
All preganglionic sympathetic axons enter the
sympathetic chain (coming from T1-L2)
Sympathetic nervous system- What happens in the grey rami
Some postganglionic sympathetic axons exit the sympathetic chain to rejoin the anterior rami of spinal nerves
Since preganglionic sympathetic cell bodies are only found at T1-L2 spinal cord segments, ________ are only present at T1-L2 vertebral levels
White rami
Since postganglionic sympathetic axons can exit the chain at any vertebral level, ________are found at all vertebral levels
Grey rami
White rami are always _______ to gray rami
Lateral
Sympathetic nervous system- If the target is in the body wall preganglionic axons travel in spinal nerves and synapse in __________
Paravertebral ganglion
Sympathetic nervous system- If the target is in the body wall POSTganglionic axons then rejoin the spinal nerve to travel to the __________
Body wall
Sympathetic nervous system- If the target is in the thoracic cavity preganglionic axons travel in spinal nerves and synapse in ____________
Paravertebral ganglion
Sympathetic nervous system- If the target is in the thoracic cavity POSTganglionic axons form ___________ to travel to the target in the thorax
Cardiopulmonary splanchnic nerves
SNS- If the target is in the abdominal or pelvic cavity preganglionic axons travel in spinal nerves; travel through the ___________; exit the sympathetic chain as abdominopelvic splanchnic nerves
Paravertebral ganglion without synapsing
SNS- If the target is in the abdominal or pelvic cavity- where do the preganglionic axons synapse
In prevertebral ganglion
SNS- If the target is in the abdominal or pelvic cavity- postganglionic axons follow ________ to reach target in abdomen or pelvis
Arteries (periarterial plexuses)
Targets in the body wall-
Targets in the thoracic cavity
Targets in the abdominal or pelvic cavity
What are the 3 types of splanchnic nerves and what to they carry
Pelvic- carry parasympathetic preganglionic axons
Cardiopulmonary- carry postganglionic sympathetics to heart and lungs
Abdominopelvic- carry preganglionic sympathetics
The posterior ramus carries sensory to ________ and motor to ________
Medial back, intrinsic back muscles
Visceral sensation- Non pain signal have what kind of receptors
Baroreceptors, chemoreceptors, visceral mechanoreceptors
Visceral sensation- Non pain signals travel back to the CNS via the ___________
Parasympathetic pathway (vagus nerve or pelvic splanchnic nerves), pseudounipolar neuron (cell body in inferior ganglion of CN X or posterior root ganglia of S2-S4)
Visceral sensation- Pain signal carried via
Visceral nociceptors
Visceral sensation- Nociceptors signal travel back to CNS via what pathway
