Autonomic & Peripheral Nervous System Flashcards
What division of the PNS is the Autonomic Nervous System a part of and what control do we have over it?
Visceral motor of PNS; Under involuntary control
How are visceral motor neurons structured?
Two motor neurons run b/w the spinal cord and target tissue. The preganglionic and post ganglionic neurons synapse within an autonomic ganglion.
What are the 2 divisions of the ANS? What are the functions?
Parasympathetic (Rest & Digest) and Sympathetic (Fight or Flight)
Where does the parasympathetic division come out of?
Exits from spinal cord and sacral spinal nerves
Where does the sympathetic division come out of?
Exits from thoracic and lumbar regions (widespread)
What NT are released in the sympathetic pathway? Where?
ACh: synapse with autonomic ganglion
Norepinephrine: synapse b/w postganglionic axon and tissue
What NT are released in the parasympathetic pathway?
ACh
What are the characteristics of the ganglion in the Parasympathetic pathway?
Preganglionic axon= Long
Postganglionic axon= Short
Where is the autonomic ganglion in the parasympathetic pathway?
Near or within target tissue
What cranial Nerve is important in the parasympathetic pathway? Why?
The Vagus nerve is important in brining about the typical rest and digest activities in visceral muscle and glands
What are the characteristics of the ganglion in the sympathetic pathway?
Preganglionic axon= Short
Postganglionic axon= Long
Where is the autonomic ganglion in the sympathetic pathway?
Near spinal cord
What is the sympathetic trunk ganglia?
Expansions of sympathetic trunk where pre- and postganglionic neurons synapse
What is the sympathetic trunk?
Runs parallel to spinal cord; pathway for neurons of sympathetic division
What does the Adrenal Medualla do? Where is it found?
Sits on top of both kidneys; Specialized sympathetic ganglion that contain norepinephrine and epinephrine that produce widespread excitatory responses.
Which structures of the PNS allow it to communicate with the CNS?
Spinal nerves and cranial nerves
How many pairs of spinal nerves are there? Where are they found?
31 total pairs
- 8 cervical
- 12 thoracic
- 5 lumbar
- 5 scaral
- 1 coccygeal
What is a dermatome?
Map showing the relationship b/w sensory receptors of the skin and the spinal nerves
Where does damage occur in a paraplegia? What is the result?
B/w T1 & L2; Loss of feeling/motor functions of legs
Where does damage occur in a quadriplegia? What is the result?
Damage above T1; Loss of feeling/motor functions of all 4 limbs
What are the classifications of sensory receptors?
Mechanoreceptors, Thermoreceptors, Chemoreceptors, Photoreceptors, Nociceptors
What is a Meissner’s Corpuscle? Where is it located?
Mechanoreceptor that responds to light touch; Located in dermal papillae of hairless skin
What is a Pacinian Corpuscle? Where is it located?
Mechanoreceptor that responds to deep pressure; Located in dermis and hypodermis
What are Ruffini endings? Where are they located?
Mechanoreceptors that adapt slowly so they are able to monitor continuous pressure; Located in dermis and hypodermis
What is a proprioceptor? Why are they important?
Mechanoreceptors that are encapsulated nerve endings that monitor stretch in their locomotory organs; Cerebellum uses information to determine where are body parts are in space
What is a root hair plexus?
Mechanoreceptor that wraps around the hair follicle to respond to movement of the hair
What is a nociceptor? What kind of stimulus does it respond too?
Free nerve ending that responds to mechanical, thermal, or chemical stimuli; Pain is the emotional way our brain interprets the stimulus
How is an itch receptor different from a nonciceptor?
Pain elicits a withdrawal reflex, itch elicits a scratch reflex
What does an itch receptor respond too?
Inflammatory chemicals
What are the broad steps of the gustatory pathway?
Chemoreceptor of taste bud –> spinal cord –> thalamus –> gustatory cortex in insula
What do the spinal nerves split into?
Dorsal Ramus and Ventral Ramus
What is a plexus? What are they made of? What are the different nerve plexuses?
A plexus is a network of nerves that supply specefic regions of the body; Made of ventral rami of all spinal nerves except thoracic region; Cervical, Brachial, Lumbar, Sacral
What is the cervical plexus? What would damage here cause?
Innervated back of neck and diaphragm; Damage can impair breathing
What is the Brachial plexus?
Innervated upper limbs
What is the Lumbar plexus?
Innervates anterior region of lower limb
What is the Sacral plexus?
Innervated posterior region of lower limbs
What is the sciatic nerve formed from?
Sacral plexus
What does polio do to the body? What is postpolio syndrome?
Virus that targets motor neurons; Surviving neurons extend axonal branches to muscle missing innervation, but these neurons are exerted and lose function
