Efferent Division of Nervous System Flashcards
The efferent division consists of all the ____ neurons in the PNS
MOTOR
The efferent division can be subdivided into..
the somatic motor
and
autonomic motor divisions
The SOMATIC MOTOR division consists of motor neurons that lead to….
SKELETAL MUSCLES
the SOMATIC DIVISION is under what type of CONTROL?
VOLUNTARY CONTROL
at neuromuscular junctions, SOMATIC MOTOR NEURONS always release ____, which acts in an ____ matter
ACh; EXCITATORY MANNER
Where in the body does inhibition of skeletal muscle contraction take place?
INHIBITION of skeletal muscles occurs in the CNS, not at the effector
How many neurons run from the CNS to an individual SKELETON MUSCLES FIBER (somatic division)?
a SINGLE NEURON
the AUTONOMIC MOTOR DIVISION consists of motor neurons that lead to:
smooth muscle, cardiac muscle, and glands
the AUTONOMIC MOTOR DIVISION is under what type of control?
INVOLUNTARY CONTROL
What neurotransmitters are used in the AUTONOMIC MOTOR DIVISION?
ACh and Norepinephrine (NE); both can have either an excitatory or inhibitory effect
how many neurons run from the CNS to individual portions of the AUTONOMIC EFFECTORS?
TWO NEURONS - A PREGANGLIONIC NEURON AND POSTGANGLIONIC NEURON
DUAL INNERVATION
most autonomic effectors receive sets of sympathetic and parasympathetic neurons — one subdivision excites while the other inhibits at the EFFECTOR, not the CNS
What is similar about the sympathetic and parasympathetic motor divisions?
both consists of motor neurons that lead to smooth muscle, cardiac muscle, or glands
both divisions are under INVOLUNTARY CONTROL
both usually have a pathway consisting of preganglionic and postganglionic neurons
Key difference between sympathetic and parasympathetic divisions
SYMPATHETIC divisions dominate under FIGHT OR FLIGHT situations
PARASYMPATHETIC dominates under REST AND DIGEST situation
Origin of preganglionic neurons in the sympathetic and parasympathetic divisions
SYMPATHETIC - found in the thoracolumbar region
PARASYMPATHETIC - found in the craniosacral region
know specifics? slide 8
most SYMPATHETIC GANGLIA are located:
NEAR THE VERTABRAL COLUMN
This means that most PREGANGLIONIC neurons are relatively SHORT and…
the POSTSYNAPTIC neurons are relatively LONG
most PARASYMPATHETCI GANGLIA are located:
NEAR OR WITHIN THE EFFECTOR
this means that most PREGANGLIONIC neurons tend to be relatively LONG AND…
POSTSYNAPTIC neurons are relatively SHORT
a single preganglionic neuron in the SYMPATHETIC division may display a great deal of:
Divergence
One preganlionic diverges to many postganglionic neuron
Since the SYMPATHETIC DIVISION can have HIGH DIVERGENCE, when the body is under sympathetic dominance, the EFFECTS ON THE BODY tend to be
widespread
PARASYMPATHETIC EFFECTS tend to be more LOCALIZED because:
they lack divergence
Cholinergic
neurons that release Ach
Adrenergic
neurons that release NE
ALL PREGANGLIONIC neurons of both the SYMP. AND PARASYMP. divisions are…
CHOLINGERGIC (RELEASE ACH)
ALL POSTGANGLIONIC neurons of the PARASYMP. are…
CHOLINERGIC (RELEASE ACH)
