Nervous System 114-129 Flashcards
Gray matter has which three types of horns…
Dorsal posterior horns-sensory fibers and interneurons
Ventral anterior horns-nerve cell bodies of motor neurons
Lateral horn-in thoracic and lumbar regions, nerve cell bodies of sympathetic system
The spinal cord is elongated mass of nervous tissue that transmits electrical signals between the periphery and the brain. The two major functions of the SC are…
Carries nerve impulses and Center for spinal reflexes
*** Lateral horn
Located in thoracic and lumbar regions, nerve cell bodies of sympathetic ns
***dorsal root
Sensory fibers pass through
***ventral root
Motor fibers pass through
Knee-jerk reflexes use _______ neurons.
Withdrawal reflexes use ________ neurons.
2;3
This system is part of the PNS that operates continuously without conscious thought.
Autonomic nervous system
Visceral efferent nerve fibers associated with the ganglia make up the…
Autonomic n.s.
Sympathetic vs parasympathetic
SNS primarily prepares the body for energy expending stressful or emergency situations fight or flight (shoot)
Parasympathetic ns- functions under normal everyday activities and to return the body to normal after sympathetic discharge (point)
All Autonomic fibers are ________ fibers.
Afferent or efferent
Efferent motor fibers
Always two neurons, a preganglionic fiber and a postganglionic fiber
White rami vs gray rami
White rami-preganglionic fibers are short, myelinated
Gray rami-postganglionic fibers are long, unmylinated
The parasympathetic division is also known as…
Craniosacral division
Paras. Division
Preganglionic fibers-
Postganglionic fibers-
Pre-long, myelinated
Post-short, unmyelinated (ganglion -> organ)
Parasympathetic fibers are carried in what nerves from the brain?
Three, seven, nine, ten, S2-S4
Autonomic neurotransmitters
Preganglionic of paras. and sym divisions, postganglionic of parasympathetic division all secrete Ach acetylcholine. They are cholinergic fibers***
The postganglionic fibers secrete _______ and are ________.
Norepinephrine; adrenergic
***BV only have ________ intervention.
Sympathetic
Digestive system is controlled primarily by _______ system.
Parasympathetic
***Ach (Acetylcholine) binds to what two receptor tyes
Mucarinic receptors- located at ends of all postg. paras. fibers.. Responses are excitatory and slow
Nicotinic receptors- occurs synapses b/w pregang. and postga. neurons of both divisions
NE and Epi combine with ______ receptors.
Adrenergic.
NE excitatory
Epi inhibitory
Enteric n.s. controls the ____________ __________ activity.
Gastrointestinal tract; has as many neurons as all of the spinal cord
The PNS includes the ______ nerves and the _______ nerves.
Cranial and spinal
Cranial and spinal nerves that connect the CNS to skin and skeletal muscle are part of the…
Somatic nervous system (of the peripheral nervous system)
Concious activities
Nerve fibers connecting the CNS to the viscera (internal organs) and are involved with unconscious activities are part of the…
Autonomic n.s.
This is all part of the peripheral nervous system
