Johnson 1 Flashcards
CNS is composed of…
Brain and Spinal Cord
Convey information from receptors to the central nervous system
Afferent Fibers
Convey information from the central nervous system to effectors (muscles and glands)
Efferent Fibers
Efferent fibers go to…
- Somatic Nervous System
- Autonomic Nervous System
Conveys information
from the CNS to Skeletal Muscles
Somatic Nervous System
Conveys information from the CNS to smooth muscle, cardiac muscle, and glands.
Autonomic Nervous System
Autonomic Nervous System consists of…
- Sympathetic
- Parasympathetic
(Thoraco-lumbar) Nervous System
Sympathetic
(Cranio-sacral) Nervous System
Parasympathetic
There are ___ pairs of spinal nerves and ___ pairs of cranial nerves.
- 31
- 12
The functional unit of the nervous system is the _____.
Neuron
A _____ is the nerve cell body and all of its processes.
Neuron
A ______ consists of an axon covered by a sheath (neurolemma). Axons may be myelinated or unmyelinated. In the peripheral nervous system, the sheaths are formed by Schwann cells.
Nerve fiber
A _____ is a functional contact between neurons.
Synapse
In a ______, a neurotransmitter is released from the axonal ending of one neuron into a cleft and acts on receptors on the membrane surface of the second neuron.
Synapse
A collection of nerve cell bodies WITHIN the CNS
Nucleus
A collection of nerve cell bodies OUTSIDE the CNS (i.e., in the PNS)
Ganglion
A _____ is a bundle of nerve fibers held together by connective tissue and located outside the CNS. It may contain more than one type of nerve fiber, and a nerve fiber may lie in several different nerves throughout its course.
Nerve
Can a nerve fiber travel in more than one nerve?
Yes
There are only ____ basic types of nerve fibers in the peripheral nervous system.
four
Name the four basic types of nerve fibers in the PNS.
Afferent: afferent
Efferent: efferent to skeletal muscle, preganglionic efferent (autonomic), postganglionic efferent (autonomic)
Neurons of ANS innervate:
- All smooth muscle
- All cardiac muscle
- All glands
Primarily the domain of cranial nerves
Head
Domain of spinal nerves; From skin externally to layer lining body wall internally (includes extremities)
Body wall
a. Thorax
b. Abdomen
c. Pelvis
Viscera
31 pairs of spinal nerves
Cervical: 8 pairs Thoracic: 12 pairs Lumbar: 5 pairs Sacral: 5 pairs Coccygeal: 1 pair
Which fibers are necessary for the body wall and extremities?
- Afferent fiber
- Efferent to skeletal muscle
- Preganglionic and postganglionic efferent fibers
For the body wall and extremities, where is the location of the afferent fibers?
Dorsal root ganglion
For the body wall and extremities, where is the location of the efferent to skeletal muscle fibers?
Ventral gray horn
For the body wall and extremities, where is the location of the preganglionic efferent fibers?
Intermediolateral cell column
For the body wall and extremities, where is the location of the postganglionic efferent fibers?
Sympathetic trunk
Nerve fiber types found in NERVES supplying a skeletal muscle
- Efferent to skeletal muscle
- Afferent
- Postganglionic efferent
Nerve fiber types found in NERVES supplying skin (cutaneous) or a joint (articular)
- Afferent
2. Postganglionic efferent
A ______ is the area of skin supplied by afferent fibers in the dorsal root ganglion of a single spinal nerve
Dermatome
In many regions of the body, major branches of adjacent ventral primary rami join in networks called ______. Note that dorsal primary rami always remain segmental.
plexuses
