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Chapter 13—A&P Part 2

Terms in this set (57)

Grey matter is
deep to white matter in the spinal cord
Grey matter is also
butterfly shaped
Nuclei in the central nervous system are?
Functional groupings of neurons, or cell bodies
What is grey matter?
bilaterally symmetric areas composed of neuron cell bodies, neuroglia and unmyelinated axons
What is grey matter organized into?
horns
What does each grey matter contain?
one or more nuclei
What do sensory nuclei do?
Receive information from sensory receptors
What do motor nuclei do?
send commands to peripheral effectors
What do anterior/ventral horns contain?
somatic motor nuclei
What is the function somatic motor nuclei?
delivering motor commands to somatic effectors (skeletal muscle)
What do lateral grey horns contain?
visceral motor nuclei
Where are lateral grey horns found?
only in thoracic and upper lumbar segments of the spinal cord
What is the function of visceral motor nuclei?
deliver motor commands to visceral effectors
What are visceral effectors?
cardiac muscle, smooth muscle, adipose tissue and glands
What do posterior/dorsal grey horns contain?
somatic sensory nuclei and visceral sensory nuclei
What is the function of somatic SENSORY nuclei?
receiving somatic sensory information from peripheral receptors (general senses)
What is the function of visceral SENSORY nuclei?
receives visceral sensory information from peripheral receptors (pain, pressure or vibration from internal organs)
What is the grey commissure?
area of crossover between the grey matter on the left side and the grey matter on the right side of the spinal cord
What is the central canal?
space within the grey commissure that is lined with ependymal cells and filled with cerebrospinal fluid
White matter is
superficial to grey matter
What is white matter?
Bilaterally symmetric areas where myelinated and unmyelinated axons are conducting action potentials up and down the spinal cord
What is white matter organized into?
anterior/ventral, lateral, and posterior/dorsal white columns or funiculi
What is the anterior white commissure?
connects the two anterior white columns and axons cross over at this point
What does each column contain?
one or more tracts
What are tracts?
bundles of axons contained within the white columns
Each specific tract relays
the same type of information in the same direction
What are ascending tracts?
ascending (sensory) tracts are conducting action potentials toward the brain
What are descending tract?
Descending (motor) tracts conduct action potentials away from the brain
What is the purpose of grey matter?
information processing
Where do spinal nerves begin?
where dorsal and ventral roots merge
Where are spinal nerves found?
in pairs, emerging from each side of a spinal cord segment
Which nervous system are spinal nerves apart of?
the peripheral nervous system
How are spinal nerves classified?
they are mixed; carrying both afferent and efferent fibers
How do spinal nerves C1-C7 emerge?
above same name vertebrae
How does spinal nerve C8 emerge?
Below vertebrae C7
How do spinal nerves T1-Co1 emerge?
below same name vertebrae
What is the function of connective tissue around the spinal nerves?
support the nerve and contain blood supply for the nerve
What are the layers of connective tissue around a spinal nerve?
Epineurium, perineurium, endoneurium
What is epineurium?
the outermost layer of spinal nerve CT and is made of a dense network of collagen fibers that covers the outside of the nerve
What is the perineurium?
middle layer of spinal nerve CT and surrounds bundles of axons called fasicles
What is endoneurium?
innermost layer that surrounds each individual axon
What is the function of the dorsal root of a spinal nerve?
bringing sensory information into the spinal cord
What does the dorsal root ganglion contain?
cell bodies of unipolar sensory neurons surrounded by satellite cells
What is the function of the ventral root of the spinal nerve?
brings motor commands from the spinal cord and toward effector
What does the ventral root contain?
axons of motor neurons
What do spinal nerves diverge into?
dorsal and ventral rami
What control/information does the dorsal ramus have?
somatic SENSORY information from the skin and skeletal muscles of the back
What control/information does the dorsal ramus have?
somatic MOTOR control of the skeletal muscles of the back?
What control/information does the dorsal ramus have?
visceral MOTOR control of smooth muscles and glands of the back
What control/information does the ventral ramus have?
somatic SENSORY information from the skin and muscles of the ventrolateral body wall and limbs
What control/information does the ventral ramus have?
somatic MOTOR control of skeletal muscles of the ventrolateral body wall and limbs
What control/information does the ventral ramus have?
visceral MOTOR control of smooth muscles, glands and adipose of the ventrolateral body wall and limbs
Where does the white rami communicans exist?
only between T2-T12
What does the white rami communicans (white ramus) control/receive information from?
visceral SENSORY information via the sympathetic nerves from visceral organs
What does the white rami communicans (white ramus) control/receive information from?
visceral MOTOR control visceral effectors in the visceral organs
What does the grey rami communicans (grey ramus) control/receive information from?
visceral MOTOR control of effectors
Where are the grey rami communicans (grey ramus) located?
in the back via the dorsal ramus/ in the ventrolateral body wall and limbs via the ventral ramus
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