Anatomy 7.1 Flashcards
How does the CNS learn how to control movement of the body more efficiently?
With practice
CNS
Brain and spinal cord (1-2 cranial nerves)
PNS
All other nerves
What sensory receptor is part of the deep tendon reflex?
Muscle spindle
How do we assess cutaneous sensation in clinical examination?
Cotton ball test
Sharp end test
Afferent types
Sight and sound
Vestibular (where head is in space)
Muscle spindle and GTO
Nociception
Temp
Skin mechanoreceptors
What are the type of skin mechanoreceptors?
Merkel discs
Ruffini corpuscles
Meissner corpuscles
Lamellar corpuscles
Efferent types
Muscular force
Muscular endurance
Muscular timing
Accuracy of motion
Coordination
Myotome
Muscle tissue innervated by a single spinal nerve
Dermatome
Skin innervated by a single spinal nerve
Cervical enlargement
Larger portion due to more nerves running through due to UE
Lumbosacral enlargement
Larger portion due to more nerves running through due to LE
Where is the cervical enlargement?
C5-T1
Where is the lumbosacral enlargement?
L2-S3
What is the conus medullaris?
End of the spinal cord
Where is the conus medullaris?
L1-L2
What branches out of the conus medullaris?
Cauda equina (lumbar, sacral, coccygeal nerves)
How do spinal nerves come out of the skull?
Through the foramen magnum
How do spinal nerves exit in the cervical region?
Above the vertebrae
How do the spinal nerves exit from thoracic and down?
Below the vertebrae
How many spinal nerves are in the cervical region?
8
How many spinal nerves are in the thoracic region?
12
How many spinal nerves are in the lumbar region?
5
How many spinal nerves are in the sacral region?
5
How many spinal nerves are in the coccyx region?
1
Where is white matter the greatest?
Cervical (decreases as you move down)
Where is gray matter the greatest?
Sacral (decreases as you move up)
White matter
Axons
Gray matter
Cell bodies
Why is white matter greatest at the cervical region?
Because more nerves are innervating it and less nerves innervate as you move down
Why is gray matter greatest in the sacral?
More muscle control in LE
Oligodendrocytes
Myelin produced in CNS
Schwann cells
Myelin produced in PNS
Where are the thickest portion of the lateral horns present?
Middle of the body
What muscles does the dorsal rami control?
Back and neck muscles
What muscles does the ventral rami control?
UE and LE
What does the dorsal horn control?
Sensory
What does the ventral horn control?
Motor
What does the lateral horn control?
Visceral autonomic (motor of organs)
What is the most superficial covering of the spinal cord?
Dura mater
What is the middle covering of the spinal cord?
Arachnoid mater
What is the deepest covering of the spinal cord?
Pia mater
Is the cauda equina a component of the PNS or CNS?
CNS
What does lose somatic afferent neurons equal?
Hypoactive
What does lose descending inhibition with brain or spinal cord injury equal?
Hyperactive
Where do the axons of somatic efferent neurons pass through and where do their cell bodies reside within?
Ventral root
Gray matter of spinal cord
Where is the cell body of the lower motor neuron located?
Ventral horn
What sensory receptor is involved in the deep tendon reflex?
Muscle spindle
Upper motor neuron
Running from the cell body in the primary motor cortex in the brain to where it synapses in the ventral root in the spinal cord
Lower motor neuron
Runs from the cell body in the ventral root of the spinal cord to the muscle tissue
What does a neurological examination help you do?
Localize a lesion in the nervous system
Upper motor neuron lesion
Lesion that occurs before the upper motor neuron synapses with the cell body of the lower motor neuron in the central horn
Lower motor neuron lesion
Lesion that occurs anywhere from the cell body in the anterior horn to the synapse of the muscle tissue
What does upper motor neuron lesion cause?
Hyperreflexia
Hypertonicity
Spastic paresis
Positive ankle clonus
Positive babinski sign
What does lower motor neuron lesion cause?
Hyporeflexia
Hypotonicity
Flaccid paresis
Negative ankle clonus
Negative babinski sign
What does the lumbosacral trunk encompass?
Nerves L4-L5
