Lecture Exam #2 Review questions Flashcards
What are the 4 lobes of the brain?
Frontal
Temporal
Parietal
Occipital
Frontal Lobe
Temporal Lobe
Parietal Lobe
Occipital Lobe
What happens when the frontal lobe is lesioned?
What happens when the temporal lobe is lesioned?
What happens when the parietal lobe is lesioned?
What happens when the occipital lobe is lesioned?
What does the spinal region include?
Spinal cord
Dorsal and ventral roots
Spinal nerves
Meninges
Each segment of the cord is connected to a specific region of the body by axons traveling through a pair of _____.
Spinal nerves
Connections of nerve rootlets to the exterior of the cord indicate _____.
segments
In the cervical region, spinal nerves are found above the corresponding vertebrae except_____.
the eighth spinal nerve
horn processes sensory information
Dorsal horn
horn processes motor information
Ventral horn
horn processes autonomic information
lateral horn
the region of neural tissue where neuron cell bodies (somas) are concentrated
gray matter
the region of neural tissue where bundles of myelinated axons are concentrated
white matter
What are the names of the 3 connective tissue sheaths that the parallel bundles of axons that the peripheral nerves are made up called?
Endoneurium: Separates individual axons.
Perineurium: Surrounds fascicles.
Epineurium: Encloses the entire nerve trunk.
nerves that are mixed and include the sensory, autonomic, and motor axons
Somatic peripheral nerves
_____ branches that supply the skin and subcutaneous tissues; _____ branches that supply the muscles, tendons, and joints.
Cutaneous ; Muscular
What type of information do afferent neurons carry?
sensory
What type of information do efferent neurons carry?
motor
Sensory has _____ tracts; Motor has _____ tracts.
ascending; descending
Afferent axons _____; Efferent axons _____.
Ascend; Descend
What are the 4 nerve plexuses that the junctions of anterior rami form?
Cervical
Brachial
Lumbar
Sacral
a plexus that provides:
- cutaneous sensory information from the posterior scalp to the clavicle.
- innervates the anterior neck muscles and diaphragm
Cervical plexus
a plexus where:
the entire upper limb is innervated by the branches.
Brachial plexus
a plexus where:
the branches innervate the skin and muscles of the anterior and medial thigh.
Lumbar plexus
a plexus that:
innervates the posterior thigh and most of the leg and foot; contains parasympathetic axons
Sacral plexus
motor axons synapse with muscle fibers at
neuromuscular junctions
A motor neuron and all the skeletal muscle fibers innervated by its axon terminals
motor unit
What happens if there is peripheral motor nerve damage?
paralysis/paresis
What happens if there is peripheral sensory nerve damage?
anesthesia (numbness)/paresthesia (pins & needles)
Touch is categorized as
fine or crude
touch includes a variety of receptors and sub sensations
fine touch
touch is mediated by free endings throughout the skin
crude touch
Cutaneous receptors respond to
touch, pressure, vibration, stretch, noxious stimuli, and temperature
connect motor or sensory end-organs with the central nervous system (CNS)
Peripheral nerves
are used to diagnose radiculopathy and to determine the sensory level affected by spinal cord injury
dermatomes
For the limbs the two distinct distributions of sensory innervation are
peripheral nerve and dermatome
The Brachial Plexus starts at _____ and ends at _____.
C5; T1
The ventral rami of the thoracic nerves are usually called
intercostal nerves
a segmental structure that is attached to the spinal cord by a sensory dorsal root and a ventral motor root.
typical spinal nerve
Because the 5 rami of the brachial plexus sends no cutaneous branches to the pectoral region, what happens?
the supraclavicular branches of C3 and C4 descend in the front of the clavicle to the level of T2, closing the gap
nerves whose roots exit directly from the spinal cord
spinal nerves
region of the skin supplied by a single spinal nerve
dermatome
the cell bodies of the somatic motor neurons lie in this horn of spinal cord gray matter
Ventral root
cell bodies are found in the spinal ganglion. cell body axons divide into a central process and a peripheral process.
Dorsal root
the large branch of the spinal nerve that runs into the lateral and ventral body wall to innervate all the rest of that body segment’s muscles, bones, and skin.
Ventral rami
the small branch of the spinal nerve that passes dorsally to innervate that body segments intrinsic spinal muscles and overlying skin on the back.
Dorsal rami
What are nuclei considered?
gray matter
What are tracts considered?
white matter
Which column is medial?
fasciculus gracilis
Which column is lateral?
fasciculus cuneatus
Which column is responsible for the lower tract?
fasciculus gracilis
Which column is responsible for the upper tract?
fasciculus cuneatus
What are the 4 Somtosensory Conscious Pathways?
- Dorsal Column Upper Tract (Cuneatus)
- Dorsal Column Lower Tract (Gracilis)
- Anterior Spinothalamic Tract
- Lateral Spinothalamic Tract
What are the 2 Somtosensory Unconscious Pathways?
- Anterior Spinocerebellar Tract
- Posterior Spinocerebellar Tract
Somatosensory Conscious Pathways:
1st order neuron (DRG) >DR> 2nd order (medulla) neuron > 3rd order neuron (VP thalamus) > internal capsule > corona radiata > postcentral gyrus
Somatosensory (Dorsal Column Pathways):
1st order neuron > 2nd order neuron “decussate in medulla” > 3rd order neuron “VP thalamus” > Internal capsule > Corona radiata > Postcentral gyrus
Somatosensory Unconscious Pathways:
1st order neuron (DRG) > 2nd order neuron (DH) > Lateral column > peduncles (cerebellum)
Dorsal Column Pathway (Lower tract, fasciculus gracilis):
DRG (1st cell body)
DR
Fasciculus gracilis (first axon)
Nucleus gracilis (2nd cell body)
Medial lemniscus (second axon “decussate”)
VP thalamus (3rd cell body)
Internal capsule (third axon)
Corona radiate
Postcentral gyrus
Dorsal Column Pathway (Upper tract, fasciculus cuneatus):
DRG (1st cell body)
DR
Fasciculus cuneatus (first axon)
Nucleus cuneatus (2nd cell body)
Medial lemniscus (second axon “decussate”)
VP thalamus (3rd cell body)
Internal capsule (third axon)
Corona radiata
Postcentral gyrus
What type of sensations are the dorsal column tracts responsible for?
fine touch and proprioception
What type of sensations is the anterior spinothalamic tract responsible for?
crude touch and pressure
What type of sensations is the lateral spinothalamic tract responsible for?
pain and temperature
Anterior Spinothalamic Tract Pathway:
DRG > DR > DH > AST > VP Thalamus > Internal Capsule > Corona Radiata > Postcentral gyrus
Lateral Spinothalamic Tract Pathway:
DRG > DR > DH > LST > VP Thalamus > Internal Capsule > Corona Radiata > Postcentral gyrus
Anterior Spinocerebellar Tract Pathway (Contralateral):
1st order neuron (DRG) > 2nd order neuron (DH) > Lateral column AST (decussate) > superior peduncles (cerebellum)
Posterior Spinocerebellar Tract Pathway (Ipsilateral):
1st order neuron (DRG) > 2nd order neuron (DH) > Lateral column PST > inferior peduncles (cerebellum)
What type of sensations is the Posterior Spinocerebellar Tract Pathway responsible for?
Subconscious proprioception
What type of sensations is the Anterior Spinocerebellar Tract Pathway responsible for?
Subconscious proprioception
What can you expect to see if there is a lesion in the Dorsal Column?
Multiple Sclerosis, loss of proprioception in the hands and fingers, Astereognosis
What can you expect to see if there is a lesion in the Dorsal Column Upper Tract Pathway?
Astereognosis
What can you expect to see if there is a lesion in the Dorsal Column Lower Tract Pathway?
Sensory Ataxia
*high steppage
*unsteady gait
*Romberg sign
What can you expect to see if there is a lesion in the Spinothalamic Tract Pathway?
Syringomyelia, loss of pain & temp awareness, charcots joints
What can you expect to see if there is a lesion in the Anterior Spinothalamic Tract Pathway?
What can you expect to see if there is a lesion in the Lateral Spinothalamic Tract Pathway?
What can you expect to see if there is a lesion in the Anterior Spinocerebellar Tract Pathway?
What can you expect to see if there is a lesion in the Posterior Spinocerebellar Tract Pathway?
What can you expect to see if there is a lesion on the cerebellum?
Cerebellar Syndrome
*Nystagmus
*Dysarthria
*Tremors
*Ataxia
What can you expect to see if there is a lesion on the spinocerebellar tract?
Friedreich’s ataxia
tremors, ataxia, unsteady gait
What can you expect to see if there is a lesion on the lateral spinothalamic tract?
loss of pain and temperature awareness
“Charcot’s Joints”
What doesn’t the postcentral gyri homunculus have?
genitals and teeth
What are the 2 Pyramidal Somatomotor Pathways?
Lateral Corticospinal
Anterior Corticospinal
Lateral Corticospinal (Contralateral): 75%-90%
Precentral gyrus (Upper motor neuron) > Corona radiata >
internal capsule >
cerebral peduncles >
pyramids (decussate) >
LCT >
Lateral Column >
Ventral horn (Lower motor neuron)
Anterior Corticospinal Pathway (Contralateral): 10%-25%
Precentral gyrus (Upper motor neuron) > Corona radiata >
internal capsule >
cerebral peduncles >
pyramids >
ACT >
Anterior column >
Ventral horn (decussate)
Skeletal muscle
Upper Motor Neuron Lesions:
Spastic paralysis
*hyperreflexia
*hypertonia
*spasticity
Lower Motor Neuron Lesions:
Flaccid Paralysis
* hyporeflexia
*hypotonia
*atrophy
*flaccidity
What are the 5 portions of the Brachial Plexus?
Roots
Trunks
Divisions
Cords
Terminal branches
What are the 5 ventral roots of the brachial plexus?
C5-T1
What are the 3 trunks of the brachial plexus?
Superior
Middle
Inferior
How many divisions are in the brachial plexus?
3 anterior
3 posterior
What are the 3 cords of the brachial plexus?
Lateral
Posterior
Medial
What are the 5 terminal branches of the brachial plexus?
Musculocutaneous nerve
Axillary nerve
Radial nerve
Median nerve
Ulnar nerve
Where does the brachial plexus start?
Roots
What does the axillary nerve innervate?
Shoulder
What does the radial nerve innervate?
upper arm and forearm
What are terminal branches made of?
mixed nerves
Cutaneous means
Skin (sensory)
the anatomical structure of the brachial plexus?
bunch of nerves that mix
What nerves does the “M” in the brachial plexus stand for?
Musculocutaneous
Median
Ulnar
What are the 4 “D’s” of the Brainstem?
dysphagia
dysarthria
dysmetria
diplopia
Atypical spinal nerves are
plexuses (any nerves mixed)
Typical spinal nerves:
T1-T12 thoracic (all nerve are single)
