Lecture 5 Flashcards
What are the 3 functions of the brain stem
- connects diecephalon to spinal cord
- contains neuronal centers critical for survival, respiratory center
- contains 10 to 12 nerves
reticular formation neurons are in________________________________
core of brainstem, mainly in the pons and medulla
Neurons of the __________________ activating system terminate widely in the thalamus that is conveyed to the cerebral cortex
ascending reticular activating system
Incoming sensory axons synapse on____________ neurons in the brainstem
reticular activating system
Function of Reticular activating system
increased in response to sensory information, maintains consciousness, and has a role in sleep wakefulness
Where does the cerebellum originate from
metecephalon
The cerebellum forms a cortical structure with ____________ on the outside and _______________ on the inside and _______________
grey matter
white matter
deep cerebella nuclei
4 functions of the cerebellum
- to coordinate and smooth body movements
- Participates in learning skilled voluntary movements
- Assists with postural control
- Assists with equilibrium and eye movement
what are the three layers of the cerebellum
- molecular layer
- purkinje layer
- Granular layer
___________ are the only neurons that project deep into cerebellar nuclei
purkinje cells
________________ form parallel fibers
granule
affarent projections to cerebellar cortex called mossy fibers and originate form
- vestibular nuclei
2. receptors in mussels, joints, and tendons (information on movement and position of limbs)
_________________ is a nerve tract originating in the spinal cord and terminating in the same side (ipsilateral) of the cerebellum. Professes information on movememt and position of limbs
spinocerebellar tract
______________ in the primary motor cortex synapse in the pons. Soma in the ponds project to cerebellar cortex
pyramidal neurons
afferent projections to perkinje cells called ____________ and originate from ____________________
climbing fibers
inferior olive
Only ____________ cells project into deep cerebellar nuclei
purkinje
deep cerebellar nuclei neurons ___________________
project out of the cerebellum
Where do efferent projections from the deep cerebellar nuclei project to
- Thalamus
- Reticular formation
- Vestibular nuclei
Damage to cerebellum
problems with balance and tremors are seen in reeler mutant mice
Posterior view of spinal cord shows__________________ Letters and numbers indicate corresponding spinal nerves
attached dorsal root ganglion.
Spinal cord extends from
fromanen magnet to lumbar level
The spinal cord receives ____________ and provides __________________ for the entire body but not the head
somatosensory information
motor output to muscles
The spinal cord provides a two way conduction pathway between the body and the brain by way pf the __________________________ axons pathways
ascending and descending
The spinal cord is a _____________
major reflex center
________________ the most distal bulbus parts of the spinal cord
conus medlars
_________________ tapering end of the spinal cord
filum terminal
____________ a bundle of spinal nerves and spinal nerve rootlets
cauda equina
somatic mortar neurons with axons that exit in the ventral root
motor component
___________ dorsal root ganglian neurons (pseudo unipolar cells with no dendrites and one axon with Central and peripheral branches
sensory component
ventral and dorsal roots form mixed spinal nerve and exit via the _______________
intervertebral foramen
_________________contain nerves that provide visceral motor, somatic motor, and sensory information, with the dorsal ramus feeding the dorsal trunk (skin and muscles of the back), and the ventral ramus feeding the ventral trunk and limbs through the ventrolateral surface
The dorsal and ventral rami
___________ a simple reface involving only one synapse between sensory and motor neurons
monosynaptic reflex
_____________ reflex action that involves an electrical impulse being transferred from a sensory neuron to a motor neuron
polysynaptic reflex
general trends about major spinal tracts
- most decussate- contralateral; projections
- Most form a chain of 2-3 neuron
- Most exhibit somatotopy
- All are paired and mirror images of each other
Spinothalamic tract:
dorsal root ganglian neurons relay _______________________ from peripheral receptors and synapse on neurons in dorsal horn of the spinal cord
pain and temperature
Spinothalamic tract:
axons of dorsal horn cells cross the opposite side of the spinal cord through the ventral commissure, ascend in ____________ and synapse in ______________________
the lateral funicular
the central posterior nucleus in the thalamus.
Spinothalamic tract:
axons of _______________ project to the appropriate part of the somatotopically organized ____________________
thalamic neurons
Somatic sensory neurons
Dorsal column pathway:
dorsal root ganglian neurons relay touch, pressure, and proprioception from the __________________ where axons branch, one branch enters the dorsal columns, ascends on the same side and synapses in ne
periphery into the dorsal horn
Dorsal column pathway:
axons of neurons in the nucleus gracilis or cuneatus cross the midline and ascend to the ______________________ where they synapse
ventral posterior lateral thalamus
Dorsal column pathway:
axons of the thalamic neurons project to the appropriate part of the ___________________
somatosensory cortex
spinocerebellar Tract:
dorsal root ganglian neurons relay muscle position information from ________________ that synapse in dorsal horn of spinal cord
proprioceptors
spinocerebellar Tract:
axons of spinocerebellar neurons ascend in the lateral funicular to the cerebellar cortex and synapse _______________
on granule cells
spinocerebellar Tract:
axons of spinocerebellar neurons ascend in the lateral funicular to __________________
the cerebellar cortex
cortico spinal tract:
pyramidal neurons located ______________ of the primary motor cortex. Axons decent in the _____________
layer V
internal capsule
cortico spinal tract:
axons course ______________ in the brainstem:
anteriorly
cortico spinal tract:
In the midbrain axons travel
in cerebral peduncles
cortico spinal tract:
In the pons axons travel
between pontine nuclei
cortico spinal tract:
In the medulla axons travel
in pyramids
cortico spinal tract:
Lateral corticospinal tract axons _____________ din the pyramid of the medulla
decussate
cortico spinal tract:
Axons travel in 2 seperate pathway’s in spinal cord: Lateral corticospinal tract in the _________ and anterior corticospinal tract in the _______________-
lateral funiculus
anterior funiculus
cortico spinal tract:
axons of anterior corticospiinal tract decussate in ventral commissure. Neurons in the ___________ cerebral cortex synapse oil the __________ somatic motor neurons
left
right
corticobular tract:
pyramidal neurons in the face area of the primary Moto cortex synapse on somatic motor neurons win cranial nerve nuclei. Axons travel with those of the corticospinal tract and then at the appropriate brainstem levels, decussate and synapse on _________________
cranial somatic motor neurons
What are the two cutaneous sensory receptors
- free nerve endings
- mechanorecptors
________________ pain and itch receptor of the cutaneous sensory receptors
free nerve ending
_____________________ touch pressure and receptors of the cutaneous sensory receptors
mechanoreceptors
__________ proprioceptive receptors that is located within the tendons found on each send of a muscle.
Golgi tendon organs
_______________ consist of intramural muscle fibers enclosed in a sheath, they run paralll to the fugal muscle fibers enclosed in a sheath, they run parallel to the extrafusal muscle fibers enclosed in the sheath spinal
muscle spinals
What are the two somatic motor and sensory components at the thoracic level
- dorsal remas
- ventral remas
___________ contains nerves that serve the dorsal portion of the trunk, it carries visceral motor, somatic sensory information
dorsal remas
________________ nerve 12 is known as the subcostal nerve
ventral remas
the _______________ supplies the deep muscles of the back at all levels
dorsal remus
______________ divided into medial and lateral and intervals the muscles
dorsal ramus
________________ form nerve plexus to innervate muscles of upper and lower limbs
ventral ramus
nerve plexus organization
- brachial
- lumbar and sacral plexus combined and
- lumbosacral plexus
____________ defined as area of skin innervated by the sensory fibers of a single spinal nerve
dermatome
during what injury are the brachial and lumbosacrial affected
quadriplegic
during what injury are the lumbosacral plexus is affected
paraplegic
