Week 7 - Spinal Cord Flashcards
In an adult, the spinal cord originates at the level of ___________, and ends at the level of ____________.
foramen magnum
inter-vertebral disk L1-L2
Arbitrarily, the spinal cord is divided into _________ segments, namely: ___ cervical; ___ thoracic; ___ lumbar; ___ sacral; and ___ coccygeal. The segments are represented by emerging from the spinal cord roots of the _______ nerves.
31 8 12 5 5 1 spinal
The anterior (ventral) roots of each spinal nerve represent a bundle of axons from ___________ and __________ motor neurons of the spinal cord. These neurons (soma) are correspondingly situated within the _______ gray horns and _______ gray horns of the spinal cord.
somatic
visceral
ventral
lateral
The posterior (dorsal) roots of each spinal nerve represent a bundle of axons from__________ and _________ sensory neurons, somas of which are situated within __________ .
somatic
visceral
dorsal root ganglia
The spinal cord is of the following approximate length __________ and width __________. It is flattened in __________________ direction.
45cm
2cm
anterio-posterior
There are two spinal cord enlargements: the ________________ enlargement, which represents the _____________ segments of the spinal cord, supplying upper trunk and upper extremities, and the lumbar enlargement, which represents the segments ________________ of the spinal cord, supplying the lower trunk and the lower extremities.
cervical
C4-T1
T9-T12
The spinal cord is divided onto two halves by the __________ fissure and the __________ sulcus.
anterior median
posterior median
The end of the spinal cord is called ____________ as it is narrows down, and resembles a cone or a sharpened pencil. This structure is anchored to the coccyx by the extension of the pia matter, resembling thin thread. It is called: _____________.
conus medullaris
filum terminale
Horizontally, the spinal cord is anchored to the spinal column by projections of the pia matter, which are called: ________________.
denticulate ligaments
The spinal cord is covered by the following meninges from the outside to inside direction: ____________.
dura mater, arachnoid mater, pia mater
Overall, the spinal cord is protected from the physical injury by the following layers: ________________.
vertebra, epidural space (adipose tissue), dura mater, arachnoid mater, subarachnoid space (CSF), pia mater
The outside matter of the spinal cord is _______________ and represents spinal cord ________________. There are the following white matter columns: __________________________.
white matter
funiculli
anterior white columns, posterior white columns, lateral white columns
List spinal cord tracts to master and whether they are motor or sensory tracts: _______________________________.
pyramidal/corticospinal tracts - motor
dorsal column tracts, spinocerebellar tracts, spinal thalamic tracts - sensory
The gray matter of the spinal cord is in a shape of a _________, and is comprised of ___________. There are ________ horns, ____________ horns, and in some segments (____________) ___________ horns.
H or butterfly horns anterior posterior thoracic, lumbar, sacral (T1-L3, S2-S4) lateral
Posterior or dorsal horns hold ______ neurons. Anterior or ventral horns hold __________ neurons. Lateral horns hold _________ neurons.
somatic & visceral sensory
soma of somatic motor
soma of visceral motor
The cross-bar of the gray matter and surrounding white matter represent the connections between right and left halves of the spinal cord. They are called respectively as the following: __________ and ___________.
median gray commissure
median white commissure
Cortico-spinal (pyramidal) R/L tracts (situated within ____________ and ___________ columns of the spinal cord), are efferent tracts, connecting upper motor neurons of the opposite hemisphere with the lower motor neurons of the _______________. This paired tract provides conscious control of _________________.
lateral
anterior
ventral gray horns of the spinal cord
skeletal muscle contraction
Posterior (dorsal) column R/L tracts are afferent tracts, conducting the following sensations from the body below the head to the opposite hemisphere (somato-sensory areas) via the thalami for the conscious use: ______________.
conscious proprioception, vibration, fine touch, stereognosis
Spino-cerebellar (R/L postero- and antero-lateral) tracts are afferent tracts, carrying the following sensations from the body below the head to the corresponding cerebellar hemispheres for sub-conscious use: __________.
subconcious proprioception, vibration
Spino-thalamic tracts (R/L lateral and anterior) are afferent tracts providing the following sensations from the body below the head to the contra-lateral thalamus, and, subsequently, to the somato-sensory areas of the opposite site hemispheres: _____________________.
pain, temperature, light or crude touch
Spinal nerves are very short. They are only ________cm in length. They are located within _______.
1
intervertebral foramena
First seven cervical spinal nerves emerge from the spinal cord at the level: ____________.
above corresponding vertebrae
The eighth cervical spinal nerve emerges from the spinal cord at the level of: _________________.
between C7 & T1
All subsequent spinal nerves below C8 emerge from the spinal cord at the level of: ___________.
below corresponding vertebra
The spinal nerves, emerging from the spinal cord below vertebrae L2, comprise the following “tail-like” structure: ______________.
cauda equina
As the spinal nerves emerge from the spinal cord, they split onto ____________ and ____________ rami.
posterior/dorsal
anterior/ventral
_____________ rami of certain spinal nerves represent the roots of _____________ nerves. They intermingle together and comprise the plexi (networks) of ___________ nerves.
anterior
peripheral
peripheral
Retrograde degeneration of a neuron is __________
degeneration along an axon approaching the soma
Anterograde degeneration of a neuron is ________. It is also known as _________
degeneration along an axon approaching the synaptic plate
Wallerian degeneration
The CNS develops from which embryonic layer?
ectoderm
Describe sensory pathway from 1st order to 3rd order sensory neurons
dorsal root ganglia
posterior/dorsal horns (spinal gray matter)
thalamus
Anterior/Ventral rami supply the __________ of the body, including _________ extremities
muscles and the skin of the sides and front of the body
upper & lower
Posterior/Dorsal rami supply the __________
back of the trunk
