spinal cord Flashcards
The spinal cord extends from the foreman magnum to what vertebra ?
foreman magnum to L1
What are the three functions of the spinal cord ?
Conduction , passes info up and down the spinal
Locomotion, repetitive actions of muscle groups
Reflexes, involuntary responses to stimuli
What are central pattern generators?
Pools of neurons providing control of flexors and extensors EX. like walking
How many pairs of spinal nerves arise from C, L, T and sacral regions of the cord ?
31
Where do the nerves that control the upper limbs arise and what is this enlargement called ?
C4-T1 are cervical and control upper limbs , the enlargement is the cervical enlargement and is the whole cervical region.
Where do the nerves that control the lower limbs and pelvic?
T9-T12 are pelvic and lower limbs , the enlargement is called the lumbar enlargement and is before the lumbar region.
define medullary cone
Taper of the distal cord
define cauda equina
“horse tail” bundles of nerves originating form the lumbar enlargement and the medullary cone .
What vertebra make up the cauda equina?
L2-L5
Define terminal filum
fibrous continuation of the cord beyond the medullary cone. consists of pia matter and neuroglia elements.
Where is epidural anesthesia utilized during childbirth?
In the epidural space that is filled with fat and blood vessels
What anchors the cord to the coccyx ?
filum terminale and denticulate ligaments
Define denticulate ligaments
extension of the pia that extends through the arachnoid to the dura.
What does the denticulate ligament do?
suspends the spinal cord in the dural sheath.
What is spinabifida ?
Failure of vertebral arch to close covering spinalcord affects one in a thousand babies.
What are the two froms of spina bifida?
spinabifida occulta and spinabifida
manifesta
.
Dorsal root of spinal nerve is totally what kind of fibers
Sensory nerves
Ventral roots of the spinal nerve is totally what kind of fibers?
Motor nerves
What is white matter in the spinal column ? What two names is assigned to the white matter ?
The white matter is called White columns or funiculi , they are bundles of myelinated axons that carry signals up & down the cord
What are the symptoms of spina bifida ?
Bowel and bladder control , ADD, and learning disabilities
Define Coccygeal ligament
fused terminal filum and dura that anchors the cord and meninges to Co1
Explain spina bifida occulta
Hidden , the most mildest form , most children with occulta wont have health problems and the cord is unaffected
Explain spina bifida Myelomeningocele
Most severe form, occurs when the meninges and spinal cord push through a hole in the back . Typically will have some sort of paralysis and hydrocephalies” accumulation of fluid in and around the brain”.
How is spina bifida diagnosed
Test between 16-18 week of pregnancy. They measure the amount of Alpha-fetoprotein that the fetus produces. They check through ultrasound, or aminocentesis
Define decussation
Fibers cross sides
How many pathways do the motor neurons have ?
two pathways
How many pathways do the sensory neurons have ?
Three pathways, they must go through the thalamus to get to the central gyrus
What are the three ascending pathways of sensory neurons?
1st order, detect signal and sends to cord.
2nd spinal cord to thalamus “main sensory relay center”
3rd Thalamus to sensory “Precenteral gyrus”