15CHAPTER 13: SPINAL CORD, SPINAL NERVES, REFLEXES Flashcards
What are the function of the spinal cord?
Conduction – sensory info in, motor info out.
Locomotion – Contain central pattern generators = Control extensors and involved in walking
Reflexes – Involuntary stereotyped responses to stimuli
What are the regions of the spinal cord?
Cervical, Thoracic, Lumbar, and Sacral
Where is there lots of nerves to supple upper and lower limbs?
Cervical and lumbar enlargements
What is the medullary cone?
Tapered tip of cord
What is the cauda equine?
Collection of lumbar and sacral spinal nerves (L2 to S5)
What are menings?
Fibrous layers enclosing spinal cord
What are the 3 layers of meninges?
Dura mater, Arachnoid mater, pia mater
What is dura mater?
Tough collagenous sleeve around SC (dural sheath)
Where are epidural spaces found and what are they filled with?
Between dural sheath and vertebral bones – filled with fat and blood vessels
What is considered the ‘site of epidural anesthesia utilized during childbirth’?
Epidural space
What is arachnoid mater?
Adheres to dura mater
Subarachnoid space = loose mesh of fibers filled with CSF
located between dura mater and pia mater
What is pia mater?
Thin membrane covering spinal cord
Extends beyond medullary cone à terminal filum (coccygeal ligament) and anchors cord to Co1
What ligament anchor the cord laterally to the dura mater?
Denticulate ligaments
Sensory info always goes _____, while motor info always goes.
Up, down
What does decussation mean?
when a tract crosses to the other side
What does contralateral mean?
Origin and destination are on opposite sides
What does ipsilateral mean?
Origin and destination are on same side
In general, sensory input to the brain passes through what 3 neurons?
- 1st order neuron from receptor to spinal cord or medulla
- 2nd order neuron from spinal cord and medulla to thalamus
- 3rd order neuron from thalamus to cerebral cortex
State the origin, destination and the information provided by the cuneate fasciculus tract.
O= Chest and upper limb (T6 and up) D= medulla, Info= touch and proprioception
State the origin, destination and the information provided by the gracile fasciculus tract.
O= below chest (below T6), D= medulla, Info= touch and proprioception.
State the origin, destination and the information provided by the spinothalamic tract.
O= spinal cord, D= thalamus, Info= pain and temp, tickle, itch
State the origin, destination and the information provided by the spinocerebellar tract.
O=Spinal cord, D= Cerebellum, Info= proprioception from limbs and trunk
Motor pathways involve what 2 neurons?
- Upper motor neuron from brain à spinal cord
- Lower motor neuron from spinal cord à muscle or target organ
State the origin, destination and the information provided by the corticospinal tract?
O= motor cortex, D= ventral grey matter of spinal cord, Info= fine motor control of limbs