Spinal Cord & Spinal Nerve Flashcards
____________: Part of peripheral nervous system taking messages to and from spinal cord. They are mixed, carrying both sensory and motor info
Spinal nerve
________: The caudal-most spinal nerves pass caudally together, resembling a horse’s tail, before exiting the appropriate intervertebral foramen.
Cauda equina
Overall function of the spinal cord
Carry messages to and from brain, and spinal reflexes.
Location of the spinal cord
Vertebral foramen/canal. It runs from foramen magnum to about L2.
Significance of two spinal cord enlargements
Arms & legs nerves entering & exiting spinal cord
Protective coverings of CNS
General is meninges, specific is dura mater (outermost), arachnoid, then pia mater.
Location of CSF
Subarachnoid space
Where are anesthetics given?
Epidurals are given outside of the dura mater. L2 or below would be a safe place to administer the anesthetic without hitting the spinal cord.
Of the gray matter of the spinal cord, the ______________ receive sensory information and the _____________ transmit motor information. Since it is gray, it would contain neuron cell bodies, and unmyelinated neurons.
Dorsal grey horn
Ventral grey horn
___________: Includes the The lateral, dorsal (posterior) and ventral (anterior) columns within the spinal cord
White matter of spinal cord
Within the ____________________ are the ascending tracts carrying sensory information toward the brain and the descending tracts carrying motor information away from the brain.
White columns of the spinal cord
_________: is a fast repetitive response to a stimulus. It is involuntary i.e. not at the conscious level
Reflex
Generalized reflex arc
Stimulus – Receptor – afferent sensory neuron – CNS (spinal cord) – efferent motor neuron – effector (such as a skeletal muscle)
One synapse in the spinal cord is _____________ reflex and would be very fast.
Example patellar
Monosynaptic
A_________________ has more than one synpase in the spinal cord – thus synapsing on interneurons or association neurons before synapsing on the motor neuron. These are slower reflexes and if they stay ipsilateral may describe the withdrawal reflex and if they go contralateral may describe the crossed extensor reflex.
polysynaptic reflex
If you hit the patellar tendon, you stretch the quad. muscle and stimulate the stretch receptor. It is an ______________, ______________reflex ending with the quad. muscle contracting, thus extending the knee.
Ipsilateral
Monosynaptic
If you step on the nail, the pathway is the withdrawal reflex resulting in an ipsilateral contraction of your flexors so that you pull away from the nail and a compensatory extension of the contralateral leg so that you can support your weight. This is known as a _________ ____________ reflex
Crossed extensor relfex
The spinal nerve has a dorsal root carrying ___________ info into the dorsal gray horn and a ventral root carrying _____________ info exiting the ventral gray horn.
Sensory
Motor
After the mixed spinal nerve leaves the vertebra, it branches into a _______ ramus (branch) going toward your back and a _______ ramus going everywhere else in your body, including limbs and viscera.
Dorsal and ventral
_________: Network of successive spinal nerves.
Plexus
4 main plexuses
Cervical (about C1-4);
Brachial (about C5-T1),
Lumbar (about L1-4)
Sacral (about L4-S4)
_________ nerve: originates from Brachial plexus innervates pectoral limb extensors
Radial
_________ nerve: originates from Brachial plexus innervates distal medial flexors (e.g. flexor carpi ulnaris)
Ulnar
_____________ nerve: originates from Brachial plexus innervates elbow flexors (e.g. biceps brachii)
Musculocutaneous nerve
______ nerve: originates from Brachial plexus innervates distal lateral flexors (e.g. flexor carpi radialis)
Median
______ nerve: originates from Lumbar plexus innervates hip flexors and knee extensors (e.g. quadriceps)
Femoral
__________ nerve: originates from Sacral plexus innervates knee flexors (hamstrings) as well as all distal to your knee.
Sciatic nerve
________ nerve: originates from Cervical plexus innervates your diaphragm and needed to breathe!
Phrenic
