Spinal Cord & Spinal Nerves Flashcards
three layers of protective tissue around the brain
meninges
tough outermost membrane enveloping the brain and spinal cord
dura mater
a fine, delicate membrane, the middle one of the three membranes or meninges that surround the brain and spinal cord, situated between the dura mater and the pia mater
arachnoid
the delicate innermost membrane enveloping the brain and spinal cord
pia mater
area between the dura mater (a membrane) and the vertebral wall, containing fat and small blood vessels. the space is located just outside the dural sac which surrounds the nerve roots and is filled with cerebrospinal fluid.
epidural space
corresponds with the attachments of the large nerves which supply the upper limbs. it extends from about the fifth cervical to the first thoracic vertebra
cervical enlargement
a widened area of the spinal cord that gives attachment to the nerves which supply the lower limbs. it commences about the level of T11 and ends at S2
lumbar enlargement
the tapered, lower end of the spinal cord. it occurs near lumbar vertebral levels 1 (L1) and 2 (L2), occasionally lower
conus medullaris
(from Latin horse’s tail) is a bundle of spinal nerves and spinal nerve rootlets, consisting of the second through fifth lumbar nerve pairs, the first through fifth sacral nerve pairs, and the coccygeal nerve, all of which arise from the lumbar enlargement and the conus medullaris of the spinal cord
cauda equina
(“terminal thread”) is a delicate strand of fibrous tissue, about 20 cm in length, proceeding downward from the apex of the conus medullaris. it is one of the modifications of pia mater
filum terminale
a groove along the anterior midline of the spinal cord that incompletely divides it into symmetrical halves. —(ventral median fissure)
anterior median fissure
a shallow groove along the midline of the posterior part of the spinal cord that separates the two posterior funiculi and is the external boundary of the posterior median septum
posterior median sulcus
is the front column of grey matter in the spinal cord. contains cell bodies of alpha motor neurons, which innervate skeletal muscle to cause movement
anterior gray horns
the back column of grey matter. receives several types of sensory information from the body, including fine touch, proprioception, and vibration
posterior gray horns
a thin strip of grey matter that surrounds the central canal of the spinal cord and, along with the anterior white commissure, connects the two halves of the cord
gray commissure
the cerebrospinal fluid-filled space that runs longitudinally through the length of the entire spinal cord
central canal
large bundle of fibers located between the anterior median fissure of the spinal cord and the anterolateral sulcus of the spinal cord
anterior white column
largest column in the spinal cord, which is located between the posterior median sulcus of the spinal cord and the dorsolateral fasciculus of the spinal cord
posterior white column
the fiber tract located between the anterolateral sulcus of the spinal cord and the posterolateral sulcus of the spinal cord
lateral white column
a mixed nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body
spinal nerve
travels to the dorsal root ganglion, sensory nerve fibers enter the spinal cord here (posterior)
dorsal root
a cluster of neurons (a ganglion) in a dorsal root of a spinal nerve. the cell bodies of sensory neurons known as first-order neurons are located
dorsal root ganglion
efferent motor root of a spinal nerve (anterior)
ventral root
bilateral thickenings of the collagen component of pia mater. has a lateral extension that attaches to dura mater and thus provides a means of suspending the spinal cord in subarachnoid fluid within the subarachnoid space
denticulate ligaments
is the posterior division of a spinal nerve. is the dorsal branch of a spinal nerve that forms from the dorsal root of the nerve after it emerges from the spinal cord. carries information that supplies muscles and sensation to the human back.
posterior ramus
is the anterior division of a spinal nerve. supply the antero-lateral parts of the trunk and the limbs. they are mainly larger than the dorsal rami
anterior ramus
carry preganglionic sympathetic fibers from the spinal nerves to the sympathetic ganglia (w). carry postganglionic sympathetic fibers from the sympathetic ganglia to the spinal nerves (g).
rami communicantes (white & gray ramus)
the ganglia of the sympathetic nervous system. they deliver information to the body about stress and impending danger, and are responsible for the familiar fight-or-flight response. located just ventral and lateral to the spinal cord
sympathetic chain ganglion
a network of nerve fibres that supplies innervation to some of the structures in the neck and trunk
cervical plexus
nerve that originates in the neck (C3–C5) and passes down between the lung and heart to reach the diaphragm
phrenic nerve
a network (plexus) of nerves (formed by the ventral ramus of the lower four cervical nerves and first thoracic nerve (C5, C6, C7, C8, and T1). this plexus extends from the spinal cord, through the cervicoaxillary canal in the neck, over the first rib, and into the armpit
brachial plexus
a nerve of the human body, that originates from the brachial plexus (upper trunk, posterior division, posterior cord) at the level of the axilla (armpit) and carries nerve fibers from C5 and C6. innervates the teres minor and the deltoid muscles
axillary nerve
one of the five main nerves originating from the brachial plexus. is the only nerve that passes through the carpal tunnel. the main nerve of the front of the forearm.innervates all of the flexors in the forearm except flexor carpi ulnaris and that part of flexor digitorum profundus that supplies the fourth and fifth digits.
median nerve
originates from the lateral cord of the brachial plexus. The nerve innervates the biceps, brachialis, and coracobrachialis muscles
musculocutaneous nerve
innervates the medial and lateral heads of the triceps brachii muscle of the arm (back)
radial nerve
largest unprotected nerve in the human body (meaning unprotected by muscle or bone), so injury is common (haha funny bone. you hit this a lot) controls the fine movements of the fingers (front)
ulnar nerve
a branch of the radial nervea nerve in the forearm. is the continuation of the deep branch of the radial nerve, after this has crossed the supinator muscle
posterior interosseous nerve
(a nervous plexus) in the lumbar region of the body which forms part of the larger lumbosacral plexus. it is formed by the divisions of the first four lumbar nerves (L1-L4) and from contributions of the subcostal nerve (T12), which is the last thoracic nerve
lumbar plexus
major nerve supplying the anterior compartment of the thigh. It is the largest branch of the lumbar plexus
femoral nerve
enters the thigh, through the obturator canal, and divides into an anterior and a posterior branch, which are separated at first by some of the fibers of the obturator externus, and lower down by the adductor brevis. is responsible for the sensory innervation of the skin of the medial aspect of the thigh
obturator nerve
a nerve plexus which provides motor and sensory nerves for the posterior thigh, most of the lower leg and foot, and part of the pelvis
sacral plexus
the main nerve of the perineum
pudendal nerve
a large nerve in humans and other vertebrate animals which begins in the lower part of the sacral plexus and runs through the hip joint and down the lower limb. It is the longest and widest single nerve in the human body, going from the top of the leg to the foot on the posterior aspect. provides the connection to the nervous system for nearly the whole of the skin of the leg, the muscles of the back of the thigh, and those of the leg and foot
sciatic nerve
a branch of the sciatic nerve. travels through the popliteal fossa, giving off branches to muscles in the superficial posterior compartment of the leg.
tibial nerve
one of two main muscular branches of the sciatic nerve. a nerve in the lower leg that provides sensation over the posterolateral part of the leg and the knee joint. damaged or compressed, foot drop can be the end result
common fibular nerve
a condition of muscular weakness caused by nerve damage or disease; partial paralysis
paresis
refers to various types of paralysis, often accompanied by weakness and the loss of feeling and uncontrolled body movements such as shaking
palsy
excessive physical sensitivity, especially of the skin
hyperesthesia
a common side effect of various medical conditions which manifests as a reduced sense of touch or sensation, or a partial loss of sensitivity to sensory stimuli. in everyday speech this is generally referred to as numbness
hypoesthesia