BIO 3 111L
is the narrow tapered terminal end of the spinal cord
Conus medullaris
Outermost layer of meninges is the
dura mater
Middle layer of meninges is the
arachnoid mater
Innermost layer of meninges is the
pia mater
connects the 2 sides of gray matter.
Gray commissure
It is traversed by the ___ which contains cerebrospinal fluid
central canal
gray horn contains motor neurons
Anterior/ventral
gray horn contains sensory neurons
Posterior/dorsal
contains autonomic neurons
Lateral gray horn
is the collection of the lower spinal nerves. They form a bundle similar to the horse’s tail and pass in the lower part of the spinal canal so each nerve can reach the level of its foramen of exit.
Cauda equina
is a group of nerves joined in a network. There are 4 plexuses formed by the ventral rami of spinal nerves; cervical, brachial, lumbar, sacral.
The plexus
supplies the skin and muscles of the neck, shoulder and the diaphragm.
The cervical plexus
The nerve supply of the diaphragm is the
phrenic nerve
supplies the upper limb
The brachial plexus
The gluteal region is supplied by the
superior gluteal nerve and the inferior gluteal nerve
is the outermost layer
around the entire nerve
Epineurium
is around each fascicle/bundle. The fascicle is a group axons
Perineurium
is around each individual axon
Endoneurium
supplies the pelvis, gluteal region and most of the lower limb.
sacral plexus
supplies the anterolateral abdominal wall, external genitals, anterior and medial surfaces of the thigh.
lumbar plexus
is the largest nerve arising from the lumbar plexus, and it supplies the anterior surface of the thigh.
The femoral nerve
is another branch which supplies the medial surface of the thigh.
The obturator nerve
supplies the skin and muscles of the neck, shoulder and the diaphragm.
The cervical plexus
is the posterior attachment/origin of the spinal nerve to the spinal cord, and it contains sensory axons.
Dorsal root
is a collection of sensory neurons along the pathway of the dorsal root.
Dorsal root ganglia
is the anterior attachment/origin of the spinal nerve to the spinal cord, and it contains motor axons.
Ventral root
is a mixed nerve containing both sensory and motor axons.
Spinal nerve
is the smaller posterior branch of the spinal nerve. The dorsal rami are
mixed and they innervates the skin and muscles of the back.
Dorsal ramus
is the larger anterior branch of the spinal nerve. The ventral rami are mixed and they innervate the anterior and lateral skin and muscles of the trunk. They also innervate the upper and lower limbs.
Ventral ramus
are two branches from the ventral ramus which communicate with autonomic ganglia.
Rami communicantes