Spinal cord 4th exam Flashcards
Cervical part
Superior-most region of the spinal cord and is continuous with the medulla oblongata
What does the cervical part contain
motor neurons whose axons contribute to the cervical spinal nerves
Thoracic part
Lies inferior to the cervical region
What does the thoracic part contain
motor neurons for the thoracic spinal nerves
Lumbar part
shorter segment of the spinal cord that contains the motor neurons for the lumbar spinal nerves
Sacral part
Lies inferior to the lumbar region and contains the motor neurons for the sacral spinal nerves
Coccygeal part
most inferior tip of the spinal cord and one pair of spinal nerves arises from this region
conus medullaris
the tapering inferior end of the spinal cord
Where does the conus medullaris mark the official end of the spinal cord
first lumbar vertebra
Cauda equina
inferior to the conus medullaris, a group of axons
Filum terminale
within the cauda equina, a thin strand of pia mater that helps anchor the conus medullaris to the coccyx.
Where is the spinal cord thickest
around the upper and lower limbs
Cervical enlargement
located in the inferior cervical region of the spinal cord, contains the neurons that innervate the upper limbs
lumbosacral enlargement
extends through the mid-lumbar region of the spinal cord and innervates the lower limbs
How many pairs of spinal nerves is the spinal cord associated with
31
how many cervical nerves are there
8
how many thoracic nerves are there
12
how many lumbar nerves are there
5
how many sacral nerves are there
5
how many coccygeal nerves are there
1
Structures and spaces that encircle the spinal cord, from outermost to innermost
vertebra, epidural space, dura mater, subdural space, arachnoid mater, subarachnoid space, pia mater
where does the epidural space lie and what does it house
between the dura mater and the inner walls of the vertebra, and houses loose connective tissue, blood vessels, and adipose connective tissue
Arachnoid
Deep to the dura mater and subdural space
lumbar puncture
clinical procedure for obtaining CSF
Where does the needle need to enter for a lumbar puncture.
subarachnoid space
Where is a lumbar puncture done
between L3 and L4 or L4 and L5
Pia mater
deep to the subarachnoid space, is a delicate, innermost meningeal layer composed of elastic and collagen fibers
Where is the white matter of the spinal cord and what does it do
peripheral, provides a means of neural communication to and from the brain
Where is the gray matter of the spinal cord and what does it do
central, serves as a center for spinal reflexes
What is the white matter of the spinal cord composed of
myelinated axons
What is the gray matter of the spinal cord composed of
dendrites, cell bodies of neurons, glial cells, and unmyelinated axons
central canal
at the center of the butterfly-shaped gray matter that is filled with cerebrospinal fluid
What do the spinal nerves connect to
they connect the central nervous system to muscles, glands, and receptors
What kind of nerves are spinal nerves
mixed nerves
Dermatome
a specific segment of skin supplied by a single spinal nerve
Shingles
reactivation of one’s childhood chickenpox infection
referred visceral pain
a phenomenon in which pain or discomfort from one organ is mistakenly referred to a dermatome
Where is pain associated with a myocardial infarction
the skin dermatomes innervated by T1-T5 spinal nerves, which lie along the left pectoral region and the medial side of the left arm
Where is pain associated with kidney disease
along the T10-T12 dermatomes, which typically overlie the inferior abdominal wall in the groin and loin regions
Brain freeze
caused by the rapid warming of the hard palate after consumption of very cold substance
Myotome
muscle served by a single nerve root. the motor equivalent of a dermatome
nerve plexus
a network of interweaving spinal nerves
Which nerves dont form nerve plexus
T2-T12 and S5-Co1
cervical plexuses
located deep on each side of the neck, immediately lateral to cervical vertebrae C1-C4
What do the cervical plexuses innervate
anterior neck muscles as well as the skin of the neck and portions of the head and shoulders
Phrenic nerve
important branch of the cervical plexus. formed primarily from C4 nerve and some contributing axons from C3 and C5
What does the phrenic nerve innovate
The diaphragm
What causes hiccups (singultus)
irritation to the phrenic nerve causing spasmodic contractions of the diaphragm
Brachial plexus
networks of nerves that supply the upper limb
What forms the brachial plexus
spinal nerves from C5-T1
What does the brachial plexus innervate
pectoral girdle and the entire upper limb of one side
What are the five major named nerves that arise from the brachial plexus
Axillary nerve, median nerve, musculocutaneous nerve, radial nerve, ulnar nerve
What does the axillary nerve innervate
both the deltoid and teres minor muscles. it receives sensory information from the superolateral part of the arm and skin
What does the median nerve innervate
most of the anterior forearm muscles and several muscles in the palm. it receives sensory information from the palmar side of fingers 1,2,3 and the lateral one-half of finger 4
musculocutaneous nerve
innervates the biceps brachii, coracobrachialis, and another anterior arm muscle. It also receives sensory input form the lateral surface of the forearm
radial nerve
innervates the triceps brachii and other muscles of the posterior of the forearm. It receives sensory information from the posterior arm and forearm surface and the dorsolateral side of the hand
Ulnar nerve
innervates some of the anterior forearm muscles and many of the muscles in the palm. It receives sensations from the skin of the dorsal and palmar aspects of fingers 5, and the medial half of finger 4.
Lumbar plexuses
formed by spinal nerves L1-L4 located lateral to the L1-L4 vertebrae and along the psoas major in the posterior abdominal wall
femoral nerve
arises from lumbar plexus. innervates the quadriceps femoris, the sartorius, and iliopsoas. it also receives sensory information from the anterior and inferomedial thigh as well as the medial aspect of the leg
lateral femoral cutaneous nerve
a branch of the femoral nerve that passs between the upper front of the ilium and the inguinal ligament near the anterior superior iliac spine.
meralgia paresthetica
When the lateral femoral cutaneous nerve is compressed causing pain, tingling, a burning sensation, or numbness in the outer side of the thigh.
obturator nerve
arises from lumbar plexus. innervates gracilis and several other thigh muscles. it receives sensory information from the superomedial skin of the thigh.
Sacral plexuses
formed from spinal nerves L4-S5 and are located immediately inferior to the lumbar plexuses
Sciatic nerve
arises from sacral plexus. largest nerve in the body and is actually composed of two nerves wrapped in a connective tissue sheath.
Tibial nerve
part of sciatic nerve. innervates the hamstrings, gastrocnemius, soleus, and several other muscles fo teh leg and foot. It receives sensory impulses from skin covering the sole of the foot
Common fibular nerve
part of the sciatic nerve. innervate peroneus longus, tibialis anterior, and several other muscles of the leg and foot. receives sensory input from the anterolateral part of the leg, the toes, and the dorsal surface of the foot.
Neural tube
Where the central nervous system forms primarily from
Neural Crest cells
where the cranial and spinal nerves primarily form from
Neural canal
develops into the central canal of the spinal cord
Where does a newborn’s spinal cord extend to
about the level of L3
Where does a child’s spinal cord extend to
the level of L2
Where does an adult’s spinal cord typically terminate
the level of L1
What typically happens when trauma occurs above C3
Death by asphyxiation
What happens when trauma is experienced between C3 and C7
A person will become a quadriplegic
When trauma happens between T1 and L1 what happens
A person may become a paraplegic
