Exam 4 NERVES pt2 Flashcards
how many pairs of spinal nerves that serve defined segments of the human body.
31 pairs of spinal nerves
8 pairs of cervical spinal nerves
This is possible because the first pair (C1 spinal nerves) exits the spinal column between the occipital bone and the atlas (C1). The remaining 7 pairs (C2-C8 spinal nerves) exit below each of the 7 cervical vertebrae via the intervertebral foramina. All the spinal nerves are mixed nerves.
The spinal cord is surrounded by
the dura, arachnoid, and pia maters (the meninges)
is a real space filled with CSF
site of needle insertion for lumbar puncture
extends along the entire length of the vertebral canal and surrounds the spinal cord. It also extends along the initial portion of the radiating spinal nerves
dura mater
location of white and grey matter
directly adheres to the spinal cord
pia mater
contains ascending and descending tracts of nerves traveling to and from the brain
peripheral white matter
serves as a center for spinal reflexes.
central gray matter
conducts signals from dilating blood vessels in the palate to the brain, which interprets the pain as coming from the forehead.
runs the entire length of the spinal cord, is contiguous with the brain and contains cerebrospinal fluid (CSF)
The central canal
each of which gives rise to a pair of spinal nerves that emerge from the cord through the intervertebral foramina
The spinal cord develops as 31 segments
can be sensory, motor, or mixed (sensory and motor)
nerves
________________carry both types of information and some axons are transmitting impulses in one direction,
while other axons are transmitting impulses in the opposite direction
Mixed nerves
All spinal nerves are mixed nerves.
Most of the spinal nerves are associated with specific ____________(an area of skin innervated by all the cutaneous neurons of a certain spinal or cranial nerve).
dermatomes
Dermatomes of the ______________ are seen on the face
trigeminal nerve (cranial nerve V)
is acquired by the respiratory route and causes a head-to-toe rash in children.
Chickenpox (varicella) virus
Numerous cutaneous and visceral sensory neurons share the same ascending tracts.
Explanation of referred pain.
is the muscle(s) served by a single nerve root (spinal nerve or cranial nerve). It is the motor equivalent of a dermatome
A “myotome”
The majority of the spinal nerves combine and then split again as networks of nerves referred to as
plexuses
The exceptions are T2-T12 and S5-Co1, which do NOT form plexuses
formed primarily by spinal nerves C1-C4 (C5 is not considered to part of this plexus, even though it contributes some axons)
cervical plexus
The cervical plexus, and particularly spinal nerves C3, C4, and part of C5, give rise to the
phrenic nerve
which innervates the diaphragm. Injury above C3 would lead to death by suffocation.
is formed primarily by spinal nerves C5-C8, and T1. This plexus gives rise to five nerves that serve the arm or hand.
The brachial plexus
innervates the teres minor muscle and the deltoid muscle
The axillary nerve
innervates muscles in the antebrachium and manus.
The median nerve
It receives sensory information from the palmar side of fingers #1, #2, #3, and the lateral one-half of finger #4 and from the dorsal tips of these same fingers.