CNS: spinal cord, spinal nerve Flashcards
where does spinal cord begin
Begins at medulla oblongata (brain stem) down to the level of L2
what’s the name of the spinal cord end-point
conus medullaris
2 enlargements within spinal cord
cervical and lumbar enlargement
cervical enlargement come from
• From which the brachial plexus is formed •
innervation of cervical enlargement
upper extremity C5-T1
innervation of lumbar enlargement
lower extremity L1-
S4
lumbar enlargement come from
from which the lumbar plexus is formed
name of the depression in spinal cord
Anterior (ventral) median fissure
Posterior (dorsal) median sulcus
the H-form in center of SC is white or gray mater
gray
name of the center of grey matter
central canal
pathway of central canal
continuous the length of the spinal cord
• continuous with the 4th ventricle of the brain
• filled with CSF
which glia cells surround the area around the H-form
oligodendrocyte
name of each bundle of myelinated nerve fibers
tract
ascending tract is sensory or motor
sensory
descending tract is sensory or motor
motor
relay impulse of ascending tract
Relay impulses from the periphery or spinal levels to the brain
relay impulse of descending tract
Relay impulses from the brain to different spinal levels and the periphery
what type of horn is only found in T-spine and upper L-spine
lateral horn
name of groups of nerve fibers which enter the Dorsal Horn are called
dorsal roots
name of The groups of nerve fibers which enter the Ventral Horn are called
ventral roots
where does the cell bodies of dorsal roots lies and names
Their cell bodies lie outside the s.c. in the intervertebral foramen and are called,
• Dorsal root ganglia or, • Spinal ganglia
location of cell bodies of ventral roots
Cell bodies are contained within the anterior and lateral horns
ventral roots contains what
axons of motor neurons
dorsal roots contains what
sensory neurons
the spinal nerve is form by what
Dorsal and ventral roots come together
the spinale nerve divides into
dorsal and ventral rami
innervation of dorsal rami
eep vertebral muscles and skin of
the back
innervation of ventral rami
ventral and lateral musculature
spinal nerve are sensory of motor
both
how many pair of spinal nerve is there
31
function of meninges
- protect brain and spinal cord
- form supporting framework for artery brain and venous sinus
- enclose subarachnoid space for circulation of CSF
what cover the pituitary gland
Diaphragm Sellae
what layer of meninges contain the CSF
subarachnoid space
where is located the denticulate ligament
pia mater
when does the spinal nerves stop being cover by meninges
until they exit through intervertebral foramina
which nerve act primarily as pain receptors of the body but Also act as tickle, itch and thermal, and touch receptors
free nerve ending
where does the free nerve ending bracnch
between epithelial cells, connective cells, muscle
cells, etc.
which nerve are surrounded by CT capsule
encapsulated sensory ending
how many Encapsulated Sensory Endings in total
6
which nerve are Encapsulated Sensory Endings
Meissner Corpuscles • Pacinian Corpuscles • End bulbs of Krause • Ruffini Corpuscles • Muscle Spindles • Golgi Tendon Organs
location, function and adaptation of messiner corpuscle
Surrounds spinal ending of a dendrite
• Sensitive to light touch, pressure, and slow vibrations
• Rapidly-adapting
Found in the:
• Skin (dermis) - especially the finger tips
• Mucous membrane of the tongue
• Other sensitive regions of the body (ex: eyelids)
location, function and adaptation of pacinian corpuscle
• Located in the dermis and subcutaneous tissue, submucosa,
joints, periosteum, and some viscera
• Adapt rapidly
• Stimulated by heavy pressure, fast vibrations, tickling
location, function and adaptation of end-bulbs of Krause
• Located in the mucous of the lips, tongue, conjunctiva,
external genitalia
• Common throughout the body (dermis of skin) • Serve as cold receptors
location, function and adaptation of Ruffini corpuscle
- Located in sub-cutaneous tissue, ligaments, tendons
- Slow-adapting
- Respond to stretching of the skin
- Contribute to the kinesthetic sense of, and control of, joint position and movement
location, function and adaptation of muscle spindle
found in skeletal muscle, react to change in muscle length
what is contain in the capsule of muscle spindle
Within this capsule are skeletal muscle fibers called intrafusal fibers
• They are supplied by sensory neurons
what happens with muscle spindle when a muscle is stretch
• When the muscle is stretched so are the intrafusal fibers which
send afferent nerve impulses back to the spinal nerve
• In response, there is stimulation of the efferent (motor) neurons to the same muscle that contracts it
• Therefore stretch is reflexively resisted
function and adaptation of GTO
react to muscle tension
Composed of dendrites that have many branches on the muscle tendon junction
The stimulus will go back to the s.c. where the motor neurons to the same muscles are inhibited, thus relaxing the muscle
• Principle of PNF stretching and hold/relax stretch
which spinal nerve is not a cutaneous innervation
C1
explain the somatic reflex
see powerpoint
