Ch. 13 Powerpoint Flashcards
Neural Integration
spinal neurons recieve input from multiple sources, integrate it, and execute the appropriate output
where does the spinal cord start
foramen magnum of the skull
What are the two areas of enlargement in the spinal cord
Cervical enlargement and lumbrosacral enlargement
Cervical enlargement
nerves to upper limb
lumbrosacral enlargement
nerves to pelvic and power limbs
CSF is found where in the spinal cord
between the arachnoid mater and the pia mater
Lumbar puncture
sample of CSF
Grey Matter
site of information processing; synaptic integration
White matter
carries signals from one part of the CNS to another
Posterior horn
carries sensory information to spinal cord
lateral horn
contain neurons of sympathetic nervous system
anterior horn
carries motor fibers to skeletal muscle
Tracts
bundes of axons that course up and down the cord, providing communication between different levels of the CNS (White Matter)
Ascending tracts
carry sensory information up the spinal cord
descending tracts
carry motor information down the spinal cord
endoneurium
surrounds a signle nerve fiber
perineurium
wraps around fascicles of nerve fibers
epineurium
wraps around entire nerve
Schwann Cells
make mylin in the peripheral nervous system
Sensory (afferent) nerves
carry sensory info from receptors to CNS
Motor (efferent) nerves
carry motor signals from CNS to muscles and glands
Mixes Nerves
consists of both afferent and efferent nerves
Ganglion
cluster of neurosomas outside of the CNS
Poliomyelitis
-caused by poliovirus
- destruction of motor neurons
Symptoms:
-muscle weakness
-muscle pain
-loss of reflexes
*spreads via fecal contamination of water
Amyotrophic Lateral Sclerosis (ALS)
-destruction of motor neurons
-scarring of lateral regions of spinal cord
Symptoms:
-muscle weakness
-difficulty speaking, swallowing, and using hands
How many spinal nerves
31
Types of Proximal branches
posterior and anterior root
Posterior root
sensroy input in to spinal cord
anterior root
motor signal out of spinal cord
Types of distal branches
anterior ramus, posterior ramus, meningeal branch
anterior ramus
-in thoracic region gives rise to intercostal nerve
-forms plexuses in other regions
posterior ramus
innervates muscles joints and the skin of the back
Meningeal Branch
reenters vertebral canal and innervates meninges, vertebrae, and spinal ligaments
Proprioception
brain recieves info about body position and movements form nerve endings in muscles, tendons, and joints
Cervical plexus
supplies neck and phrenic nerve to diaphragm
Brachial Plexus
supplies upper limb and some shoulder and neck
Lumbar Plexus
supplies abdominal wall, anterior thigh, and genitalia
Sacral Plexus
supplies lower trunk and lower limb
Coccygeal Plexus
supplies levator ani, skin over coccyx, and sacrotuberous ligament
How much do dermatomes overlap
up to 50%
you need to anesthetize ——- successive spinal nerves
three
reflexes
quick, involuntary, stereotyped reactions of glands or muscles to stimulation
Integrating Center
point of synaptic contact between neurons in grey matter or brainstem
Proprioceptors
specialized organs that monitor the position and movement of body parts
Muscle Spindles
inform brain of muscle length and body movement to allow it to send commands back to the muscles
Stretch Reflex
when a muscle is stretched, it will then contract
-helps maintain equilibrium and posture
Flexor Reflex
flexing to avoid injury from a dangerous stimuli
crossed extension reflex
opposite limb extends during flexor reflex to maintain balance
tendon reflex
inhibits muscle from contracting strongly when there is excessive tension on a tendon
