Chapter 13 Spinal Cord Flashcards
What is the spinal cord divided into?
- cervical 2. thoracic 3. lumbar 4 sacral
Which areas of the spinal cord are thicker than elsewhere?
- cervical enlargement - nerves to upper limb
- lumbar enlargement - nerves to pelvic region and lower limbs
cord tapers to a point inferior to lumbar enlargement
medullary cone (conus medullaris)
Label the spinal cord
bundle of nerve roots that occupy vertebral canal from L2 to S5
cauda equina
Label the spinal cord
Where is CSF produced?
Choroid Plexus
What is the composition and function of CSF?
Neuron cell bodies with little myelin
gray matter
gray matter is the site of information processing called ____ and is shaped like a ___
synaptic integration, butterfly
abundantly myelinated axons(tracts)
white matter
What does white matter do in the CNS?
carries signals from one part of the CNS to another
What do Ascending and descending tracts carry?
- ascending tracts carry sensory signals up the spinal cord
- Dsecending tracts carry motor signals down brainstem and spinal cord
What are the neurons involved in the ascending tracts and the fuction?
What are the neurons in the descending tract and what are their functions?
How does the spinal cord communicate with the rest of the body?
spinal nerves
a cord like organ composed of numerous nerve fibers (axon) bond together by connective tissue
nerve
What is the only cell body found in the PNS?
Dorsal root ganglion
What is the pathway for sensory information?
Sensory Infor -> Dorsal Horn -> Dorsal Root-> Brain
What is the pathway for motor information?
Brain -> Ventral Root -> Ventral Horn -> Motor Info -> location ex. muscles
What are the five branched nerve plexuses and their location?
carry sensory signals from bones, joints, muscles, and skin
Somatosensory function
primarily to stimulate muscle contraction
motor function
Supply/ recieve from the muscles of the neck and diaphragm
The cervical Plexus
What nerves work to keep the diaghragm alive?
C 3,4,5
What nerve intervates the diaphragm?
phrenic nerve
What nerves rise from the brachial plexus?
Ulnar, Musculocutaneous, axillary, radial, median nerve
supply/ recieve from the muscles and skin of the arm
the brachial plexus
supply/receive from the muscles of the abdomen and thigh
the lumbar plexus
What is the major nerves in the lumbar plexus?
femoral, illioinguinal,obturator, lateral femoral cutaneos nerve
supply/ receive from the buttock, lower limb, pelvic structures
Sacral and Coccygeal Plexuses
What are the major nerves of the Sacral and Coccygeal Plexuses?
Sciatic nerve which rises from the common fibular nerve and tibial nerve
Complete transection of the spinal cord can cause?
Above _ poses the threate of respiratory failure
C4
- paralysis of both lower limbs
- paralysis of all four limbs
- paraylsis on one side of the body
- partial paraylsis or weakness of the limbs
- paraplegia
- quadriplegia
- hemiplegia
- paresis
a specific are of skin that conveys sensory input to a spinal nerve
dermatome
a diagram of the cutaneous regions innervated by each spinal nerve
dermatome map
Why are dermatomes important in anesthesia?
Explain the pathway of a reflex arc
What are the four types of reflexes?
receptors embedded in skeletal muscle
stretch receptors
specialized sense organs to monitor position and movement of body parts
proprioceptor
inform the brain of muscle length and body movement
muscle spindles
stretching is detected by?
muscle spindles
muscle spindles enables the brain to send ___ back to the muscles that control coordinated ___
motor commands
coordinated movement, corrective reflexes, muscle tone, and posture
Explain the patellar tendon refex
Explain the flexor and crossed extention reflexes
proprioceptors in a tendon near its junction with a muscle
tendon organs
in response to excessive tension on the tendon
tendon reflex
What is the function of the tendone reflex?
- inhibits muscle from contracting strongly
- moderates muscle contraction before it tears a tendon or pulls it loose form the muscle or bone
