Spinal cord Flashcards
Cauda equina is
Nerve roots of the lumbar, sacral and coccygeal spinal nerves.
LMN are found in
Ventral horn of the spinal cord and in CN nuclei in the brain stem
Cell bodies of UMN are found in
Brain stem and cerebral cortex
Red nucleus
Reticular formation
Lateral vestibular nuclei of the brain
How do Axons of these UMN travel
Corticospinal tract
Corticospinal fibers decussate at
Pyramids of medulla
What motoneurons supply intrafusal muscle fibers
Gamma motoneurons
Deep tendon reflex is
Stretch myotatic
Monosynaptic and ipsilateral reflex
Knee (patellar) reflex chord involved
L2-L4 (Femoral N)
Ankle reflex chord involved
S1 (Tibial N)
Elow reflex chord involved
C5-C6 (Musculocutaneous N)
C7-C8 (Radial N)
Forearm Cord involved
C5-C6 (Radial N)
Knee reflex muscle tested
Quadriceps
Ankle reflex muscle tested
Gastrocnemius
Elbow C5-C6 reflex muscle tested
Biceps
Elbow C7-C8 reflex muscle tested
Triceps
Forearm reflex muscle tested
Brachioradialis
Inverse muscle stretch reflex ues
Golgi tendon organs
Golgi tendon organs are
encapsulated groups of nerve endings that terminate between collagenous tendon fibers at the junction of muscle and tendon
UMN lesions result in
Hyperactive muscle stretch reflexes
Clasp knife reflex due to oversensitive Golgi Tendon Organs
Early sign of LMN lesion
Fasciculations: twitches or contractions of groups of muscle fibers
LMN lesions produce what type of paralysis
Flaccid paralysis
Babinski sign is present in
A lesion of Coticospinal tract (UMN)
UMN lesions produce what type of paralysis
Spastic paralysis
What are the 2 sensory systems
Dorsal column - medial leminiscal system
Anterolateral (Spinothalamic) system
Dorsal column - medial lemniscal system function
- Discrimitive touch
- Conscious proprioception
- Vibration
- Pressure
Anterolateral (Spinothalamic) system function
Pain
Temperature
Dorsal column - medial leminiscal system fibers
Class 2 or A-β
Astereognosis is
Inability to identify the characteristics of an object:
- Size
- Consistency
- Form
- Shape
Dorsal column - medial leminiscal system decussates
In the medulla
Anterolateral (spinothalamic tract) system decussages
1 to 2 segment above entry into sc
Spinocerebellar tract carry
Unconscious proprioceptive input from muscle spindles and GTOs to the cerebellum
Cell body of the dorsal spinocerebellar tract are found in
Clarke’s nucleus
Both spinocerebellar tracts travel through
Inferior cerebellar peduncle
In Argyll Robertson pupil, the pupil reacts to
Accommodation but not to light
Brown-Séquard syndrome is
Hemisection of the cord resultsin a lesion of each of the 3 main neural systems
Brown-Séquard sydrome presents with
2 ipsilateral signs and one contralateral sign
- Corticospinal tract: ipsilateral spastic paresis below the level of injury
- Fasciculus gracilis or cuneatus: ipsilateral loss of joint position, tactile discrimination, and vibratory sensations below level of lesion
- Spinothalamic tract: contralateral loss of pain and Tem starting one or 2 segments below the level of the lesion
Polio leads to
- Flaccid paralysis
- Muscle atrophy
- Fasciculations
- Areflexia
- Common at lumber levels
Tabes Dorsalis leads to
- Parethesias, Pain, Polyuria
- Late stage syphilis, sensory ataxia, Positive Romberg
- Argyll Robertson pupils
- Sppressed reflexes
