Spinal Cord Quiz Flashcards
(29 cards)
The area of skin innervated by a single posterior spinal nerve (sensory nerve?
Dermatomes
What Ascending sensory information comes in to the nervous system from peripheral areas and moves upward – usually toward the thalamus?
Includes pain, temperature, skin and muscle sense (via the pseudounipolar and bipolar neurons)
What do Descending tracts (motor information coming from higher levels and moving toward the periphery) transmit?
- Volitional (done by an act of will) or subconscious (without perception)
- Forms the “final common pathway” for the lower motor neuron system
- Last synapse before connection with a muscle
What nerve is located at the C4-C5 level and what is its function?
Phrenic nerve – the motor nerve of the diaphragm
Send impulses for respiratory function
What are the Functions of the Spinal Cord?
Sensory Tracts
Motor tracts
Repiratiory Control Center
Mediates reflex mechanisms
Connectons with the visceral (aka autonomic) nervous
system
assists in muscle tone
Fasiculus Gracilis Ascending or Descending and its function?
Ascending– ipsilateral (uncrossed)
-Carries sensory information from the lower part of the body
-Brings proprioception and tactile/vibratory sense to:
Nucleus gracilis in the medulla
Medial lemniscus in the remainder of the brainstem
Thalamus
Is the Fasiculs Cuneatus Ascending or Descending and what is its function?
Ascending-ipsilateral
Carries sensory information from the upper part of the body
Originates at about T-6 (doesn’t extend the length of the spinal cord)
Carries proprioception and tactile/vibratory sense from the upper cervical and thoracic areas to:
Nucleus cuneatus in the medulla
Medial lemniscus in the remainder of the brainstem
Thalamus
Is the Posterior Spinocerebellar ascending or descending and what is its function?
Ascending-ipsilateral
Carries proprioception (muscle stretch) to:
Inferior cerebellar peduncle
Cerebellum
(sometimes called the dorsal spinocerebellar tract)
What is the function of the Anterior Spinothalmic and is it ascendingo or descending?
Ascending– Contralateral
Carries proprioception and skin sense to :
Spinal lemniscus in the brainstem
Joins the medial lemniscus in the midbrain
Thalamus
Sensation is generally pressure and light touch
Sometimes called the ventral spinothalamic tract
What is the funciton of the Spinotectal and ascending or descending?
Forms a loop with the tectospinal tract
Carries proprioception from the upper body to the tectum (“roof”) of the midbrain
Primary tract for orientation to sight and sound
For example, turning your head and attending to noise from a bee stinging your arm
Also carries sensation of pain
What is the function of the Spino-Olivary and is it ascending or descending?
Forms a loop
Carries proprioception from the upper body (head and shoulder area) to:
Inferior olive of the medulla
Cerebellum
What is the function of the Spinoreticular and ascending or descending?
Ascendng
Forms a loop
Carries proprioception for awareness to the brainstem reticular formation nuclei
Provides information about muscle tone in conjunction with parasympathetic and sympathetic nervous system activities
Also carries perception of deep, chronic pain
What is the difference between Pyramidal and Extrapyramidal?
Pyramidal
Volitional
Fine, fast
Few synapses
From cerebral cortex (Broadmann’s area 4)
Two divisions
Corticospinal
Lateral corticospinal (crossed fibers)
Anterior corticospinal (uncrossed fibers)
Corticobulbar
To cranial nerve nuclei in brainstem
Extrapyramidal
Subconscious
Slower
Multisynaptic
From cerebral cortex (Broadmann’s area 6), basal ganglia nuclei, cerebellum, brainstem centers, reticular formation, vestibular nuclei, midbrain tectum, inferior olive, etc.
Is Lateral Corticospinal ascending or descending and what is its function?
Descending-Crossed pathway
55% synapse in the anterior horns of the spinal cord in the cervical region; 20% in the thoracic region; and 25% in the lumbar/sacral region
Voluntary, discrete, skilled movements
What is the function of the Anterior Corticospinal tract ascending or descending?
Descending-Uncrossed pathway
Voluntary, discrete, skilled movements
Follows the same course to the spinal cord as the lateral corticospinal pathway, but does not cross in medulla
Ultimately becomes the “final common pathway” to the muscle
Expalin how the reflex arc works?
What are the types of Reflexes?
Primitive postural reflexes
Types:
Flexor (withdrawal)
Extensor (stretch)
Proprioceptive
Typical of spinal cord “local” reflexes
Exteroceptive
“Higher order” reflexes
Superficial
Reflex occurs on the surface of the body (skin)
Deep
Requires stimulating a “subsurface” structure to respond
**Visceral
Pathologic**
Abnormal, atypical responses
What is the function of the Tectospinal ascending or descending?
Descending-Loops with the spinotectal tract (ascending)
Provides visual and/or hearing reflex movement from the superior and inferior colliculi of the midbrain tectum, through the medial longitudinal fasciculus and ending on the anterior horns of the spinal cord gray where it synapses with motor neurons
What is the fuction of the Reticulospinnal ascending or descending
Descending-Control of muscle tone from the brainstem reticular formation nuclei to end on the anterior horns of the spinal cord gray where it synapses with motor neurons of the final common pathway
Extends the full length of the spinal cord
Brings input from the reticular formation to the spinal cord
What is the function of the Vestibulospinal ascending or descending?
Descending-Input from cranial nerve VIII and the cerebellum to the spinal cord for muscle tone and balance
From the lateral vestibular nuclei and cerebellum to the anterior horns of the spinal cord gray
Coordinates with the medial longitudinal fasciculus
What is the function of the Olivospinal ascending or descending?
Descending-Loops with spino-olivary
From the inferior olive of the medulla to the anterior horns of the spinal cord gray
Reflex movement to the head and shoulder area
What is the function of the Rubrospinal ascending or descending?
Descending-Primary pathway used by the cerebellumCrossed pathway (at the midbrain)Cerebellar and cortical path to the spinal cord for locomotion and muscle tone From the red nucleus of the midbrain to the anterior horns of the spinal cord gray
What is the function fo the Medial Longitudinal Fasiculus ascending or descending?
Related to eye and upper body movement
Coordinates the three cranial nerves for eye movement (III, IV, and VI)
Coordinates with the vestibular system
Arises from various brainstem nuclei to descend to the cervical portion of the spinal cord
Functions may parallel those of the tectospinal tract
List the causes of Spinal cord injury:
- *Accident** (auto – 44%, sports – 18%; falls – 22%)
- *Disease** (polio, ALS, etc)
- *Compression** (mechanical, tumor)
- *Edema** (swelling after trauma)
- *Gliosis** – build up of glial cells after trauma
- *Blood flow disorders** (aneurysms)
- *Tearing or twisting**
