Nervous system 1 Flashcards
Simple pattern reflexes involve what circuit/s?
Spinal cord circuits only (no cortical input)
Complex postural adjustments involve what circuits?
Spinal cord and supraspinal centers (extrapyramidal systems in brainstem/ cerebellum)
Voluntary movement involve what circuits?
Spinal cord, brainstem, motor cortex
Do upper motor neurons always stay in the CNS?
Yes
Do axons of upper motor neurons depart to the PNS?
No
What is a motor unit?
A group of motor neurons innervating group of muscle
Do muscles for precise contraction have big or small motor units?
Small (external eye muscles)
In power generating muscles, large or small motor units?
Large
What is neuromuscular junction?
Synapse of motor unit axon terminal and muscle fibres
From inner to outer, list the the sheaths which wrap around nerve fibres to form a whole nerve
- Endoneurium
- Perineurium
- Epineurium
How many pairs of spinal nerves are there in the body?
31
8 for cervical
12 for thoracic
5 for lumbar
5 for sacral
1 coccygeal nerves (Co1)
What is a dermatome?
Area of skin mainly supplied by single spinal nerve
What is a myotome?
Group of muscles innervated by single spinal nerve
A peripheral never is often comprised of…
multiple spinal nerves
Names of the 4 nerve plexuses
Cervical: Head, neck, diaphragm
Brachial: Upper limbs
Lumbosacral: Lower limbs
Sacral: Lower limbs
Crazy B Loves Singing
How is the brachial plexus divided?
Roots (ventral rami), trunks, divisions, cords, branches
Name of three trunks of brachial plexus
Upper, middle, lower
Roots of ventral rami for the brachial plexus is…
C5-T1
What is the name of the three cords for the brachial plexus?
Lateral, medial, posterior
What is the major terminal branches of the cords of brachial plexus?
Musculocutaneous
Median
Ulnar
Radial
Axillary
Is spinal cord white matter outside and grey inside, or the other way around?
White matter outside, grey inside
Where is the pre and post ganglionic neurons located for sympathetic nerves?
Pre: Lateral horn of thoracic spinal cord (exits through ventral root)
Post: Sympathetic trunk/prevertebral ganglia, reach target through gray communicating ramus
Where is the pre and post ganglionic neurons located for parasympathetic nerves?
Pre: Sacral spinal cord or brainstem (travel via pelvic splanchnic ganglia)
Post: Near target organs
Where are Olfactory I (nose) and Optic II (eye) located?
Cerebral hemisphere
Where are Oculomotor III (all eye muscles except IV and VI supplied), IV Trochlear (superior oblique eye muscle) located?
Midbrain
What are the four cranial nerves in Pons?
V Trigeminal (face and teeth sensory, muscle for chewing), VI Abducens (external eye), VII Facial (Face muscle), VIII Vestibulocochlear (inner ear)
What are the 5 cranial nerve for Medulla?
VII Vestibulocochlear, IX Glossopharyngeal (pharyngeal muscle, tongue tonsil and pharynx sensory), X Vagus (Heart, lungs, Gi tract) XI Accessory (trapezius muscles, sterno-cleidomastoid), XII Hypoglossal (muscles of tongue)
Primary motor cortex is on the…
precentral gyrus
Primary sensory motor cortex is one the…
Post central gyrus
Central sulcus has motor cortex at front, sensory at back (T or F)
T
What is the Broadmann areas
Microscopic analysis of whole brain, looking for differences in organisation
What brodmann areas are responsible for movement?
BA4 Primary motor cortex, BA6 Pre-motor cortex and prefrontal cortex
What Broadmann areas are responsible for sensation?
BA3,1,2 Primary sensory cortex, BA5,7, Sensory association areas
The lateral fissure have what cortices surrounding it
Primary gustatory and auditory
Calcerine sulcus has what cortex surrounding it?
Primary visual
Is tertiary the highest order cortices?
Yes, it surrounds secondary, and then primary
What is the two motor descending pathway names and its subcategories?
Pyramidal:
Lateral and anterior corticospinal tract
Extrapyramidal:
1. Rubrospinal tract
2. Reticulospinal tracts
3. Olivospinal tract
4. Vestibulospinal tract
What is the three sensory ascending pathway names and its subcategories?
Dorsal column medial lemniscus system:
1. Gracile fasciculus
2. Cuneate Fasciculus
Spinocerebellar Tracts:
Posterior and anterior spinocerebellar tract
Anterolateral system:
Lateral and anterior Spinothalamic tract
Spino-olivary
What does the dorsal column medial lemniscus system sense?
Touch, vibration, proprioception (sensing position and movement of self)
What does anterolateral system sense?
Pain, temperature, crude touch
List the pathway for the anterolateral system?
- Crosses at spinal cord
- Ascend anterior and lateral contralaterally up medulla
- Pass brain stem
- Pons
- Central lateral nucleus and ventral posterior lateral nucleus in thalamus
- Postcentral somatosensory cortex
Dorsal column medial lemniscus system crosses at…
Crosses at medulla oblongata
