CNS Flashcards
What is the electrolyte that is responsible for the Resting membrane potential (RMP)?
K+
What is the electrolyte responsible for the Action potential (depolarization)?
NA+
The main 1ry active transport pump in the action potential is the…
Na-K pump
What are the types of fibers in:
Lateral horn…
Posterior horn…
Anterior horn…
-Sympathetic
-Sensory (also Dorsal root ganglion is sensory)
-Motor
Where is the Acetylcholine found as a neurotransmitter?
-Pre-ganglionic neurotransmitter in all autonomic nervous system (Sym¶)
-Somatic motor neuron that I debated the skeletal muscles.
-Post-ganglionic in parasympathetic.
-Post-ganglionic in sympathetic to sweat and skeletal muscle blood vessels.
Where is the Adrenaline and Nor-Adrenaline found as neurotransmitters?
-Post-ganglionic in sympathetic except sweat and skeletal muscle blood vessels
-From the adrenal glands
What are the difference between the Adrenaline and Nor-Adrenaline secreted from the nerve ending and from the adrenal gland?
-From Adrenal gland:
Adrenaline>Nor-Adrenaline
-Post ganglionic:
Nor-Adrenaline>Adrenaline
What are the types of receptors for the Adrenaline, nor-adrenaline and Acetylcholine?
Adrenaline and Nor-Adrenaline - alpha 1&2, Beta 1&2
Acetylcholine- Nicotinic and Mascarinic
Beta1 acts on the heart and alpha1 acts on blood vessels
What are the changes that happens in response to sympathetic stimulation?
-Pupil dilatation (Mydriasis)
-Bronchodilatation
-CVS stimulation by increase cardiac properties and VC
-GIT inhibition (decrease gastric emptying and paralytic ileus)
-Ejaculation (sym=semen)
What are the changes that happen in response to para sympathetic stimulation?
-Pupil constriction (miosis)
-Bronchoconstriction
-CVS inhibition by desecrating the cardiac properties (no action on blood vessels and if VD)
-GIT stimulation (increase gastric emptying and peristalysis)
-Erection (para=point)
What are the ascending (sensory) tracts in the spinal cord?
Pain and temperature that crosses to the opposite side forming the lateral spinothalamic tract
Proprioception and vibration that passes in the same side of the spinal cord as the dorsal column then crosses at the medulla to the opposite side
What are the descending or motor tracts in the spinal cord?
Motor cortex send UMN to the anterior horn cells which is called pyramidal tract or corticospinal tract
Anterior horn cells send LMN to the muscle
What is meant by UMNL and what are the main characteristic features?
Damage of the cortical motor areas or along the course of descending pyramidal or corticospinal tracts.
Characterized by:
-Opposite side of body and widespread hemiplegia
-Hypertonia (clasp knife spasticity)
-Hyperreflexia or brisk reflexes (Clonus appears)
What is meant by LMNL and what are the main characteristic features?
Damage of the Anterior horn cells or their axons or muscles
Characterized by:
-Same side of injury and localized
-Atonia (Flaccidity)
-Areflexia
What is Myasthenia Gravis?
It is a n autoimmune disease which result from antibodies that block nicotinic acetylcholine receptors at the neuromuscular junction.
-Weakness starts at eye and moves down
-Weakness worse by activity
-May be associated with thymoma
What is Lambret-Eaton syndrome?
It is a n autoimmune disorder which result from autoantibodies damage to the voltage gated calcium channels so prevents the release of acetylcholine at the neuromuscular junction.
-Weakness start at extremities and moves up
-Weakness worse with rest
-May be associated with small cell lung cancer
What is Botulinum toxin?
It is a neurotoxin produced by clostridium botulinum and it prevents the release of neurotransmitter acetylcholine at neuromuscular junction
What is the cause and clinical picture of brown sequard syndrome?
It is hemi section of spinal cord by stab or gunshot
Clinical picture:
-Ipsilateral paralysis or weakness of the muscle (pyramidal tract)
-Loss of proprioception and fine discrimination (dorsal columns) in the affected side
-Pain and temperature sensation are lost on the contra lateral side
What is the cause and clinical picture of syringomyelia or central cord tumor?
It is degenerative disease around the central canal that affects the cervical region more than the lumbar region
Clinical picture:
-Decussating spinothalamic tract are involved as pain and temperature
-Upper/lower limbs bilaterally affected
What is the cause and clinical picture of Quada equina?
It is a lesion below level of conus medulla row (L1 in adult)
Clinical picture:
-LMNL affect of both lower limbs (weakness)
What is the cause and clinical picture of Posterior cord syndrome?
Hyper extension causing fracture of posterior part of vertebrae
Clinical picture:
-Loss of proprioception
-Good power, pain and temperature
What is the cause and clinical picture of Anterior cord syndrome?
Flexion rotation injury producing anterior dislocation of vertebrae
Clinical picture:
-Loss of power, pain and temperature
-Dorsal columns remain intact
What are the manifestations of ACA ischemia? عكّة
Opposite side LL paralysis
What are the manifestations of MCA ischemia? مكّة
Opposite side hemiplegia (If aphasia occur, this means dominant hemisphere is affected so left MCA ischemia)
