موضوع: SEQs on nervous system physiology with their answers by Dr Khaled A Abulfadle الثلاثاء يناير 01, 2013 10:23 pm
Q: Tonic neck reflexes
Tonic neck reflexes
Definition: When the face is turned to the affected side (spastic hemiplegic side in UMNL), the arm and leg on the affected side to which the face is turned extend and abduct
Nature: they are primitive reflexes found in newborn, but, reappears in upper motor neuron lesion
Cause of reappearance in UMNL: the reappearance of the tonic neck reflex in UMNL may be due to: 1-lesion in pyramidal tract which inhibits normally this primitive reflex 2-in UMNL due to internal capsule lesion is accompanied by intact vestibular nucleus which may be responsible for these reflexes
عدل سابقا من قبل Admin في الإثنين يناير 09, 2017 8:16 pm عدل 5 مرات
موضوع: رد: SEQs on nervous system physiology with their answers by Dr Khaled A Abulfadle الأحد مارس 03, 2013 4:52 am
Q: Explain mechanism of rigidity in case of meningitis
A: Neck stiffness (rigidity) in meningitis occurs because the lining of the spinal cord is connected to the lining of the brain. When this infected and inflamed lining is stretched by looking down, it causes severe pain.
In meningitis, if the patient flexes the neck, the spinal canal elongates and the meninges stretch, which is painful if they are inflamed. As a result, the patient will guard against neck flexion and this is what results in nuchal rigidity.
موضوع: رد: SEQs on nervous system physiology with their answers by Dr Khaled A Abulfadle الأربعاء مارس 02, 2016 6:25 am
?Q: What is the skin temperature at which hot and cold pain receptors are stimulated ========== A: The average person begins to perceive pain when the skin is heated above 45°C. This is also the temperature at which the tissues begin to be damaged by heat; indeed, the tissues are eventually destroyed if the temperature remains above this level indefinitely. Below 10°C, cold pain fibers are stimulated.
موضوع: رد: SEQs on nervous system physiology with their answers by Dr Khaled A Abulfadle الإثنين يناير 09, 2017 8:18 pm
Define, Doctrine of specific nerve energy and law of projection ==============
=Doctrine of Specific Nerve Energies (Labeled Line): the sensation evoked by stimulation of a receptor or its pathway is sensed as being caused by the receptor's adequate stimulus, no matter what the actual stimulus. =Law of Projection: sensation is sensed as arising from (projected to) the receptor's receptive field as each part of the body is represented in the sensory cortex.
موضوع: رد: SEQs on nervous system physiology with their answers by Dr Khaled A Abulfadle السبت مارس 18, 2017 8:42 am
Question Pathophysiology of Parkinsonism
Direct pathway in basal ganglia causes inhibition of Globus Pallidus interna which is inhibitory to thalamus and hence motor cortex
Indirect Pathway in basal ganglia stimulates globus Pallidus interna which is inhibitory to thalamus and hence motor cortex
Dopamine inhibits globus Pallidus interna both directly (stimulate direct pathway) and indirectly (inhibit indirect pathway) with resulting stimulation of motor cortex
In parkinsonism, depleted dopamine causes hyperactive globus Pallidus interna with inhibition of thalamus and motor cortex causing hypokinesia and that is why in treatment of parkinsonism you should either compensate for dopamine or even do destruction of globus Pallidus interna
SEQs on nervous system physiology with their answers by Dr Khaled A Abulfadle