Nervous System (GATE - XL)

Nissl bodies synthesise protein for intracellular use. They consist of rough endoplasmic reticulum and associated ribosomal RNA.

Bezold-Jarisch reflex involves a variety of cardiovascular and neurological processes which cause hypopnea and bradycardia.

Pigment neuromelanin is linked to Parkinson's disease. Neuromelanin-containing neurons in the substantia nigra undergo neurodegeneration during Parkinson's disease. This makes the cell deficient of neuromelanin.

Granule cell is a Golgi type II neuron. Granule cell is the only excitatory neuron present in the cerebellar cortex of brain.

Renshaw cells are targetted by the toxin of Clostridium tetani. When wounds are contaminated with Clostridium tetani, the toxin travels to the spinal cord where it inhibits the release of glycine, an inhibitory neurotransmitter, from Renshaw cells. As a result, alpha motor neurons become hyperactive and muscles constantly contract.

Niemann-Pick disease type C involves the progressive loss of Purkinje cells. In this disease, sphingomyelin accumulates in lysosomes in the cells.

Interneurons in neurostriatum are tonic or regular spiking neurons. They are constantly active.

Oligodendrocytes are the glial cells that coat axons in the central nervous system (CNS) with their cell membrane, forming a specialised membrane differentiation called myelin, to produce the so-called myelin sheath. Myelin sheath provides insulation to neuron and allows electrical signals to propagate more efficiently.

The glial/neuron ratio in the cerebral cortex is 3.72 (60.84 billion glia : 16.34 billion neurons).

Contactin present at nodes of Ranvier in the CNS enhances the surface expression of Na⁺ channels.

Polar artery and inferolateral artery supply blood to the thalamus.

Tentorium cerebelli is a fold of the dura mater separating cerebrum from cerebellum.

In holoprosencephaly, embryonic forebrain fails to divide into two lobes. In most cases of holoprosencephaly, the malformations are so severe that babies die before birth.

The neurons of the subthalamic nucleus contain glutamate that has excitatory effects over neurons of globus pallidus and substantia nigra.

Huntington's disease is a choreiform disorder and is caused by a degenerative process in the striatum. It affects muscle coordination and leads to mental decline and behavioral symptoms.