Neural Control and Coordination

Parkinson's disease (characterized by tremors and progressive rigidity of limbs) is caused by degeneration of brain neurons that are involved in movement control and make use of neurotransmitter

1. acetylcholine
2. norepinephrine
3. dopamine
4. GABA

Four healthy people in their twenties got involved in injuries resulting in damage and death of a few cells of the following. Which of the cells are least likely to be replaced by new cells -

1. Malpighian layer of the skin
2. Osteocytes
3. Neurons
4. Liver cells

In the resting state of the neural membrane, diffusion due to concentration gradients, if allowed, would drive

1. K+ into the cell
2. K+ and Na+ out of the cell
3. Na+ into the cell
4. Na+ out of the cell.

Injury to vagus nerve in humans is not likely to affect

1. tongue movements
2. gastrointestinal movements
3. pancreatic secretion
4. cardiac movements.

What used to be described as Nissl's granules in a nerve cell are now identified as

1. cell metabolites
2. fat granules
3. ribosomes
4. mitochondria.

Which of the following statements is correct for node of Ranvier of nerve?

1. Neurilemma is discontinuous
2. Myelin sheath is discontinuous
3. Both neurilemma and myelin sheath are discontinuous
4. Covered by myelin sheath

When we migrate from dark to light, we fail to see for some time but after a time visibility becomes normal. It is an example of

1. accommodation
2. adaptation
3. mutation
4. photoperiodism

Which of the following statements is the characteristic of human cornea?

1. It is secreted by conjunctiva and glandular layer.
2. It is a lacrimal gland which secretes tears.
3. Blood circulation is absent in cornea.
4. In old age it becomes the cause of cataract.

Depolarization of axolemma during nerve conduction takes place because of

1. equal amount of Na+ and K+ move out across axolemma
2. Na+ move inside and K+ move more outside
3. more Na+ outside
4. none of these

Which food should be eaten during deficiency of rhodopsin in eyes?

1. Carrot and ripe papayas
2. Guava, banana
3. Mango and potato
4. None of the above