Consider the following statements:
I: | Impulses travel by the visceral nervous system from the CNS to the viscera and from the viscera to the CNS. |
II: | Impulses travel by the autonomic nervous system from the CNS to the involuntary organs and smooth muscles of the body. |
1. Only I is correct
2. Only II is correct
3. Both I and II are correct
4. Both I and II are incorrect
The part of the brain that has the most effect on maintenance of homeostasis is:
1. | thalamus | 2. | hypothalamus |
3. | infundibulum | 4. | mammillary body |
A funnel shaped structure, the infundibulum, connects hypothalamus and:
1. | anterior pituitary | 2. | posterior pituitary |
3. | pineal gland | 4. | thalamus |
Match the parts of the human brain in Column I with function in Column II and select the answer from the codes given:
Column I | Column II | ||
A. | Medulla oblongata | a. | Coordinating center for sensory and motor signaling |
B. | Thalamus | b. | Regulation of gastric secretions |
C. | Hypothalamus | c. | Thermoregulation and osmoregulation |
D. | Hippocampus | d. | Consolidation of short term memory into long term memory |
Codes
A | B | C | D | |
1. | a | b | c | d |
2. | b | a | d | c |
3. | a | b | d | c |
4. | b | a | c | d |
Very fast correction during the ongoing rapid muscular activity initiated elsewhere is done by:
1. | Primary motor cortex | 2. | Wernicke’s area |
3. | Basal ganglia | 4. | Cerebellum |
The resting axonal membrane is impermeable/nearly impermeable to:
I. Sodium ions
II. Potassium ions
III. Negatively charged proteins
1. | Only I and II | 2. | Only I and III |
3. | Only II and III | 4. | I, II and III |
When a neuron is resting, the axonal membrane is relatively more permeable to potassium ions and nearly impermeable to sodium ions. This would mean that:
1. | in resting conditions, all sodium channels in the axonal membrane are closed while few potassium channels are open |
2. | in resting conditions, the electrogenic sodium-potassium pump will pump only the sodium ions |
3. | in resting conditions, the electrogenic sodium-potassium pump will pump only the potassium ions |
4. | in resting conditions, the outer surface of the axonal membrane will carry a negative charge |
I: | The resting axonal membrane is relatively more permeable to potassium ions and nearly impermeable to sodium ions. |
II: | Sodium potassium pump transports 3 Na+ outwards for 2 K+ into the cell. |
1. | Only I |
2. | Only II |
3. | Both I and II |
4. | Neither I nor II |
All the following statements regarding nerve impulse conduction are correct except:
1. Myelinated neurons have a higher conduction velocity than unmyelinated neurons.
2. Nerve impulses occur in an all-or-none manner.
3. The neuron cannot be stimulated during the depolarization phase.
4. The strength of impulses carried along a single nerve fiber can vary with the strength of their stimulus.
Branched protoplasmic extensions of a nerve cell that propagate the electrochemical stimulation received from other neural cells to the cell body, or soma, of the neuron are the:
1. | axons | 2. | axon hillocks |
3. | axon collaterals | 4. | dendrites |