Nervous Coordination MCQs for MDCAT

Correct answer: D. Increase in Heart Rate

Over-activity of the sympathetic nervous system increases heart rate as part of the body's fight-or-flight response.

Correct answer: B. 12 pairs

Humans have 12 pairs of cranial nerves, which emerge directly from the brain rather than the spinal cord.

Correct answer: A. Fore brain

The thalamus and cerebrum are both structures of the forebrain, which also includes the hypothalamus.

Correct answer: D. Acetylcholine

Acetylcholine is the neurotransmitter released at synapses outside the central nervous system, including the neuromuscular junction and autonomic ganglia.

Correct answer: C. Alzheimer's Disease

Alzheimer's disease is a progressive neurological disorder marked by declining brain function, with symptoms overlapping those of other dementias.

Correct answer: C. Nociceptors

The pain receptors are nociceptors. They are known to exist in muscle, joints, and skin.

Correct answer: A. Acetylcholine

Acetylcholine is a neurotransmitter that is active both in the central nervous system (CNS) and outside the CNS. It is involved in various functions, including muscle contraction, autonomic nervous system regulation, and cognitive processes.

Correct answer: C. 0.05 Volts

The action potential of a neuron typically peaks at around 0.05 V (or 50 mV) during the depolarization phase, which is the rapid increase in membrane potential when a neuron fires. This is the most appropriate value for the peak of the action potential.

Correct answer: A. Inward movement of Na+

The inward movement of Na+ (sodium ions) occurs during the depolarization phase of a nerve impulse. When a neuron is stimulated, voltage-gated sodium channels open, allowing Na+ to rush into the cell. This influx of positively charged sodium ions causes the inside of the neuron to become less negative (or more positive), leading to the generation of an action potential. This rapid change in membrane potential is what propagates the nerve impulse along the axon.

Correct answer: A. K+

During the non-conducting state (resting state) of a neuron, the neuronal membrane is primarily permeable to the efflux of potassium ions (K⁺). This permeability is due to the presence of potassium channels that allow K⁺ to flow out of the cell, contributing to the resting membrane potential, which is typically around -70 mV. The efflux of K⁺ ions occurs because of their higher concentration inside the neuron compared to the outside, leading to a net outward movement and a negative charge inside the neuron.

Correct answer: B. Continuous impulse

Option B is correct. The type of nerve impulse that occurs in non-myelinated neuron fibers is a continuous impulse. A continuous impulse is a type of nerve impulse that travels down the axon of a neuron without jumping. This is in contrast to a saltatory impulse, which is a type of nerve impulse that jumps from node to node along the axon of a myelinated neuron. Myelinated neurons are neurons that have a myelin sheath, which is a fatty substance that insulates the axon. The myelin sheath helps to speed up the transmission of nerve impulses by allowing them to jump from node to node. Non-myelinated neurons do not have a myelin sheath, so nerve impulses travel down the axon continuously. This means that nerve impulses travel more slowly in non-myelinated neurons than in myelinated neurons. Saltatory impulse: A type of nerve impulse that jumps from node to node along the axon of a myelinated neuron. Rapid impulse: A type of nerve impulse that travels quickly. Jumping impulse: A type of nerve impulse that jumps from node to node along the axon of a myelinated neuron.

Correct answer: B. Hippocampus

The hippocampus is a structure in the temporal lobe that plays a critical role in the formation and consolidation of long-term memories, especially those related to emotions and experiences. It is involved in encoding new memories, consolidating information from short-term to long-term memory, and Spatial navigation and memory. Damage to the hippocampus can lead to difficulties in forming new memories, a condition known as anterograde amnesia.