Exam 4: NU110 / NU 110 (New 2025 / 2026 Update) Integrated Human Sciences | Questions with Verified Answers | 100 % Correct | Grade A – Galen.

Exam 4: NU110 / NU 110 (New 2025 /
2026 Update) Integrated Human
Sciences | Questions with Verified
Answers | 100 % Correct | Grade A –
Galen.
Question:
Which of the following neurotransmitters stimulates skeletal muscles??
i,- i,- i,- i,- i,- i,- i,-




Answer:
A. Serotonin
i,-




B. Dopamine
i,-




C. Norepinephrine
i,-




D. Acetylcholine (Ach)
i,- i,- i,-




Explanation:


Acetylcholine (ACh) is the neurotransmitter that stimulates skeletal
i,- i,- i,- i,- i,- i,- i,- i,-


muscles at the neuromuscular junction by binding to nicotinic receptors.
i,- i,- i,- i,- i,- i,- i,- i,- i,-




Breakdown of options: i,- i,-




i,- • A. Serotonin
i,- i,- i,-




• Involved in mood, appetite, and sleep regulation; not involved in muscle
i,- i,- i,- i,- i,- i,- i,- i,- i,- i,- i,- i,- i,-


contraction.

,i,- • B. Dopamine
i,- i,- i,-




• Regulates movement in the brain (e.g., Parkinson's disease) but does
i,- i,- i,- i,- i,- i,- i,- i,- i,- i,- i,- i,-



not directly stimulate skeletal muscles.
i,- i,- i,- i,-




i,- • C. Norepinephrine
i,- i,- i,-




• Functions in the sympathetic nervous system, but does not stimulate
i,- i,- i,- i,- i,- i,- i,- i,- i,- i,- i,- i,-


skeletal muscles. i,-




i,- • D. Acetylcholine (ACh)
i,- i,- i,- i,-




• Directly responsible for triggering muscle contractions by activating
i,- i,- i,- i,- i,- i,- i,- i,- i,- i,-


nicotinic cholinergic receptors at the motor end plate of skeletal muscle.
i,- i,- i,- i,- i,- i,- i,- i,- i,- i,-




i,- Key Point: Nicotinic receptors = skeletal muscle
i,- i,- i,- i,- i,- i,-




Muscarinic receptors = parasympathetic organs i,- i,- i,- i,-




Question:
Which of the following is referred to as association neurons and relays
i,- i,- i,- i,- i,- i,- i,- i,- i,- i,- i,- i,-


information from place to place within the central nervous system? (CNS)?
i,- i,- i,- i,- i,- i,- i,- i,- i,- i,-




Answer:

A. Mixed neurons
i,- i,-




B. Nerve tracts
i,- i,-




C. Interneurons
i,-




D. Axonsi,-




Explanation:

,Interneurons (also called association neurons) are found only in the
i,- i,- i,- i,- i,- i,- i,- i,- i,- i,-



central nervous system (CNS) and are responsible for:
i,- i,- i,- i,- i,- i,- i,-




i,- • Relaying information between sensory neurons and motor neurons
i,- i,- i,- i,- i,- i,- i,- i,-




i,- • Processing and integrating information within the brain and spinal cord
i,- i,- i,- i,- i,- i,- i,- i,- i,- i,-




⸻



Breakdown of options: i,- i,-




i,- • A. Mixed neurons
i,- i,- i,- i,-




• Contain both sensory and motor fibers; typically part of peripheral
i,- i,- i,- i,- i,- i,- i,- i,- i,- i,- i,- i,-


nerves, not specific to processing within the CNS.
i,- i,- i,- i,- i,- i,- i,-




i,- • B. Nerve tracts
i,- i,- i,- i,-




• Bundles of axons in the CNS that carry signals to or from different
i,- i,- i,- i,- i,- i,- i,- i,- i,- i,- i,- i,- i,- i,- i,-



regions, but not neurons themselves.
i,- i,- i,- i,-




i,- • C. Interneurons
i,- i,- i,-




i,- • Located entirely within the CNS
i,- i,- i,- i,- i,-




• Responsible for information processing and communication within the
i,- i,- i,- i,- i,- i,- i,- i,- i,- i,-



CNS.

i,- • D. Axons
i,- i,- i,-




• Long projections of neurons that transmit impulses away from the cell
i,- i,- i,- i,- i,- i,- i,- i,- i,- i,- i,- i,- i,-


body; not specific to relay and integration like interneurons.
i,- i,- i,- i,- i,- i,- i,- i,-




Key Point: Interneurons = CNS-only neurons that connect and integrate
i,- i,- i,- i,- i,- i,- i,- i,- i,- i,- i,-


sensory and motor pathways. i,- i,- i,-

, Question:

Efferent neurons carry impulses:? i,- i,- i,-




Answer:

A. Toward the spinal cord
i,- i,- i,- i,-




B. To the body
i,- i,- i,-




C. To the central nervous system (CNS)
i,- i,- i,- i,- i,- i,-




D. Toward the brain
i,- i,- i,-




Explanation:



Efferent neurons (also called motor neurons) carry impulses away from the
i,- i,- i,- i,- i,- i,- i,- i,- i,- i,- i,-


central nervous system (CNS) to the body, specifically to:
i,- i,- i,- i,- i,- i,- i,- i,-




i,- • Muscles (to initiate movement)
i,- i,- i,- i,-




i,- • Glands (to trigger secretion)
i,- i,- i,- i,-




This is in contrast to afferent neurons, which carry signals toward the CNS
i,- i,- i,- i,- i,- i,- i,- i,- i,- i,- i,- i,- i,-


from sensory receptors.
i,- i,-




⸻


Breakdown of options: i,- i,-