,BIOL251/BIOL 251 Human Anatomy & Physiology I w/Lab
1. The afferent division of the peripheral nervous system is responsible for:
A) Carrying motor commands from the CNS to muscles and glands
B) Transmitting sensory information from receptors to the CNS
C) Controlling voluntary skeletal muscle movements
D) Regulating the "fight-or-flight" response
Correct Answer: Transmitting sensory information from receptors to the CNS
Rationale: The afferent (sensory) division conducts nerve impulses from sensory receptors toward the
central nervous system. The efferent (motor) division conducts impulses away from the CNS to effectors
such as muscles and glands.
2. Which division of the autonomic nervous system is responsible for the "rest and digest" response?
A) Sympathetic division
B) Somatic division
C) Parasympathetic division
D) Enteric division
Correct Answer: Parasympathetic division
Rationale: The parasympathetic division of the autonomic nervous system is responsible for the "rest
and digest" response, which conserves energy and promotes routine maintenance activities such as
digestion and salivation. The sympathetic division controls the "fight-or-flight" response.
3. Which type of neuroglial cell is responsible for forming the myelin sheath in the central nervous
system?
A) Schwann cell
B) Oligodendrocyte
C) Astrocyte
,D) Microglia
Correct Answer: Oligodendrocyte
Rationale: Oligodendrocytes are the myelinating cells of the central nervous system, producing myelin
sheaths that insulate axons and increase the speed of nerve impulse conduction. Schwann cells perform
this function in the peripheral nervous system.
4. The resting membrane potential of a typical neuron is approximately:
A) -55 mV
B) 0 mV
C) -70 mV
D) +30 mV
Correct Answer: -70 mV
Rationale: The resting membrane potential of a typical neuron is about -70 mV, meaning the inside of
the cell is negatively charged relative to the outside. This is maintained by the sodium-potassium pump
and the selective permeability of the membrane.
5. An action potential is triggered when the membrane potential reaches which value?
A) Resting potential
B) Threshold potential
C) Equilibrium potential
D) Repolarization potential
Correct Answer: Threshold potential
Rationale: An action potential is initiated when the membrane potential reaches the threshold potential
(typically around -55 mV). At this point, voltage-gated sodium channels open, and the neuron fires in an
all-or-none manner.
, 6. Which neurotransmitter is released at the neuromuscular junction to stimulate skeletal muscle
contraction?
A) Dopamine
B) Serotonin
C) Acetylcholine
D) Norepinephrine
Correct Answer: Acetylcholine
Rationale: Acetylcholine is the neurotransmitter released from motor neurons at the neuromuscular
junction. It binds to receptors on the muscle fiber's sarcolemma, initiating an action potential and
muscle contraction.
7. The spinal cord is part of which structural division of the nervous system?
A) Peripheral nervous system
B) Central nervous system
C) Autonomic nervous system
D) Somatic nervous system
Correct Answer: Central nervous system
Rationale: The central nervous system (CNS) consists of the brain and spinal cord. The peripheral
nervous system (PNS) includes all nerves and ganglia outside the CNS.
8. How many pairs of cranial nerves are there in the human body?
A) 12
B) 24
C) 31
D) 10
1. The afferent division of the peripheral nervous system is responsible for:
A) Carrying motor commands from the CNS to muscles and glands
B) Transmitting sensory information from receptors to the CNS
C) Controlling voluntary skeletal muscle movements
D) Regulating the "fight-or-flight" response
Correct Answer: Transmitting sensory information from receptors to the CNS
Rationale: The afferent (sensory) division conducts nerve impulses from sensory receptors toward the
central nervous system. The efferent (motor) division conducts impulses away from the CNS to effectors
such as muscles and glands.
2. Which division of the autonomic nervous system is responsible for the "rest and digest" response?
A) Sympathetic division
B) Somatic division
C) Parasympathetic division
D) Enteric division
Correct Answer: Parasympathetic division
Rationale: The parasympathetic division of the autonomic nervous system is responsible for the "rest
and digest" response, which conserves energy and promotes routine maintenance activities such as
digestion and salivation. The sympathetic division controls the "fight-or-flight" response.
3. Which type of neuroglial cell is responsible for forming the myelin sheath in the central nervous
system?
A) Schwann cell
B) Oligodendrocyte
C) Astrocyte
,D) Microglia
Correct Answer: Oligodendrocyte
Rationale: Oligodendrocytes are the myelinating cells of the central nervous system, producing myelin
sheaths that insulate axons and increase the speed of nerve impulse conduction. Schwann cells perform
this function in the peripheral nervous system.
4. The resting membrane potential of a typical neuron is approximately:
A) -55 mV
B) 0 mV
C) -70 mV
D) +30 mV
Correct Answer: -70 mV
Rationale: The resting membrane potential of a typical neuron is about -70 mV, meaning the inside of
the cell is negatively charged relative to the outside. This is maintained by the sodium-potassium pump
and the selective permeability of the membrane.
5. An action potential is triggered when the membrane potential reaches which value?
A) Resting potential
B) Threshold potential
C) Equilibrium potential
D) Repolarization potential
Correct Answer: Threshold potential
Rationale: An action potential is initiated when the membrane potential reaches the threshold potential
(typically around -55 mV). At this point, voltage-gated sodium channels open, and the neuron fires in an
all-or-none manner.
, 6. Which neurotransmitter is released at the neuromuscular junction to stimulate skeletal muscle
contraction?
A) Dopamine
B) Serotonin
C) Acetylcholine
D) Norepinephrine
Correct Answer: Acetylcholine
Rationale: Acetylcholine is the neurotransmitter released from motor neurons at the neuromuscular
junction. It binds to receptors on the muscle fiber's sarcolemma, initiating an action potential and
muscle contraction.
7. The spinal cord is part of which structural division of the nervous system?
A) Peripheral nervous system
B) Central nervous system
C) Autonomic nervous system
D) Somatic nervous system
Correct Answer: Central nervous system
Rationale: The central nervous system (CNS) consists of the brain and spinal cord. The peripheral
nervous system (PNS) includes all nerves and ganglia outside the CNS.
8. How many pairs of cranial nerves are there in the human body?
A) 12
B) 24
C) 31
D) 10
