BIO 201 EXAM 4 – A&P I – ACTUAL QUESTIONS &
ANSWERS (STRAIGHTERLINE) (UPDATED PDF)
THIS PRACTICE EXAM IS DESIGNED TO REFLECT THE CORE CONCEPTS
TYPICALLY COVERED IN EXAM 4 OF BIO 201 (ANATOMY & PHYSIOLOGY
I) THROUGH STRAIGHTERLINE, WHICH PRIMARILY FOCUSES ON THE NERVOUS
SYSTEM (CENTRAL AND PERIPHERAL), THE AUTONOMIC NERVOUS SYSTEM,
AND SPECIAL SENSES.
Table of Contents
1. Section 1: Nervous Tissue and Action Potentials (Questions 1–20)
2. Section 2: Spinal Cord and Spinal Nerves (Questions 21–40)
3. Section 3: Brain Anatomy and Cranial Nerves (Questions 41–65)
4. Section 4: The Autonomic Nervous System (Questions 66–85)
5. Section 5: Special Senses (Questions 86–100)
Section 1: Nervous Tissue and Action Potentials
1. Which division of the nervous system is responsible for "fight or flight" responses?
• Answer: Sympathetic Nervous System.
• Rationale: The sympathetic division of the autonomic nervous system prepares the body
for physical activity or stressful situations.
2. What are the two main components of the Central Nervous System (CNS)?
• Answer: Brain and Spinal Cord.
• Rationale: The CNS acts as the integration and command center, consisting solely of the
brain and spinal cord.
3. Which glial cell forms the myelin sheath in the Peripheral Nervous System (PNS)?
• Answer: Schwann cells.
• Rationale: While oligodendrocytes myelinate the CNS, Schwann cells perform this
function in the PNS.
4. What is the gap between two myelin sheaths called?
, • Answer: Node of Ranvier.
• Rationale: These gaps allow for saltatory conduction, where the action potential "jumps"
from node to node, increasing speed.
5. Which part of the neuron typically receives incoming signals?
• Answer: Dendrites.
• Rationale: Dendrites are branching processes that act as the primary input zone for
electrical signals from other neurons.
6. During depolarization, which ion rushes into the cell?
• Answer: Sodium (Na+).
• Rationale: Depolarization is caused by the opening of voltage-gated sodium channels,
allowing Na+ to flow down its concentration gradient into the cell.
7. What is the typical resting membrane potential of a neuron?
• Answer: -70 mV.
• Rationale: This represents the electrical charge difference across the plasma membrane
when the cell is not excited.
8. Which glial cell helps form the Blood-Brain Barrier (BBB)?
• Answer: Astrocytes.
• Rationale: Astrocytes have "perivascular feet" that wrap around capillaries, regulating
the passage of substances into the brain tissue.
9. What happens during repolarization?
• Answer: Potassium (K+) ions exit the cell.
• Rationale: Repolarization occurs as Na+ channels close and K+ channels open, allowing
positive charge to leave the cell and return it to a negative state.
10. What is the "All-or-None" principle?
• Answer: If a stimulus reaches threshold, an action potential happens completely; if not, it
does not happen at all.
• Rationale: Action potentials are not graded; they are consistent in magnitude once the
threshold (usually -55mV) is met.
11. Which neurotransmitter is primarily used at the neuromuscular junction?
• Answer: Acetylcholine (ACh).
ANSWERS (STRAIGHTERLINE) (UPDATED PDF)
THIS PRACTICE EXAM IS DESIGNED TO REFLECT THE CORE CONCEPTS
TYPICALLY COVERED IN EXAM 4 OF BIO 201 (ANATOMY & PHYSIOLOGY
I) THROUGH STRAIGHTERLINE, WHICH PRIMARILY FOCUSES ON THE NERVOUS
SYSTEM (CENTRAL AND PERIPHERAL), THE AUTONOMIC NERVOUS SYSTEM,
AND SPECIAL SENSES.
Table of Contents
1. Section 1: Nervous Tissue and Action Potentials (Questions 1–20)
2. Section 2: Spinal Cord and Spinal Nerves (Questions 21–40)
3. Section 3: Brain Anatomy and Cranial Nerves (Questions 41–65)
4. Section 4: The Autonomic Nervous System (Questions 66–85)
5. Section 5: Special Senses (Questions 86–100)
Section 1: Nervous Tissue and Action Potentials
1. Which division of the nervous system is responsible for "fight or flight" responses?
• Answer: Sympathetic Nervous System.
• Rationale: The sympathetic division of the autonomic nervous system prepares the body
for physical activity or stressful situations.
2. What are the two main components of the Central Nervous System (CNS)?
• Answer: Brain and Spinal Cord.
• Rationale: The CNS acts as the integration and command center, consisting solely of the
brain and spinal cord.
3. Which glial cell forms the myelin sheath in the Peripheral Nervous System (PNS)?
• Answer: Schwann cells.
• Rationale: While oligodendrocytes myelinate the CNS, Schwann cells perform this
function in the PNS.
4. What is the gap between two myelin sheaths called?
, • Answer: Node of Ranvier.
• Rationale: These gaps allow for saltatory conduction, where the action potential "jumps"
from node to node, increasing speed.
5. Which part of the neuron typically receives incoming signals?
• Answer: Dendrites.
• Rationale: Dendrites are branching processes that act as the primary input zone for
electrical signals from other neurons.
6. During depolarization, which ion rushes into the cell?
• Answer: Sodium (Na+).
• Rationale: Depolarization is caused by the opening of voltage-gated sodium channels,
allowing Na+ to flow down its concentration gradient into the cell.
7. What is the typical resting membrane potential of a neuron?
• Answer: -70 mV.
• Rationale: This represents the electrical charge difference across the plasma membrane
when the cell is not excited.
8. Which glial cell helps form the Blood-Brain Barrier (BBB)?
• Answer: Astrocytes.
• Rationale: Astrocytes have "perivascular feet" that wrap around capillaries, regulating
the passage of substances into the brain tissue.
9. What happens during repolarization?
• Answer: Potassium (K+) ions exit the cell.
• Rationale: Repolarization occurs as Na+ channels close and K+ channels open, allowing
positive charge to leave the cell and return it to a negative state.
10. What is the "All-or-None" principle?
• Answer: If a stimulus reaches threshold, an action potential happens completely; if not, it
does not happen at all.
• Rationale: Action potentials are not graded; they are consistent in magnitude once the
threshold (usually -55mV) is met.
11. Which neurotransmitter is primarily used at the neuromuscular junction?
• Answer: Acetylcholine (ACh).
