BIO-Exam 4: Neuroscience

Question 1

Central Nervous System (CNS)

Answer 1

Located in the brain and spinal cord; processes and integrates information from the body.

Question 2

Axon hillock

Answer 2

Found at the junction between the cell body and axon; initiates action potentials if the signal is strong enough.

Question 3

Resting potential

Answer 3

Occurs across the neuron membrane at rest; maintains a negative charge inside the cell (~–70 mV).

Question 4

Potassium leak channel

Answer 4

Located in the neuron membrane; allows K⁺ ions to diffuse out, helping maintain the resting membrane potential.

Question 5

Peripheral Nervous System (PNS)

Answer 5

Located outside the CNS; transmits signals between the CNS and the rest of the body.

Question 6

Glia

Answer 6

Found throughout the nervous system; support, protect, and nourish neurons.

Question 7

Depolarization

Answer 7

Happens at the nueron membrane during action potential; the inside becomes positive due to Na⁺

Question 8

Action potential

Answer 8

Initiated at the axon hillock and travels along the axon; a rapid electrical signal for neuron communication.

Question 9

Cerebrospinal Fluid (CSF)

Answer 9

Fills spaces in the brain and spinal cord; cushions the CNS and removes waste.

Question 10

Astrocyte

Answer 10

A type of glial cell in the CNS; supports neurons, forms the blood-brain barrier, and regulates the extracellular environment.

Question 11

Repolarization

Answer 11

Occurs after depolarization during an action potential; restores the negative resting membrane potential.

Question 12

Cell body

Answer 12

Part of the neuron containing the nucleus; Reads incoming signals and maintains cell function.

Question 13

Oligodendrocyte

Answer 13

A glial cell in the CNS; produces myelin sheaths that insulate axons.

Question 14

Graded potential

Answer 14

Happens in dendrites and cell body; small, changes in membrane potential

Question 15

Dendrites

Answer 15

Branch-like extensions of neurons; receive incoming signals from other neurons.

Question 16

Microglia

Answer 16

Immune cells of the CNS; remove pathogens and debris through phagocytosis.

Question 17

Voltage-gated sodium channel

Answer 17

Located along the axon membrane; opens in response to depolarization, allowing Na⁺ influx to propagate the action potential.

Question 18

Axon

Answer 18

A long projection of a neuron; transmits electrical signals to other neurons or effectors

Question 19

Ependymal cell

Answer 19

Lines brain and central canal of the spinal cord; helps produce and circulate cerebrospinal fluid.

Question 20

Voltage-gated potassium channel

Answer 20

Found on the axon membrane; opens after depolarization to let K⁺ out, aiding in repolarization.

Question 21

Myelin

Answer 21

Wraps around axons (produced by oligodendrocytes in CNS and Schwann cells in PNS); insulates axons and speeds up signal conduction.

Question 22

Electrical Synapse

Answer 22

Found between some neurons via gap junctions; allows direct, rapid transmission of electrical signals.

Question 23

Ligand

Answer 23

Present in the extracellular space near receptors; a molecule (like a neurotransmitter) that binds to a receptor to initiate a response.

Question 24

Nodes of Ranvier

Answer 24

Gaps between myelinated segments of axons; where voltage-gated channels cluster so electrical signals get a boost so they can keep moving fast along the nerve.

Question 25

Chemical Synapse

Answer 25

Occurs between neurons at synaptic terminals; neurotransmitters are released and bind to receptors to relay the signal.

Question 26

Voltage-gated Ca²⁺ channel

Answer 26

Located at the axon terminal; opens during an action potential to allow Ca²⁺ influx, triggering neurotransmitter release.

Question 27

Contiguous Conduction

Answer 27

Happens in unmyelinated axons; action potential moves along every part of the membrane sequentially.

Question 28

Neurotransmitter

Answer 28

Stored at synaptic terminals; chemical messengers that cross synapses to send signals to other cells.

Question 29

Temporal Summation

Answer 29

Occurs at the postsynaptic neuron; multiple signals from the same presynaptic neuron add up over time to reach threshold.

Question 30

Saltatory Conduction

Answer 30

Happens in myelinated axons; action potential "jumps" from one node of Ranvier to the next for faster transmission.

Question 31

Neurotransmitter Receptor

Answer 31

Located on the postsynaptic membrane; binds neurotransmitters to generate a response in the target cell.

Question 32

Spatial Summation

Answer 32

Happens in the postsynaptic neuron; signals from multiple neurons combine to initiate an action potential.