C2.2 SL / HL

Question 1

Central nervous system (CNS)

Answer 1

the part of the nervous system that includes the brain and spinal cord, and is responsible for processing and responding to sensory information

Question 2

Interneurons

Answer 2

a neuron that connects sensory and motor neurons, and is responsible for integrating information and communication between neurons

Question 3

Peripheral nervous system (PNS)

Answer 3

bundles of nerve fibers or axons conduct information to and from the CNS

Question 4

Sensory neurons

Answer 4

nerve cells that receive and transmit information about changes in the environment to the central nervous system

Question 5

Motor neurons

Answer 5

nerve cells in the central nervous system (CNS) that transmit signals from the brain and sensory systems to muscles, glands, and organs

Question 6

Nerve

Answer 6

a bundle of fibers that carries electrical and chemical signals between the brain and the rest of the body

Question 7

impulse

Answer 7

an electrical signal that travels along a nerve fiber, or neuron, in response to a stimulus

Question 8

Neuron

Answer 8

a cell that transmits signals throughout the body, using electrical and chemical signals to send information between the brain, spinal cord, and the rest of the body

Question 9

Dendrite

Answer 9

a branch-like extension of a neuron that receives and transmits electrical signals from other cells

Question 10

Cell body

Answer 10

the central part of a neuron that contains the nucleus and controls the cell’s functions

Question 11

Axon

Answer 11

a long, thin fiber that extends from the main part of a neuron and transmits electrical impulses to other neurons, muscles, and glands

Question 12

Myelin sheath

Answer 12

a fatty layer that surrounds the axon of a nerve cell, insulating it and allowing electrical impulses to travel quickly and efficiently

Question 13

Axon terminal buttons

Answer 13

small structures at the end of an axon that transmit signals to other neurons, muscle cells, or glands

Question 14

Membrane potential

Answer 14

the difference in electrical potential between the inside and outside of a biological cell

Question 15

Resting potential

Answer 15

the electrical potential difference across the plasma membrane when the cell is in a non-excited state

Question 16

Na+ / K+ pump cycle

Answer 16

a process that moves sodium ions out of a cell and potassium ions into it in a repeating cycle. The cycle involves the pump changing shape between two forms, and the addition or removal of a phosphate group

Question 17

phosphorylate

Answer 17

the process of adding a phosphate group to a molecule or ion

Question 18

conformational change

Answer 18

a change in the shape of a macromolecule, such as a protein or molecule, in response to environmental factors or other stimuli

Question 19

action potential

Answer 19

a rapid change in the electrical charge across a cell membrane, also known as a nerve impulse

Question 20

voltage-gated Na+ channels

Answer 20

transmembrane proteins that control the flow of sodium ions across a cell membrane.They are responsible for generating action potentials in excitable cells, such as neurons and muscle cells, which are electrical signals that trigger responses like contractions or the release of neurotransmitters.

Question 21

voltage-gated K+ channels

Answer 21

transmembrane proteins that regulate the movement of potassium ions across cell membranes in response to changes in membrane potential

Question 22

Non-myelinated nerves

Answer 22

nerve fibers that do not have a myelin sheath, a white covering that surrounds axons

Question 23

Myelinated nerves

Answer 23

nerves that have a myelin sheath, which is an insulating layer that surrounds the nerve and allows electrical impulses to travel quickly and efficiently

Question 24

Schwann cells

Answer 24

glial cells in the peripheral nervous system that insulate and support nerve cells

Question 25

nodes of Ranvier

Answer 25

gaps in the myelin sheath that insulates the axon of a neuron, allowing electrical signals to travel quickly down the axon

Question 26

Synapse (synaptic cleft)

Answer 26

the small gap between two neurons where electrical signals are converted into chemical signals and then back into electrical signals:

Question 27

neurotransmitters

Answer 27

chemical messengers that transmit signals between nerve cells and muscles

Question 28

excitatory

Answer 28

something has the ability to excite or stimulate a nerve cell, causing it to receive critical information and pass along a message to the next cell

Question 29

inhibitory

Answer 29

a type of neuron that release chemicals to stop other neurons from firing

Question 30

presynaptic neuron

Answer 30

a neuron that sends information to another neuron through a synapse

Question 31

postsynaptic neuron

Answer 31

a neuron that receives signals from a presynaptic neuron through a junction called a synapse

Question 32

Effector

Answer 32

a cell, tissue, or organ that produces a response to a stimulus

Question 33

Acetylcholine

Answer 33

a neurotransmitter that carries chemical messages between nerve cells and other cells in the body

Question 34

neuromuscular junction

Answer 34

the connection point between a motor nerve and a muscle fiber where electrical impulses are transmitted to cause muscle contraction

Question 35

terminal bud

Answer 35

a bud that is located at the tip of a plant’s stem or branch, where most of the plant’s growth occurs

Question 36

Depolarization

Answer 36

a process that occurs when a cell’s internal charge becomes less negative, or more positive, relative to the outside of the cell

Question 37

Voltage-gated Ca2+ channels

Answer 37

transmembrane proteins that allow calcium to enter cells in response to changes in membrane potential

Question 38

exocytosis

Answer 38

the process of moving large molecules out of a cell and into the extracellular space

Question 39

ligand-gated Na+ channels

Answer 39

membrane proteins that allow Na+ to pass through when a ligand molecule binds to the channel:

Question 40

acetylcholine receptor protein

Answer 40

a protein that responds to the binding of acetylcholine, a neurotransmitter, by changing the permeability of the cell membrane

Question 41

Neonicotinoids

Answer 41

a class of synthetic insecticides that are absorbed into plants and used to control harmful insects

Question 42

Acetylcholinesterase

Answer 42

a cholinergic enzyme primarily found at postsynaptic neuromuscular junctions, especially in muscles and nerves. It immediately breaks down or hydrolyzes acetylcholine (ACh), a naturally occurring neurotransmitter, into acetic acid and choline.