C2.2 SL / HL Flashcards
Central nervous system (CNS)
the part of the nervous system that includes the brain and spinal cord, and is responsible for processing and responding to sensory information
Interneurons
a neuron that connects sensory and motor neurons, and is responsible for integrating information and communication between neurons
Peripheral nervous system (PNS)
bundles of nerve fibers or axons conduct information to and from the CNS
Sensory neurons
nerve cells that receive and transmit information about changes in the environment to the central nervous system
Motor neurons
nerve cells in the central nervous system (CNS) that transmit signals from the brain and sensory systems to muscles, glands, and organs
Nerve
a bundle of fibers that carries electrical and chemical signals between the brain and the rest of the body
impulse
an electrical signal that travels along a nerve fiber, or neuron, in response to a stimulus
Neuron
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
Dendrite
a branch-like extension of a neuron that receives and transmits electrical signals from other cells
Cell body
the central part of a neuron that contains the nucleus and controls the cell’s functions
Axon
a long, thin fiber that extends from the main part of a neuron and transmits electrical impulses to other neurons, muscles, and glands
Myelin sheath
a fatty layer that surrounds the axon of a nerve cell, insulating it and allowing electrical impulses to travel quickly and efficiently
Axon terminal buttons
small structures at the end of an axon that transmit signals to other neurons, muscle cells, or glands
Membrane potential
the difference in electrical potential between the inside and outside of a biological cell
Resting potential
the electrical potential difference across the plasma membrane when the cell is in a non-excited state
Na+ / K+ pump cycle
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
phosphorylate
the process of adding a phosphate group to a molecule or ion
conformational change
a change in the shape of a macromolecule, such as a protein or molecule, in response to environmental factors or other stimuli
action potential
a rapid change in the electrical charge across a cell membrane, also known as a nerve impulse
voltage-gated Na+ channels
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.
voltage-gated K+ channels
transmembrane proteins that regulate the movement of potassium ions across cell membranes in response to changes in membrane potential
Non-myelinated nerves
nerve fibers that do not have a myelin sheath, a white covering that surrounds axons
Myelinated nerves
nerves that have a myelin sheath, which is an insulating layer that surrounds the nerve and allows electrical impulses to travel quickly and efficiently
Schwann cells
glial cells in the peripheral nervous system that insulate and support nerve cells
nodes of Ranvier
gaps in the myelin sheath that insulates the axon of a neuron, allowing electrical signals to travel quickly down the axon
Synapse (synaptic cleft)
the small gap between two neurons where electrical signals are converted into chemical signals and then back into electrical signals:
neurotransmitters
chemical messengers that transmit signals between nerve cells and muscles
excitatory
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
inhibitory
a type of neuron that release chemicals to stop other neurons from firing
presynaptic neuron
a neuron that sends information to another neuron through a synapse
postsynaptic neuron
a neuron that receives signals from a presynaptic neuron through a junction called a synapse
Effector
a cell, tissue, or organ that produces a response to a stimulus
Acetylcholine
a neurotransmitter that carries chemical messages between nerve cells and other cells in the body
neuromuscular junction
the connection point between a motor nerve and a muscle fiber where electrical impulses are transmitted to cause muscle contraction
terminal bud
a bud that is located at the tip of a plant’s stem or branch, where most of the plant’s growth occurs
Depolarization
a process that occurs when a cell’s internal charge becomes less negative, or more positive, relative to the outside of the cell
Voltage-gated Ca2+ channels
transmembrane proteins that allow calcium to enter cells in response to changes in membrane potential
exocytosis
the process of moving large molecules out of a cell and into the extracellular space
ligand-gated Na+ channels
membrane proteins that allow Na+ to pass through when a ligand molecule binds to the channel:
acetylcholine receptor protein
a protein that responds to the binding of acetylcholine, a neurotransmitter, by changing the permeability of the cell membrane
Neonicotinoids
a class of synthetic insecticides that are absorbed into plants and used to control harmful insects
Acetylcholinesterase
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.
