A2 - Nervous system Flashcards
Central Nervous System (CNS)
Consists of the brain and spinal cord.
Peripheral Nervous System (PNS)
Consists of sensory and motor neurons.
Sensory Neurons
Neurons that receive information from receptors and transmit it to the CNS.
Motor Neurons
Neurons that carry information from the CNS to effectors, such as muscles.
Neurons
Cells that receive and transmit nerve impulses or action potentials.
Soma
The large cell body of a neuron.
Dendrites
Small projections on a neuron that receive signals from other neurons.
Axon
A long projection of a neuron that carries nerve impulses away from the soma.
Axon Terminal
The end of the axon that communicates with the dendrite of the next neuron
Synaptic Cleft
The small gap between the axon terminal and the dendrite of the next neuron.
Nerve Impulse
Electrical signals that carry information along neurons.
Action Potential
Brief change in voltage across a neuron’s membrane, resulting in a nerve impulse
Ion Balance
The equilibrium of ions (charged particles) within a nerve cell.
Nerves
Bundles of neurons that form a network throughout the body.
Neurotransmitters
Chemicals released by neurons that transmit signals across the synaptic cleft.
Synaptic Cleft
The small gap between neurons where neurotransmitters are released and received.
Receptors
Proteins on the post-synaptic membrane that bind to neurotransmitters
Glial Cells
Cells that support and nourish neurons, digesting dead neurons and producing neuronal components.
Resting Potential
Potential difference across the membrane of a neuron in its resting state, with the interior of the cell negative compared to the exterior.
Concentration Gradient
Difference in ion concentration between the inside and outside of a neuron
Voltage-Gated Ion Channels
Ion channels that open or close in response to changes in voltage.
Threshold Voltage
The minimum voltage required to trigger an action potential (around -55mV).
Depolarization
Change in membrane potential where the inside of the membrane becomes less negative.
Polarization
State of a neuron’s membrane when at rest, with a positive charge outside and negative charge inside.
Stimulus
Chemical, mechanical, thermal, or electrical signal that triggers a response in a neuron.