11.2 Flashcards
Synapse
A functional connection between neurons and effectors.
Chemical synapse
A synapse in which a neurotransmitter moves from a presynaptic cell to a postsynaptic cell through the synaptic cleft.
Neurotransmitter
A chemical that is released from vesicles into synapses to facilitate nerve signal transmission.
Synaptic cleft
The tiny gap between presynaptic and postsynaptic cells in a chemical synapse, across which the neurotransmitter diffuses.
Electrical synapse
A synapse in which the presynaptic cell makes direct contact with the postsynaptic cell, allowing current to flow via gap junctions between the cells.
Membrane potential
The electrical potential of a membrane, which is cause by an imbalance of charges on either side of the membrane.
Ion channel
A protein embedded in the plasma membrane that allows ions to pass through it.
Resting potential
The voltage difference across a nerve cell membrane of an unstimulated neuron; usually negative.
Action potential
The voltage difference across nerve cell mementsbe when the nerve is excited.
Threshold potential
The potential at which an action potential is generated by a neuron.
Refractory period
The period of time during which the threshold required for the generation of an action potential is much higher than normal.
Meninges
Three layers of connective tissue that surround and protect the brain and spinal cord.
Cerebrospinal fluid
Circulating fluid that surrounds the membranes of the brain and spinal cord; provides neural connection to the endocrine system.
Grey matter
The tissue of the brain and spinal cord where the cell bodies and dendrites of neurons are located.
White matter
The tissue of the brain and spinal cord, composed of axons of neurons; in the spinal cord, it surrounds the grey matter.
Medulla oblongata
The hindbrain region that connects the spinal cord to the cerebellum; important in autonomic nerve control.
Cerebellum
The hindbrain region that is involved in muscle movement and balance.
Pons
The brain region that transfers nerve signals between the cerebellum and the medulla.
Cerebrum
The brain region that is involved in motor activities and sensory information; the largest and most developed region of the brain.
cerebral cortex
The outermost layer of the cerebral hemispheres.
Thalamus
The brain region that interprets sensory input and signals the cerebrum.
Blood-brain barrier
A barrier formed by tight junctions between endothelial cells in the capillaries in the brain that blocks the movement of most substances into the brain via the bloodstream.
