4 Flashcards
Central Nervous System (CNS)
brain and the spinal cord
Spinal Cord
a long, thin collection of nerve cells attached to the base of the brain and running the length of the spinal column
Nerve
a bundle of fibres that transmits information between the CNS and the body’s muscles, sense organs and gland
Peripheral Nervous System
the cranial and spinal nerves that part off the CNS
Cranial Nerve
a bundle of nerve fibres attached to the base of the brain; conveys sensory information from the face and head and carries messages to muscles and glands
Spinal Nerve
a bundle of nerve fibres attached to the spinal cord; conveys sensory information from the body and carries messages to muscles and glands
Brain Stem
the ‘stem’ of the brain; including the medulla, pons and midbrain
Cerebral Hemisphere
the largest part of the brain; covered by the cerebral cortex and containing parts of the brain that have evolved most recently
Cerebellum
a pair of hemispheres resembling the central hemisphere but much smaller; controls posture and movements
Vertebra
one of the bones that encase the spinal cord and constitute the vertebral column
Meninges
the 3 layered set of membranes that enclose the brain and spinal cord
Cerebrospinal Fluid (CSF)
the liquid in which the brain and spinal cord float; provides a shock-absorbing cushion
Blood-Brain Barrier
a barrier between the blood and the brain produced by the cells in the walls of the brain’s capillaries; prevents some substances from passing from the blood into the brain
Cerebral Cortex
the outer layer of the cerebral hemispheres of the brain; approx 3mm thick
Grey Matter
the portions of the CNS that are abundant in cell bodies of neutrons rather than axons; colour appears grey relative to white matter
White Matter
the portions of the CNS that are abundant in axons rather than cell bodies of neutrons; colour derives from the presence of the axon’s myelin sheaths
Neuron
a nerve cell; consists of a cell body with dendrites and an axon whose branches end in terminal buttons that synapse with muscle fibres, gland cells or other neurons
Glial Cell
- a cell of the CNS that provides support for neurons and supplies them with some essential chemicals
Dendrite
a tree-like part of a neuron on which other neurons form synapses
Soma
a cell body; largest part of a neuron
Dendritic Spine
a small bud-like protuberance on the surface of a neuron’s dendrite
Axon
a long thin part of a neuron attached to the soma; divides into branches ending in terminal buttons
Terminal Button
the rounded swelling at the end of the axon of a neuron; releases a neurotransmitter
Neurotransmitter
a chemical released by the terminal buttons that cause the postsynaptic neutron to be excited or inhibited
Myelin Sheath
he insulating material that encases most large axons
Action Potential
a brief electrochemical event that is carried by an axon from the soma of the neuron to its terminal buttons; causes the release of a neurotransmitter
Ion
positive or negatively charged particle
Ion Channel
a special protein molecule located in the membrane of the cell; controls the entry/exit of particular ions
Ion Transporter
a special protein molecule located in the membrane of a cell; actively transports ions into or out of the cell
All-Or-None Law
the principle that once an action potential is triggered in an axon it is sent to the end of the axon
Sensory Neuron
a neuron that detects changes in the external or internal environment and sends info about these changes to the CNS
Motor Neuron
a neuron whose terminal buttons form synapses with muscle fibres. When an action potential travels down its axon the associated muscle fibres will twitch
Synapse
the junction between the terminal button of one neutron and the membrane of a muscle fibre, gland or another neuron
Presynaptic Membrane
- a neuron whose terminal buttons form synapses with and excite or inhibit another neuron
Postsynaptic Neuron
- a neuron with which the terminal buttons of another neutron form synapses with and that is exited or inhibited by that neuron
Synaptic Cleft
fluid filled space between the presynaptic and postsynaptic membranes; the terminal button releases a neurotransmitter into this space
Neurotransmitter Receptor
a special protein molecule located in the membrane of the postsynaptic neuron that responds to molecules of the neurotransmitter
Reuptake
the process by which a terminal button retrieves the molecules of a neurotransmitter that it has just released; terminates the effect of the neurotransmitter on the receptors of the postsynaptic neuron
Glutamate
he most important excitatory neurotransmitter in the brain and spinal cord
GABA
the most important inhibitory neurotransmitter in the brain
Barbiturate
a drug that causes sedation; one of several directives of barbituric acid
Anti Anxiety Drug
a ‘tranquilizer’ which reduces anxiety
Acetylcholine (ACh)
a neurotransmitter found in the brain, spinal cord and parts of the peripheral nervous system; responsible for muscular contraction
Botulinum Toxin
a drug that prevents the release of acetylcholine by terminal buttons
Black Widow Spider Venom
a drug that stimulates the release of acetylcholine by terminal buttons
Neostigmine
a drug that enhances the effects of acetylcholine by blocking the enzyme that destroys it
Nicotine
a drug that bind with and stimulates acetylcholine receptors; mimicking the effects of this neurotransmitter
Curare
- a drug that binds and blacks acetylcholine receptors, preventing the neurotransmitter from exerting its effects
Monoamine
a category of neurotransmitters that include dopamine, norepinephrine and serotonin
Dopamine (DA)
a monoamine neurotransmitter involved in control of brain mechanisms of movement and reenforcement
Parkinson’s Disease
a neurological disorder characterized by tremors rigidity of the limbs, poor balance and difficulty initiating movements; caused by degeneration of a system of dopamine secreting neurons
