Human Nervous System Flashcards
Effectors
Muscles and glands
Sensory function
Sensory receptors detect the changes in the external environment and the environment within the organism
Integrative function
CNS integrates the information
Motor function
Effectors to bring about response
Stimulus
Any physical or chemical change in the environment ( both internal and external) that is capable of causing a response in an organism
Myelinated
Neuron covered by myelin sheath
Neurolgia
Cells bind neurons together to give support and help with nutrition of the cells
Nerve impulse
A wave of depolarization ( also called an action potential) traveling along a nerve fiber in response to stimulation
Synaptic cleft
The gap separating neurons
Synapse
The junction across which a nerve impulse passes from an axon terminal to a neuron, a muscle or a gland cell.
Neurotransmitter
A chemical substance released from axon terminals at a synapse to either stimulate or inhibit the postsynaptic membrane
Myoneural synapse
The synapse between the terminal branches of a motor neuron and a muscle
Nerve fiber
Extension of a nerve cell or neuron
I.e. Axon or dendrite
Nerve
Large number of neuron fibers (which may/ my not be myelinated) bound together by connective tissue into bundles and surrounded by epineurium
Meninges
Protective and nourishing connective tissue covering brain
Cerebrospinal fluid
A fluid formed from blood plasma in special areas in the walls of the ventricles. It protects CNS & prevents cells drying out
Vasodilation
Widening of blood cells
Vasoconstriction
Narrowing of blood vessels
Spinal cord
Elongated rod of nervous tissue that extends from the medulla oblongata through the foramen magnum
Ganglion
A small mass of sensory neuron cell bodies, found mainly in the peripheral nervous system
Automatic
Done without having to think
Reflex action
Fast, automatic response by an effectors organ or a gland, to a stimulus received by a receptor organ
Reflex arc
Pathway along which nerve impulses are carried from a receptor to am effectors to bring about a reflex action
Nissl granules
Groups of ribosomes int the neuroplasm that are involved with protein synthesis
Neurilemma
A collective name for the outer sheath made up of Schwann cells
Schwann cells
Wrap themselves around the axon several times.
The inner, concentric layers of fatty tissue fuse to form myelin sheath
Free nerve endings
Sensory nerve endings
Myoneural synapse
The terminal branch of a motor neuron and muscle
Nerve fiber
Extension of a nerve cell or neuron, i.e. An axon or dendrite
Nerve
Consists of a large number of neuron fibers (may/ may not be myelinated) bound together by connective tissue into bundles and surrounded by a sheath of connective tissue, the epineurium
Gyri
Folds
Sulci
Grooves
Co- ordination
The way in which information is communicated between the receptors of the body, the central nervous system and the effectors to bring about appropriate reactions to any change in environment
