Biology Response Key Words Flashcards
Nerve
A series of cells in the body that transmits impulses to or from the brain or spinal cord.
Synapse
A gap allowing a connection between two neurones.
Receptor
A molecule inside or on the surface of a cell that binds to a specific substance and causes an effect in the cell.
Stimulus
A change in the environment.
Sensory neuron
Transmit electrical impulses from the sensory receptors to the CNS.
Relay neurone
Transmit electrical impulses from the sensory neurone to the relay neurone.
Motor neurone
Transmit electrical impulses from the CNS to the effectors.
Effector
A structure or organ (such as a gland or muscle) that becomes active in response to nerve stimulation.
Reflex
An automatic, rapid response to a stimulus which reduces the chance of being injured.
Hormone
Chemical messenger produced in glands and carried by the blood to specific organs in the body.
Glucose
A simple sugar used by cells for respiration.
Glycogen
Animals store glucose as glycogen in their liver and muscle tissues.
Glucagon
A hormone that is released when the blood glucose levels fall too low.
Insulin
A hormone that regulates the level of sugar in the blood and can be produced by genetically modified bacteria.
Target organ
The organ with receptor molecules on its cell surfaces which recognise a specific hormone.
Negative feedback
A mechanism where changes to conditions cause an action to reverse the change, to keep conditions stable.
Response
How the organism reacts to a stimulus
Axon
the part of the the neurone, carries the electrical impulse away from the axon
CNS
The central nervous system, made up of the brain and spinal cord
Neurotransmitter
A chemical messenger, released from one neurone at the synapse and triggering a new electrical impulse in the other neurone at the synapse
Reflex arc
The route which an electrical impulse takes in a reflex, from receptor to effector.
Gland
An organ or tissue that makes a substance for release
Secretion
A process by which substances are produced and discharged from a cell, gland, or organ for a particular function in the organism or for excretion.
Endocrine system
A messenger system comprising feedback loops of the hormones released by internal glands of an organism directly into the circulatory system, regulating distant target organs.
