Ch5 Biology Vocab Flashcards
Homeostasis
An organism maintaining a stable constant internal environment (physiological)
Stomata (Stomate)
The opening between two guard cells in the epidermis of a plant leaf through which gases are exchanged with the air
Sensory neurons
Nerve Cells that transmit information from a sense organ to the brain
Physiological response
An automatic change generated by the body of an organism that is triggered by an external or internal stimulus
Motor neurons
A nerve cell that conducts information to muscles or glands
Behavioral response
Actions taken by an organism in response to some stimulus
Reflexes
An involuntary reaction or response to a stimulus
Nervous system
A coordinating mechanism in almost all multicellular organisms that regulates internal body functions and response to external stimuli. In vertebrates, it consists of the brain, spinal cord, nerves, ganglia and receptor/effector organs.
Neurons
A nerve cell (brain, sensory and motor nerves are examples)
Negative feedback
A kind of feedback that creates equilibrium between input and output in a system or process
Positive feedback
A kind of feedback that disturbs or prevents equilibrium between input and output in a system or process
Dendrites
A structure that extends out from a neuron and transmits impulses toward the cell body;
Part of a neuron that RECEIVES incoming messages/impulses
Axon
A structure that extends out from a neuron and conducts impulses away from the cell body;
Part of the neuron that SENDS impulses to another cell
Stimulus
A change or signal that causes an adjustment or reaction by an organism
Synapse
An open junction between neurons, across which an impulse is transmitted by a chemical messenger called a neurotransmitter
Neurotransmitters
A chemical messenger that diffuses across the synapse and transmits a nerve impulse from one neuron to another
