Nervous System and Neurons Overview

The ability of living organisms to react to changes in their environment.

Specialized cells that detect changes in the environment.

Organs or parts of an organism that carry out a response to a stimulus.

A system of communication in the body that uses chemical messengers called hormones, carried by the bloodstream, to produce slower but long-lasting responses.

A rapid communication system using nerve impulses that transmit information quickly and precisely to specific targets.

Specialized cells that transmit electrochemical signals (nerve impulses) throughout the body.

The central part of a neuron containing the nucleus and other essential organelles.

Branch-like extensions of the cell body that receive nerve impulses and carry them towards the cell body.

A long, slender projection of the cell body that carries nerve impulses away from the cell body.

Specialized cells that wrap around axons, forming an insulating myelin sheath.

Neurons that transmit nerve impulses from receptors to relay or motor neurons. They have one afferent dendron and one axon.

Neurons that transmit impulses between other neurons, like from sensory to motor neurons. They usually have numerous short extensions.

The strength of a stimulus affects the size of the generator potential. A larger generator potential releases more neurotransmitter.

A generator potential must reach a certain threshold value to trigger an action potential in the sensory neuron. It's all or nothing!

Constant stimulation leads to a decrease in the frequency of action potentials in the sensory neuron. This prevents the nervous system from being overwhelmed by unimportant information.

Rods and cones are secondary receptors in the retina that detect light. Rods are responsible for black and white vision, while cones detect color.

Rhodopsin, a light-sensitive pigment found in rod cells, changes shape when light hits it. This change triggers a cascade of events that ultimately generates a nerve signal.

Specialized cells that detect specific stimuli, converting it into a signal that can be interpreted by the nervous system.

Structures containing sensory receptor cells, responsible for detecting specific stimuli like taste, sight, or sound.

The process of converting a stimulus into a signal that can be transmitted to the nervous system.

Sensory receptor cells located on the tongue that detect dissolved chemicals, generating the sensation of taste.

Small projections on chemoreceptor cells that increase surface area, allowing for greater contact with dissolved chemicals in saliva.

The opening at the top of a taste bud through which dissolved chemicals reach the chemoreceptor cells.

The change in electrical potential across the membrane of a sensory receptor cell in response to a stimulus.

The process of converting a receptor potential into a signal that is transmitted by a sensory neuron.

The four basic tastes that can be detected by chemoreceptor cells in taste buds.

The release of a chemical transmitter from the chemoreceptor cell, which activates a sensory neuron.