nervous system

Axon

________: Long fiber that allows a quicker carrying process from neuron to neuron.

Lens

A transparent disc that changes its shape through accommodation with the help of the suspensory ligaments and ciliary muscles to regulate the light that enters the retina.

Relay neurons

________: Impulses can travel both ways.

Motor neurons

________: From the central nervous system towards effectors (muscles and glands)

Presynaptic neuron

________: Has vesicles that are carrying the neurotransmitters, the vesicles are triggered by the electrical impulse.

Photoreceptors

________ detect the change in the environments light conditions.

Dendrites

________: Extensions that mainly receive and improve synaptic neuronal communication.

Sensory neurons

________: From sense organs to the Central Nervous System.

In dim light the pupil....

dilates to enter as much light as possible.

Lens

The ________ is elastic and has a changing shape, relying on how tight the suspensory ligaments are.

optic nerve

A neve that carries impulses from the retina towards the brain, producing the images.

In bright light the pupil...

constricts preventing too much light entering and damaging the retina.

Postsynaptic neuron

________: Has receptors with whom specific neurotransmitters bind.

reflex

a(n) ________ is an involuntary action, co ordinated by the CNS, that responds to a stimulus and is automatic.

what happens to neurotransmitters that do not bind?

are uptaken again into the presynaptic neuron, or broken down by enzymes.

lens accommodation

The change in ________ is mainly causes bythe relaxation or contraction of the ciliary muscles.

Define the term sense organ

A sense organ is a group of tissues with the same task that contain a bunch or sensory neurons and rreceptor for specific stimuli. They are mainly known for the 5 senses.

List three parts of the eye that light passes through to reach the retina

Pupil, Cornea, and Lens.

Reflex arc

stimulus, receptor, sensory neuron, relay neuron, motor neuron, effector, repsonse

Central

The brain and spinal chord form the ________ nervous system

Peripherical

The nerves coming into and out of the spinal chord are part of the ________ nervous system.

Antagonistic response

State the term that describes the action of a pair of muscles working in opposition to each other.