The Nervous System Flashcards
Name and explain the three different types of neurone.
Sensory Neurone - Carries nerve impulses from receptors to central nervous system.
Relay Neurone - Makes connections between neurones inside brain and spinal chord.
Motor Neurone - Carries nerve impulses from central nervous system to muscles and glands.
State the parts of a Motor neurone and explain what each part does.
- Elongated shape (Makes connections from one part of body to another)
- Insulating Sheath (speeds up nerve impulse)
- Dendrites (Allows a single neurone to connect to many other neurones.
State the stages in the central nervous system in order.
1) Receptors
2) Sensory Neurones
3) Relay Neurones
4) Spinal Chord
5) Brain
6) Motor Neurones
What are the main components of the Nervous System?
1) Brain
2) Spinal Cord
3) Neurones that comprise peripheral nervous system
What types of receptors are there and where are they in the body?
1) Retina - Light receptors
2) Ears - Sound and change receptors
3) Tongue - Taste receptors
4) Nose - Smell receptors
5) Skin - Touch, pressure, pain and temperature receptors.
What are effectors?
Muscles or glands that make the change in response to the signal from the receptor.
What is the difference between a Voluntary Action and a Reflex Action?
Voluntary Action - Person decides how to react to a stimulus.
Reflex Action - Automatic response to a stimulus.
What is the pathway for processing information and acting on it in a Voluntary Action?
Stimulus - Receptor - Sensory Neurone - Coordinator - Motor Neurone - Effector - Response
What is the pathway for processing information and acting on it in a Reflex Action (Reflex Arc)?
Stimulus - Receptor - Sensory Neurone - Relay Neurone - Motor Neurone - Effector - Response
What is the difference between Binocular Vision and Monocular Vision?
Binocular Vision - Eyes are close together on the front of an animal’s head. Narrow field of view but when they overlap, the brain interprets the information to create a 3D image. Animal can judge distance or speed accurately.
Monocular Vision - Eyes set on each side of an animal’s head. Wide field of view. Animal has 360 degree vision. Very little overlap in fields of view so it’s difficult for an animal to judge distance or speed.
How does the eye work?
Eye focuses light onto the Retina. Cornea and Lens refracts rays of light so they converge at a single point of focus on the Retina. This stimulates light - sensitive receptor cells in Retina and causes nerve impulses to pass along sensory neurones to the Brain. The Brain interprets the impulses (perception) and an image is made.
What happens when the eye focuses on a distant object?
- Ciliary Muscles relax
- Suspensory Ligaments stretch
- Lens becomes Long and Thin
- A small amount of light is focused on the Retina
What happens when the eye focuses on a nearby object?
- Ciliary Muscles contract
- Suspensory Ligaments slack
- Lens becomes Short and Fat
- More light is refracted to focus on the Retina
How is Long Sight caused and how can it be corrected?
Long Sight is caused by an eyeball that is too short or a lens that stays long and thin. A Convex Lens converges the light rays from close objects so they focus on the Retina.
How is Short Sight caused and how can it be corrected?
Short Sight is caused by an eyeball that is too long or has weak Suspensory Ligaments which can’t pull the Lens into a thin, flat shape. A Concave Lens diverges light rays so they focus on the Retina.
What is the difference between Long Sight and Short Sight?
Long Sight - When you can see distant objects but not close objects.
Short Sight - When you can see close objects but not distant objects.
