nervous system Flashcards
Why do we need communication systems?
Communication systems serve to coordinate and regulate bodily functions, so that appropriate responses can be made.
Changes the bring about responses: stimuli (detected by a receptor, and an effector brings about a response)
Specialised nerve cells (___) are organised into ____ nervous system and ___ nerves linking sense organs, muscles and glands with the ___ or ___ ___.
Specialised nerve cells (neurones) are organised into central nervous system and peripheral nerves linking sense organs, muscles and glands with the brain or spinal cord.
What are the 3 types of neurones?
Motor neurone, relay neurone, sensory neurone
What is the structure and function of a sensory neurone?
It has a single long dendron, which brings impulses towards the cell body and a single axon which carries impulses away from the cell body (dendron –> cell body –> axon)
- To transmit impulses from receptors to spinal cord / brain (central nervous system)
What is the structure and function of a relay neurone?
It has numerous, short fibres, each fibre is a thread-like extention of a nerve cell. Relay neurones occur in the central nervous system.
- To relay impulses from sensory neurones to motor neurones (inter-neurones)
What is the structure and function of a motor neurone?
Its cell body lies within the brain / spinal cord. Dendrites receive impulses from other neurones and conduct them towards the cell body. A single long axon transmits impulses away from the cell body.
- To transmit impulses from the central nervous system to effector organs such as muscles or glands
What are synapses?
Synapses are the link point between neurones. Where two neurones meet, they do not actually touch.
When you touch a piece of ice, ___ ___ in your skin are stimulated. ___ are produced and transmitted to the ___. The brain interprets the impulses and you have a sensation of ___.
When you touch a piece of ice, temperature receptors in your skin are stimulated. Impulses are produced and transmitted to the forebrain. The brain interprets the impulses and you have a sensation of coldness.
When you raise your hand in class, ___ are produced in the forebrain and transmitted by a ___ neurone from the forebrain to the ___ neurone in the ___ ___. The ___ neurone then transmits the impulses to the ___ muscles in your arm.
When you raise your hand in class, impulses are produced in the forebrain and transmitted by a relay neurone from the forebrain to the motor neurone in the spinal cord. The motor neurone then transmits the impulses to the effector muscles in your arm.
What is a reflex action?
A reflex action is an involuntary action. It is an immediate response to a specific stimulus without conscious control.
What is a reflex arc?
A reflex arc is the shortest pathway by which nerve impulses travel from the receptor to the effector in a reflex action. It is the structural basis of a reflex action
The reflex arc consists of a ___, which may be a sensory organ, connected by ___ to an ___, which may be a muscle or gland.
The reflex arc consists of a receptor, which may be a sensory organ, connected by neurones to an effector, which may be a muscle or gland.
