Response and Regulation 1 Flashcards
(47 cards)
What is the role of the nervous system?
It controls and coordinates responses and senses in your body
What do we use to detect stimuli?
Receptors
Which sense organ & receptors detects movement?
Ear & skin
Position receptors
Pressure receptors
Which sense organ & receptors detect changes in heat?
Skin & blood vessels
Heat receptors
Where are the different taste receptors in the tongue located?
Front: Sweet
Between front and side: Salty
Side: Sour
Back: Bitter
What two parts is the human nervous system comprised of?
Central nervous system (CNS) - Brain and spinal cord
Peripheral nervous system - Nerve cells that carry information to or from the CNS
Electrical signals called ____ travel along ____
1) Impulses
2) Neurones
How are nerve cells (neurones) adapted to carry electrical impulses?
Long fibre (axon) to carry messages over long distances Insulated by a fatty sheath (myelin sheath) which increases speed of nerve impulses Tiny branches (dendons) which branch out into dendrites - these receive incoming nerve impulses from other neurons
What are receptors?
Groups of specialised cells in sense organs that respond to specific stimuli
What are effectors?
Parts of the body that produce a response to a stimulus e.g. muscles and glands
What are nerves?
Bundles of neurones that connect receptors and effectors to CNS
What is a synapse?
The gap between the ends of two neurones
How do synapses work?
The electrical impulse reaches the end of the neurone before the synapse which triggers the release of chemicals called neurotransmitters. These diffuse (move down a concentration gradient) across the synapse. The neurotransmitters bind to receptors on the next neurone. The presence of the neurotransmitter causes the production of an electrical impulse in the next neurone.
What is the point of synapses?
They help to regulate the speed and direction of impulses.
+ If the stimuli affects too few neurones the impulse is not transmitted across the cleft. This allows the ‘filtering out’ of continual unnecessary or unimportant background stimuli.
What are reflex actions?
Automatic, rapid responses, often to harmful situations
What are voluntary actions?
Responses coordinated by the brain
What is the role of a sensory neurone?
To carry impulses from the RECEPTOR to the SPINAL CORD
What is the role of a relay neurone?
To carry impulses from SENSORY to MOTOR neurones
What is the role of motor neurones?
To carry impulses from CNS to EFFECTORS
Describe the journey from detecting a stimulus to carrying out an action
RECEPTORS —sensory neurones—> CNS —motor neurones—> EFFECTORS
Why do we have reflex actions?
A way for the body to automatically and rapidly respond to stimulus to minimise any damage to the body
Do reflex actions involve the brain?
NO, they don’t have to go through neurones in the brain
Where in the nervous system do relay nerves live?
Peripheral nervous system
Which direction do nerve impulses travel?
From dendrites to axon terminals
