B5 Flashcards
What are the 2 functions of the nervous system?
enables us to detect our surroundings and respond to stimuli and coordinate behaviour
what is the nervous system made up of? (4)
- brain
- receptor cells
- spinal cord
- nerve cells
what do receptors do?
detect changes in the environment
what is the function of the axon?
- nerve cell
carries impulses along the neurone
what is the function of the myelin sheath?
- nerve cell.
insulates the axon
- stops electrical impulses from leaving
What is the function of the Dendron?
- nerve cell
receives impulses from another neurone/ receptor
What is the function of the Node of Ranvier?
small parts of exposed axon that promote fast conduction of electrical impulses
What are the parts of the ‘reaction pathway’ that always stay the same? in what order?
stimulus –> receptor –> sensory neurone –> spinal chord –> relay neurone —> motor neurone –> effector —> response
which neurones carry electrical impulses from the receptor cells to the central nervous system?
sensory and motor neurone
what is a key role of the nervous system?
it enables humans to react to their surroundings and coordinate their behaviour - this is done through the reflex arc
what do coordination centres do?
receive and process information from receptors
what do effectors do?
bring about responses to stimuli
what is generated when a receptor cell detects a stimulus
an electrical impulse
what is the gap between 2 neurones called?
a synapse
Explain/ Describe
the general features of an automatic control system
- Receptor cells detect a stimulus (changes in the environment)
e.g internal change - conc of glucose in blood or external - skin temp - Receptor cell pass information to a coordination centre e.g brain, spinal chord or pancreas
- Coordination centre sends instructions to the effector ( a muscle that contracts or gland that secretes a hormone)
what is a reflex
an automated response to a stimulus
- the impulses generated do not travel to the brain so you can’t even think about it
what can automatic control systems in the human body involve?
nervous system or hormones
what do all automatic control systems involve? (5)
a stimulus, a receptor, a coordination centre, an effector and a response
what is homeostasis?
the regulation of the internal conditions of a cell or organism to maintain optimum conditions for functions in response to internal and external changes
what conditions do we control in the body?
temperature, blood glucose levels and water
what is the function of the nervous system?
enables us to detect our surroundings and respond to stimuli and coordinate our behavoir