Nervous System Flashcards
State the function of the nervous system
The nervous system consisting of the brain, spinal cord and nerves, serves to coordinate and regulate bodily functions
State the parts making up the nervous system
The nervous system is built from specialised nerve cells called neurones. The nervous system is organised into the central nervous system (CNS) consisting of the brain and the spinal cord peripheral nervous system (PNS) consisting of nerves.
State the 3 types of neurone and explain their function.
- Motor neurones transmit impulses from the central nervous system to effector organs such as the muscles or glands.
- Relay neurones relay impulses from sensory neurones to motor neurones
- Sensory neurones transmit impulses from receptors to the spinal cord or brain (i.e. central nervous system)
State the function of a synapse.
The link point between neurones. Nerves impulses at the axon of a neurone are transmitted via chemical signals in the form of neurotransmitters, which diffuses across the synapses o the dendron of another neurone. This allows impulses to be transmitted towards the effector to trigger a response.
Define reflex action
it is an immediate response to a specific stimulus without conscious control. Reflex actions can be classified as cranial reflexes (controlled by the brain) or spinal reflexes (controlled by the spinal cord).
Define reflex arc
The shortest pathway by which nerve impulses travel from the receptor to the effector in a reflex action.
Compare the endocrine and nervous systems.
The endocrine system tends to produce effects over a longer period of time ranging from minutes to hours or longer while the nervous system produces effects within milliseconds. While the effects of hormones tend to be long-lasting (e.g. growth hormone), the effects of nerve impulses tend to be short-lived and reversible. Both hormones and nerve impulses target specific cells or organs.
