Nervous system and communication Flashcards
why good for animals to respond to environment
increase chances of survival e.g by avoiding harmful env lsuch as those that are too hot or too cold, also respond to internal changes to make sure conditionals are optimal for metabolism (THESE CHANGES ARE CALLED STIMULI)
what do receptors do
detect stimuli, 1 in particular e.g pressure, light or glucose concentration. different receptor for different stimuli
different types of receptors
pressure receptors detect pressure
some receptors are cells- that connect to the NS
some are proteins on CSM e.g glucose receptors are found in CSMs of some pancreatic cells
what are effectors?
cells that bring about a repose to stimuli to produce an effect. these include muscle cells and cells found in glands e.g pancreas
why are receptors and effectors important?
communication of information form one part of the organism to another. to ensure activities of different organs are coordinated to keep the organism working effectively.
E.G receptor cells in the pancreas detect a lw concentration of glucose in the blood, the communicate with effector cells in the liver to release more glucose in to the blood.
what is cell signalling
receptors communicating with effectors via the nervous system or the hormonal system.
how does the nervous system pass information from one part of an organism to another?
using nerve impulses via neurones very fast!!
what are the three main types of neurone and what do they do?
sensory- transmit nerve impulses from receptors to the central nervous system (brain and spinal cord)
relay- transmit nerve impulses between sensory neurones and motor neurones
motor- transmit nerve impulses from the CNS to effectors
structure of neurones: what do the extensions connect to?
other neurones
what the are names of the neurone extension and what do they do
dendrites and dendrons. carry nerve impulses towards the cell body (dendrites are smaller branches of dendrons)
what do axons do?
carry nerve impulses away from the cell body.
structure of sensory neurone describe..
short dendrites and one long dendron to carry nerve impulses from receptor cells to the cell body and one short axon that carries nerve impulses from the cell body to the CNS
structure of motor nerone described,,,
many short dendrites that carry nerve impulses from the CNS to the cell body, and one long axon that carries nerve impulses from the cell body to the effector cells.
the pathway of nervous communication
stimulus- receptor-sensory neurone-CNS-motor neurone-effectors-response
describe the nervous communication when you see a friend waving
stimulus- see friend waving
receptors- light receptors (photorecp) in your eyes detect the wave. electrical impulse is carried by a sensory neurone to the CNS.
CNS- processes information and decides what to do about it. an electrical impulse is sent along a motor neurone
Effectors- muscle cells are stimulated by the motor neurone
response- muscle contract to make arm wave
