Neurons and neural communication Flashcards
how does the nervous system work-give an overview
-it needs to detect changes in the internal/external environment , changes known as stimulus
-this information then needs to be processed and an appropriate response to be triggered
what is the role of neurones
they transmit electrical impulses rapidly around the body so it can respond to a stimuli
what is the nervous system made of
billions of specialised nerve cells called neurones
what is the difference between nerve cells and neurones
a bundle of neurones are called a nerve
is it true that neurones work together to carry information detected by a sensory receptor do a effector which carried to response
yes true
what are the 3 main components of a neurone
-cell body
-dendrons
-axon
also some have:
-node of Ranvier
also may contain :myelin sheath
what is the role of the cell body
it uses mitochondria ,endoplasmic reticulum and ribosomes for the production of neurotransmitters
what is contained within the cell body of a neurone
contains the nucleus which is surrounded by the cytoplasm
-also contains endoplasmic reticulum and mitochondria and ribosomes
role of neurotransmitters
pass signals from one neurone to the text
describe the structure of dendrons
- short extension which come from the cell body
what is the name of the smaller branches dendrons divide into
dendrites
role of dendrons
they are responsible for transmitting electrical impulses towards the body
describe the structure of an axon
singular ,elongated nerve fibre, has a cylindrical shape,
consists of narrow region of cytoplasm
and it is surrounded by a layers of plasma membrane-myelin sheath- if myelinated neurone
role of an axon
transmits impulses away from the cell body
what are the three types of neurones
-sensory neuron
-motor neuron
-relay neurone
how do cells in the nervous system communicate
cells secrete neurotransmitters which send signals to adjacent cells
how do cells in the hormonal system communicate
cells release hormones ,they then travel in the blood and act as signals to distant cells
role of sensory neurone
it transmits electrical impulses from a sensory receptor cell to the CNS
role of motor neurone
transmit electrical impulses from the relay neurones in the CNS to an effector such as a muscle or a gland
role of relay neurone
transmits /relays electrical impulses between sensory and motor neurons
structure of sensory neurone
-one dendron which carriers the electrical impulse to the cell body
-one axon which carries the impulse away from the cell body
structure of motor neurone
one long axon, many short dentrites