Coordination
All the activities of multicellular organisms require co-ordinating, some very rapidly and some more
slowly. The nervous system and the endocrine system provide co-ordination in mammals. Similar
co-ordination systems exist in plants.
Control and co-ordination in mammals
The nervous system provides fast communication between receptors and effectors.
Transmission between neurones takes place at synapses.
Animals and plants have internal communication systems that allow information to pass between different
parts of their bodies to help them respond to changes in external / internal environment.
aspect nervous endocrine
Communication in the form of Electrical transmission by Hormones (chemical messenger)
nerve impulses and chemicals secreted in endocrine glands,
at synapses. travel in the blood and generate
Travel along nerve cells response in a target cell/gland
(neurones) directly to target
cells.
Speed of response rapid Relatively slow
Associated with what length of Usually associated with short Can control long term changes
response term changes eg. Muscle such as growth and puberty
contractions
Targets Area at the end of neurone Specific target cell/glands
localised (entire organs or several organs)
The nervous system contains cells called neurones.
Neurones are of 3 different types:
Sensory neurones transmit impulses from receptors to the CNS (central nervous system). Cell
body near source of stimuli or in swelling of spinal nerve ganglion.
Intermediate neurones ( relay or connector neurones) transmit impulses from sensory neurones
to motor neurones. Found entirely within CNS.
Motor neurones transmit impulses from the CNS to effectors. Cell bdy lies within spinal
cord/brain
Myelin sheath is composed
of schwann cells wrapped
many times around the
axon. This provides
electrical insulation
around
name
the axon, which Structural description function
greatly speeds
dendrites up the Highly branched fibres Receive neurotransmitters from
transmission of action containing cytoplasm extending relay neurone. Action potential
potentials. Not all neurons form cell body generated here
Cell body
are mylenated. Contains nucleolus + other Day to day function of cell
organelles including production of energy
axon Long single fibres, within Transmit AP to other neurone or
channel proteins + protein pump effectors
Myelin sheath Thick insulating layer around Has high electrical resistance.
the axon that has a high Myelinated neurones transmit
electrical resistance nerve impulses faster than
unmyelinated neurones.
Nodes of Ranvier Gaps along myelin sheath where Aid the transmission of the
All the activities of multicellular organisms require co-ordinating, some very rapidly and some more
slowly. The nervous system and the endocrine system provide co-ordination in mammals. Similar
co-ordination systems exist in plants.
Control and co-ordination in mammals
The nervous system provides fast communication between receptors and effectors.
Transmission between neurones takes place at synapses.
Animals and plants have internal communication systems that allow information to pass between different
parts of their bodies to help them respond to changes in external / internal environment.
aspect nervous endocrine
Communication in the form of Electrical transmission by Hormones (chemical messenger)
nerve impulses and chemicals secreted in endocrine glands,
at synapses. travel in the blood and generate
Travel along nerve cells response in a target cell/gland
(neurones) directly to target
cells.
Speed of response rapid Relatively slow
Associated with what length of Usually associated with short Can control long term changes
response term changes eg. Muscle such as growth and puberty
contractions
Targets Area at the end of neurone Specific target cell/glands
localised (entire organs or several organs)
The nervous system contains cells called neurones.
Neurones are of 3 different types:
Sensory neurones transmit impulses from receptors to the CNS (central nervous system). Cell
body near source of stimuli or in swelling of spinal nerve ganglion.
Intermediate neurones ( relay or connector neurones) transmit impulses from sensory neurones
to motor neurones. Found entirely within CNS.
Motor neurones transmit impulses from the CNS to effectors. Cell bdy lies within spinal
cord/brain
Myelin sheath is composed
of schwann cells wrapped
many times around the
axon. This provides
electrical insulation
around
name
the axon, which Structural description function
greatly speeds
dendrites up the Highly branched fibres Receive neurotransmitters from
transmission of action containing cytoplasm extending relay neurone. Action potential
potentials. Not all neurons form cell body generated here
Cell body
are mylenated. Contains nucleolus + other Day to day function of cell
organelles including production of energy
axon Long single fibres, within Transmit AP to other neurone or
channel proteins + protein pump effectors
Myelin sheath Thick insulating layer around Has high electrical resistance.
the axon that has a high Myelinated neurones transmit
electrical resistance nerve impulses faster than
unmyelinated neurones.
Nodes of Ranvier Gaps along myelin sheath where Aid the transmission of the
