Hormonal communication- Animals Flashcards
What must an animals communication system enable?
- detection of changes in the environment
- cell signalling to occur between all parts of the body
- coordination of a range of effectors to carry out responses to the sensory input.
- suitable responses
to ensure survival, what must environmental changes be?
rapid and well coordinated responses.
What are the most obvious divisions of the nervous system?
CNS
PNS
what is the PNS further divided into?
sensory system and motor system
what is the motor system further divided into?
somatic nervous system
autonomic nervous system
what does the CNS consist of?
the brain and the spinal cord
what neurones are the brain most composed of?
relay neurones
why relay neurones?
they are non myelinated and they have multiple connections enabling complex neural pathways.
if there is a lot of relay neurones, what is the colour of the brain matter and if there are a lot of myelinated neurones?
relay neurones- non-myelinated-grey matter
spinal cord- a lot of myelinated- outer region of white matter
what is the spinal cord protected by?
the vertebral column.
what is the role of the PNS?
ensures rapid communication between the sensory receptors, the CNS and the effectors.
What is the PNS composed of?
sensory and motor neurones that are usually bundled together in a connective tissue sheath to form nerves.
what are the sensory fibres entering the CNS and what do they do?
they are the dendrons of the sensory neurones. These neurones conduct action potentials from the sensory receptors into the CNS.
Where do sensory fibres have their cell body?
in the dorsal root leading to the spinal cord
what is the axon like and what does it do?
it is short axon connecting to other neurones in the CNS.
