What are the 3 basic functions of the nervous system?
- Detect/sense changes in internal/external environment
- Process and integrate sensory information
- Initiate a response against the change
What are the divisions of motor neurone
- somatic
- autonomic
What are the classes of autonomic motor neurones
- parasympathetic
- sympathetic
Name the structures involved in the CNS
Spinal cord, brain, brainstem
Name the structures involved in the PNS
- motor neurone
- sensory neurone
- 31 pairs of spinal nerves
- ganglion (plural: ganglia)
What neurones are involved in the transmitting afferent information?
sensory neurones
State the pathway of afferent division
- carry information towards the CNS (in response of pain, pressure or stretch)
- synapse/communicate with neurones in the spinal cord which results in an appropriate response to stimulus
Where are the cell bodies of the sensory neurones located?
in the dorsal root ganglion adjacent to the spinal cord
What neurones are involved in the efferent division
motor neurones
State the pathway of the efferent division
motor neurones carry information away from the spinal cord to the skeletal muscle fibres
How would a response be carried out at the motor nerves/neurones?
motor nerves release transmitter molecules that will result in an appropriate response to occur
Function of neurones
- receive signals from other cells
- transmit signals from the cell body
- transmit signals to other cells
Function of glial cells
- form myelin sheath surrounding axons
- repair damage to cells
- maintain ionic environment around cells
- help in removal of neurotransmitters
Function of ependymal cells (3)
- make up ependymal membrane
- secrete cerebrospinal fluid
- make up brain-CSF barrier
function of astrocytes (4)
- regulate chemicals in the brain’s extracellular fluid
+ [ions], [glucose], take up neurotransmitters - maintain blood-brain barrier
- repairs nervous system
- provide structural supprt for neurones (provide scaffolding)
Function of oligodendrocytes
- form myelin sheath around axons in CNS
Function of Schwann cells
- form myelin sheath around axons in PNS
- help in regeneration and regrowth of axons
function of microglia
- phagocytose abnormalities (pathogens, plaques and damaged cells)
How is action potential generated?
- electrical signal arrives at the dendrites and changes the electrical charge of the membrane
- potential is generated
- when potential threshold is passed, an action potential is generated which passes down the axon
How do neurones communicate chemically? (using chemical messengers)
- when the action potential is passed down to the axon terminal, calcium is released
- release of calcium triggers vesicles containing neurotransmitters to move and fuse with the membrane
- neurotransmitters are released by exocytosis into the synaptic gap
- neurotransmitters bind with receptors on the post-synaptic membrane of the dendrite (of the next cell)
