co-ordination electrical messenger chemical messenger
TRANSCRIPT
Co-ordination
Electrical messenger
Chemical messenger
Nervous System
Neuron
cytoplasm dendron
cell membrane
nucleus
nucleus of cell which makes the myelin sheath
axon
direction of nerve
impulses
Nerve fiber
Myelin Sheath
•Protection of nerve fiber•Speed up impulse transfer
Rest Potential- - +
+
+
More + ion outside the nerone
1. Na K pump
2. K channel
3. Big - ions
Action potential
Action potential mechanism
• DepolarizationStimulus to thresholdNa channel openInside nerone turn +ve.• RepolarizationPotential rise inside nerone to maxNa channel closeMore k channel open so hyperpolarisedRest potential established by na k pump.
Na open
K open
Na close
Refractory period
ending of axon secretes a chemical which diffuses into synapse and stimulates the next neurone to pass on the impulse
the chemical is unstable and will be destroyed later
synapse
Synapse
Synapse mechanism
Go
SynapticCleft
Neurotransmitter in vesicle release to cleft. It diffuse to another side and attach on surface receptor. Enzyme next to receptor break down. Transmitter
Brain
dorsal root ganglion
dorsal root (sensory nerve)
associationneurone
spinal cord
ventral root (motor nerve)motor neurone
sensory neurone
effector(muscle)
receptor(pain)
Reflex arc : sensory, association, motor neurones
white matter grey matt
er central canal
spinal cord
spinal nerve
Peripheral Nervous SystemPeripheral Nervous System
consist of cranial nerves and spinal nerves
these nerves leave CNS and run out to every part of the body
spinal nerve
cranial nerve
Spinal Cell
Endocrine System
Hormone conceptSteroid concept
Endocrine organs
Hormone concept
Hormone is chemical messenger.It required a fitted receptor.Hormone attaching to receptor calls response.
Hormone concept 2
Hormone required blood vessel to transport to whole
body.
Water soluble hormone
Water soluble hormone only attach to membrane receptor.
Fat soluble hormone (steroid)
Steroid can penetrate cell membrane and bind to internal receptor.
Example of steroids
Feedback mechanism
Negative feedback reduce hormone production when effect of hormone
expressed
Endocrine and Exocrine
Blood vessel
Secretary duct
Endocrine organs
Adrenal gland
Adrenalin
Photo of adrenal gland
Pancreas
Islet of langerhans
Thyroid gland
Pituitary gland
Control of endocrine system
Hormone control hormone Nerve control hormone
Anterior and Posterior Pituitary gland
AnteriorPosterior
Photo of pituitary gland