Wk5-Neural Tissue

Functional classification of neurons: What are the 3 classes of neurons? 1. S (Afferent) 2. M (efferent) 3. In?

Sensory (Afferent) neurons : Attach to sensory receptors Transmit signal to _ _ _ , information _ _

Motor (efferent) neurons: Transmit impulses _ _ _ _ from CNS to effector organs, muscles and glands. Information _ _ _

Interneurons: Situated in between s- and m- neurons. Interneurons act as messengers for impulse signals, distribute signal through _ _ _.

Neuroglia: Glia meaning _ _ _ _ Neuroglia are non - _ _ _ _ _ _ _ _ cells in nervous system Neuroglia provide s- , nutritional needs, m?

Neuroglia: How many types are there ? How many in CNS ? How many in PNS?

CNS Neuroglia: Astrocytes L- and most n- Neuroglia Physically s- and a- neurons structure Wrap around capillaries and form the B B B

CNS Neuroglia: Oligodendrocytes Contact exposed surfaces of neurons Form a m- s- along a- in CNS M- a- permit faster transmission

CNS neuroglia: Microglia “W- disposal” Help protect CNS via p—-cytosis of waste, d- and p-

CNS Neuroglia: Ependymal cells Line the ventricles of the b- and central c- of the s- cord Secrete C ?? Monitors comp? and cir? C??

PNS neuroglia: Schwann cells Wrap around PNS a- Multiple Schwann cells form m- s- Also encase non myelinated axons

PNS Neuroglia: Satellite cells Surround cell bodies of n- in PNS Provide s- s- Regulate passage of material between n- s- (body) I- fluid

Myelination of axons: Electrically in- a- Allows ? conduction jumps CNS: O- PNS: S- cells Gaps in Myelination are nodes of Ranvier

Resting Membrane potential: Chemical g- exists across the cell m- Maintained by S- P- Pump Outer membrane= greater Na+ less K+ Inner membrane= greater _+ less _ _ +

Sodium potassium pump : 3 Na+ out 2K+ in ATP_ converts to A_ _ Loses 1 p-

Resting membrane potential: Potassium ions leak OUT of cell more easily than sodium ions leak INTO cell. Electrical potential / gradient = (?) inside and (?) outside Resting potential= -?0 mV

Resting membrane potential/ electrical potential is measured in ?

The synapse The synapse permits the transmission of a nerve ? to another cell Synapse can be either e? or c? Chemical synapse Action potential reaches axon terminal causes ca2+ channels on axons terminal to open Concentration gradient travel across synaptic cleft.

Action potentials depolarisation and repolarisation Neurons fire when the axon resting membrane potential is reversed / ? by stimulation of dendrites Causes opening of ? channels in trigger zone / axon Due to chemical and ? gradient ? flows across axon membrane Membrane potential changes from -70mv to +?0mV = 100mv difference Inside membrane = + , outside membrane = - Resting membrane potential is r?

Membrane repolarisation: Neuron must be reset before can fire again. Na+ channels ? and K+ channels ? Sodium potassium pump recreates chemical gradient across membrane. R? membrane potential is restored

Neurons and n? make up neural tissue Neurons generate and conduct e? information They rely on ? ? to fire The synapse permits the transmission of a n? signal to another cell

Chemical synapse: Similar process to neurons action potential. ?+ channels open , ?+ ions travel along axon. ?+ enter axon terminal , trigger exocytosis of synaptic vesicle (neuro?) Ca+ flows across concentration ? Receptor channels open allows ions to enter cell = change in v? = ion con?

Neurotransmitters = chemicals released from a neuron a? terminal that effect another cells membrane p?

Neurotransmitters: What are the 4 neurotransmitters? • Acetylcholine = voluntary m? movement • Nor? = / noradrenaline , heart rate and BP (ANS) • E? = major hormone CNS/ANS • Dop? = coordination movement, motivation and emotion