Wk5-Neural Tissue Flashcards
Functional classification of neurons: What are the 3 classes of neurons? 1. S (Afferent) 2. M (efferent) 3. In?
- Sensory
- Motor
- Interneuron
Sensory (Afferent) neurons :
Attach to sensory receptors
Transmit signal to _ _ _ , information _ _
Transmit signal to CNS , information in
Motor (efferent) neurons:
Transmit impulses _ _ _ _ from CNS to effector organs, muscles and glands.
Information _ _ _
Away from CNS.
Information out
Interneurons:
Situated in between s- and m- neurons.
Interneurons act as messengers for impulse signals, distribute signal through _ _ _.
Sensory motor neurons
Distribute signal through CNS
Neuroglia:
Glia meaning _ _ _ _
Neuroglia are non - _ _ _ _ _ _ _ _ cells in nervous system
Neuroglia provide s- , nutritional needs, m?
Glue
Neuroglia are non- neuronal cells
Provide support, myelin
Neuroglia:
How many types are there ?
How many in CNS ?
How many in PNS?
6 types
4 in CNS
2 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
Largest and most numerous
Physically support and anchor
Form the Blood Brain Barrier
CNS Neuroglia: Oligodendrocytes
Contact exposed surfaces of neurons
Form a m- s- along a- in CNS
M- a- permit faster transmission
myelin sheath along axon
Myelinated axons
CNS neuroglia: Microglia
“W- disposal”
Help protect CNS via p—-cytosis of waste, d- and p-
Waste disposal
Phagocytosis of waste, debris and pathogens
CNS Neuroglia: Ependymal cells
Line the ventricles of the b- and central c- of the s- cord
Secrete C ??
Monitors comp? and cir? C??
brain, canal ,spinal
Secrete CSF (cerebrospinal fluid)
Composition, Circulates CSF
PNS neuroglia: Schwann cells
Wrap around PNS a-
Multiple Schwann cells form m- s-
Also encase non myelinated axons
Axons
Myelin sheath
PNS Neuroglia: Satellite cells
Surround cell bodies of n- in PNS
Provide s- s-
Regulate passage of material between n- s- (body) I- fluid
Neurons
Structure and support
Neuron soma and interstitial fluid
Myelination of axons: Electrically in- a- Allows ? conduction jumps CNS: O- PNS: S- cells Gaps in Myelination are nodes of Ranvier
Electrically insulates axon
Faster conduction jumps
Oligodendrocytes
Schwann cells
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 _ _ +
Chemical gradient exists across cell membrane
Sodium potassium pump
greater K+ less Na+
Sodium potassium pump :
3 Na+ out 2K+ in
ATP_ converts to A_ _
Loses 1 p-
ATP3 concerts to ADP (adenosine triphosphate-> diphosphate)
Loses 1 phosphate
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
(-) inside and (+)outside
-70mv
Resting membrane potential/ electrical potential is measured in ?
Volts (V) or milivolts (mV)?
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.
Signal
Electrical / chemical
Calcium
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?
Depolarised Sodium Electrical Sodium 30 Reversed
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
Close
Open
Resting
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
Neuroglia
Electrical
Action potentials
Nerve
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?
Ca+ , ca+ Ca+ Neurotransmitter Gradient Voltage , ion concentration
Neurotransmitters = chemicals released from a neuron a? terminal that effect another cells membrane p?
Axon
Potential
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
- Muscle
- Norepinephrine
- Epinephrine
- Dopamine
Membrane potential ~ resting/ action = caused by which major ion?
Chemical synapse = caused by which major ion ?
- Sodium Na+
2. Calcium Ca++
