Chapter 12: Nervous Tissue Flashcards
The motor component of the somatic nervous system is concerned with what type of tissue ?
Skeletal muscle (voluntary)
Most nerve impulses arise where in the nerve cell ?
Trigger zone
What are the 3 Branches of the Peripheral Nervous System?
SNS, ANS, and ENS
3 parts of a neuron
Cell body, axon, dendrites
Site of communication btw a neuron and an effector cell is called what ?
Synapse
What do synaptic vesicles store?
Neurotransmitter
A molecule released from synaptic vesicles that either inhibits or excites another neuron is known as what?
Neurotransmitter
What type of neuro glia myelinate axons in the CNS?
Oligodendrocytes
The largest and most numerous neuroglia that functions to form the blood brain barrier ?
Astrocytes
This type of neuroglia function to remove cellular debris and phagocytize damaged nervous tissue
Microglia
This type of neuroglia produce, and monitor and circulate cerebral spinal fluid
Ependymal cells
What type of neuroglia encircle axons in the PNS
Schwann cells
What are clusters of cell bodies in the CNS called ?
Nucleus
Clusters of excellent bodies in the PNS?
Ganglion
A bundle of axons in the PNS ?
Nerve
A bundle of axons in the CNS?
Tract
What type of channels are used in a graded potential ?
Ligand or mechanically gated ion channels
What is a typical resting membrane potential for a neuron ?
-70mV
The main cation in the cytosol
Potassium (K+)
The main cation and anion in the EXtracellular fluid ?
Sodium (Na+) and chloride (CL-)
What feature contributes to the electrogenic nature of resting membrane potential and expels 3 sodium out of cell for every 2 Potassium imported
na+/K+ ATPases (sodium/potassium pumps)
Is saltatory conduction faster or slower the. Continuous conduction ?
Faster
What is decremental conduction, is it associated with an AP or GP
It is a mode of travel by with the graded potential (GP), dies as it spreads along the membrane
Processes in which graded potentials add together
Summation
In which phase do voltage gated sodium channels open allowing sodium to rush into the cell ?
Depolarizing phase
In the repolarizing phase what cation moves out of the cell ?
K+ ions leave via K+ channels (making the cell more negative and restoring resting membrane potential
In the depolarizing phase what voltage gated channels open ?
Na+ voltage gated channels open (na+ enters cell making it more positive )
Factors that affect speed of propagation
1) amount of myelination
2) axon diameter
3) temperature
Resting potential in skeletal and cardiac mm
-90mv
A neurotransmitter that causes depolarization of post synaptic membrane potential is called
(EPSP) excitatory postsynaptic potential
Type of neurotransmitter contains a binding site and an ion which are components of the same protein
Ionotropic
If the total inhibitory effects are greater then the excitatory effects, the membrane hyper polarizes (IPSP) what is the result ?
Inhibition of the post synaptic nerve impulse and an inability to generate a nerve impulse
A neurotransmitter that is released by many cells in the PNS and by some in the CNS. Excitatory at NMJ
Acetylcholine (ACh)
Epinephrine, norepinephrine and dopamine are classified as what biogenic amine ?
Catecholamines
Name 2 amino acid neurotransmitters in the CNS that have powerful excitatory effects effects
Glutamate asparate
What kind of neurotransmitter Are GABBA and GYLCINE ?
Important inhibitory NTs
Arousal , awakening from deep sleep, dreaming and regulating mood, doubles as a NT and hormone
Norepinephrine
This NT is active during emotional responses addictive behaviours and pleasurable activities ( also regulate skeletal mm tone )
Dopamine
What biogenic amine is involved with sensory perception, temperature regulation, control of mood, appetite, and the induction of sleep
Serotonin
Neuropeptide related to pain
Substance P
Wallerian degeneration
Degeneration of the distal part of the axon and myelin sheath
Neural circuit involved with breathing, coordinated muscular contractions, waking up, and short term memory
Reverberating circuit
Neural circuit that allows one presynaptic neuron to influence several post synaptic neuron
Diverging circuit
True or false damage to myelinated axons and dendrites in the PNS may be repaired if the cell body remains intact
True
Nerve responsible for skeletal muscle regeneration?
Satellite cells
What are nissl bodies ?
Bunches or Rough ER in neurons
