Nervous system Flashcards
The ‘NERVOUS SYSTEM’ is separated into 2 ‘MAJOR SYSTEMS’. What are they?
- CENTRAL NERVOUS SYSTEM (CNS)
2. PERIPHERAL NERVOUS SYSTEM (PNS)
The ‘CENTRAL NERVOUS SYSTEM’ contains what 2 major organs?
- BRAIN
2. SPINAL CORD
The ‘BRAIN’ is separated into 2 different types of ‘MATTER’.
What are the they?
- GRAY MATTER
2. WHITE MATTER
‘GRAY MATTER’ in the ‘CENTRAL NERVOUS SYSTEM’ is defined as what?
GRAY MATTER = NERVE CELL BODIES
‘WHITE MATTER’ in the ‘CENTRAL NERVOUS SYSTEM’ is defined as what?
WHITE MATTER = MYELINATED AXONS
Where is the ‘NERVE TRACT’ located? In what ‘MAJOR NERVOUS SYSTEM COMPONENT’?
CENTRAL NERVOUS SYSTEM (CNS)
The ‘NERVE TRACT’ which is located in the ‘CENTRAL NERVOUS SYSTEM’. Is defined as what?
GROUP OF NERVE FIBERS WITHIN THE ‘CNS’ THAT HAVE A COMMON ORIGIN/DESTINATION.
(ASCENDING/DESCENDING)
Where is the ‘NERVE TRACT’ located?
ONLY IN THE ‘CNS’
The ‘NUCLEUS’ in regards to the ‘CENTRAL NERVOUS SYSTEM’ is defined as what?
NUCLEUS = CLUSTER OF ‘NERVE CELL BODIES’
*ONLY IN THE ‘CNS’
What is the ‘PERIPHERAL NERVOUS SYSTEM’ (PNS) defined as?
*2 Things
NERVOUS TISSUE OUTSIDE THE:
- ‘BRAIN’
- ‘SPINAL CORD’
How many pairs of ‘CRANIAL NERVES’ are there in the ‘PERIPHERAL NERVOUS SYSTEM’?
12 PAIRS
How many pairs of ‘SPINAL NERVES’ are there in the ‘PERIPHERAL NERVOUS SYSTEM’?
31 PAIRS
In the ‘PERIPHERAL NERVOUS SYSTEM’, what is a ‘NERVE’ defined as?
GROUP OF NERVE FIBERS WITH COMMON ORIGIN/DESTINATION.
- AFFERENT (SENSORY)
- EFFERENT (MOTOR)
‘PERIPHERAL SYSTEM NERVES’ are separated into 2 types. What are they?
- AFFERENT (SENSORY)
2. EFFERENT (MOTOR)
What is a ‘GANGLION’ defined as? Where is it located?
CLUSTER OF NERVE CELL BODIES
ONLY IN THE ‘PERIPHERAL NERVOUS SYSTEM’
What is the ‘AUTONOMIC NERVOUS SYSTEM’ composed of?
What 2 divisions is it separated into?
COMPOSED OF SPECIFIC STRUCTURES IN THE ‘CNS’ and ‘PNS’.
- SYMPATHETIC DIVISION
- PARASYMPATHETIC DIVISION
What are the 2 ‘STRUCTURAL COMPONENTS’ of the ‘NERVOUS SYSTEM’?
- CENTRAL NERVOUS SYSTEM (CNS)
2. PERIPHERAL NERVOUS SYSTEM (PNS)
What are the 2 ‘FUNCTIONAL COMPONENTS’ of the ‘NERVOUS SYSTEM’?
- AUTONOMIC NERVOUS SYSTEM (ANS)
2. SOMATIC NERVOUS SYSTEM (SKELETAL SYSTEM)
What are the 4 ‘PRINCIPAL FUNCTIONS’ of the ‘NERVOUS SYSTEM’?
- ORIENTATION
- COORDINATION
- ASSIMILATION
- PROGRAMMING
What is ‘CEREBRAL PALSY’ and what are the 4 symptoms of it?
ABNORMAL PATHOLOGY OF THE BRAIN
- PARALYSIS
- LACK OF COORDINATION
- MOTOR/SENSORY DYSFUNCTIONS
What is a ‘COMA’ defined as?
DEGREE OF UNCONSCIOUSNESS
RESULT MAY BE FROM A MANY NUMBER OF DIFFERENT CAUSES.
There are 5 steps taking during a ‘NEUROLOGICAL EXAMINATION’. What are they?
- MENTAL STATUS/SPEECH
- CRANIAL NERVES
- THE MOTOR SYSTEM
- THE SENSORY SYSTEM
- REFLEXES
Someone diagnosed with ‘PARAPLEGIA’ has what?
PERMANENT PARALYSIS OF ‘BOTH’ LEGS DUE TO INJURY OR DISEASE OF THE ‘SPINAL CORD’
Someone diagnosed with ‘QUADRIPLEGIA’ has what?
PERMANENT PARALYSIS OF ARMS ‘AND’ LEGS DUE TO ‘SPINAL CORD’ INJURY OR DISEASE.
What is a ‘NEURON’ also known as in the ‘NERVOUS SYSTEM’ terminology?
(*There are 2 names)
- NERVE CELL
2. NERVE FIBER
What is a ‘NEURON’ defined as in the ‘NERVOUS SYSTEM’?
STRUCTURAL/FUNCTIONAL UNIT OF THE ‘NERVOUS SYSTEM’
What is the main function of a ‘NEURON’?
CONDUCT IMPULSES TOWARD/AWAY FROM THE ‘CELL BODY’
What are the 3 components to a ‘NEURON’?
- CELL BODY
- DENDRITES
- AXONS
What is the ‘CELL BODY’ of a ‘NEURON’ defined as?
What does it contain? (5 things)
ENLARGED PORTION OF THE NEURON
CONTAINS:
- NUCLEUS
- NISSL BODIES (ROUGH ER)
- NEUROFIBRILS (PROTEIN)
- OTHER ORGANELLES
What are ‘DENDRITES’ defined as?
What is their main function?
CYTOPLASMIC EXTENSIONS
RECEIVE STIMULI AND CONDUCT ‘IMPULSES’ TO THE ‘CELL BODY’
(*TOWARD NERVE BODY!)
What are ‘AXONS’ defined as?
What 2 types are there and where are each of these types generally located?
CYLINDRICAL PROCESSES THAT CONDUCT IMPULSES ‘AWAY’ FROM THE CELL BODY.
- SHORT AXONS (CNS)
- LONG AXONS (PNS)
Which type of ‘AXONS’ are usually ‘MYELINATED’?
Why?
LONG AXONS
MYELIN SHEATH HELPS CONDUCT IMPULSES FASTER
What are ‘SCHWANN CELLS’, and in what system are they located?
ANOTHER NAME FOR ‘MYELINATED ‘LONG’ AXONS’
ONLY IN THE ‘PERIPHERAL NERVOUS SYSTEM’ (PNS)
What are ‘OLIGODENDROCYTES’, and in what system are they located?
ANOTHER NAME FOR ‘MYELINATED ‘LONG’ AXONS’
ONLY IN THE ‘CENTRAL NERVOUS SYSTEM’ (CNS)
What are ‘NODES OF RANVIER’?
SEGMENTS IN THE ‘MYELIN SHEATH’
*LOCATED BETWEEN SCHWANN CELLS/OLIGODENDROCYTES
Where do ‘AXONS’ terminate?
AT THE ‘PRESYNAPTIC TERMINAL’ OF THE ‘NEURON’
Because there are many ‘NEURONS’ in the body, how are they classified?
(*3 THINGS)
- DIRECTION OF ‘IMPULSE CONDUCTION’
- NUMBER OF ‘CYTOPLASMIC PROCESSES’
- AREA OF ‘INNERVATION’
There are 3 types of ‘NEURONS’ defined by ‘IMPULSE CONDUCTION’. What are they?
- SENSORY (AFFERENT)
- INTERNEURONS
- MOTOR (EFFERENT)
What is the function of a ‘SENSORY’ neuron?
Is it ‘AFFERENT’ or ‘EFFERENT’?
TRANSMIT NERVE IMPULSE ‘TO’ THE ‘CNS’ (BRAIN)
(e.g. PAIN RESPONSE)
‘AFFERENT’
(*HINT - (A)FFERENT (A)RRIVES TO THE BRAIN)
What is the function of a ‘MOTOR’ neuron?
Is it ‘AFFERENT’ or ‘EFFERENT’?
TRANSMIT NERVE IMPULSE ‘AWAY’ FROM THE ‘CNS’ (BRAIN).
(e.g. MUSCULAR RESPONSE)
‘EFFERENT’
(*HINT - (E)FFERENT (E)XITS THE BRAIN)
What is the function of ‘INTERNEURONS’ and what are they also known as?
(*2 other names)
CONDUCT THE ‘IMPULSES’ BETWEEN BOTH SENSORY ‘AND’ MOTOR’ NEURONS.
[*HINT - (INTER)states bridge the gap between states. (INTER)neurons bridge the gap between SENSORY/MOTOR neurons.]
ALSO KNOWN AS:
- INTERNUNCIAL NEURONS
- ASSOCIATION NEURONS
‘NEURONS’ that have only ‘1 AXON’ and ‘2+ DENDRITES’ are known as what kind of neurons?
‘MULTI’POLAR
‘NEURONS’ that have only ‘1 AXON’ and ‘1 DENDRITE’ are known as what kind of neurons?
‘BI’POLAR
‘NEURONS’ that have only ‘1 SINGLE PROCESS’ (aka - DENDRITE/AXON connected together) are known as what kind of neurons?
‘UNI’POLAR
There are 4 specific types of ‘NEURON INNERVATION’. What are they?
- SOMATIC (A)FFERENT (SKELETAL)
- SOMATIC (E)FFERENT (SKELETAL)
- VISCERAL (A)FFERENT (ORGANS)
- VISCERAL (E)FFERENT (ORGANS)
[*Hint - (A)fferent (A)rrives to the brain (CNS) and (E)fferent (E)xits)the brain (CNS).]
What is the definition of a ‘SOMATIC AFFERENT’ neuron?
What is its functions?
NEURONS WITHIN SKIN, MUSCLES, JOINTS.
(SOMATIC SYSTEM = SKELETAL)
FUNCTION:
RECEIVE STIMULI -> CONVEY IMPULSE (TO) THE BRAIN (CNS).
[*Hint - (A)fferent (A)rrives to the brain (CNS) and (E)fferent (E)xits)the brain (CNS).]
What is the definition of a ‘SOMATIC EFFERENT’ neuron?
What is its functions?
NEURONS WITHIN SKIN, MUSCLES, JOINTS.
(SOMATIC SYSTEM = SKELETAL)
FUNCTION:
RECEIVE STIMULI -> CONVEY IMPULSE (FROM) THE BRAIN (CNS) -> SKELETAL MUSCLES
[*Hint - (A)fferent (A)rrives to the brain (CNS) and (E)fferent (E)xits)the brain (CNS).]
What is the definition of a ‘VISCERAL AFFERENT’ neuron?
What is its functions?
NEURONS LOCATED ON/IN ‘INTERNAL ORGANS’
(VISCERAL SYSTEM = INTERNAL ORGANS)
FUNCTION:
RECEIVE STIMULI -> CONVEY IMPULSE (TO) THE BRAIN (CNS) ‘FROM’ INTERNAL MUSCLES
[*Hint - (A)fferent (A)rrives to the brain (CNS) and (E)fferent (E)xits)the brain (CNS).]
What is the definition of a ‘VISCERAL EFFERENT’ neuron?
What is its functions?
NEURONS LOCATED ON/IN ‘INTERNAL ORGANS’
(VISCERAL SYSTEM = INTERNAL ORGANS)
FUNCTION:
RECEIVE STIMULI -> CONVEY IMPULSE (FROM) THE BRAIN (CNS) ‘TO’ INTERNAL MUSCLES
[*Hint - (A)fferent (A)rrives to the brain (CNS) and (E)fferent (E)xits)the brain (CNS).]
What is ‘RESTING MEMBRANE POTENTIAL’ defined as?
WHEN A NEURON IS ‘NOT’ CONDUCTING AN ‘IMPULSE’
What components of a ‘NEURON’ constitute the ability to create an ‘IMPULSE’?
THE ‘DIFFERENCE’ IN THE ELECTRICAL CHARGE BETWEEN THE INSIDE/OUTSIDE OF THE ‘CELL MEMBRANE’
When a ‘NEURON’ is ‘UN-STIMULATED’, how is there a difference in electrical charge inside and outside the cell membrane?
DUE TO THE ‘IMBALANCE’ OF CHARGED PARTICLES (IONS/PROTEINS) BETWEEN THE ‘INTRACELLULAR’ AND ‘EXTRACELLULAR’ FLUIDS.
What is the ‘OVERALL’ charge of ‘NEURON’ when it is at ‘REST’ or ‘UN-STIMULATED’?
Why is it like this?
OVERALL NEGATIVE (-) CHARGE
BECAUSE OF ‘LARGE’ NEGATIVELY (-) CHARGED PROTEINS THAT ARE ‘NOT’ PERMEABLE TO THE CELL MEMBRANE
When the membrane of the ‘NEURON’ is said to be ‘POLARIZED’, what does this mean?
MORE (+) POSITIVE IONS ‘OUTSIDE’
MORE (-) NEGATIVE IONS ‘INSIDE’
*MEMBRANE IS AT ‘REST’ OR ‘UN-STIMULATED’ AND AT ‘EQUILIBRIUM’
What are ‘POSITIVE (+) IONS’ also called?
CATIONS (+)
What are ‘NEGATIVE (-) IONS’ also called?
ANIONS (-)
There are 3 mechanisms that are responsible for the ‘IMBALANCE’ in particles (charge) across the ‘NEURON CELL MEMBRANE’. What are they?
- SODIUM-POTASSIUM PUMP
- PERMEABILITY OF K+ TO Na+
- PROTEIN IMPERMEABILITY
Which ‘IONS’ are more favorable with cell permeability in the ‘CELL MEMBRANE’ of a ‘NEURON’?
MORE PERMEABLE TO ‘K+ IONS’
*K+ IONS MOVE ‘OUTWARD’ AND FASTER THAN Na+ IONS MOVE ‘INWARD’
Which ‘IONS’ are ‘LESS’ favorable with cell permeability in the ‘CELL MEMBRANE’ of a ‘NEURON’?
LESS PERMEABLE TO ‘Na+ IONS’
*Na+ IONS MOVE ‘INWARD’ AND SLOWER THAN K+ IONS MOVE ‘OUTWARD’
How does the ‘SODIUM POTASSIUM PUMP’ function with respect to ‘NEURONS’?
What type of ‘TRANSPORT’ is this? Why?
MOVES ‘Na+’ IONS TO ‘OUTSIDE’
MOVES ‘K+’ IONS TO ‘INSIDE’
‘ACTIVE TRANSPORT’. REQUIRES ENERGY (ATP) TO FACILITATE TRANSPORT.
What is the ‘NORMAL’ charge inside of the ‘NEURON’ when it is at ‘REST’ or ‘UN-STIMULATED’?
-65 to -85mV
The ‘CELL MEMBRANE’ is ______ permeable to ‘K+ IONS’ and _____ permeable to ‘Na+ IONS’.
This makes it so that ‘____ IONS’ move outward faster than the ‘____ IONS’ move inward.
- MORE PERMEABLE TO ‘K+ IONS’
- LESS PERMEABLE TO ‘Na+ IONS’
- ‘K+ IONS’ MOVE OUTWARD FASTER
- ‘Na+ IONS’ MOVE INWARD SLOWER
What characteristic of the ‘CELL MEMBRANE’ holds a ‘NEGATIVE (-) CHARGE’ over a positive charge?
THE ‘IMPERMEABILITY’ OF THE CELL MEMBRANE TO LARGE NEGATIVELY (-) CHARGED ‘PROTEINS’ INSIDE THE ‘NEURON’.
‘FEWER’ (-) CHARGED PARTICLES MOVE OUT
WHEREAS
‘MORE’ (+) CHARGED PARTICLES MOVE OUT
TRUE OR FALSE
‘ALL’ CELLS OF THE BODY HAVE ELECTRICAL POTENTIALS ACROSS THEIR CELL MEMBRANES?
TRUE
‘ALL’ CELLS HAVE ELECTRICAL POTENTIALS
Which 2 types of cells have the ability to ‘ALTER/ADAPT’ their ‘RESTING MEMBRANE POTENTIAL’ in response to appropriate stimuli?
How does this work?
- NERVE CELLS
- MUSCLE CELLS
VARYING MEMBRANE PERMEABILITY TO DIFFERENT ‘IONS’.
An ‘ACTION POTENTIAL’ can be separated into 3 points. What are they?
- SPIKE
- NERVE IMPULSE
- DISCHARGE
TRUE OR FALSE
‘ACTION POTENTIALS’ ARE ‘NOT’ SIMILAR IN SIZE/DURATION.
THEY ‘DIMINISH’ AS THEY ARE CONDUCTED DOWN AN ‘AXON’.
FALSE
THEY ARE ‘SIMILAR’ IN ‘SIZE/DURATION’.
THEY DO ‘NOT’ DIMINISH AS THEY ARE CONDUCTED DOWN AN ‘AXON’
What 2 characteristics of an ‘ACTION POTENTIAL’ constitute the ‘CODE’ as well as the ‘DESTINATION’ of the ‘IMPULSE’?
- FREQUENCY
2. PATTERN
TRUE OR FALSE
ACTION POTENTIALS ‘ARE’ SIMILAR IN ‘ALL’ ORGANISMS.
TRUE
‘ACTION POTENTIALS’ ARE SIMILAR IN ALL ORGANISMS.
(FROM A SQUID TO A COLLEGE STUDENT)
How can an ‘ACTION POTENTIAL’ be recorded?
*Name of the instrument used
VIA AN ‘OSCILLOSCOPE’ OR ‘VOLTMETER’
How often does/can an ‘ACTION POTENTIAL’ occur?
VERY RAPIDLY
(Every 2 msec) or 1000/second
What happens to inside of the ‘CELL MEMBRANE’ during an ‘ACTION POTENTIAL’?
What is the state of the ‘MEMBRANE’ referred to as?
BECOMES POSITIVE (+) INSIDE
STATE OF BEING ‘DEPOLARIZED’
During an ‘ACTION POTENTIAL’ there are 5 characteristics (phases) that occur. What are they?
- RISING PHASE
- OVERSHOOT
- FALLING PHASE
- UNDERSHOOT/HYPERPOLARIZATION
- RESTORATION OF RESTING POTENTIAL
What is the ‘RISING PHASE’ of an ‘ACTION POTENTIAL’?
When does this phase occur?
RAPID ‘DEPOLARIZATION’ OF THE ‘MEMBRANE’ (Na+ IONS MOVE INTO CELL TO MAKE OVERALL CHARGE MORE (+) POSITIVE)
1st PHASE DURING ‘ACTION POTENTIAL’
What is the ‘OVERSHOOT’ phase of an ‘ACTION POTENTIAL’?
When does this phase occur?
INSIDE OF MEMBRANE BECOMES ‘POSITIVE (+)’ (+40mV)
2nd PHASE DURING ‘ACTION POTENTIAL’
What is the ‘FALLING PHASE’ of an ‘ACTION POTENTIAL’?
When does this phase occur?
MEMBRANE IS RAPIDLY ‘REPOLARIZED’ (K+ IONS MOVE OUT OF CELL TO MAKE OVER ALL CHARGE MORE (-) NEGATIVE)
What is the ‘UNDERSHOOT’ or ‘HYPERPOLARIZATION’ phase of an ‘ACTION POTENTIAL’?
WHERE THE ‘ACTION POTENTIAL’ GOES DOWN TO A MORE (-) NEGATIVE CHARGE THAN ITS NORMAL RESTING POTENTIAL. (UNDERSHOOT)
What is an ‘ACTION POTENTIAL’ defined as? What causes this to occur?
‘STIMULUS’ APPLIED TO A NEURON’S MEMBRANE. CREATES A ‘WAVE OF DEPOLARIZATION’ ALONG THE FIBER.
When an ‘ACTION POTENTIAL’ is created, there are 10 standard steps that occur. What are they 10 steps?
- STIMULATION OF MEMBRANE
- SODIUM CHANNELS OPEN
- SODIUM IONS MOVE ‘INWARD’
- THRESHOLD (-55mV) REACHED
- DEPOLARIZATION OF MEMBRANE
- REVERSE POLARIZATION
- *STEP 6 ACTS AS STIMULUS TO ADJACENT REGIONS
- POTASSIUM CHANNEL ‘OPEN’
- PUMPS TRANSPORT SODIUM BACK OUT OF ‘NEURON’ AND POTASSIUM ‘INTO’ ‘NEURON’.
What are 3 factors that can be considered ‘adequate stimulation’ of a membrane to create an ‘ACTION POTENTIAL’?
- PHYSICAL
- CHEMICAL
- TEMPERATURE
(DIFFERENT NEURONS = DIFFERENT STIMULI)
When ‘Na+ IONS’ move inward, what happens to the cell membrane?
BECOMES ‘LESS’ NEGATIVE
What is the ‘THRESHOLD LEVEL’?
What does ‘ALL or NONE’ mean with regards to this?
THRESHOLD LEVEL = -55mV
LEVEL THAT MUST BE CROSSED IN ORDER TO TRIGGER AN ‘ACTION POTENTIAL’.
‘ALL or NONE’ = Unless a ‘STIMULUS’ makes cell membrane reach -55 mV, an ‘ACTION POTENTIAL’ will ‘NOT’ be created.
TRUE OR FALSE
The ‘GREATER’ the stimulus, the larger the ‘ACTION POTENTIAL’.
FALSE
‘ALL or NONE’ MEANS THAT ONLY THRESHOLD LEVEL HAS TO BE REACHED FOR AN ‘ACTION POTENTIAL’ TO BE CREATED. (-55mV)
What happens when nerve/muscle fibers receive a ‘SUB-THRESHOLD’ stimulus?
NO RESPONSE / NO ‘ACTION POTENTIAL’
What is the ‘ABSOLUTE REFRACTORY PERIOD’ defined as?
INTERVAL DURING AN ACTIVE ‘ACTION POTENTIAL’ WHERE ANOTHER STIMULUS ‘CANNOT’ CREATE ANOTHER ‘ACTION POTENTIAL’ RESPONSE BECAUSE THE CHANNELS ARE ALREADY OPEN.
(*HINT - ‘ABSOLUTE REFRACTORY PERIOD’ = ‘ABSOLUTELY [NOT] GOING TO HAPPEN’)
What is the ‘RELATIVE REFRACTORY PERIOD’ defined as?
INTERVAL WHERE NEURON WILL ‘NOT’ RESPOND TO A NORMAL STIMULUS.
A VERY ‘STRONG’ STIMULUS WILL PRODUCE A ‘SECOND’ ‘ACTION POTENTIAL’.
(*HINT - ‘2nd ACTION POTENTIAL CREATION IS ‘RELATIVE’ TO STRENGTH OF STIMULUS’)
Until the ‘RE-POLARIZATION’ is ____ completed, a 2nd ‘ACTION POTENTIAL’ cannot be produced.
What is this referred to as?
‘1/3 COMPLETED’
‘ABSOLUTE REFRACTORY PERIOD’
(*HINT - ‘ABSOLUTELY [NOT] GOING TO HAPPEN’)
Which molecules act as ‘CHAPERONES’ for the ‘Na+ IONS’?
Why is this important?
WATER (H2O)
THIS ‘ION-WATER’ COMPLEX ALLOWS ‘Na+’ TO MOVE THROUGH PORES AND EXCLUDE ‘K+ IONS’.
TRUE OR FALSE
Na+ CHANNELS OPEN RELATIVELY ‘SLOW’
FALSE
Na+ CHANNELS OPEN ‘RAPIDLY
What are 3 characteristics about the ‘Na + CHANNELS’ in a ‘NEURON CELL’?
- OPEN VERY RAPIDLY/FIRST
- STAY OPEN FOR ~1msec
- CANNOT OPEN AGAIN UNTIL ‘AFTER’ ‘ABSOLUTE REFRACTORY PERIOD’ IS OVER.
What is ‘TTX’ and what does it do?
Where is it found?
TETRODOTOXIN (TTX)
PHYSICALLY BLOCKS ‘Na+’ PORES
FOUND IN ‘JAPANESE PUFFER FISH’
What does ‘SAXITOXIN’ do?
Where is it found?
BLOCKS ‘Na+’ PORES
FOUND IN CLAMS, MUSSELS AND OTHER SHELL FISH.
What is ‘BATRACHOTOXIN’ do?
CAUSES THE ‘Na+ CHANNELS’ TO OPEN AND STAY OPEN MUCH LONGER
What are the characteristics of ‘K+ CHANNELS’?
*THERE ARE 3 OF THEM
- DO NOT IMMEDIATELY OPEN UPON ‘DEPOLARIZATION’
- OPEN WHEN ‘Na+ CHANNELS’ CLOSE
- MOVE OF K+ DURING ‘RE-POLARIZATION’ REFERRED TO AS ‘DELAYER RECTIFIER’
Why does an ‘ACTION POTENTIAL’ most of the time only move in ‘ONE-DIRECTION’?
What is this known as?
BECAUSE THE MEMBRANE POTENTIAL BEHIND IT IS IN ‘ABSOLUTE REFRACTORY’ PHASE THUS NO IMPULSE CAN BE CREATED FROM ANY STIMULUS.
KNOWN AS ‘ORTHODROMIC CONDUCTION’
What is ‘ORTHODROMIC CONDUCTION’
Is this common/uncommon?
‘ONE-WAY’ CONDUCTION OF ‘NERVE IMPULSES’
*MOST COMMON UNDER NORMAL CONDITIONS
What is ‘ANTIDROMIC CONDUCTION’?
Is this common/uncommon?
‘TWO-WAY’ (BACKWARD PROPAGATION) CONDUCTION OF ‘NERVE IMPULSES’
*VERY UNCOMMON - UNDER ‘EXPERIMENTAL’ CONDITIONS
What is ‘CONTINUOUS CONDUCTION’?
In what type of ‘NEURON’ does this occur in?
IMPULSE TRAVELS ALONG THE ‘ENTIRE’ SURFCE OF THE MEMBRANE SURFCAE
OCCURS IN ‘UNMYELINATED NEURONS’
An ‘UNMYELINATED NEURON’ travels approximately how fast?
What type of ‘CONDUCTION’ do these types of ‘NEURONS’ use?
1m/sec
‘CONTINUOUS CONDUCTION’
A ‘MYELINATED NEURON’ travels approximately how fast?
What type of ‘CONDUCTION’ do these types of ‘NEURONS’ use?
100m/sec
‘SALTATORY CONDUCTION’
Why do ‘MYELINATED NEURONS’ travel faster than ‘UNMYELINATED NEURONS’?
(*2 MAIN FACTORS)
- ‘MYELIN SHEATH’ CREATES INSULATION TO THE ‘AXON’
2. ‘NODES OF RANVIER’ ALLOW ACTION POTENTIALS TO ‘LEAP’ WHERE ‘MYELIN SHEATH’ COVERS AXON.
What are the characteristics/benefits of ‘SALTATORY CONDUCTION’?
- INCREASE VELOCITY OF IMPULSE CONDUCTION
- CONSERVES ENERGY
(BECAUSE Na+ AND K+ PUMPS ONLY HAVE TO RE-ESTABLISH CONCENTRATION DIFFERENCES AT
‘NODES OF RANVIER’.
What is ‘MULTIPLE SCLEROSIS’?
2nd MOST COMMON ‘CNS DISEASE’
AUTOIMMUNE DISEASE WHERE BODY ATTACKS THE ‘MYELIN SHEATH’ (OLIGODENDROGLIA) IN THE CENTRAL NERVOUS SYSTEM WHICH CAUSES NERVE CONDUCTION INTERRUPTED.
What are some of the possible treatments for ‘MULTIPLE SCLEROSIS’?
- ACTH (ADRENOCORTICOTROPIC HORMONE) TREATMENT
- EXERCISE
- PHYSICAL THERAPY
What is ‘TAY-SACHS DISEASE’?
INHERITED DISEASE IN WHICH THE ‘MYELIN SHEATHS’ ARE DESTROYED.
EXCESSIVE LIPID ACCUMULATION OCCURS IN THE MEMBRANE LAYERS.
How does ‘LOCAL ANESTHESIA’ work?
What are 2 examples of drugs of this type?
BLOCK THE INITIATION OF ‘ACTION POTENTIALS’ IN NEURONS.
PHYSICALLY BLOCK SODIUM CHANNELS
LIDOCAINE AND COCAINE ARE ARE EXAMPLES OF DRUGS THAT ARE LOCAL ANESTHETICS.
What is the ‘SYNAPSE’ defined as?
JUNCTION BETWEEN ‘2 NEURONS’
WHERE THE ELECTRICAL IMPULSE OF ONE NEURON INITIATES A SERIES OF EVENTS
What are the 3 parts of a ‘SYNAPSE’?
- AXONS TERMINALS
- SYNAPTIC CLEFT
- POSTSYNAPTIC MEMBRANE
What are ‘AXON TERMINALS’ defined as?
SMALL ROUNDED/OVAL KNOBS, BOUTONS, END FEET OR ‘PRESYNAPTIC TERMINALS’.
SITE WHERE ‘SYNAPTIC VESICLES’ CONTAINING ‘NEUROTRANSMITTERS’ ARE LOCATED.
What are the 3 main ‘NEUROTRANSMITTERS’?
What do they do?
- ACETYL CHOLINE (ACh)
- NOREPINEPHRINE (NorEPI)
- EPINEPHRINE (EPI)
*STIMULATE MUSCLES
What is the ‘SYNAPTIC CLEFT’ defined as?
MICROSCOPIC SPACE BETWEEN THE ‘2 NEURONS’
What is the ‘POSTSYNAPTIC MEMBRANE’ defined as?
CELL MEMBRANE THAT CONTAINS ‘SPECIFIC RECEPTORS’ FOR THE ‘NEUROTRANSMITTER’
There are 5 events that take place each time a ‘SYNAPSE’ is made. What are they?
- IMPULSE TO AXON TERMINAL (PRESYNAPTIC NEURON)
- Ca+ CAUSES RELEASE OF NEUROTRANSMITTER INTO SYNAPTIC CLEFT
- NEUROTRANSMITTER DIFFUSES ACROSS SYNAPTIC CLEFT/DETECTED BY RECEPTORS ON POSTSYNAPTIC NEURON
- POSTSYNAPTIC MEMBRANE = STIMULATED/INHIBITED DEPENDING ON NEUROTRANSMITTER
- NEUROTRANSMITTER IS DIFFUSED OUT OF CLEFT OR METABOLIZED
What are the 2 enzymes that metabolize the excess ‘NEUROTRANSMITTER’ left in the synaptic cleft?
- CHOLINESTERASE (ACh)
2. MONOAMINE OXIDASE (NorEPI)
What ‘ENZYME’ metabolizes excess ‘ACETYLCHOLINE’ in the ‘SYNAPTIC CLEFT’?
CHOLINESTERASE
What ‘ENZYME’ metabolizes excess ‘NOREPINEPHRINE’ in the ‘SYNAPTIC CLEFT’?
MONOAMINE OXIDASE
What are the 3 characteristics of a ‘SYNAPSE’?
- SYNAPTIC DELAY
- SYNAPTIC FATIGUE (DEPLETION OF THE NEUROTRANSMITTER)
- ONE-WAY CONDUCTION
Drugs may influence/alter ‘SYNAPTIC TRANSMISSION’ in what 4 different ways?
- ‘SYNTHESIS’ OF NEUROTRANSMITTER
- ‘RELEASE’ OF THE NEUROTRANSMITTER
- ‘BINDING’ OF THE NEUROTRANSMITTER WITH THE RECEPTOR
- ‘DESTRUCTION’ OF THE NEUROTRANSMITTER
What 3 disease affect ‘SYNAPTIC TRANSMISSION’?
- PARKINSON’S DISEASE
- MYASTHENIA GRAVIS
- BOTULISM
What is ‘PARKINSON’S DISEASE’ defined as?
LACK OF THE NEUROTRANSMITTER ‘DOPAMINE’
What is ‘MYASTHENIA GRAVIS’ defined as?
BLOCKS ‘ACETYLCHOLINE’ (ACh) NEUROTRANSMITTER RECEPTORS.
What is ‘BOTULISM’ defined as?
‘INHIBITION’ OF ‘ACETYL CHOLINE’ (ACh) RELEASE
There are 2 types of transmissions in ‘NEURONS’. What are they?
- EXCITATORY
2. INHIBITORY
What is ‘SYNAPTIC INTEGRATION’ defined as?
ABILITY FOR A SINGLE ‘NEURON’ TO BY STIMULATED BY:
- EXCITATORY TRANSMISSIONS
- INHIBITORY TRANSMISSIONS
FROM ‘DIFFERENT’ ‘PRESYNAPTIC NEURONS’
What is ‘SYNAPTIC EXCITATION’?
What is it also referred as when this occurs?
‘EXCITATORY NEUROTRANSMITTERS’ INCREASE THE POSTSYNAPTIC MEMBRANE’S PERMEABILITY TO SODIUM (Na+) IONS
KNOWN AS ‘EXCITATORY POSTSYNAPTIC POTENTIAL’ (EPSP)
What is ‘EPSP’?
What is the ‘MEMBRANE’ said to be in this state?
‘EXCITATORY POSTSYNAPTIC POTENTIAL’
‘EXCITATORY NEUROTRANSMITTERS’ INCREASE MEMBRANE PERMEABILITY TO Na+ IONS.
MEMBRANE IS SAID TO BE ‘HYPOPOLARIZED’
During an ‘EXCITATORY POSTSYNAPTIC POTENTIAL’ (EPSP), the membrane is said to be what?
HYPOPOLARIZED
What are the 2 different ways in order to get ‘EXCITATORY POSTSYNAPTIC POTENTIAL’ (EPSP) to reach an ‘ACTION POTENTIAL’?
(*HINT - SUMMATIONS)
- SPATIAL SUMMATION
2. TEMPORAL SUMMATION
What is ‘SPATIAL SUMMATION’?
‘SEVERAL’ PRESYNAPTIC NEURONS SIMULTANEOUSLY RELEASE NEUROTRANSMITTERS TO A SINGLE POSTSYNAPTIC NEURON.
(*HINT - (S)PATIAL AND (S)EVERAL)
What is ‘TEMPORAL SUMMATION’?
‘EXCITATORY POSTSYNAPTIC POTENTIAL’ (EPSP) result of the ‘RAPID’ discharge from the ‘SAME’ presynaptic terminal.
What is ‘SYNAPTIC INHIBITION’?
What is it also referred as when this occurs?
‘INHIBITORY NEUROTRANSMITTERS’ INCREASE THE POSTSYNAPTIC MEMBRANE’S PERMEABILITY TO CHLORIDE (Cl-) AND POTASSIUM (K+) IONS.
KNOWN AS ‘INHIBITORY POSTSYNAPTIC POTENTIAL’ (IPSP)
What is ‘IPSP’?
What is the ‘MEMBRANE’ said to be in this state?
‘INHIBITORY POSTSYNAPTIC POTENTIAL’
‘INHIBITORY NEUROTRANSMITTERS’ INCREASE MEMBRANE PERMEABILITY TO (CHLORINE) Cl- AND (POTASSIUM) K+ IONS.
MEMBRANE IS SAID TO BE ‘HYPERPOLARIZED’
During an ‘INHIBITORY POSTSYNAPTIC POTENTIAL’ (IPSP), the membrane is said to be what?
‘HYPERPOLARIZED’
What is ‘GRAND POSTSYNAPTIC POTENTIAL’ (GPSP) defined as?
THE ‘SUM’ TOTAL OF BOTH ‘EXCITATORY’ AND ‘INHIBITORY’ POSTSYNAPTIC POTENTIALS THAT ARE BEING STIMULATED.
There are 6 basic types of ‘NEUROTRANSMITTER’ groups. What are they?
- ACETYLCHOLINE
- AMINO ACIDS
- AMINES
- POLYPEPTIDES
- PURINES
- GASES
What are the 2 main ‘AMINO ACID’ ‘NEUROTRANSMITTERS’?
- GABA (Gamma-aminobutyric acid)
- GLYCINE
Both inhibitory
What type of ‘NEUROTRANSMITTER’ is ‘GABA’ (gamma-aminobutyric acid)?
What is its function? (Inhibitory/Excitatory)
‘AMINO ACID’
‘INHIBITORY’
What type of ‘NEUROTRANSMITTER’ is ‘GLYCINE’?
What is its function? (Inhibitory/Excitatory)
‘AMINO ACID’
‘MAINLY INHIBITORY’
What are the 2 main ‘AMINE’ ‘NEUROTRANSMITTERS’?
- NOREPINEPHRINE
- EPINEPHRINE
*All made from the ‘SAME’ ‘AMINO ACID’
What type of ‘NEUROTRANSMITTER’ is ‘NOREPINEPHRINE’?
‘AMINE’
What type of ‘NEUROTRANSMITTER’ is ‘EPINEPHRINE’?
‘AMINE’
What 2 ‘NEUROTRANSMITTERS’ are in the ‘POLYPEPTIDE’ group?
What is their function?
- SUBSTANCE P
- ENDORPHINS/ENKEPHALINS
FUNCTION: TRANSMISSION/INHIBITION OF PAIN
Which ‘NEUROTRANSMITTER’ is in the ‘GAS’ group?
‘NITRIC OXIDE’
TRUE OR FALSE
EVERY TIME YOU STEP ‘NEURONS’ ARE BEING INHIBITED/STIMULATED?
TRUE
‘NEURONS’ ARE BEING ‘INHIBITED/STIMULATED’ ON OPPOSITE ENDS EACH TIME YOU STEP.
