extra- and intracellular SODIUM
140/14
shake the salt shaker 140 times but only 14 grains of salt came out
extra- and intracellular POTASSIUM
4/140
ate four bananas and got 140% of my daily potassium
extra- and intracellular CALCIUM
2.4/0.0001
even if you drank 2.4 glasses of milk a day, it’s still only 1/10,000 of how much a dairy cow can produce
extra- and intracellular MAGNESIUM
1.2/58
if you drank 1.2 bottles of mag citrate, you would have to go to the bathroom 58 times
extra- and intracellular CHLORIDE
103/4
chloride reminds me of chlorine and hot tubs, if you jumped into a hot tub that was 103* F it could give you 4th degree burns
extra- and intracellular PHOSPHATE
4/75
You’ve heard of adenosine triphosphate, but have you heard of adenosine QUADRUPLEphosphate?? It’s like supercharged ATP and has 75 calories in each phosphate bond.
extra- and intracellular GLUCOSE
90/0-20
Glucose makes me think of checking my patient’s blood sugar, and if it was 90 I would give them 0 units of insulin because that’s a perfect BG.
extra- and intracellular pO2 partial pressure OXYGEN
35-40/~20 mmHg
If you take 35 to 40 BIG breaths it could raise you oxygen sats about 20 percent.
extra- and intracellular pCO2 partial pressure CARBON DIOXIDE
40-45/~45-50 mmHg
Your carbon dioxide levels are highest if you hold your breath for 40-50 seconds.
extra- and intracellular AMINO ACIDS
30/200 mg/dL
Amino acids makes me think of protein which can be found in steaks, so if you ate 30 steaks a day you’d probably gain 200 pounds of muscle.
hyperK causes __polarization and makes the resting membrane potential __ negative
(because the extra- and intracellular K conc. are more similar than usual the rate of diffusion slows = slow depolarization, decreased amplitude, and rapid repolarization)
hyperK
hypo-polarization
less negative
hypoK causes __polarization and makes the resting membrane potential __ negative
(because the K gradient is increased, the rate of diffusion is fast. A larger than normal stimulus is needed, but once threshold is reached it will be a fast depolarization, and a slow repolarization)
hypoK
hyper-polarized
more negative
hypoCalcemia moves threshold __ the RMP, thus __ to open Na+ channels and __ to depolarize, results in irritability.
threshold CLOSER to RMP
EASIER to open Na+ channels
EASIER to depolarize
hyperCalcemia moves threshold __ the RMP, thus __ to open Na+ channels and __ to depolarize, results in a quiet, sleepy, slow, comatose, bradycardic patient.
threshold FURTHER from RMP
HARD to open Na+ channels
HARD to depolarize
__ pairs of cranial nerves and __ pairs of spinal nerves
12
31
two types of EFFERENT
somatic- muscle and motor
autonomic- unconscious (cardiac, GI)
two types of AUTONOMIC
sympathetic
parasympathetic
the nerve cell body has a __ nucleus, __ mitochondria, __ ribosomes, __ apparatus, and endoplasmic reticulum to produce lots of ATP and neurotransmitters
large nucleus
many mitochondria
many ribosomes
golgi apparatus
what is special about dendrites?
very small number of voltage gated sodium channels, so conduct action potentials VERY POORLY, conduct via ELECTROTONIC CONDUCTION DIRECTLY THROUGH CYTOPLASM
how many axons can a cell have?
how many dendrites can a cell have?
axons= one dendrites = 0,1, or more
what is electrotonic conduction
conduction of an action potential directly through the cytoplasm
the larger the diameter of the nerve cell body, the __ resistance to electrical flow
less
what is special about axons?
LOTS of voltage gated sodium channels, rapidly conduct action potentials
schwann cells form myelin in the __, while oligodendrocytes form myelin in the __
schwann = peripheral nervous system oligodendrocytes = central nervous system
what is a collateral axon
an axon that divides off of a main axon
what is telopendria?
termination of an axon, the tip of which is the terminal button where neurotransmitters are released
are nodes of ranvier covered in myelin
nope, that’s why action potentials can leap, jump, dance, saltatory conduction from node to node
multipolar neurons have __ dendrite(s) and one axon, and can be found in the __, __, and __ motor fibers
many dendrites
brain, spinal cord, and somatic motor neurons
bipolar neurons have _ dendrite(s) and one axon, and can be found in the __ neurons, eg. cranial nerves __ and __
one dendrite
sensory neurons in cranial nerves one and two (olfactory and optic)
unipolar neurons have __ dendrite(s) and one axon, and are found in all __ neurons besides for CN 1 and 2
no dendrites
all sensory neurons except for CN 1 and 2
notability the impulse BYPASSES the cell body
__cytes, along with __ junctions, form the blood brain barrier
astrocytes
tight junctions
__ cells can be ciliated or non-ciliated, they line the __ in the brain and form the choroid plexus, and synthesize __ from plasma
ependymal cells
line the ventricles
make CSF
microglia are the resident __ in the brain, they eat up all the bad stuff including brain cells when they die
macrophages
___cytes form the myelin sheaths ONLY IN THE CNS, many projections from one cell body to cover multiple neurons
oligodendrocytes
schwann cells, AKA __cytes, form the myelin in the PNS, one schwann cell per neuron, covers about 1 mm of the neuron
neurolemmocytes
in the __, all axons are myelinated. In the __, some are myelinated and some are not.
CNS all myelinated
PNS some are, some aren’t
type A nerve fibers are __ myelinated, and alpha has the largest diameter, while delta are the smallest
all
type B fibers are myelinated and associated with __ function (B is for blood pressure)
autonomic preganglionic
type C fibers are __ myelinated, what are there functions
sympathetic POSTganglionic
NOT myelinated,
aChing (aching) pain, temperature C*, tiCkle, Crude touCh and pressure,
type A alpha α
proprioception, skeletal muscle motor
type A beta β
light suBtle touch, viBration, hair receptors
type A gamma γ
deep pressure and touch, muscle spindle motor, vibration, hair receptors
type A delta δ
rapiD speeDy pain, Damaging temps, Deep pressure and touch
nerves are bundles of __
fascicles
fascicles are bundles of __
axons
tracts are bundles of __, found in __ only, connect spinal cord to brain or vice versa and connect various parts of brain to each other
why is it white?
axons and their myelin sheaths
found in CNS white matter only
it’s white because it is myelinated
gray matter is found in the center of the __ and the outer portion of the __ , and is where the nerve cell bodies and their dendrites are, also where axons synapse with those dendrites
where does the grey come from?
spinal cord
brain
the grey comes from the lack of white myelin sheaths on the dendrites and the nerve cell bodies.
white matter is found in the center of the __ and the outer portion of the __
brain
spinal cord
a nucleus is a cluster of __ matter (nerve cells bodies and dendrites) distributed throughout the __ matter of the brain
cluster of grey
throughout the white
spatial summation
two or more impulses arriving simultaneously from different sources
temporal summation
two or more impulses arrive in succession one after another and have an additive effect
combined spatial and temporal
obviously a combination of the two, impulses arriving from different sources AND in succession
sensory is __
dorsal (your back)
motor is __
ventral (your front) the motor is usually in the front of the car
if a descending axon from the brain and a sensory neuron from the spinal cord combined together on their way to a motor neuron, that would be called __
convergence
if a sensory neuron splits and one way goes to the brain and another way goes to the motor neuron, that would be called __
divergence
from last quarter, review transport processes, and action potentials
ok
there is only ONE nervous system, but it is divided into sections such as CNS, PNS.
THERE IS ONLY ONE NERVOUS SYSTEM
notice how all parts of the CNS (brain and spinal cord) are enclosed within __
bone
what is the basic structural component of the ENTIRE nervous system?
neuron
what is another name for the neuron cell body?
soma
why do you think there are so many mitochondria in a neuron cell body?
need lots of ATP via aerobic, they don’t function well anaerobically
which is the nucleoplasm of the neuron cell body so rich in electrolytes?
so it can conduct action potentials, remember-water without any electrolytes is a poor conductor
which way do dendrites conduct impulses?
toward the neuron cell body
test question
axons are connected to the neuron cell body at the __
axon hillock
why are impulses mostly conducted distally down the axon and not retrograde through the neuron cell body?
because the axon has lots of voltage gated sodium channels = great for conducting
the cell body has nucleoplams = not very good at conduction
buttons, “butons”, pre-synaptic terminals
all refer to the same thing
where the neurotransmitter is released from
how long are schwann cells?
how long are axons?
schwann 1 cm
axon 1 meter
bare areas between myelin called nodes of __ and are the only places where action potentials can be propogated along the axon
ranvier
would an unmyelinated axon have nodes of ranvier?
no, because nodes of ranvier are where one myelin meets another myelin
trick question
the diameter (micrometers) and conduction velocity (m/sec) for type C fibers are the same, what are they?
0.5 - 2
the diameter (micrometers) and conduction velocity (m/sec) for type A fibers are equal ratios 1:6, what are they?
diameter 1-20
velocity 6-120
hair receptors are type A _, _, _
alpha, beta, gamma
what is a ganglion?
part of the PNS, cluster of nerve cell bodies and associated dendrites, where axons synapse with those dendrites
a ganglion in the PNS is comparable to a __ in the CNS
nucleus
sequence of events - calcium dependent exocytosis of neurotransmitters
test question
- action potential opens voltage gated Ca++ channels
- Ca++ moves with gradient into presynaptic terminal
- synaptic vesicles release neurotransmitter into synaptic cleft
- neurotransmitter binds with receptor site on postsynaptic membrane
- ligated-gated ion channels open
how is acetylcholine released from the presynaptic terminal?
calcium-dependent exocytosis
what removes ACH from the postsynaptic membrane?
What is ACH broken down into?
acetylchoninesterase
acetic acid and choline
choline pumped back into axoplasm where acetyl-CoA is broken down into CoA and acetyl which joins with the choline to form acetylcholine (ACH)
how is norepi released into the cleft?
how is norepi removed back into the axoplasm?
calcium-dependent exocytosis of neurotransmitters
pumped back in to the axoplasm by the reuptake pump, then MonoAmineOxidase metabolizes norepi down to inactive metabolites, that which is not metabolized is reused
anything that causes the RMP to move closer to threshold is called an __postsynaptic membrane potential
excitatory
anything that causes the RMP to move further from threshold is called an __postsynaptic membrane potential
inhibitory
what is the major neurotransmitter throughout the brain and spinal cord?
acetylcholine
What neurotransmitter is synthesized from choline and acetyl coA?
Acetylcholine
where is acetylcholine stored?
stored with ATP in vesicles at the axon terminal (a little package of neurotransmitter all ready to be released)
how is acetylcholine released?
calcium dependent exocytosis
the receptors on the post synaptic membranes for acetylcholine are __ and __
nicotinic and muscarinic
nicotinic 1
ligand gated sodium channels (fast)
neuromuscular
think muscles before BP
nicotinic 2
ligand gated sodium channels (fast)
autonomic
BP after muscles
muscarinic
coupled with g-protein and secondary messengers (long)
parasympathetic
acetylcholinesterase breaks acetylcholine into __ and __
acetic acid and choline
choline taken back up to form more ACH, acetic acid to liver for metabolism
what is the major neurotransmitter for the sympathetic nervous system?
norepi
what is the major neurotransmitter for the nigrostriatal pathways
dopamine
where is the ONLY place epi is synthesized?
adrenal medulla
ALL catecholamines synthesized from the amino acid __
tyrosine
how are catecholamines released into the synapse?
calcium dependent exocytosis
how are the catecholamines removed from the synaptic cleft?
reuptake pump
if not reuptaken, MAO degrades epi/norepi into vanilla-mandela acid and dope into homo-vanilla acid
where does serotonin work?
limbic and raphe
how is serotonin made?
L-tryptophan -> 5-hydroxytryptophan -> serotonin -> eventually melatonin
how is serotonin released?
calcium dependent exocytosis
OFTEN CO-RELEASED WITH OTHERS
MOST serotonin receptors are __
inhibitory
how is serotonin removed from the cleft?
reuptake pump, repackaged for reuse
SSRI’s inhibit this pump
GABA is ALWAYS __
inhibitory
where is GABA used? how is it released?
used throughout CNS and some PNS
calcium dependent exocytosis
GABA A’s open __ resulting in hyperpolarization (inhibits nerve impulse transmission)
ligand gated chloride channels
Benzo’s work on GABA _ receptors
A
glutamate is always __
excitatory
NMDA, QA, and KA are all receptors associated with __ that increase sodium inflow and excite membranes
glutamate
which is the primary neurotransmitter for fast pain?
glutamate
type A delta
substance P stands for __
how long does it occupy receptors for?
pain, long term chronic
prolonged effect
type C - substance P
how is substance P released?
what are its receptors?
how is it inactivated?
calcium dependent exocytosis
receptors unidentified
autolysis of synaptic vesicles, enzymatic inactivation, not reabsorbed
what are the three endogenous opioid peptides?
how are they released?
what are their receptors?
endorphins, enkephalins, dynorphins
calcium dependent exocytosis
mu, kappa, delta
what is the outcome of endogenous opioid peptides?
inhibition for a prolonged period of time (extended hyperpolarization)
how are endogenous opioid peptides removed from their receptors?
autolysis and enzymatic inactivation
Mu receptors are specific for __
Kappa receptors __
Delta receptors __
endorphins
dynorphins
enkephalins
end before enk, dy in the middle
MKD EDE
endorphins, enkephalins, substance P
neurotransmitters or neuromodulators?
BOTH