Ch. 12 Flashcards
Types of neuroglia aka glial cells (found in CNS):
Bank: Microglia, Ependymal cells, Oligodendrocytes, Schwann Cells, Astrocytes, Satellite Cells
Description:
- Star-shaped cells with many processes
- Metabolize NT’s, maintain [K+] balance for CNS neurons
- Help form the blood-brain barrier (BBB)
- Serve as link between neurons & blood vessels
Nutshell: Maintains environemnt for neurons, which involves balancing POTASSIUM

Astrocytes

_______ = two or more graded potentials added together creates a greater change in membrane potential
Summation

Types of Neurotransmitters associated with CNS & PNS:
Acetylcholine is the most ______ of the neurotransmitters. It exists in both the somatic and autonomic nervous systems. It’s also excitatory (i.e. moves muscles) and inhibitory (i.e. slows heart rate)
versatile
Graded potential is
- Generated on _______ (axons/membrane of dendrites and cell body)
- Remains localized; _____ (short/long)-distance communication only
membrane of dendrites and cell body
short

Quiz: Which items fit “Graded Potential” vs “Action Potential”


____________ - small deviation from RMP caused by a certain stimulus
_______________ GP – inner membrane more negatively charged than normal RMP
_______________ GP – inner membrane less negatively charged than normal RMP
Graded Potential
Hyperpolarized
Depolarized
NOTE: Occurs due to the opening/closing of mechanically or chemically gated channels (not voltage gated)
When ions move thru these gated channels, the membrane either depolarizes OR hyperpolarizes (relative to RMP); depends on ion charge & flow direction

Faulty neurotransmitters are treated in 2 ways:
1) With drugs that _____ a NT
2) Drugs that ______ a transmission
mimic
block
Types of Neurotransmitters associated with CNS & PNS:
_____ Acids
• Excitatory CNS: Glutamate & Aspartate
• Inhibitory CNS: GABA (brain) & Glycine (spinal cord)
Amino
Types of Ion Channels: Chemically-Gated, Voltage-Gated, Mechanically-Gated, Leak Channels
- Not gated
- Randomly Open/Close
- Membrane more permeable to K+ than Na+
- More K+ leak channels and are leakier than sodium
- Found in nearly all areas & types of neurons
Leak Channels
Nervous system serves 3 basic functions that relate to maintenance of an internal balance called ___________
What are those 3?
homeostasis
- Sensing changes, both inside & outside the body (sensory function)
- Interpreting these changes (integrative function)
- Reacting to these changes by causing muscle contractions or glandular secretions (motor function)

Neurotransmitters are _____ (slowly/quickly) removed from the synaptic cleft by:
- ______ out of (away from) the synaptic cleft
- Enzymatic degradation (e.g. acetylcholinesterase)
- Uptake into cells – ______ transported back into neurons (reuptake) or into neuroglia (uptake)
quickly
- Diffusion
- actively
Branch of medical science that deals with nervous system is ___
neurology
Types of Ion Channels: Chemically-Gated, Voltage-Gated, Mechanically-Gated, Leak Channels
- Gate opens in response to neurotransmitters, hormones, and some ions
- • Found in dendrites of some sensory (pain) neurons, interneurons, & motor neurons
Chemically-Gated
What are nerve cells called?
Neurons
Other factors that can modify of membrane potential:
- Increased excitability - reduce the threshold; easier to depolarize membrane
- Alkalosis (pH > 7.45) - lightheadedness, tingling, numbness spasms, etc.
- Caffeine & nicotine
- Decreased excitability – increases threshold; more difficult to depolarize
- Acidosis (pH < 7.35) - weakness, lethargy, coma
- Hypnotics, tranquilizers, anesthetics
just look at this a few times
The PNS is divided into 3 “subdivisions”:
The _____ nervous system (SNS) is voluntary. It’s basically your muscles.
- Sensory (afferent) neurons conduct impulses from cutaneous & special sensory receptors to the CNS
- Motor (efferent) neurons send impulses from CNS to __________
Somatic
skeletal muscles
Saltatory Conduction:
• Myelin sheath = electrical insulator; blocks membrane depolarization
• Nodes of Ranvier = contains many voltagegated channels (e.g. Na+)
• Membrane depolarizes/repolarizes very _______ (slowly/quickly) at nodes
• Stops at myelin sheath
• Nerve impulse “leaps” from node to node; travels very FAST
• Also uses ______ (less/more) ATP, since only small portions of the membrane gets depolarized

Quickly
less
The word _____ means = the capability to change based on experience.
Repeat to yourself: Learning new things means making new connections! Expending the dendrites to connect to other neurons (and using your neurons!). i.e, repitition is the best way to learn).
Plasticity
Repeat to yourself: Learning new things means making new connections! Expending the dendrites to connect to other neurons (and using your neurons!). i.e, repitition is the best way to learn).
In the CNS, there is no connective tissue between nerve fiber bundles; therefore, bundle of nerve fibers (axons) are called a _____ instead of a nerve.
tract
Two basic types of synapses:
- Electrical synapse - found in smooth muscle, cardiac muscle, CNS (between neurons)
- _____ (one-way/two-way) communication between cells:
- • Ionic current spreads directly from cell to cell thru ____ junctions
- • Electrical synapses are ____(faster/slower) than chemical synapses
- • Quickly coordinates (synchronizes) activity of a group of
- neurons or muscle fibers (e.g. in heart, bladder, etc.)
two-way
gap junctions
faster

Myelination ________(decreases/increases) from birth to maturity (e.g. better coordination with time)
increases
Excitatory & Inhibitory Postsynaptic Potential:
Excitatory NT - __________ (hyperolarizes/depolarizes) the postsynaptic neuron membrane
- Inner membrane less negative; Cations IN or anions OUT
- Generates _______ (excitatory/inhibitory) postsynaptic potential (EPSP) – closer to threshold potential
- A single EPSP is not enough to start a nerve impulse. However, it is more excitable (closer to its threshold). The next EPSP may be enough to start a nerve impulse (summation).
depolarizes
excitatory
A bundle of nerve fibers in the PNS is called a nerve.
A bunde in the CNS is called a tract because it doesn’t have __________ surrounding it
nerve
connective tissue
Which cell produces the lipids and mylinates the axon?
Schwann cell
Node of __________ = Gaps in the myelin sheath; neurofibral nodes
Ranvier

Types of neurons based on transmission:
Bank: Presynaptic neuron, Postsynaptic neuron
_________________ - Sends the signal toward synapse
_________________- Receives the signal and carries message away from synapse
Prestsynaptic neuron
Postsynaptic neuron

- Chemical synapse (“slower”) - e.g. neuromuscular junction
________ (two-way/one-way) transfer of information (presynaptic to postsynaptic neuron or effector)
___________ neuron has end bulbs to release neurotransmitter
___________ neuron has receptor to recognize neurotransmitter
____________ - gap between pre-postsynaptic neurons
Bank: Postsynaptic, Presynaptic, Synaptic cleft
one-way
Presynaptic
Postsynaptic
Synaptic cleft

___________ (association neurons)
Connects sensory & motor neurons inside CNS
Most are multipolar
Interneurons

Review this “nuclei in the brain” image several times to get familiar with it

Regeneration of Nervous Tissue:
In CNS, injury ____ (can/can’t) be repaired. Learning DOES frequently stimulate production of NEW neurons in the hippocampus of the brain; but no repair of injured neurons.
Example: A spinal cord injury makes you paralyzed for good!
can’t
Durring the after-Hyperpolarizing Phase, the voltage-gated K+ channels close and RMP (resting memberate potential) returns to -70 mV with help of Na+/K+ pump.
^this pump is slowly letting # sodium out, and # potassium in until it polarizes down to -70 mV
3 sodium out, 2 potassium in
This is a ______ neuron.
It has # axon and many dendrites.
It comes in the form of both Motor Neurons & ____neurons. Located in PNS & CNS

Multipolar
1
Inter-neurons
What autoimmune disease where our body destroys our own mylin sheath in the CNS.
Caused nerve impulses to short-circut.
Multiple Sclerosis (MS)
Types of neuroglia aka glial cells (found in CNS):
Bank: Microglia, Ependymal cells, Oligodendrocytes, Schwann Cells, Astrocytes, Satellite Cells
Description:
- Looks like small astrocytes
- Form a network around axons in CNS,
- Produce the lipoprotein myelin for support

Oligodendrocytes

What is Myelination?
The process of forming a myelin sheath around a nerve to allow nerve impulses to move more quickly.
Parts of a neuron:
What is this?
Nerve fiber that conduct impulses away from cell body to another neuron OR to an effector (e.g. muscle or gland) Long, thin, cylindrical projection that may be short (mm CNS) or long (meter PNS); Has synaptic end bulbs located at terminal end; Can be myelinated.
Axon

________ - functional junction between neurons OR between a neuron & an effector (muscle or gland)
Synapse
NOTE: This is when the signal finally gets down the axon
Types of neuroglia aka glial cells (found in CNS):
Bank: Microglia, Ependymal cells, Oligodendrocytes, Schwann Cells, Astrocytes, Satellite Cells
Description:
- Phagocytic; Clean-up & protective

Microglia

Two types of neuroglial cells that myelinate neuronal axons:
_____ is in the CNS.
- Forms myelin sheath on more than one axon;
- Non-regenerative
- Myelinated (_____ matter) vs. Unmyelinated (____ matter)
Oligodendrocyte
white, grey
This is a ______ neuron.
It has # axon and # dendrites.
These are rare ________ (specialized / generalized) sensory neurons. (e.g. olfaction, seeing, & hearing)

Bipolar
1 axon, 1 (main) dendrite
specialized
The endoneurium covers the ______
axons
Excitatory & Inhibitory Postsynaptic Potential:
Inhibitory NT - ___________ (hyperolarizes/depolarizes) the postsynaptic neuron membrane
- Inner membrane more negative; Anions IN or cations OUT
- Generates ______ (excitatory/inhibitory) postsynaptic potential (IPSP) – further from threshold potential
hyperolarizes
inhibitory
review this overview of how signals transfer through a synapse

The PNS is divided into 3 “subdivisions”:
Autonomic nervous system (ANS) – _______ (voluntary/involuntary)
- _____ (afferent) neurons conduct impulses to CNS
- Motor (efferent) neurons send impulses from CNS to _____ muscle, ______ muscle, and glands
The ANS is made up of two opposing functional branches. The ___ which is Fight or Flight; and the _____ which is Rest & Digest
involuntary
Sensory
smooth, cardiac
Sympathetic & Parasympathetic
Mixed nerves contain both ______ & ______ fibers
So, a mixed nerve can take a nerve to the ____, and then bring it back out
sensory, motor
CNS
This is a ______ neuron.
It has an axon/dendrite fused process from cell body
These are ________ (specialized / generalized) sensory neurons in PNS. (e.g. touch, pressure, pain, temperature)

Unipolar
generalized

Does stimulus cause polarization or depolarization?
Depolarization
A larger stimulous = greater depolarization = larger excitation
Mylin is made of _____ + _____ (lipoprotein)
What is does:
- Electrically insulates the axon
- Increases conduction rate of nerve impulses
Lipid + protein
Conduction (Propagation) of AP’s (AP (nerve impulse) arises at trigger zone and travels down axon to axon terminal.)
Which happens on a mylinated axon, and therefore faster?
- continuous conduction
- saltatory conduction
• saltatory conduction
Note: Graded Potential can go through summation.
What is summation?
Summation, in physiology, the additive effect of several _________ impulses on a neuromuscular junction, the junction between a nerve cell and a muscle cell. Individually the stimuli cannot evoke a response, but collectively they can generate a response.
electrical
Note: makes sense because graded potentials are smaller.
Actioin Potential - a sequence of rapidly occurring events that depolarize the membrane followed by repolarization
Action Potential (unlike graded potential) • Generated on the membrane of \_\_\_\_ where voltage-gated channels are located • Good for short & long-distance communication
axons

Types of synapses based on transmission:
___________ - Synapse between axon & dendrite
___________ - Synapse between axon & cell body
___________ - Synapse between two axons
Bank: axoaxonic, axodendritic, axosomatic
axodendritic
axosomatic
axoaxonic

_________ (afferent) neurons
Conduct impulses from receptors into the CNS via
_______ or ______ nerves
Most are unipolar.
Sensory
cranial or spinal

Types of Neurotransmitters associated with CNS & PNS:
______ amines:
Big impact on sleep/wake patterns, feelings, moods, emotions
• NERPI (noradrenalin) & EPI (Adrenalin are also hormones)
These fuck with neurotransmitters like Norepinephrine, Epinephrine, Dopamine, and Serotonin
Imbalance linked to depression & bipolar disorder.
Biogenic amines
how many cranial nerves do we have?
12
Parts of a neuron:
Cell Body:
_____: contains cytoplasm, nucleus, & various organelles
Nissl bodies: “rg ER” produces _____ for growth/repair
Hillock: where soma connects to ____; where AP is generated

Soma
protiens
axon
Ion Channels
• Ions move across PM with its concentration gradient (H to L)
• Positive cations move toward negative anions and vice versa
• When ions move they generate ______ current that changes membrane potential
• Ions use channel proteins to move across PM
electrical
Each post-synaptic neuron receives input from _____ (many/one) presynaptic neurons.
many
Two body systems that help control and integrate all body activities:
Nervous & Endocrine
Two types of neuroglial cells that myelinate neuronal axons:
______ is in the PNS.
- Forms myelin sheath up to 100 layers on an axon;
- Aids in repair (regenerates axon)
- Myelinated vs unmyelinated axon
- Neurolemma – outer nucleated cytoplasmic layer
Schwann cell
Neurotransmitters Definition:
A chemical substance that is released at the end of a nerve fiber by the arrival of a _____ ______ and, by diffusing across the synapse (chemical) or junction (electrical), causes the transfer of the impulse to another nerve fiber, a muscle fiber, or some other structure.
nerve impulse
see image.


Resting Membrane Potential (RMP):
Membrane of a non-conducting (resting, non-stimulated) neuron normally is _________ charged on the outside and _________ charged on the inside.
RMP = -70 mV (milliVolts) ; Membrane is considered __________.
positively, negativity
polarized
NOTE: Being polarized means that the electrical charge on the outside of the membrane is positive while the electrical charge on the inside of the membrane is negative. The outside of the cell contains excess sodium ions (Na+); the inside of the cell contains excess potassium ions (K+).
The epineurium covers _______
the entire nerve
Factors that can modify the effects (synaptic transmission) of neurotransmitters:
- Synthesis – stimulated or inhibited
* Parkinson’s – _______ (decreased/increased) synthesis of dopamine - Release – enhanced or blocked
- Amphetamines enhance release of dopamine & norepinephrine
- Botulism toxin blocks release of Ach at NMJ causing paralysis (the problem with ____ injections because you need the right strain of the boutulism toxin)
- Receptor sites – activated or blocked
* Curare (is poison) blocks Ach receptors at NMJ causing muscle paralysis - Removal from cleft – stimulated or inhibited
* Cocaine inhibits dopamine ______ – euphoria due to excessive stimulation of brain
- decreased
- Botox
- reuptake
Alzheimer’s is linked to what neurotranmitter?
ACh (Acetylcholine)
Which ion channel generates the action potential for the Axon?
Voltage-Gated
The CNS has an integrative function. It ______ sensory information & _______ a response
Interprets, generates

Some Presynaptic signals are excitatory (EPSPs)
Some Presynaptic signals are inhibitory (IPSPs)
But it’s the sum of all messages tells the postsynaptic neuron what to do.
- If EPSPs > IPSPs, the postsynaptic neuron will ________ (depolarize/hyperpolarize)
- If IPSPs > EPSPs, the postsynaptic neuron will _________ depolarize/hyperpolarize)
depolarize
hyperpolarize
Propagation Speed related to:
- Larger the diameter of nerve fiber, ______ (slower/faster) the impulse travels
- Myelinated fibers conduct impulses _____ (slower/faster) than unmyelinated fibers
- _____ (warm/cooled) nerve fibers conduct impulses faster than _____ (warm/cooled) fibers
Stimulus Intensity due to ______ (frequency/size) of AP generated at trigger zone.
1) faster
2) faster
3) warm
Frequency
Types of Ion Channels: Chemically-Gated, Voltage-Gated, Mechanically-Gated, Leak Channels
- Gate opens in response to vibration, touch, stretch, & pressure
- Found in auditory receptors (ear); touch & pressure receptors (skin)
Mechanically-Gated
Two or more graded potentials added together creates a greater change in depolarization & membrane potential is called?
Summination
i.e. - stimuluses can overlap. Like, one might not be finished when the next one starts
CONCEPTS:
Graded potential is:
- Generated on membrane of _____ and cell body (not typically axons)
- Remains localized; does NOT travel far; _____(short/long)-distance communication only
- Note: it doesn’t travel down the axon because it’s not big enough
dendrites
short
Epilepsy is when your ___ are abnormal
neuronal circuits
Types of neuroglia aka glial cells (found in CNS):
Bank: Microglia, Ependymal cells, Oligodendrocytes, Schwann Cells, Astrocytes, Satellite Cells
Description:
- *PRODUCE CEREBRAL SPINAL FLUID*
- Simple cuboidal/columnar epithelial cells;
- May be ciliated
- Line brain ventricles & central canal of spinal cord;
- Produce CSF
Ependymal cells

The PNS is divided into 3 “subdivisions”:
Enteric Nervous System = closely related to ANS; ______ (voluntary/involuntary)
Here, the smooth muscle & glands service the _________ via enteric plexuses
In lamens terms, it helps us _____ food.
Involuntary
gastrointestinal tract
digest
What type of neuron is the sensory neuron?

Unipolar
What are the 2 “subdivisions” or body parts contained in the CNS?
Brain & Spinal Cord
Parts of a neuron:
What is this?
Nerve fiber that receives input and conducts it toward cell body; Non-myelinated, short, highly branched processes
dendrite

Structural Organization of the Nervous System (2 parts):
Central Nervous System (CNS) is contains the ________ & __________
Peripheral Nervous System (PNS) contains the cranial & spinal ______, _______, & sensory receptors
brain, spinal cord
nerves, ganglia
Review Slides 40-45 for: Steps Generating an Action Potential
Types of Ion Channels: Chemically-Gated, Voltage-Gated, Mechanically-Gated, Leak Channels
- Gate opens in response to change in membrane potential
- Found in axon of all types of neurons
- Gives nerve & muscle cells excitability via action potential
Voltage gated channels
- _______ – Clusters of neuronal cell bodies in PNS
- _______ – Clusters of neuronal cell bodies in CNS
Ganglia
Nuclei

NEUROGLIA (AKA _____ cells)
- “Support” cells for the neuron
- Smaller & more numerous than neurons
- Capable of division
- Not electrically excitable
glial
Guillain-Barre Syndrome – Immune system response to bacterial infection causing macrophages to _______ axons (PNS) resulting in acute paralysis; Most patients have complete recovery.
Macrophage Definition: a large phagocytic cell found in stationary form in the tissues or as a mobile white blood cell, especially at sites of infection.
de-myelinate
Durring the after-Hyperpolarizing Phase, the Potassium (K+) channels remain open actually a little too long, until the membrane potential becomes more negative than RMP (resting memberane potential).
It brings the cell’s polarization down to ##. From there, the sodium/potassium pump kicks in.
-90 mV
how many spinal nerves do we have?
31
All-or None Principle:
Action Potential requires a threshold
stimulus of about -____mV before
depolarization of the membrane occurs.
-55
NOTE: it’s all or nothing - it eaither reaches threashold and fires, or it doen’t.
Types of neuroglia aka glial cells (found in PNS):
Bank: Microglia, Ependymal cells, Oligodendrocytes, Schwann Cells, Astrocytes, Satellite Cells
Description:
- AKA Neurolemmocytes
- Flat cells wrapped around axons in PNS
- Produce part of the myelin sheath around one axon
Schwann Cells

_______ Refractory Period - time when another impulse cannot be generated (during depolarization and repolarization phase)
In general, frequency of nerve impulses range between ## and #### per second. So, this period doesn’t last long.
Absolute
10, 1000
Which type of Neuronal Circuit is which?
Bank:
- Converging
- Reverberating
- Diverging
- “Parallel After Discharge”

- Diverging
- Converging
- Reverberating
- “Parallel After Discharge”
Parkinson’s & schizophrenia are linked to what neurotransmitter?
Dopamine
What houses the neurotransmitter, and releases the neurotransmissions?
Synaptic end bulbs
Types of neuroglia aka glial cells (found in PNS):
Bank: Microglia, Ependymal cells, Oligodendrocytes, Schwann Cells, Astrocytes, Satellite Cells
Description:
- Flat cells around the cell bodies of neurons
- Regulates exchange of materials in/out of neuronal
- cell body (in ganglia of PNS)
Satellite Cells

_________ (efferent) neurons
Conduct impulses away from CNS to effectors
(muscles or glands) via cranial or spinal nerves;
Always ____polar.
Motor
multi-polar

Stimulus intensity (i.e. strength) affects the _______ of Action Potentials
frequency
The nervous system is ____ (fast/slow) to respond but it’s effects are _____ (short-term/long-term)
The encocrine system is ____ (the same^ / opposite^)
The ____ system can overide the ____ system whenever nessisary.
fast, short-term
opposite
nervous, endocrine
_______ connect all regions of body to brain and spinal cord
They don’t undergo _____ divisions, so in other words, they can’t reproduce. We’re born with them and they last like 100 years.
Neurons
mitotic
Just review this image a few times

The 3 types of nerves are motor, ____, and _____.
sensory, mixed
The Perineurium covers _____
A bundle of axons called a fascicle
Name that neuron!


Depression, Bipolar, and Seasonal Affective Disorder (SAD) are linked to the neurotransmitters - Serotonin, Norepi, and Dopamine.
Why do meds like Prozac, Paxil, and Zoloft help?
They inhibit serotonin reuptake. this prolongs activity of
serotonin at synapses in brain!
Regeneration of Nervous Tissue:
In ___ (CNS/PNS), myelinated axons & dendrites can be repaired, IF the cell body and the Schwann cell are not damaged (can surgically re-attach a severed nerve)
Example: You can reattach a severed pinky to your hand!
Why: Becasue Schwann cell can regenerate
PNS
Action Potentials go as high as ## in memberate potential millivolts
+30
The PNS has 2 components to how it functions: ______ & ______ functions. Of those 2, the:
- _____ component has _______ (incoming); Contains many different receptors which detect change (e.g. general & specific sense receptors)
- _____component = _______ (outgoing); It conducts impulses from CNS to muscles & glands!
Sensory & Motor functions
Sensory, Afferent
Motor, Efferent

Between the nerve fibers/bundles is ________
(e.g. endoneurium, perineurium, and epineurium)
connective tissue
Regeneration of Nervous Tissue:
At ~# months of age, neuronal cell body loses mitotic apparatus; can’t divide
6
What is a bundle of nerve fibers (axons) in PNS?
Nerves
i.e. a bunch of axons wrapped up together