Unit 3 Flashcards
What is the receiving area of a neuron
Dendrite
What is the entire middle section of the cell that contains a majority of the organelles
Cell body/soma
What is the center structure inside the cell where DNA is housed?
Nucleus
What is a myelin sheath
Formation of several bundles of white material that are wrapped around a thin gray structure. The bundles function as an insulation. It spreads up a action potential
What part of a neuron is a specialized area of a neuron that generates action potentials when appropriate stimulated
Axon
What is the enteric nervous system?
It act to autonomously or can be controlled by the CNS through the autonomic division of the PNS. Regulated digestive system.
Define sympathetic
The fight / flight mode
Define parasympathetic
Rest and digest
Define efferent neurons
Involuntary control
Where are the voltage gated channels on a neuron?
On the axon
Where are the receptor channels on a neuron?
On the dendrites
Define a axon hillock
It is a thin , long gray cellular extension inside white bundles. This part of a neuron conducts or transmits action potentials from the cell body to where a neurotransmitter or neuromuscular it’s are released
What is an axon collateral?
When a axon splits off into multiple terminals
Define a pseudounipolar neuron
It have a single proceeds called the axon during the development the dendrite fuse with an axon
Define a interneuron
Have bits and pieces that communicate between one part of the brain to another part. Internal CNS communication
Define a bipolar neuron
Have two relatively equal fibers extending off the central cell body
Define anaxonic neuron
Have interneurons with no apparent axon
Define a oligodendrocytes
A specific cells to form a myelin sheath in the CNS. They wrap a few separate neurons with their arm like extensions
Define microglia cells
Modified immune cells. They act as scavangers during brain development. To remove excess neurons
Define astrocytes. What do they do
•They take up k+, water and neurotransmitters
•The secrete neurotrophicfactors
•They help form blood brain barrier , therefore provide substrates for ATP
• A source of neural stem cells like ependymal cells
Define neurotrophic
Neurogrowth
What are ependymal cells?
They form a barrier between brain tissue and the ventricles.
What are the glial cells of the CNS
Ependymal cell
Astrocyte
Microglia
Oligodendrocytes
What are the PNS glial cells?
Satélite cell
Schwann cell (neurolemmocytes)
What do satélite cells?
Protect cluster of neuron cell bodies outside the CNS
What is a Schwann cell (neurolemmacyte)
Form myelin sheaths and secrete neurotrophic factors
What voltage do neurons test at
~-70 mV
What type of channels on dendrites and cell body control ion permeability and allow for changes in a neuron membrane potential
Gated channels allow the neuron to go from resting to active state
If sodium and calcium in flux what is the intracellular charge
Depolarized
If sodium and calcium efflux what change in intracellular charge
Hyperpolarized
If chloride channel influx what is the change of intracellular charge?
Hyperpolarized
If chloride efflux what is the intracellular charge
Depolarize the cell
If potassium efflux what is the intracellular charge
Hyperpolarized , depolarized
What is a axon terminal
The bulbous end of a neuron where it interfaces with another cell by realeasing neurotransmitter or mueromodulators
What is the gap between two neurons?
Synaptic cleft
Define Central Nervous System
Division of the nervous system that consist of the brain and spinal cord only
Define peripheral nervous system
Branch in the nervous system that contains only sensory (afferent) neurons and motor (efferent ) neurons
What type of nerves carry afferent signals only from the periphery to the central nervous system
Sensory nerves
What nerves only carry out efferent signals from the CNS out to skeletal muscles
Motor nerves
Nerves that carry both sensory and motor signals are called what?
Mixed nerves
What is the general type of cell that function as a unit in the nervous system
Neuron
What is a grade potential
The vary in strength and effect of a stimulus
What is a excitatory post synaptic potentials (EPSP’s)
Increase the likelihood that the neuron will generate its own AP. Small depolarization of the dendrites and soma body
Sodium and calcium influx
What type of neuron contain all its components such as dendrites, soma, axon , axon terminal completely within the CNS to communicate from one side of the CNS to the other
Interneurons
Define glial cells
General kind of cell in the nervous system the support neurons and form insulation around their axons
What are nodes of ravier
Tiny gaps in the myelin sheath
What is an action potential?
A all or nothing phenomenon that transmits an electrical signal down the axon. A rapid change in membrane potential
What is a inhibitory post synaptic
hyper-polarization / repolarization of the dendrites or the soma
Potassium efflux or chloride influx
What is threshold voltage
The sum of all graded potentials at the axon hillock surpasses a particular membrane potential. The neuron will fire a AP
What is the milivolts an action potential be generated by a typical neuron
-55 mg
Define absolute refract period
When a neuron generates its own action potential how ever it cannot send a second Action Potential no matter how much additional stimulation it receives
When a neuron depolarizes causing an action potential this is due to the influx of what ions
Na+ , ca2+
During depolarization of an action potential, which ion channels will be slow to open and achieve maximum permeability just after the membrane reaches maximum potential
K+
Since potassium is slow to open and close what phase do the contribute (depolarization, hyper-polarization, repolarization ) when the cells membrane potential dips below its resting level
Hyperpolarization
Define relative refracting period
When a neuron membrane potential slowly returns to a resting level from a Hyperpolarized state, it CAN fire a second action potential IF the stimulus is larger than normal
What is saltatory conduction
The description of an Action Potential moving rapidly down a myelinated axon
What is the general category of neurotransmitter that includes noreepinephrine, dopamine, serotonin and histamine
Amines
This general neurotransmitter category includes adenosine
Purines
This is the only gas that is shown as a neurotransmitter
Nitric oxide
What is the specific neurotransmitter / signal molecule that has two types of receptors nicotinic and muscarinic
Acetylcholine
Many antipsychotic drugs are antagonists for this neurotransmitter. Drugs of abuse are also typically agonist of this neurotransmitter
Dopamine
Molecules such as glutamate, GABA, glycine belong to this general family of neurotransmitter
Amino Acids
Curare and alpha bungartoxin will block the action of these acetylcholine receptors so avoid be shot by poison darts
Nicotinic
Atropine will
Block the action of acetylcholine receptors. This is why atropine is used to elevate heart rate during anestesia 
Muscarinic
What is GABA
GABA : gamma aminobuytric acid. Alcohol, barbiturates and benzodiazepines potentials the effects of this neurotransmitters
What neurons control the smooth muscle, cardiac muscle many glands and some adipose tissue?
Autonomic neurons
What is the name for the efferent peripheral nervous system neurons always control skeletal muscles
Somatic motor neuron
What autonomic neurons is dominant in stressful or active situations and is often linked to the “fight or flight” response
Sympathetic branch
What branch in the autonomic nervous system is more active if you are resting quietly after a meal or during the quiet activities of day to day living. Aka “rest & digest”
Parasympathetic branch
All autonomic neural circuits consist of two neurons connected in series between the CNS and the effector. The first neuron has its cell body within the CNS
Pregangolinc neuron
What neurotransmitter is secreted by pre- gangolic neurons in both parasympathetic and sympathetic nervous system
Acetylcholine
The next neuron in circuit has its cell body out side the CNS and projects to an effector organ or target tissue
Post ganglionic neuron
What neurotransmitter is secreted by post ganglionic neurons of the sympathetic nervous system onto effector cells
Noreepinephrine
What neurotransmitter is secreted by post gangolinic neurons in the parasympathetic nervous system on effector cells
Acetylcholine
What is the adrenal medulla
It contains chromaffin cells and are modified post-gangolinic sympathetic neurons that secrete their neuron prime into the blood stream
What neurohormone is secreted by the adrenal medulla / chromaffin cells
Epinephrine
Pregangolinic Neurons of both the sympathetic and parasympathetic nervous system release, acetylene onto what type of receptors on the postganglionic neurons
NN nicotinic receptors
Somatic motor neurons always release acetylcholine onto what type of receptors? They are located on the motor and plates of skeletal muscle cells.
NM nicotinic receptors
What kind of receptors are NM & NN nicotinic receptors
Cholinergic channels, always excitatory
Postgangolinic parasympathetic neurons release acetylcholine onto their target cells. However what type of receptors accept acetylcholine
Muscarinic receptors
What kind of receptor is muscarinic receptor?
In the category of Cholinergic receptor but also G-protein coupled receptor (they can be excitatory or inhibitory
What subtype of adrenergic receptors is more sensitive to epinephrine than norepinephrine? It is found in certain blood vessels and smooth muscle organs
Beta-2
What sub-type
Of adrenergic receptor has a higher affinity for norepinephrine? They are found in the digestive tract and pancreas
Alpha -2
What subtype of adrenergic receptor is sensitive to norepinephrine and found in adipose tissue.
Beta-3
What subtype of adrenergic receptors equally bind to epinephrine and norepinephrine and found on the heart and kidneys
Beta-1
What subtype of adrenergic receptor has a higher affinity for norepinephrine and is common in sympathetic target tissues
Alpha-1
What kind of receptor are the adrenergic receptors?
G-protein coupled receptor
Input from what nervous system to the lungs were well results and airway, dilation to More air into the lungs during times of physical or emotional stress
Sympathetic nervous system
Input from what nervous system causes beonchiole constrictions because demand on the lungs is less during times of rest
Parasympathetic nervous system
Heart rate and contraction force are increased by what nervous system? It signals to increase delivery of oxygen and nutrients to the body and times of stress.
Sympathetic
Signaling by what nervous system decreases heart rate during times of rest
Parasympathetic nervous system
The control of bronchiole diameter, and a heart rate use input from both the sympathetic and parasympathetic nervous systems. These are both prime examples of what control system.
Antagonistic
What nervous system takes input to the adrenal medulla and increase the secretion of catecholamines such as epinephrine into the blood
Sympathetic nervous system
What nervous system will increase fat breakdown to mobilize energy stores for increased cellular respiration
Sympathetic nervous system
What nervous system to the kidney will increase rennin secretion which is very important for the retention of Na+ and elevation of blood pressure
Sympathetic nervous system
Only one branch control autonomic nervous system on target tissue function. The amount signaling by one system determines what the defector organ actually does. What type of control system?
Tonic
When pupils dilate to bring more light in the eyes what type of nervous system takes over
Sympathetic nervous system
When the pupils receive input to construct back to their baseline diameter and receive less light into light. What nervous system takes hold
Parasympathetic nervous system
What nervous system decreases digestive motility and secretion
Sympathetic nervous system
What nervous system increase digestive motility and secretion
Parasympathetic nervous system
What type of muscle tissue is found only in the heart.
Cardiac muscle tissue
What type of muscle tissue is found on internal organs and tubes like the stomach, urinary bladder and blood vessels
Smooth muscle tissue
What type of muscle is attached to bones and allows movement
Skeletal muscle
When a muscle contract it describes bringing two bones closer to one another
Flexor
When moving skeletal muscle this is the description of moving two bone away from one another
Extensor
What attached a skeletal muscle to bone
Tendon
What is the name for a bundle of muscle fibers
Fascicle
What does connective tissue do for the muscle
There are two layers that surround and protect the entire muscle!
What is the name for a single functional unit of a whole muscle
Skeletal muscle cell (fiber )
What is the specific term for the muscle cell plasma membrane?
Sarcolemma
What area on a skeletal muscle are tunnels that penetrate deep into the skeletal muscle cell. This allows action potentials to activate all scarmeres simultaneously
T-tubules
Which organelle in a muscle cell provides a majority of the chemical energy needed for muscle contraction
Mitochondria
What is a bundle of thick and thin filaments
Myofibril
What intracellular organelle releases Ca2+ ions into the sarcoplasm when the muscle cells is activated by an action potential
Sarcoplamsic reticulum
What type of muscle fibers are most resistant to fatigue, largely, because they have a lot of mitochondria, dense, capillaries, and get their ATP from oxidative and aerobic respiration
Slow twitch oxidative
What type of muscle fibers make up White muscle, are quick to twitch, but are also easily fatigued
Fast twitch glycolic
What muscle fibers make up red muscle and get that color due to large stores of protein, myoglobin, which stores access oxygen for long-term use
Slow twitch oxidative
What type of muscle fibers can be thought of as a hybrid between those that develop maximum tension, the fastest, and those that develop maximum tension the slowest
Fast twitch oxidative, glycolic
What type of muscle fibers has a least mitochondria and the lowest capillary density?
Fast twitch glycolic
What type of muscle cells are largely fatigue resistant and I used for standing and walking
Fast twitch oxidative glycolic
Suprathreshold
Supra:above, action potential will be started at the axon hillock
Subthreshold
Sub: below, no action potential is generated at the axon hillock
Define spatial summation
Multiple signals that converge to make a signal. Can be excitatory and / inhibitory signals
Define temporal summation
When sub threshold potential happen when they are imitated close to tether to make a bigger potential or separate potentials
Muscle contraction process map
• somatic motor neuron axon
( influx of
• calcium
( that causes an exocytosis of
• acetylcholine
( to the
• nicotonic receptor
( that is
• chemically gated channels
( in the
• motor end plate
( with a
• sodium influx & potassium efflux
( occur & depolarizes
• end plate potential
(That causes the
• action potential
( to move along the
• sarcolemma
( to the
• transverse tubules
( where the action potential triggers
• dibydropydridine voltage sensitive gated channels
( that are connected to
• ryanodine channels
( that release
• calcium
(From the
• sarcoplasmic reticulum
(To the
• terminal cisternae
( to go to the
• thin filament
( where ca2+ bind to
• tropinin
( and moves tropomyosin
• tropomyosin
( for the myosin to attach to
• actin
( thick filament aka myosin
• power generated
(To cause relaxation
• somatic motor neuron
( stop releasing
• ACH
( which causes
• ca
( to be removed from the toponin
• ATP
( causes the ca to return back to the
• sarcoplasmic reticulum
Define propagation conduction
Slow Action potential along non-myelinated axons
Na influx and as the AP pass down K influxes
Saltatory conduction
Fast conduction. Action potential along myelinated axons
Myelinated sheath have little loss of electrical current because of insulation
What is refractory period
It prevents backward conduction
Steps of Action potentials :all or non signal generated by neurons
- Resting membrane potential
- Depolarize stimulus
- Membrane depolarizes to threshold voltage gated na+ & k+ channels begin to open
- Rapid Na+ influx to depolarizes cell
- Na+ channels and k+ channels are fully open
6.K+ efflux
7.K+ channels remain open and more k+ efflux hyperpolarize - Voltage gated k+ channels close , less k+ leaks out of the cell
- Cell return to resting ion permeability and tlresting membrane potential
What are the theee phases of the action potentials in a neurons. In order to
Depolarization phase
Repolarization phase
Hyper polarization phase
Voltages gated sodium channels have two channels (explain)
Sodium influx is turned off because it has two channels .
They have an activation gate and inactivation gate.
During RMP Activation gate is closed and inactivation gate is open
When a neuron reaches Supra threshold = stimulated the activation gate is open
Small amount of Na+ influxes through the voltage gated Na channel and the neurons starts to depolarizes
After 0.5 seconds inactivation gate closes
After activation gate is open and inactivation gate closes both gates will return to their original positions after a few miliseconds
Describe voltage gated K+ channels
They have one gate and are slow to open and closed.
They open during threshold
They don’t fully open until peak depolarization
Channels slowly close during re polarization phases and hyperpolarization phases
What is the list of peptide neuroscience
Vasopressin , oxytocin , substance P and opioid peptides
What is the list of purine neurosciences
Adenosine , AMP ATP
What is the list of gas neurosciences
NO & CO
What is substance P and opioid peptides like endorphins and enkephalins
Part of the pain perception and pain suppression pathway in the nervous system
What is vasopressin (antidiuretic hormone )
Part of the water balance story we learn in unit 5
What is oxytocin
It’s involved in child birth that stimulate terrine contractions & lactation in females alone with social bonding and sexual attraction in males and females
What is NO & CO
The my stimulate vasodilation to bring more nutrients and increase waste pick up from hard working neurons
Define relative refractory period
When only a larger than normal stimulus can stimulate a new action potential
What is multiple sclerosis
Immune disorder that degenerates myelin causing bad communication and loss of strength to generate AP
Pre-synaptic cell
Action potential arrived at the axon —> voltage ca channels open causing calcium influx to trigger exocytosis of neuroscience signal molecules
Post synaptic cell
It is the target cell, that have receptor for neuroscience secreted onto it
How does signal molecule stop
There are various mechanisms such as reputable or removed by glial cells
Or Inactivstion enzyme
Or diffusion from the site
What drugs is used to treat mental illness
Selective serotonin reuptake inhibitors
What are the seven classes of neurocrines?
GLAAMP
GASES
LIPIDS
ACETYLCHOLINE
AMINO ACIDS
MONOAMINES
PEPTIDES
Tell me about ACH
It’s both a neurotransmitter and meuromodulator in the CNS
excitatory neurotransmitter for skeletal muscle
Used by parasympathetic branch of ANS to control body organs
It’s formed by acetyl CoA and choline
What forms Acetylcholine
Acetyl CoA and choline
Is acetylcholine always an excitatory neurotransmitter for skeletal muscle?
Yes
What receptors bind to acetylcholine
Cholinergic receptors
What are the two types of cholinergic receptors that bind to acetylcholine
Nicotinic receptors and muscsrinic receptors
Function, where and important line of nicotinic receptor
Located in skeletal muscle in PNS and CNS
AKA ionotropic channels
Function , where and importance of Muscarinic receptors
They will either excitatory or inhibit depending on cellular cascade
AKA metabotropic
Are G-protein coupled receptors
Located in CNS and PNS
What’s the life cycle of acetylcholine
What is amines?
It’s a neruocrine derived from a single amino acid
It’s involved with sympathetic neurocrines
Involve catecholamines which houses : epinephrine, norepinephrine and dopamine
What is epinephrine
A neurohormone that’s secreted from adreneegic neurons called chromaffin cells in the adrenal medulla
What do chromaffin cells of the adrenal medulla secrete?
Epinephrine
What is norepinephrine?
A neurotransmitter and neuromodulator that’s secreted by adrenergic neurons.
It also acts of a neurohormone when secreted from the adrenal medulla
What are adrenergic receptor. What are the two sub categories?
They are the receptors that bind to epinephrine or norepinephrine. They are G-protein coupled receptors meaning they will either excite or inhibit intracellular cascade
There’s alpha and beta receptors
What adrenergic receptor bind to norepinephrine only
Alpha 1,2 & beta 3
What adrenergic receptor binds to epinephrine only
Beta 2
What adrenergic receptors bind to norepinephrine and epinephrine
Beta 1
What do adenosine AMP and ATP function
Important neurocrines in sleep/wake cycles of attention
What are the two branches of autonomic nervous system
Parasympathetic and sympathetic
They are part of the efferent pathway
What are the body parts that use tonic control?
ALASKA
arterioles
Lymph nodes
Adipose
Sweat glands
Kidney
Adrenal medulla
What’s the sub category autonomic reflex for integration centers
Hypothalamus
Medulla oblongata
Pons
What does the hypothalamus do?
Control temperature, water balance and hunger
What does the médula oblongata do?
Cardiovascular
Respiration
Vomiting
Swallowing
What does the Pons do?
Secondary respiratory control
What signal molecule does the sympathetic pathway use?
Acetylcholine and norepinephrine. That binds to adrenergric receptors
What autonomic efferent pathway only uses acetylcholine
Parasympathetic bind to muscarinic receptors
What is autonomic ganglia
A junction between the preganglionic neuron and postganglionic neuron
What receptor allows acetylcholine to bind
Muscarinic
Chromaffin cells create what signal molecule
Epinephrine
Where do chromaffin cells come from
Adrenal medulla
What the process map of sympathetic pathway from spinal cord to heart?
• preganglinc neuron send
• ACH to
• Autonomic ganglia
• ACH accepted by Nn receptor
• post ganglionic neuron sends Norepinephrine
• NE binds to adrenergic receptor
What’s the process map for kidney?
• Ganglionic neuron sends ACH to
• Nn receptor
• chromaffin cells of the adrenal medulla make epinephrine
• epinephrine is sent into the blood stream
Give proceeds map for somatic motor neuron
Neuron sends ACH to attach to Nm skeletal muscles
What are varicosity
Hold neurotransmitters to be realsed over the surface of target cells
What inactivated ACH?
Acetylocholinesterase (AChE)
What is the A band
Area where thick filament and thin filament overlap
Which runs down the middle of the sarcomere?
M line
What is Tutin?
Stabilizes the thick filament. It bind from the Z - disk through the thick filament that connect to the M line
Which one only contains thin filaments in a relaxed muscle
I band
What is a sarcomere
The section of a myofibril from Z dick to Z disk
Which contains only thick filaments in a relaxed muscle?
H zone
Which one is the length of the thick filament and also defines the area where thick and thin filament overlap?
A band
What is nebulin
Arranges the thin filament in the sarcomere to be stabilized and parallel to the thick filament
What is ATP hydrolysis in regards to myosin
When ATP breaks down into ADP + Pi & energy . In case of myosin it uses the energy to perform a power stroke
What is G actin
The monomer of actin chain
What is F actin
A polymer of the connection of G actin
What is tropomyosin
A long strand of protein that physically covers active sites on the actin relaxed muscle. It’s attached to troponin
What is the name of the proceeds when the myosin head told after attaching to actin
Which proteins bind to active site on actin
Myosin
Give a story of” the contraction “ of protein interaction
• myosin cross bridge bind to nearest actin
(Has just finished a power stroke
• ATP
( binds to myosin and loses affinity to
• actin
(Now
• myosin
(Will
• hydrolysis ATP
( cause the myosin head to be in a
• cocked position
( AKA
• recovery stroke
(Causing the myosin to bind
• weakly
(Next
• ca2+ signal (from sarcoplasmic reticulum)
(Will allow
• ADP disassociates
•
Protein interaction : the contraction story
- Myosin bind ATP and detached from actin active site
- Myosin- ATPase activites : ATP —> ADP + Pi + energy
- That energy is used to cock the myosin head to store potential energy
(If the actin site is still uncovered when ca is still present - Myosin binds tightly to actin
- Inorganic phosphate is released from motion head
- Power stroke occurs
- ADP is released from myosin head
What is a recovery stroke
The muscle relaxing
How does a smooth muscle contract?
- A voltage or chemical gate allows Ca influx
- The influxed Ca stimulates the SR causing calcium induced calcium
- Calcium from SR binds to (CaM) calmodulin
- Ca-CaM activates the (MLCK) myosin light chain kinase
- MLCK phosphate in the myosin head taking ATP —> ADP + P
- Active myosin cross bridges slides along actin and create muscle tension
How does a smooth muscle relax?
- Left over Ca is either pumped back into the SR (use ATP ) or out of the cell (while sodium influxes)
- Ca unbinds from calmodulin causing MLCK activity to decrease
- Myosin phosphate removes phosphate from MLCP that decreases myosin ATPase activity
- Smooth muscle relaxes due to less power stroking
Define slow axonal transport
It’s passive that moves vesicles 0.2-2.5 mm/ day
Define fast axonal transport
It’s active and uses ATP. Moved 400 mm/day
