Nervous System Flashcards
Creatine supplementation is at what dose and frequency
5 grams qid
Name some side effects of creatine supplementation
Gain some water weight and has a dehydrating effect
Glycolyosis involves breakdown down glucose into what 2 molecules
Lactic acid and Pyruvate
Net ATP from 1 glucose molecule, where is the majority of the ATP produced?
32 ATP, Electron Transport Chain
______ is what it takes to increase the temperature by one degree
Calorie
What is triglyceride composed of?
Glycerole and 3 Fatty Acids
How do fat cells get bigger?
Increased number of fatty acids present
_____ is used when carbohydrates are not available for brain energy while on a Keto diet
Acetyle Co Enzyme A
What organ combines two molecules of Acetyle Co Enzyme A to make a carbohydrate while on a Keto diet
the liver
Describe Ketoacidiosis
When the liver breaks down fat for fuel, it produces ketones. Ketones are then released leading to an overall increase of ketones in the blood. Has an associated fruity smell
What is a ketone
2- Acetyle Co Enzyme A
Described equilibrium point
When the concentration gradient forces equals the electric repulsive force
Potassium (K+) is high ______ and ____ outside
Inside the membrane, low outside the membrane
Sodium (Na+) is _____ on the inside
Low
Sodium rushes inside the cell is polarization or depolarization
Depolarization
When you are looking at a gradient with Potassium by itself, and the potassium leaves the cell, what is the electronegativity?
-94mV
Talking about putting probes to test the electronegativity, where do we put them? Inside or outside the cell
Inside the cell always
When you are looking at a gradient with Sodium by itself, and the Sodium comes into the cell, what is the electronegativity?
+61mV
Describe polarization in terms of diffusion potentials
Positive on the outside, negative on the inside
Describe diffusion potential
the potential difference between the inside and outside
Why will K+ never reach it’s chemical equilibrium?
because at -94mv there is enough charge repulsion to prevent futher movement of K+ to the outside. Negative attraction of the phosphate ions and negatively charged side chains
The Nernst Equation is looking at (one or many) types of molecules. Inside or outside the membrane?
ONE type, INSIDE
What is the Nernst Equation:
+/- 61 * log (concentration Inside/ concentration Outside)
Nernst Equation: The answer will be _____ if the ion diffusing from the inside to the outside is a negative ion
Positive
Nernst Equation: __ if the ion diffusing from the inside to the outside is a positive ion
Negative
During the Sodium Potassium pump: _____ is pumped to the outside and _____ is to the inside
Sodium -> outside
Inside <- Potassium
During the Sodium Potassium pump: ____ Na+ goes to the outside and ____ K+ to the inside
3 and 2, leads a net deficit of + ions on the inside
During the Sodium Potassium pump: if the cell is NOT excited the sodium channels are ____
closed
During the Sodium Potassium pump: if the cell is NOT excited potassium channels are ____
leaking
Why is the cell usually negative on the inside, give 3 reasions:
- More positive charges on the outside, because Na does not come in but is being pumped out
- Na is being pumped out much faster than K+ is being pumped in
- Once K+ is pumped in, it can leak back out
What starts the action potential?
Receptor receives stimuli that causes a protein to change shape which allows the sodium in, and that triggers the next channel to open etc etc
The Goldman equation is ____ ions (when compared to the Nernst Equation
ALL the ions versus SINGLE ion
a nerve action potential starts at ____ mv
-90
What does this graph illustrate? What is on the ascending? Descending?
What it takes to stimulate the action potential, need to get from -90mv to 0 in order for the signal to get transported. Depolarization, Repolarization
Resting = “_______”
Polarized, -90mv
Describe some things that happen during repolarization: Is it fast or slow?
- Fast
- Sodium channels close
- Potassium channels open more than normal-> potassium goes to outside
- the negative “normal” state of the membrane potential is restored
What happens when the voltage gated channel is activated?
a protein changed the shape of the activation gate and the channel is opened
What happens when the voltage gated channel is closed?
The cell is repolarized back to -90mv
What is this picture illustrating?
The impulse will travel in both directions
Describe the All-or- None principle.
Once an action potential has been reach, it will travel over the entire membrane
The average nerve trunk contains about _____ as many UNmyelinated fibers as myelinated fibers
Twice
Describe Saltatory Conduction. Is it slower or faster than traveling across the entire cell membrane?
Where the signal jumps from myelinated fiber node to myelinated fiber node, much faster
Saltatory Conduction _____ energy. Why?
Conserves, because only the node depolarizes
Label the structure indicated by 1
Node of Ranvier
Is myelinated or unmyelinated nerves faster?
Myelinated is faster
What are 2 factors that cause sodium ions to diffuse inwards?
Mechanical disturbance
Chemical effects on the membrane
How do local anesthetics work?
Calcium in the extracellular fluid stabilizes the membrane which decreases membrane excitability
How does Procain and tetracaine work as an anestetic?
Makes it harder for the activation gate of the sodium channel to open, nerve impulses fail to pass along the anesthetized nerves
Afferent neuron travel from the ____ to _____
from the periphery to the spinal cord
Efferent neuron travels from the _____ to _______
Spinal cord to the effector organ
The somasensory map in the brain tells us…..
where the sensation is occurring in the body
What happens after the neuron travels to the effector organ?
The organ creates a chemical transmission into the synapse and that chemical substance will act on receptors for some sort of action.
The motor neuron is in the _____
gray matter of the spinal cord
The axons are _______ gate
voltage
Why is the gray matter gray?
The interneurons have very little mylenation so they are gray.
Why is the white matter white?
Due to higher levels of mylenation
_______ acts on receptor proteins in the membrane of the next neuron
Neurotransmitters
All the synapes used for signal transmission in the CNS are _____ synapses
Chemical
Where are the majority of presynaptic terminals located?
85% on dendrites, 15% on soma
In order for the action potential to proceed the _____ must be more than ______
Excitatory Post Synaptic Potentials (EPSP) more than IPSP -Inhibitory
There are more ____ than _____ in the body at any given time.
IPSP than EPSP, (think about glasses resting on your nose, you do not feel unless you focus on them)
Second messenger activators are part of the receptor protein called ______
G proteins
What component of the G protein is separated from the rest? Describe its function.
Alpha
-opens specific channels
- activates a C-AMP cascade system
- Activates gene transcription
*****Excitation can happen in multiple ways. Describe a few.
-Opening of sodium channels (widely used)
- Depress conduction through chloride/potassium channels
- Decrease chloride ions to the inside
-Decrease diffusion of positively charged potassium ions to the outside
- Increase number of excitatory membrane receptors
-Decrease the number of inhibitory receptors
Give an example of a type of medication that works on the drug synpases
SSRI
Slow acting neurotransmitters are called ______
neuropeptides- they are very small
Describe decremental conduction
When the excitatory effects are near the tip of the dendrites but are “leaking” potassium and some of the “electrical current” is lost due to distance
temporal sumation
one neuron is firing off faster
spacial sumation
bunch of neurons firing off at the same time
Name some causes of cell fatigue
________ predisposes epileptic seizures. Why?
hyperventilation, pt is breathing out too much CO2
______ greatly increased excitability
Alkalosis (High pH)
_____ greatly depressed neuronal acitivity
Acidosis
Caffeine, theophylline, theobromine and strychinine all ______ neuronal excitablity
increase
______ increase neuronal membrane threshold for excitation
Anesthetics
Somatic nervous system is _____ and conducts impulses from the _____ to ________
Voluntary, CNS to the skeletal muscles
______ nerve endings serve as specialized receptors to detect conscious and subconscious sensory information
Peripheral sensory
_____ receptors show sensitivity to body position (temperature, light, sound, smell, taste etc)
Conscious
_______ respond to blood gas tension and pH
Chemoreceptors
______ react to small changes in arterial blood pressure
baroreceptors
________ refers to the sensory receptors that react to mechanical stimuli of touch, pressure, stretch and motion
Mechanoreceptors
Describe the pyramidal nerve tracks
Impulses that are shot downwards through the spinal cord through direct routes and interconnected neurons. Nerve excite the alpha motor neurons that control the fine and gross properties of skeletal muscle during intentional movements
Why is it called the pyramidal tract?
Because it goes through the medulla oblonga (part/space?) that look like a pyramid, it passes through it that space
About 80% of the information received through the pyramidal tract does what? 20% does what?
crosses sides of the brain, stays on the same side of the brain
Extrapyramidal tract has how many different pathways? Pyramidal tract?
4
2- Corticospinal and Rubrospinal
What is the main difference between pyramidal and extra-pyramidal tracts?
Pyramidal tract has to due with voluntary/thought out muscle movements, Extra-Pyramidal is balance and posture (involuntary)
*****Babinski sign manifests as what? What is normal? What does this indicate?
When the bottom of the foot is stroked, the toes are extended in a fanning motion
Toes curl down
Damage to descending upper motor neuron pathway (pyramidal)
Name some additional signs of pyramidal tract disorders.
- Babinski sign
- hypertonic spasticity
- Clonus
- hyper-reflexia
- loss of ability to perform fine movements
- muscle wasting from prolonged non-use
**Define clonus. Pyramidal or extra-pyramidal?
oscillatory motor response to muscle stretching (Anti-brake locking mechanism)
Name some signs of Extra-pyradmial disorders.
- twitching
- resting tremors
- chorea
- myocolonus
-tics
-dystonia
Define chorea:
Brief, irregular movements that are not repetitive or rhythmic but appear to flow from one muscle to the next
Define myocolonus
continuous flow of involuntary irregular movements. movements are rapid, jerky and explosive in random sequence
Define dystonia
related to involuntary and abnormal muscle tension that force patients into awkward and sometimes painful twisted or bent positions
Define motor unit
the nerve and all the muscle fibers that it innervates
How can you change the amount of force you place on an object?
By changing the number of motor units your body recruits to pick it up.
Acetyle Coline is the _____
neurotransmitter
What does the cerebellum do in terms of muscle/nerves?
Compares where your body is in space versus where you want the body to be.
Refine movements by recruiting the right number of motor units for the specific task
What is the motor pool?
all alpha motor neurons that project to a given muscle collectively
What is the size principle?
Within a single motor pool, motor neurons will be recruited in the order of ascending size, smallest first and largest last
Name some qualities of small motor neurons
- have the smallest soma membrane surface area
- fewest dendrites and branches
- innervate the fewest muscle fibers
- generate the smallest amount of force
White muscle cells in the body equal:
Powerful and fast, but get tired fast, larger cells (according to the size principle)
Red muscle cells in the body equals:
fatigue resistance. (marathon runners) Smaller cells (according to the size principle)
Red or white motor units get recruited first?
Red first then white
What are the two types of mechanoreceptors:
Spindles and Golgi Tendon organs
______ detect stretch in the muscle fibers
Spindles
______ are the junction of the tendon and skeletal muscle
Golgi Tendon Organs
_____ detect tension in the muscle
Golgi Tendon Organs
______ sends IPSP to the spinal cord
Golgi tendon organs
______ protects the muscle from tearing. How?
Golgi tendon, by sending signals that make the muscle relax
The mechanoreptors sends information to the spinal cord or brain? Why is this important?
Spinal cord, because it allows for some refinement of the muscle without the brain aka conscious control
What is a muscle spindle?
4 to 6 muscle fibers surrounded by a collageous sheath
The size of the collagenous sheath is equal to:
about the size of the EXTRAfusal fibers
The fibers inside the sheath are called _____
Intrafusal fibers
INTRAfusal fibers are innervated by:
Gama-motor neurons
INTRAfusal fibers are surrounded by:
Several sensory axons
Extrafusal and Intrafusal fibers are running ______
Parallel
______ nuclei are located in the middle of the fiber
Nuclear bag fiber
______ nuclei are located across the length of the fiber in a chain like fashion
Nuclear chain fiber
_____ Tell EXTRAfusal fibers to contract
Alpha motor neurons
Primary spindle afferents are also called ______. These are primary used for ______.
Annulospiral endings, Fast/quick motions
***Secondary spindle afferents are also called ______. These are primary used for _____.
Flower- spray endings, posture
The stretch of the intrafusal fibers can be caused by two events:
Activation of the gama motor neurons
passively lengthening and shortening the intrafusal fibers
What does activating the gama motor neurons mean?
Shortening the distal ends of the intrafusal fibers which stretches the center where the annulospiral sensory nerve endings are
Describe some things about the Golgi Tendon Organs
-Within the muscle tendon unit
-Able to detect small changes in force generated within the muscle
- Very sensitive to force
- Sensory info will excite some muscle and inhibit others
