Part 1 Chiropractic Boards: Physiology -- Neuro, Muscle, & Exercise Physiology

What are the 3 parts of a neuron?

Cell body (soma, perikaryon, karyon)

Dendrites

Axon (endoneural tube)

What is the junction of axon and soma that transmits electrical impulses through the cell?

Hillock

What is the propagation of action potentials along myelinated axons from one node of Ranvier to the next node, increasing the conduction velocity of action potentials and is FAST?

Saltatory Conduction

What is a change in permeability in the membrane?

Action Potential

What is the ascending phase of an action potential, where an impulse is likely? What is the threshold for this?

Depolarization

Threshold = -55 & -50 mV

During depolarization, what element is involved in the facilitated diffusion? Is it an influx or an efflux? How does this affect the inside of the membrane's charge?

Influx of Sodium

Na++ gates close

Inside membrane MORE positive

What is the descending phase of the membrane potential when it's towards "resting"?

Repolarization

During repolarization, what element is involved in the facilitated diffusion? Is it an influx or an efflux? How does this affect the inside of the membrane's charge?

Efflux of Potassium

Inside membrane less positive

What are the fine terminal extensions/bulbs at the end of the axon and its collaterals, storing NT?

Telodendrion

____ helps to release neurotransmitters?

Ca++

What is the state before the action potential (AP) begins? What charge is the membrane at? Is this depolarized or polarized at this state?

Resting state

-90mV (-70)

More K+ inside = polarized

What is the state when there is an increased permeability to Na+ (influx) into the neuron, causing a more positive charge and the -90 mV is neutralized?

Depolarization Stage

What is the state when Na+ channels begin to close and the potassium (K+) channels will open wider, including a rapid diffusion of K+ to the exterior (efflux) whcih re-establishes the normal negative resting membrane potential?

Repolarization state

What is the threshold for a neuron action potential?

+30 mV

There are two voltage-gated sodium channels, one is outside of the channel called the ________, and one inside the channel called the _____________.

Activation gate

|nactivation gate

At -70 to -50 mV, the __________ gate flips all the way open, allowing Na+ ions pour in, while the ___________ gate closes more slowly.

Activation gate

Inactivation gate

Inactivation gate will not re-open until what occurs?

Membrane potential is at or nearly at "resting membrane potential" level

What is the neuron sending the signal? The neuron receiving the signal?

Presynaptic neuron

Postsynaptic neuron

What type of synapse is from axon to dendrite and makes up the most synapses? What type is from axon to soma? Axon to axon?

Axodendritic

Axosomatic

Axoaxonic

What are the tunnels (connexons) to connect cytosol of two cells?

Gap junctions

What are the 3 common locations for gap junctions?

1) Visceral (single unit)

2) Cardiac & smooth muscle

3) Embryo & CNS

What are synapses that transmit information via the secretion of chemical signals (neurotransmitters), and are close together but their membranes DO NOT TOUCH?

Chemical synapses

What is the narrow gap that separates the presynaptic neuron from the postsynaptic cell? What type of transmission is used?

Synaptic cleft

One way transmission (since only synaptic end-bulbs of presynaptic neurons will release NT)

What is the time for the synaptic delay?

0.5 m/s

What are the 3 excitatory NT?

Excitatory =

1) Norepinephrine (brain stem, hypothalamus)

2) Glutamate (CNS, cerebral cortex)

3) Nitric Oxide (brain; diffuses quickly)

What are the 5 inhibitory NT?

Inhibitory =

1) ACh (motor cortex)

2) Dopamine (substantia nigra)

3) Glycine (spinal cord)

4) GABA (spinal cord, cerebellum, basal ganglia)

5) 5-HT (brain stem)

What is increased force of contraction/stimulation for a neuron, with up to 1,000-10,000 synapses received (CNS)?

Summation

For summation of PSPs (post synaptic potentials), what is the buildup of NT's released involving several presynaptic bulbs? What is NT release form a single presynaptic bulb that fires 2x or more?

Spatial summation

Temporal summation

What are the cells that make myelin in the PNS and CNS? What two material is myelin made up of ?

PNS = Schwann

CNS = oligodendrocytes

Fat & B12 (cobalamin/cobalt)

In sclerosis, the myelin (fat) is stripped off and replaced with what?

Scar tissue

What are 3 common demyelinating diseases?

1) MS

2) Posterolateral sclerosis (PLS)

3) ALS

What are the pain receptors that are free nerve endings, also invlolving tickle, itch, and temperature?

Nociceptors

What are the 4 locations of the most nociceptors? How about the 3 locations with the least number of nociceptors?

MOST

1) Tip of tongue

2) Lips

3) Finger tips

4) Genitalia

LEAST

1) Upper arm

2) Buttock

3) Trunk

What is another name for pain?

Algesia

Which type of mechanoreceptors are encapsulated and involve pressure?

Krause (end bulbs)

NOTE: "Crouse" is under pressure for us to know mechanoreceptors

Which type of mechanoreceptors are encapsulated & multibranched, with 2-5 degrees of perception, and involve temperature & pressure perception?

Corpuscles of RUFFINI

NOTE: Temp & pressure

Which of the 3 touch receptors is for general touch (anterior spinothalamic tract), hair follicles, and is NOT encapsulated?

Merkel's Discs

NOTE: ONLY one NOT encapsulated!!

- the mermaids hair

Which of the 3 touch receptors is for fine touch (dorsal columns), located on NON-hairy skin, and is encapsulated?

Meissner's Corpuscles

NOTE: Missy Meissner is fiiiiiine

What is grouped Merkel's discs called?

Iggo Dome receptors

Which of the 3 touch receptors is encapsulated and for pressure and vibration, and is a phasic receptor and quick adaptor?

Pacinian Corpuscles

NOTE: Pressure & Vibration = Pacinian

Which of the 3 proprioceptors is for stretch, and is dynamic/static ONLY in skeletal muscle)?

Muscle Spindles

Which of the 3 proprioceptors is for load or weight?

Golgi tendon organs

Which of the 3 proprioceptors is for preventing excessive tension in a muscle?

Golgi Tendon Reflex

What is the general function of the sympathetic nervous system? Parasympathetic nervous system?

S = Fight or Flight

P = Wine & Dine

What is the function on blood vessels & skin or muscle in the sympathetic nervous system? Parasympathetic nervous system?

S = VasoCONSTRICT (shunts blood via vasomotor control to proximal lubms and lungs)

P = Little to no effect on blood vessels/skin; DOES affect muscle

What is the function on the heart in the sympathetic nervous system? Parasympathetic nervous system?

S = Increase Rate

P = Decrease Rate

What is the function on the lungs/bronchi in the sympathetic nervous system? Parasympathetic nervous system?

S = Deep breaths and DILATES bronchi

P = Shallow breaths & CONSTRICS bronchi

What is the function on the eyes/puppils in the sympathetic nervous system? Parasympathetic nervous system?

S = DILATES (mydriasis)

-- myDriasis = Dilate

P = CONSTRICTS (miosis)

What is the function on the GI, Peristalsis, and Colon in the sympathetic nervous system? Parasympathetic nervous system?

S = Decrease secretions & digestion

P = Increase secretions & bowel movement

What is the function on the receptors in the sympathetic nervous system? Parasympathetic nervous system?

S = Adrenergic

P = Cholinergic

What are the NT (Preganglionic & Postganglionic) for the sympathetic nervous system? Parasympathetic nervous system?

S = Pre --> AcH; Post --> Epi & Norepi

P = Both --> ACh

What are the nerves associated with the parasympathetic nervous system? Sympathetic nervous system?

P = CN 3, 7, 9, 10 & S2-4

S = T1-L2

What is the influx of sodium? Efflux of potassium?

Depolarization

Repolarization

What is the period where NO Action potential is possible? The period where action potential may be available with an increased potential?

Absolute refractory

Relative refractory

What are many synapses on a single cell? What are rapid succession of action potentials with few synapses?

Spatial summation

Temporal summation

What can bind to and block glycine receptors, causing massive tetanic contractions, meaning the diaphragm cannot relax, we can't breathe, so it leads to death?

Strychnine (poisoning)

Normally inhibitory neurons in the spinal cord known as _______________ will release _______ to prevent excessive muscular contraction?

Renshaw cells

glycine

What is the threshold for stimulation (while the membrane potential starts at -90 mV)?

-65 mV

What is the somatosensory area?

Postcentral gyrus (parietal lobe)

What is the visual sensory area? (3)

Occipital lobe, striate cortex, calcarine fissure

What is the auditory cerebral sensory area? (2)

Superior temporal lobe, gyrus (Heschl's gyrus)

What is the gustatory cerebral sensory area?

Base of postcentral gyrus

What is the olfactory cerebral sensory area?

Medial temporal lobe

What is the Wernicke's cerebral sensory area? What is it's function/

Superior temporal lobe

RECEPTIVE portion of language

What is the Cerebral motor area?

Precentral gyrus (frontal lobe)

What is the cerebral premotor area? What is its function?

Anterior and motor cortex

SKILLED movement

What is the cerebral Broca's area? What is its function?

Inferior posterior frontal lobe

EXPRESSIVE portion of language (speaking)

What functions in the COORDINATION of muscle contraction?

Cerebellum

What are the 3 signs of a cerebellum lesion?

1) Staccato or Slurred speech

2) Intention tremor

3) Nystagmus

SIN

What is the main relay between cortex and spinal cord involved in CRUDE SENSATION?

Thalamus

What are the 5 functions of the hypothalamus?

1) Controls ANS & Endocrine system

2) Controls body temperature (median eminence), food intake, thirst

3) Rage & Aggression

4) Maintain waking state and sleep

5) Release somatostatin

What is the function of somatostatin?

Decrease insulin and glucagon secretion

What functions in the emotional aspecs of behavior related to survival including the fornix, hippocampus, cingulate gyrus, amygdala, the parahippocampas gyrus, & part of the thalamus?

Limbic System

What part of the midbrain coordinates eyeball movement in response to visual stimuli? What part coordinates head & trunk auditory stimuli using CN III and IV?

Superior colliculi

Inferior colliculi

What is the pneumotaxic & apneuristic area (breathing)? This is the origin of what 4 cranial nerves?

Pons

CN 5-8

What is part of the reticular formation (w/ diencephalon, pons, midbrain) that functions in consciousness & arousal and houses the vital reflex centers that regulate heartbeat, breathing, and blood vessel diameter in addition to coordinating swallowing, vomiting, coughing, sneezing, and hiccuping? What 5 cranial nerves is this an origin for?

Medulla

Origin of CN 8-12

What part of the medulla helps maintain equilibrium?

Vestibular nuclei

What are dark spots from aging that are products of oxidation?

Lipofuscin

What is the cell membrane found in skeletal and cardiac muscle?

Sarcolemma

What stores Ca++ to be released in skeletal muscle?

Sarcoplasmic reticulum

What is the "telephone" line to send the action potential into the muscle to cause calcium release from the sarcoplasmic reticulum?

T-tubules

What are the 2 types of myofibrils and what are their ratio to eachother?

Actin : Myosin

2:1

What is the thick myofibril that is in the H zone, making cross bridges? Where does ATPase attach?

Myosin

ATPase attaches to Myosin HEAD

What is the thin myofibril that is made up of the F-actin filament, tropomyosin, and troponin in the I bands?

Actin

What part of actin contains the binding sites?

F-actin filament

NOTE: Think F like f**k, like teenage son who wants to "uncover binding site" for first time

What part of actin covers the F actin's binding sites?

Tropomyosin

NOTE: MOM; strict and prevents the "uncovering of binding site" (F-actin)

What part of actin binds calcium and moves tropomyosin off binding sites?

Troponin

NOTE: DAD; provides materials (Ca) and moves MOM (tropomyosin) off binding site

What consists of actin, myosin, and sarcoplasmic reticulum? What is needed for this to contract?

Smooth muscle

NEEDS Calmodulin to contract

What is the length of the Sarcomere?

Z-line to Z-line

What is contained in the A-band? H-band? I-band?

A = actin and myosin

H = Myosin ONLY

I = Actin ONLY

When going form a relaxed to contracted muscle, the ______ band gets smaller, but the _____ band doesn't change.

I band smaller

A band doesn't change

Why does Rigor mortis occur after death?

Crossbridge form but are unable to release

What type of muscle contraction is when the muscle lengthens while it contracts?

Eccentric

What type of muscle contraction is when the muscle shortens while it contracts?

Concentric

What type of muscle contraction is when the muscle contracts without joint movement or muscle lengthening?

Isometric

What type of muscle contraction is when the muscle contracts with joint movement & constant weight?

Isotonic

What type of muscle contraction is when the muscle contracts with joint movement & constant weight/speed?

Isokinetic

What is a single motor neuron and all the muscle fibers it innervates?

Motor unit

What type of muscle fibers slit ATP rapidly?

Fast-twitch muscle fibers

What are the 2 types of ventral root fibers?

Alpha = extrafusal

Gamma = intrafusal