Physiology Exam Practice Questions

Either an Action potential occurs, or not.

All or none law.

What does amplitude mean? What does frequency mean? Given the two types of sleep, use these terms to describe the waves.

Amplitude is how high a wave is, frequency is how short it is

What does it mean to have varying amplitude or varying duration? Is this relatable with a graded potential or action potential? Which potential has a constant amplitude and duration?

Amplitude is the charge of the graded or action potential. It varies with a graded potential, and in an action potential it has one value. Duration is the amount of time it takes for the Na channels to close and allow the wave to propagate down the axon.

What is loudness? What are other names for loudness?

Amplitude, decibels,

The subscript 1 and 2 means the signal is excitatory or inhibitory, which type of signal belongs to the subscript?

1: excitatory; 2: inhibitory

What kind of receptors are present on the EPP?

ACh

What is ATP converted to after binding with the myosin head?

ADP

Astrocytes are the scaffolding (physical support) of the brain and even form scar tissue. Why else are astrocytes important? What is their relationship to the blood brain barrier? Neurotransmitters? Potassium?

Astrocytes support the blood brain barrier, facilitate neurotransmission.

What occurs during the PR segment? Why is this step so important?

AV nodal delay

Which signal would be primarily responsible for propagating sensory information to the CNS?

Afferent

Our withdrawal reflex is an unconscious act. Describe the reflex arc after touching a hot stove.

Afferent neuron > excitatory interneuron > motor neuron

Describe the pathway of the negative feedback system.

Bad touch > sends to sensor > sensor sends action > draw back

What two structures are part of the central nervous system?

Brain and spinal cord.

How can you control venous return

Breathing, vasoconstriction

Which ion binds to tropomyosin and what is the result? How is this ion released? What now is able to bind?

Ca binds to tropomyosin, which releases it from the myosin head, which allows myosin to bind to actin.

What is the relationship between Ca++ availability and heart muscle action potential and contraction? Which phase of the action potential is Ca++ availability seen in?

Ca makes the heart contract during cardiac excitation

What leads to exocytosis?

Ca signal

What does it mean to accommodate?

Change shape of lens

What is excitation contraction coupling?

Converting electrical stimulus into mechanical response

What would happen to Ef if contractility increased and why?

Decrease because heart can contract better

What is acuity?

Discriminative ability

The dorsal and ventral horn are either ascending or descending. Which is which? Relate this to pathways.

Dorsal is ascending, ventral is descending.

When does phasic flow occur, ventricular systole or ventricular diastole?

During diastole

Given the stimulus property "Intensity of stimulus (strength)", what is the mechanism of coding?

Frequency of action potential firing

Which muscle type would enzymes for glycolysis be most present?

Glycolytic

Which of your body parts has more acuity: your hand or the back of your calf? How so?

Hand, smaller and used more

Which structures are involved in the primary motor cortex and what is the function of the PMC?`

In frontal lobe; execute movement

If you increase arterial pressure what happens to afterload? What would then happen to CO?

Increases; decreases CO

Where in relation to the lens is the vitreous humor located? What is the function?

Inside the body of the eye, keep shape.

What effect does voltage have on ion selective channels?

Ions flow easily in the direction of their gradient?

What is the role of the hippocampus?

Learning and memory

What solubility are protein hormones, peptides, and neurotransmitters?

Lipid soluble.

What energy conformation is myosin in when relaxed?

Low (for skeletal muscle), high (for smooth muscle)

What does aortic pressure look like during IVR, Ventricular filling, IVC, and Ventricular ejection and why?

Low, high, low, low

Why is the amplitude of a twitch smaller than tetanus?

Many twitches = tetanus

At RMP of -70 mV, are Na+ or K+ voltage gated channels open or closed?

Na channels are open, and K channels are closed.

What occurs during the TP segment? Is there any electrical activity?

No, refractory period

Do hydrophilic hormones enter the cell? If not how is the cellular response induced?

No: they bind to GPCR on the surface of the cell.

Describe the H zone at Optimal Length, is force generation optimal or less than optimal?

Optimal

What is the difference between origin and insertion of a skeletal muscle?

Origin is the anchor to relatively stationary bone, insertion is on the affected moving part.

Which muscle types are capillaries most present in?

Oxidative

On what axes do our semicircular canals lay on? Why is this important? (think dimension)

Rotational or angular acceleration; turning side to side

Which type of conduction is faster? How can this be?

Saltatory, because jumping is faster than running

What is the function of the peripheral receptors/ sensory receptors?

Sensory

What is stored and released from the sarcoplasmic reticulum (SR) ?

Stores Ca

Golgi tendon organ and what does tension have to do with it?

Stretch and tension in conscious awareness

Describe the functions of subcortical structures.

The brain is organized into different "layers," increasing in complexity from the brainstem to the cerebrum. Create a mnemonic to fill in the missing layers of the brain and their functions

How is CSF reabsorbed?

Through arachnoid villi into venous blood

What is the labeled line principle? What do we perceive if we stimulate the second neuron in line?

Types of input stay in their lanes. We see the signal move?

What is the curvature of the lens when one has astigmatism? How are light rays refracted?

Uneven curvature of cornea

In which direction of movement will our otolith organs be stimulated?

Up and down or side to side

Would vasodilation of veins or vasoconstriction of veins lead to more venous return?

Vasoconstriction to push blood along

Cerebro

planning and muscle memory

Broca's area

plans sound pattern of speech.

A typical synapse can require multiple EPSPs to fire, does the end plate potential (EPP) need multiple EPSPs as well?

yes

Describe the functions of the prefrontal association cortex.

"thinks", personality, creativity, planning

The equation for ejection fraction is stroke volume over end diastolic volume

(Ef = SV / EDV ).

Scotopic

(nightvision) is where you can only use rods and see in shades of grey, photopic is where you use cones and usually during the day limited in terms of light sensitivity (does not need rods as much because of day brightness makes up for rod deficit)

Given CAMP, DAG, IP3, and Ca second messengers, which of the effector proteins (Adenylyl cyclase and Phospholipase C) are related to the given messengers?

-Adenylyl cyclase, cAMP -Phosspholipase C, DAG IP3 and Ca

Slow-wave sleep is cool, describe slow-wave and REM sleep via these characteristics. EEG, motor activity, arousal, and the other important characteristics listen in table 5-4 of your book.

-Slow wave-sleep: delta waves; regular activity, muscle tone, respiratory; easily awakened, rarely dreams, less visual thoughts -REM sleep: paradoxical sleep, fluctuating respiration, blood pressure, heart rate; imitation of beta / gamma waves

What happens to the I band when a muscle contracts? The Z lines? The H zone? A band?

A band shrinks

What does pacemaker potential mean? What is the difference between pacemaker and slow-wave potentials?

Ability to self-generate action potentials

Say we have reached threshold and our membrane potential is nearing 0mV. Are we in absolute or relative refractory period? At what point are we no longer in absolute or refractory period and which period do we transition into once we are at or below threshold again? At what membrane potential are we no longer in relative refractory period?

Absolute refractory period is during the action potential, while relative refractory period is after the initial curve, when the nerve can fire again. Absolute is before 0mV, relative begins when we dip below 0mV, and relative ends when we move back to -70mV again

What is another name for thin filaments? What three structures are present? What is the importance of the structures?

Actin filaments; actin, troponin, tropomyosin

Taking a portion of a myofibril, what structure is defined by Z-lines? Within the structure, what other filaments are present, and what is the role of titin?

Actinin fibers to anchor actin filaments; titin anchors myosin to z-line

Starting with an action potential and opening of Ca++ voltage gated channels, explain the remaining steps necessary for action potential propagation down the muscle cell.

Action potential > Ca influx > exocytosis of ACh > graded (endplate) potential in muscle cell > Na gates open to propagate action potential

What propagates down the sarcolemma?

Action potential for muscle contraction

What can a neuromuscular junction only do in relation to a typical synapse?

Activate muscle to contract

Phosphorylization is the result of second messenger systems. What is the purpose of phosphorylation?

Activate proteins by changing their shape.

What is an agonist and what is its role? Antagonist? What are the effects of each on receptor ligands?

Agonists encourage function and signals, while antagonists inhibit it.

Which receptors, when sympathetically innervated, are present on the effector organ?

Alpha, beta1 or 2

What is refraction? Can you give an example too?

Altering the path of light, like through a glass of water distortion.

Advantages of secondary messenger systems are that the primary messenger stays outside the cell and cell regulation can occur. However, the main advantage is missing, what is it?

Amplification of original signal via branching pathways.

How do we reach threshold?

As more Na influxes into the cell through Na channels, the membrane potential rises to be closer to threshold. Once we reach threshold, the neuron fires and sends the Na membrane gradient and potential down the axon

We have ascending and descending tracts. Which of the two relate to efferent pathways? Afferent pathways? Which of the two pathways are sensory? Motor control?

Ascending are afferent, descending are efferent; ascending is sensory, descending is motor control.

During which intervals do we see end diastolic volume and end systolic volume? Also, what do these terms even mean?

At the end of diastole and systole; volume left in ventricle

Assume that due to enough graded potentials there is a hypo-polarizing event that allows us to reach threshold. At threshold, which voltage gated channel is open? Which is still closed? Which ion is influxing into our membrane and is which of the three polarizations is this considered?

At threshold, Na channels are open and K channels are closed. Na is influxing to hyperpolarize the membrane.

In order for the atrial valve to be open, what must the difference be between the atrial and ventricular pressures. In order for all valves to be closed, what must the pressures be like between the atria, ventricle, and aorta? In order for ejection to occur, what must the pressure difference be between the ventricle and aorta?

Atrial valve opens when ventricular pressure is lower than pressure in atrium. Ejection occurs when pressure in ventricle is higher than pressure in aorta.

Where is a synapse located in relation to two neurons?

Between them

The medulla is important because...?

Brain stem integrates information, reflexes, involuntary controls

Within our midbrain we have our reticular formation. What two regions of the brain are within and what is the significance of our reticular activating system? What does this have to do with waking up in the morning?

Brainstem, thalamus; RAS, arousal and consciousness

What are three functions of the basal nuclei? Relate the functions to your daily activities.

Brainstorms, plans activity, decision making, creativity

What is Flaccid Paralysis?

Cannot contract

What is Spastic Paralysis?

Cannot stop contracting

What structure produces the aqueous humor? Vitreous humor?

Capillaries form AH in ciliary body, drains at edge of cornea

What is the role of the transverse tubules and what do they release?

Carry Ca to muscle cells

Compare and contrast a synapse with a neuromuscular junction.

Cell bodies in spinal cord or ganglia, termination on muscle

What forms CSF?

Choroid plexus (pia mater)

Key structures to recognize are the optic nerves, pretectal nuclei, and oculomotor nerves. What happens to the light reflex when there is a lesion of the optic nerve? What happens to pupil constriction ability if there is a lesion on the oculomotor nerves? Describe what the result of shining light on the left eye only is if the optic nerve had a lesion. Using the same idea, what if the oculomotor nerve had a lesion?

Ciliary ganglia > pretectal nuclei > E-W nucleus > oculomotor nerves > pupil constricts

What is the deal with sensorineural deafness?

Cochlea or auditory nerve is damaged

What is the deal with myopia and which lens do we correct with?

Concave lens to diverge

What are five major functions of the brain stem? Relate these to the different regions as we continue.

Connecting link between brain and spinal cord; sensory and command signals, Innervation, cranial nerves, Heart and blood vessel function, respiration, digestion, Muscle reflexes, Incoming sensory input, alertness, Sleep

What does the word contiguous mean? How does this relate to the propagation of an action potential?

Contiguous conduction is down the full length of the axon

What effect does sympathetic activity have on heart contractility? What would then happen to venous return? What would then happen to CO?

Contracts harder and faster to increase VR and CO

What does it mean to converge? Which lens, convex or concave will converge light?

Convergence is to bring closer together; convex lens

What is the deal with hyperopia and which lens do we correct with?

Convex lens to converge

Which of the refractive structures have a greater refractive power?

Cornea and lens

What are the eye's refractive structures and what are their functions?

Cornea, lens, iris, retina, fovea

The energy sources of muscle contraction are oxidative phosphorylation, creatine phosphate, glycolysis, and natural stores of ATP. List, in order,, the speed and capacity at which each can supply ATP

Creatine phosphate is first used, then glycolysis, then ox phos

What is a cross bridge cycle? Cross-bridge cycles do not stroke concurrently rather...?

Cross bridges have the myosin head 'climb' the actin filament

What is the functional significance of CSF?

Cushions and oxygenates brain and spinal cord

What would happen to Ef if ESV increased?

Decreases

What does ventricular pressure look like during IVR, Ventricular filling, IVC, and Ventricular ejection and why?

Decreases, gets higher, increases, lowers.

If you decrease arterial pressure what happens to afterload? What would then happen to CO?

Decreases; increases CO

What is the purpose of acetylcholinesterase?

Degrades ACh to stop firing

Where are muscle spindle fibers located in relation to muscle? What do the muscle spindle fibers detect?

Distributed throughout skeletal muscle, detect change in length

What does it mean to diverge? Which lens, convex or concave will diverge light?

Divergence to push further apart; concave lens

When is the atria contracting?

During P wave

How do the surface areas compare between the two?

EPP is much larger and denser

What is preload equivalent to, ESV or EDV? Would SV increase or decrease with a lower preload? Would ventricular force development increase or decrease?

ESV; increase, increase

There are two sides to the steroid hormone receptor. What does each side bind to?

Each bind to one side of the HRE's half-sites.

Furthermore, in relation to dark and light in the bipolar and ganglion cells, where are action potentials occurring and where are they not? Include the aspect of depolarization and hyperpolarization

Each photoreceptor synapses with an on and off center bipolar cell, which terminate on their respective ganglions, which are continuous with the optic nerve. Glutamate hyperpolarizes on center and depolarizes off center bipolar cells, which pass on the information to the ganglion, which change the rate of neurotransmitter release based on this information.

The peripheral nervous system consists of "everything else." Which signals propagate to the CNS? Which signals propagate away from the CNS? (Efferent and Afferent)

Efferent signals are the 'effect' of the brain on the outside world, and go from the brain to the effectors. Afferent signals are the outside world 'affecting' the brain, and go from sensory organs to the brain.

What does the ventricular volume look like during IVR, Ventricular filling, IVC, and Ventricular ejection and why?

Empty plateau, rising, full plateau, falling

What is the result of steroid hormones, or in other words lipophilic hormones? How does this differ from hydrophilic messengers?

Enter cells to modify their function.

What does adrenergic mean and which neurotransmitter is adrenergic?

Epinephrine, norepinephrine

What is the deal with conductive deafness?

Equipment is fine, sound waves do not reach the cochlea

What does EPSP mean? Which ligand gated channel opens? Which ion influxes into the cell? Which polarization effect does this have on the membrane potential?

Excitatory post synaptic potential. Na K antiport, where Na influxes to excite cell

How is a chemical messenger released from one neuron to another?

Exocytosed into the synaptic cleft

Where does calcium come from within smooth muscle? Does smooth muscle have a sarcoplasmic reticulum?

Extracellular stores; no.

In myopia, what is the strength of your lens and cornea? Is your eyeball too short or too long?

Eyeball too long, lens too strong

In hyperopia, what is the strength of your lens and cornea? Is your eyeball too short or too long?

Eyeball too short, lens too weak

Between what two structures is the aqueous humor located? What is the function?

Eyelid and sclera; keeps eye lubricated

Does a myelinated neuron propagate action potentials slower or faster than an unmyelinated neuron?

Faster

Describe the physiological effects of enhanced sympathetic tone

Fight or flight

When does the first heart sound occur? The second one?

First heart sound when atria contract, second when ventricles contract

Considering both flexion and extension, what is the deal with the cross extensor reflex?

Flexes muscles for Get Away, inhibits muscles for Hold Still

What is timbre?

Fluctuations in sound waves; not pure notes

What is the equation for starling's law?

Fluid movement = k ( Pc - Pi) - (Nc - Ni)

What is afterload?

Force against which the heart contracts; arterial blood pressure

Which compound will act on the coronary vessels? Will it vasoconstrict or vasodilate? Will more or less blood be available to cardiac muscle cells? Will there be more or less oxygen available? Will the oxygen need be met?

Free adenosine (A from ATP) triggers vasodilation, more blood, more oxygen

What is pitch? What are other names for pitch? Describe what a sound wave is to look like with different pitches.

Frequency; higher pitches are faster waves

What cell(s) does heart muscle have that skeletal muscle does not?

Gap junctions?

Define the properties and relate them to the voltage-gated channels

Gating decides specificity of a channel and when it is open or closed. Activation allows the gate to open and function. Inactivation forces the gate to close.

How is it that a graded potential can lead to an action potential? Do they always lead to an action potential? Why or why not?

Graded potentials are close to threshold, moving closer to +40 from -70mV. When many of them occur in the same place, they summate to reach +40mV and create an action potential. This does not always happen.

Where on the neuron do graded potentials occur? Where do action potentials occur?

Graded potentials occur all over the soma, but are closest to the threshold at the axon hillock. At the axon hillock, graded potentials become action potentials and travel down the axon to become a graded potential at the next synapse.

What is a motor unit and what does it consist of?

Group of muscle fibers that can cause contraction on their own + nerve

What is the difference between habituation and adaptation? Where do these mechanisms occur?

Habituation is getting 'used to' a stimulus and reducing your response; adaptation is having a specific response.

What is habituation and sensitization and is this an example of long or short term memory? Which region of the brain can you relate to these two examples and why?

Habituation is when you have lower responses to repeated stimuli. Sensitization is when you have higher responses to repeated stimuli. Long term memory keeps track of this and neuromodulates the pathways to have a reaction

What is the mechanism behind transduction?

Hair cell stimulation

Where is the receptor cell unit located in the semicircular canals? Which actions would stimulate the receptor cell and which would not?

Hair cells in half circle; rotational or angular acceleration

Grand Post Synaptic Potential (GPSP) involves both IPSPs and EPSPs. What would happen if we have more EPSP than IPSP? What if they were the same? In relation to membrane potential on the presynaptic neuron.`

Have to have enough EPSPs to outweigh the IPSPs to reach threshold

What is the deal with striated and unstriated muscle? Which muscle types fall under these categories?

Heart and skeletal muscle is striated, smooth is unstriated.

What is phasic flow and why is it important?

Heart cuts off own blood supply during systole

Would an action potential occur if a low frequency of temporal summations were occuring? Higher/ high enough frequencies?

High enough to get to threshold

What is the pressure difference between the left and right side of the heart? Which side has a greater pressure and why?

Higher pressure on left side, must pressurize blood

The hypothalamus is outside the blood brain barrier. This allows for the control of homeostatic functions. What does this include? Which nervous system is present? Which patterns are associated with the hypothalamus?

Hormones into blood stream; integrating center for most regulation and feedback systems.

What is venous return?

How much blood comes back through the vena cava

Which type of drug is able to cross the BBB? Which is not able to cross? (philic or phobic)

Hydrophilic cannot cross, lipophilic can cross.

What is the mitochondrial count in Type II x fibers? How about in Type I and Type IIa?

I, IIa: many; IIx: few

Given Type I, Type IIx, and Type IIa, match the terms with the above muscle types in the objective.

I: slow oxidative; IIx: fast glycolytic; IIa: fast oxidative

In relation to dark and light (absence or presence of light) differentiate between the concentration of cGMP, open or closed Na+ channels, depolarization or hyperpolarization, and neurotransmitter release

In the dark, cGMP is high to depolarize the cell. When activated by light, photopigment cascades to degrade cGMP and hyperpolarize the cell, which sends a signal down the optic nerve.

What would happen to Ef if afterload increased and why?

Increase because its harder to push all of it ou

How is contractility increased? What happens to the ventricular force development if contractility is increased? Would SV increase or decrease? Would ESV increase or decrease? Would CO increase or decrease?

Increase length-tension relationship; higher force, higher SV, lower ESV, increased CO

Where does long term potentiation start? Can you form long term potentiation if long term memory is already formed?

Increased use at the synapses results in permanent modifications.

If EDV decreases what happens to Ef

Increases

What happens to CO if you decrease afterload?

Increases

What happens to CO if you have an increase in venous return and why?

Increases

What does atrial pressure look like during IVR, Ventricular filling, IVC, and Ventricular ejection and why?

Increases, steady, increases, stead

What happens when neurotransmitters bind to receptors on the post synaptic membrane?

Induce graded potential

What happens after a chemical messenger crosses the synaptic cleft onto the next neurons membrane receptors?

Induces a graded potential that can turn into an action potential

What does IPSP mean? Which ligand gated channel opens? Which ion influxes into the cell? Which polarization effect does this have on the membrane potential?

Inhibitory post synaptic potential. K influx to move farther from threshold.

The hypothalamus is important because...?

Integrating center to modulate control

Which structures are included in the extrapyramidal/multinational motor system and what are the functions of this system?

Involuntary actions; in medulla

What is nystagmus?

Involuntary movement of the eyeballs in an up/down, back/forth motion. Interferes with head control.

Will a convex lens bring light inward or outward?

Inward

Which phase is transitioned into next and can this phase be shortened and elongated? How so?

K efflux; moderated by leaky K channels

What does the gamma efferent system do in relation to the stretch reflex?

Keeps extrafusal fibers at optimal length

What is the relationship between diameter and speed of conduction?

Larger diameter means faster conduction

How is acuity influenced by receptive field size? Take note of how many receptors are present

Larger fields have less densely packed receptors and less acuity

What is the deal with lateral inhibition in acuity and where does it occur?

Lateral inhibition turns off neighboring receptors to pinpoint the location of a stimulus

Given the stimulus property "location of stimulus and duration", what is the mechanism of coding?

Lateral inhibition, duration of action potential firing

What are three characteristics of the left cerebral hemisphere? Right cerebral hemisphere?

Left: logical, analytical, sequential, verbal. Right: spatial perception, art and music

Describe the relationship of the length of the H zone and the overall muscle length - force relationship.

Length-tension relationship

What would happen if there was no alpha-gamma co-activation?

Less sensitivity to stretch and less range of motion

What is the difference between ligand gated channels and voltage-gated channels? Which of the channels is more associated with an Action Potential?

Ligand gated channels allow the action potential to initiate. The ligand signals the channel to open as an external signal. Voltage gated channels prevent the action potential from going backwards, and allow the action signal to propagate down the axon.

Describe in order the structures light passes through from the front to back of the retina. Then, describe the direction of retinal visual processing through the same structures previously mentioned.

Light passes through optic nerve, ganglia, amacrines, bipolar, then rods and cones; processing starts at rods and cones and goes to optic nerve.

What is the importance of the refractory period?

Limiting the frequency of action potentials.

What is the purpose of neuromodulation? In what scenario may we use neuromodulation?

Long term change in the way neurons fire and work; neuropeptides. Sensitivity, enzymes.

Describe the differences between short and long term memory in capacity, retrieval time, inability to retrieve information and mechanism of storage. And any other characteristics you deem important.

Long term memory has a larger storage but a longer retrieval time.

The function of the outer ear is to collect sound. Specifically, we begin to collect sound at the Pinna of the external ear. Next in line is the middle then inner ear. Which structures will sound waves travel through from now until acting on the basilar membrane in order to stimulate our auditory nerve? Take note on conversion and amplification

Mallus, incus, stapes > perilymph > basilar membrane > organ of corti hair cells > bend in response to sound waves > stimulate auditory nerve

What is the relationship between a motor unit and muscle fibers?

Many muscle fibers in a motor unit innervated by same nerve

What is the difference between a muscle fiber (myofiber) and a myofibril?

Many myofibrils in a myofiber.

Why is sleep important and what are the two types of sleep?

Memory and sanity; REM deep sleep and light sleep

Which type of synapse produces a faster reflex?

Monosynaptic is fastest

The neuronal activity for the patellar tendon reflex is simple compared to the others. What type of synapse is present?

Monosynaptic stretch reflex

What is the difference between intracellular events between the two?

More Ca released, more actin binding sites uncovered

Why is there a lot of ATP required during contiguous conduction but not saltatory?

More Na channels are used, and more Na has to be pumped out

In what order do we recruit motor units in relation to various strengths?

More for more strength

How does an increase in stimulus affect the frequency of action potentials?

More frequent!

The tectorial membrane will stay in place as our basilar membrane oscillates via soundwaves. What now happens (mechanically) to the receptor hair cell on the basilar membrane? Take note of which ion is influxing and what happens after the Ca+ voltage gated channel is opened.

Moves back and forth to open channels, which forms graded potentials

Which receptor, when parasympathetically innervated, is present on the effector organ?

Muscarinic

How is skeletal muscle contracted? How is cardiac muscle contracted? How is smooth muscle contracted? Does the presence of striation indicate how the muscle contracts?

Myosin and actin bridges; smooth muscle does not have regular striations, but still has the components!

What is another name for thick filaments? How would you describe the structure? What are important sites on the thick filament?

Myosin head bundles

What is important about the M line and which zone is present here?

Myosin heads bundle, shows division between actin fibers, allows stretch here.

Which ion (Sodium or Potassium) will hypo-polarize our membrane potential? Which ion will hyper-polarize or re-polarize a membrane?

Na's normal RMP is 61mV, while K's is -90mV. RMP is -70mV due to the different concentration of these ions. Hypopolarization is when the RMP dips closer to -90mV, which is caused by an influx of K. Hyperpolarization is when the RMP rises closer to 61mV, which is caused by an influx of Na.

What ion selective channels are present on our neurons?

Na, K

In a normal eye, describe when we accommodate. Near light source and far light source?

Near requires stronger lens; relaxed the lens is flat and weak, flexed it is spherical and strong.

How do our muscles relax? How do our actin-myosin bridge detach?

Need ATP to release

What is the deal with Rigor-Mortis?

No ATP, no release of muscle fibers

Does smooth muscle have troponin? If not, how does calcium influx allow for phosphorylation of myosin cross bridges? Does smooth muscle have T tubules?

No and no! Diffuses throughout

Does an action potential diminish in a myelinated neuron? An unmyelinated neuron?

No! Action potentials are constant.

Do action potentials diminish as they propagate?

No! Action potentials are sustained as they move down the axon.

Given the stimulus property "type of stimulus (modality)", what is the mechanism of coding?

Nocicreceptors

What role do the nodes on Ranvier play when a neuron is myelinated?

Nodes that the action potential jumps on to move down the axon.

Which valves are open during IVR, Ventricular filling, IVC, and Ventricular ejection and why?

None, mitral, none, aortic

What does hypo-polarization mean and what is happening to the membrane potential during hypopolarization? Use the same question for Repolarization and Hyperpolarization.

Normal resting membrane potential is -70mV. Hypo and hyperpolarization occur when the RMP differs from normal. These are forms of graded potentials. The membrane is hyperpolarized, followed by a wave of hypopolarization, and then repolarizes and goes back to normal in an action potential propagation down the axon.

What is the strength of the lens and cornea when one has presbyopia? Which lens would you correct with?

Old eyes, lens too weak; corrected with convex lens

What is the main role of oligodendrocytes? Microglia? Ependymal cells?

Oligodendrocytes myelinate the brain's neurons. Microglia are macrophage cells. Epedymal cells form epithelial lining of brain.

What happens to the Na+ inactivation gate once we reach threshold? How does the inactivation gate play a role in our action potential?

Once threshold is reached, Na inactivation gates move to block the channel and stop the influx of Na into the neuron.

Do action potentials travel in multiple directions or one?

One direction down the axon of a neuron

Will a concave lens bring light rays inward or outward?

Outward

Which muscle types have the most capacity for oxidative phosphorylation?

Oxidative

What is the glycogen content of oxidative fibers? Glycolytic fibers?

Oxidative: low; glycolytic: high

What are the colors of the muscle types?

Oxidative: red; glycolytic: white

Which type of muscle can you increase oxidative capacity in and through which physiologic method is this achieved?

Oxidative; endurance

Which wave initiates atrial contraction and what does ventricular volume look like at this point? At what point (pressure differential) will the heart enter the isovolumetric ventricular contraction phase? What would the electrocardiogram look like? Is the volume in the ventricle changing? In order to reach the ejection phase, which pressure must rise above the other? When entering the ejection phase, what happens to the ventricular volume? At what point (pressure differential) will we enter isovolumetric ventricular relaxation?

P; ¾ full; when pressure is equal; no; ventricular pressure more than aortic pressure

Association areas are on the borders of different lobes. In other words, they have multiple responsibilities. What are the responsibilities of the prefrontal association area? Parietal-temporal-occipital association cortex? Limbic association cortex? Try to build bridges between the association cortex and actions instead of plain memorization. Find videos online that give a brief intro to the cortexes and their roles

PTO association: sensory. Limbic: how you feel and what you know

What part of the brain is excluded? Why does this part need to be excluded?

Parts of the brain that secrete hormones; part of hypothalamus

What is the purpose of having synapses connect neurons?

Pass on a signal or affect an effector neuron

Thinking about a utricle, what are otoliths and what are they suspended in?

Perilymph! Hair cells in horizontal and vertical sheets

What forms the blood-brain barrier? What type of junctions is being formed?

Pia mater, which forms tight junctions.

Which of the pathways are interneurons present? Which do not have interneurons?

Polysynaptic have interneurons, monosynaptic the efferent connects to

What is the first neuron called? The second neuron? In relation to -synaptic

Pre and post synaptic

In relation to the sympathetic pre ganglion and post ganglion, which neurotransmitters are released from each site?

Pre: ACh; post: E, NE

In relation to the parasympathetic pre ganglion and post ganglion, which neurotransmitters are released from each site?

Pre: ACh; post; ACh

What would happen to Ef if preload decreased and why?

Preload is the amount of blood left in the ventricle after contraction; it would increase

We have different hormones that send signals across our bodies. What is the difference in solubility between proteins/ peptides and steroids/ thyroid hormones?

Proteins/ peptides are water soluble, and steroids are lipid soluble.

What colors do the three types of cones perceive? What are the differences in wavelength? How are the cones able to distinguish the wavelengths?

RBG; different activation of photopigment

Which of the intervals are occurring during ventricular systole? When does ventricular systole start and when does it end and what phase is in between?

RST

What is the law of specific nerve energies? Take note of the types of stimuli that our skin perceives, our eyes, Etc.

Receptors can only respond to one stimulus at a time, which is why we are specialized

What is the function of the pons region? Is this primary or secondary control of respiration and bp? Relate the word fine tune to the pons region.

Regulation of processes carried out by the brain stem

Where is the thalamus located? Other than motor control, what is the main function? Is the thalamus involved in waking up in the morning? How?

Relay station at brain stem; consciousness and awareness of sensations.

What occurs after the action potential propagates down the SR?

Release AChE

What is a demyelination disease and what effect does this have on a neurons action potential?

Removes myelin sheath; slows down propagation of action potentials.

What is typically the end result of any of these? (paralysis)

Respiratory failure

Describe the physiological effects of enhanced parasympathetic tone.

Rest and digest

What are the differences between rods and cones with respect to light perception, sensitivity, acuity, and location of the retina? Can you describe the physiology behind the differences?

Rods are black and white light-sensitive vision, while cones need bright light but perceive color.

How do pacemaker cells repolarize?

SA node controls opening and closing of Ca and Na channels

What does the P-wave represent? Which node is firing in order for the p-wave to occur?

SA node; atria contract

As you increase EDV, what happens to SV? What about a decrease in SV?

SV goes up when EDV goes up and vice versa

What happens to CO if you decrease ESV?

SV increases and CO increases.

What does the word saltatory mean? How does this relate to the propagation of an action potential?

Saltatory conduction jumps between nodes on a myelinated axon, which is faster.

Where are Schwann cells formed? Oligodendrocytes? (CNS or PNS)

Schwann cells from neural crest, PNS. Oligodendrocytes from progenitor cells, CNS.

Which of the of the two will be able to re-establish connection after injury: Schwann cells or Oligodendrocytes? Where are these located?

Schwann cells in the PNS remove fragments of nerves and induce repair.

Which "system" is a G-protein coupled receptor part of? Would the messenger activating the g-protein be extraceullular or intracellular?

Second messenger; extracellular, since GPCRs are on the surface of the cell.

Water-soluble are commonly called extracellular messengers because they do not enter the cell. In other words, you bind to a receptor enzyme lying within the membrane. In all, what is activated to induce a cellular response?

Second-messenger systems

In relation to normal force, what happens to necessary force generation if you shortened the length between the origin and insertion? What would happen if you increase the length between the two? -- Think of the classic lever system

Shorter length- more strength (breaking and shortening collarbones)

In relation to the pacemaker cells, which channels open in order to depolarize the membrane? Why do we have a peak before plateauing in a pacemaker cell? Which channels are now open/ closed?

Slow Ca influx; open Na channels

Why else may it be advantageous to have unmyelinated neurons?

Slower or shorter nerve fibers, such as pain fibers.

Do smaller motor units or larger motor units get recruited first?

Smaller

Which of the three can be excited without nervous input stimulation?

Smooth

Hormonal secretion involves the transport of hormones via the bloodstream to distant target cells. What must the target cell have on its membrane in order for an effect to occur?

Specific receptors

What is the mechanism of transduction after fluid stimulates the capula to move the receptor cells in the ampulla?

Stereocilia bend! Hair cells

Not all hormones are lipophilic, which ones are?

Steroid and thyroid hormones

Where are golgi tendon organs located? What do the golgi tendon organs detect? Which of the three motor control systems is the golgi tendon a part of?

Stretch and heaviness of load; afferent nerves in tendon

What reflex is the muscle spindle fiber incorporated?

Stretch reflex

With an increase in EDV, does the heart contract towards optimal length or stretch towards optimal length?

Stretches towards optimal length

Given the two factors: contractility and heart rate, what effect does the parasympathetic nervous system have on the two? How about sympathetic?

Sympathetic increases both, parasympathetic does the opposite

What is the main difference between the sympathetic and parasympathetic nervous systems?

Sympathetic is fight or flight, parasympathetic is rest and digest.

What effect would sympathetic stimulation have on HR and would CO increase or decrease? What effect would parasympathetic stimulation have on HR and would CO increase or decrease?

Sympathetic makes us have a higher HR and CO, while parasympathetic can decrease them.

Which wave on the electrocardiogram initiates ventricular diastole? Which valves are open and or closed during isovolumetric ventricular relaxation? Is there a change in ventricular volume during this phase? At which pressure difference will IVR end and Ventricular filling begin? During ventricular filling, is atrial or ventricular pressure higher?

T waves; all closed; no; when pressure in ventricle is lower than atrium

What is occurring in the electrocardiogram during IVR, Ventricular filling, IVC, and Ventricular ejection?

T, TPQ, RS, T

Which of the intervals are occurring during Ventricular diastole? Which interval starts ventricular diastole and which phase follows?

TPQ

Everyone had heard of the medulla oblongata. What are the functions of the medulla?

Talks between brain stem and brain; heart/ breathing

How many presynaptic inputs are involved in temporal summation? In spatial summation?

Temporal summation is a bunch of EPSPs going to ONE postsynaptic neuron. Spatial summation is a bunch of EPSPs from different places

Which filaments are present within an A band? Within an I band?

The A-band is the thick filaments sandwiched by the thin filaments; the i-band is the Z line

Considering that our membrane potential is now back to threshold. Which ion gated channel is now reset and ready to open again? Which ion gated channel is slow to close, causing our RMP to hyperpolarize below -70mV?

The K channel is slow to close, making the RMP hypopolarize, and the Na channel resets, opens, and repolarizes the membrane.

Which Channel opens after our inactivation gate closes? Which ions are now effluxing out of our membrane and which of the three polarizations is occuring?

The K channels open after the inactivation gate closes, allowing K to influx into the cell to hypopolarize it

Differentiate between the channels present during a cardiac pacemaker cell action potential and the action potential on say a typical neuron

The action potential spreads down and then back to activate both the atria and ventricles.

Describe chemical neurotransmission, listing in correct temporal sequence events beginning with the arrival of a wave of depolarization at the pre-synaptic membrane and ending with a graded potential generated at the post-synaptic membrane.

The action potential's wave of depolarization arrives at the synaptic knob, which contains vesicles full of neurotransmitters. Ca2+ enters the synaptic knob, and triggers the exocytosis of the neurotransmitters into the synaptic cleft. These neurotransmitters cross the cleft and bind to receptors on the post-synaptic membrane, which triggers the opening of ion channels to create a graded and then an action potential.

What is a terminal button and what is its function?

The end of the axon for the neuromuscular junction's synapse

What is the relationship between stroke volume and end diastolic volume?

The higher SV, the higher EDV.

What is the relationship between the absolute refractory period and the frequency of action potentials?

The longer the absolute refractory period, the less frequent the action potentials.

What is the difference between Resting Membrane Potential and Threshold? What happens when we reach threshold?

The resting membrane potential is -70mV, and threshold is +40mV. This is due to the concentrations of Na and K in the ICF and ECF.

Where is the slow wave sleep center located? Do we pass through here before entering the paradoxical sleep center?

The slow-wave sleep center is in the hypothalamus. The paradoxical sleep center is in the brain stem.

What is the main difference between the somatic and autonomic nervous systems? Are these afferent or efferent signals?

The somatic system consists of muscles and systems, while autonomic is the rest/digest or fight/flight systems.

What is sensory transduction? Describe the process of transduction for a special receptor ending in an afferent fiber and a receptor that is separate from the afferent fiber.

Transduction: the process that turns an efferent signal into an afferent signal

Intracellular communication is vital to maintain homeostasis. What is the difference between neurotransmitter secretion and neurohormone secretion? Consider target cell location and passage

Transmitters are between neurons and synapses, while hormones are secreted into organs and the blood to effect a larger target area.

What is the difference between the force development of a twitch versus tetanus?

Twitch is a single event, tetanus is rapid action potentials over a period of time to maximally contract

What is a twitch in relation to tetanus?

Twitch is single action potential, tetanus is summation of twitches to contract maximally

Between our utricle and saccule, which is associated with elevation? Which is associated with say acceleration or deceleration in a vehicle

Utricle: side to side; Saccule: up and down

What are the effects of venous return on EDV? What would happen to CO?

Venous return increases EDV, increases CO

What occurs during the ST segment? Between the atria and ventricle, which one is contracting?

Ventricles contract and empty

What occurs during the QRS complex? Between the ventricle and atria, which one is repolarizing?

Ventricles contract; atria repolarize

What occurs right before the TP segment? Between the atria and ventricle, which one is repolarizing?

Ventricles repolarize

Describe the pathway from when you see or hear words, and the intermediates, until you reach the primary motor cortex.

Visual and auditory stimulation > PTO and primary visual cortex > wernicke > broca > motor

Which lobe is associated with visual processing? Auditory? Sensory?

Visual: occipital. Auditory: parietal. Sensory: temporal.

What is the deal with voluntary and involuntary muscle? Which muscle types fall under these categories?

Voluntary is often skeletal, and we can move it. Involuntary is smooth muscle, and we cant move it

The frontal lobe sends out an efferent signal. What kind of activity is taking place? What ability does the efferent signal give?

Voluntary movement

Water-soluble substances and lipid-soluble substances can interact with receptors. Which of the two can only interact with receptors on the outside of the membrane? Which will enter the cell instead?`

Water-soluble substances can only interact with the outside of the cell membrane (faster), while lipid soluble substances diffuse through the lipid cell membrane and into the cell.

How do we compensate with fatigue? What is asynchronous recruitment?

We use the fine muscles for accuracy first, so if we fatigue, we're clumsy

Which type of muscle can you induce hypertrophy and which exercise can achieve this outcome?

Weight lifting; glycolytic

If you increase preload/ EDV, is the heart stretched more? What is the relationship between EDV and SV? Does SV increase or decrease and furthermore, what happens to CO?

When EDV increases, SV increases, and CO increases

Which frequencies are associated with the narrow, stiff end of the basilar membrane and the wide, flexible basilar membrane? Where are these ends in relation to the cochlea?

Wide and flexible (near cochlea): low pitches; narrow and stiff (near oval window): high pitches

What does the term isometric mean? What are some examples of an isometric movement?

Without changing length

What does the term isotonic mean and what are some examples of an isotonic movement?

Without changing tone

Do lipophilic hormones enter the cell? If so what do they bind to and what is the result?

Yes! They enter the cell to modify its function and bind to nuclear membrane receptors.

Does a presynaptic neuron release more than one type of NT?

Yes, as of recent evidence.

At which points are cardiac pacemaker cells in the refractory period? Do pacemaker cells have a relative refractory period?

Yes, when K is effluxing.

Would reducing the diastolic time have a drastic effect on ventricular filling/ preload/ EDV? Why or why not?

Yes-- heart needs time to fill and empty to physically move blood around

Is there a relationship between gravity and the otoliths? If so, how so?

Yes: orientation, telling what is up, moving the perilymph back to neutral

What does cholinergic mean and which neurotransmitter is cholinergic?

acetylcholine

Which neurotransmitter is present between the pre-ganglion and post-ganglion? (In other words, in the ganglion)

acetylcholine

In relation to neurotransmitter release what are the effects of the following: Stimulus strength, magnitude of receptor potential and frequency of action potentials?

all increase it

ESV

amount of blood in ventricles at end of contraction

EDV

amount of blood in ventricles before heart contracts

Vestibulo

balance, eyes

Why is the limbic system important? (three answers) How does the limbic system contribute to our daily lives?

emotion, behavior (motivation), memory formation

Afterload

force against which heart contracts to eject blood

Preload

initial stretching of heart in EDV

Describe the H zone at longer than optimal length (extended), is force generation optimal or less than optimal?

less

Describe the H zone at shorter than optimal length (flexed), is force generation optimal or less than optimal?

less

Do cardiac muscle cells need more or less oxygen when working out?

more

Does the motor end plate consist of more or less receptor channels than a typical synapse?

more

What type of transmitter is our chemical messenger?

neurotransmitter

Do all reflexes require conscious input?

no

Do our reflex pathways have to reach our brain before the resulting action?

no

Wernicke's area

plans content of spoken words.

The clinical signs of vestibular dysfunction is the inability to perform desired functions, which are?

poor balance, inability to focus eyes during movement, ringing in ears, loss of hearing, dizziness

Phasic

rapidly adapting, monitor outside of normal

Spino

skilled movement, correct error

Tonic

status quo monitoring, do not adapt or adapt slowly

An exception: Acetylcholine can be released at postganglionic terminals at sweat glands. Which system is in control of this release?

sympathetic

At a constant rate, will we receive stimulus? What must occur for a stimulus to ensue?

variation

Does a synapse in a neuromuscular junction release more neurotransmitters than a typical synapse?

yes