PSL 311L midterm

How many main categories of blood types are there?

Four

Be able to match sensory receptors with the sense that each is specialized for. also define adequate stimulation.

GTOs = proprioception (tendons) Hair cells = hearing Nociceptors = pain muscle spindles = proprioception (skeletal muscle) retinal cells like rods and cones - = sight olfactory receptors = smell thermoreceptors = temperature mechanoreceptors = touch Pacinian corpuscles = vibration (high frequency) Meissner's corpuscles = vibration (low frequency) Adequate stimulation= is a property of a sensory receptor that determines the type of energy to which a sensory receptor responds with the initiation of sensory transduction.

Explain any differences, issues, and benefits of using various measurement devices for taking body temperature? Which of our modalities gives a closer measure to the "core" temperature? Why?

Gold standard is the rectal thermometer, which gives an approximate value of 37.6 deg C. We used the digital, mercury, forehead strip, infrared thermometer. Some of the inaccurate ones gave reading more quickly. The oral digital thermometer gives the closest reading of central core temperature but still gives an underestimation of the value

Objects at usual room temperatures can feel as though they are at different temperatures when they are initially held in the hand. Why is this? 1 / 1

Heat is conducted from the hand at different rates depending on the nature of the object.

Your little brother doesn't want to go to school today. He tells your mother that he is feeling sick and has a fever. Just before your mother comes to measure his oral temperature, he has a hot drink. Will his temperature indicate a fever, and should he not go to school?

His temperature may initially indicate a fever but to get a more accurate reading you should do multiple temperature readings to find his true central core temperature. Since this fever is induced by a hot drink he would not be sick and should attend school

what are some physiological or pathological conditions that may influence the observed reflex response of say a patellar or achilles deep tendon reflex? how might these change the response? be able to describe the changes that and upper v. lower motor lesion may have on the reflex response.

Hot/cold, or excitability/ lesions/ altering reflux responses could be observed to influence the response. they could cause an increase or a decrease to the stimulation in the reflex. Upper motor neuron lesion: could cause increase in spasticity, muscle weakness without wasting, brisk tendon jerk reflexes and dorsiflexion with Babinski. - HYPERREACTION Lower motor neuron lesion: could cause muscle paralysis, fibrillations, fasciculation, hypotonia, hyporeflexia, no Babinski sign. - NO REACTION

What determinants influence how "cold" an object feels

How fast or slow heat is conducted away from a source (your palm) and towards the object. Faster rate = colder the object feels and Slower rate = warmer the object feels

During sustained skeletal muscle contraction, can you think of three places in which true fatigue might occur within or even outside the muscle fiber? (Be very specific). For example, what aspects of muscle contraction at the neuromuscular junction, muscle fiber, or even down to the sarcomere may be limited causing a reduction in performance? (CITE YOUR SOURCE)

One place is at the neuromuscular junction where ACh receptors are desensitized due to a depolarization block, leading to muscle fatigue. Another place is decreased blood flow which limits the amount of oxygen that can reach the cells. Finally, the production of lactic acid increases muscle acidity and prevents further contractions from occurring.

Which statement regarding body temperature is true? 1 / 1

Oral temperature is close to core body temperature.

What are some of the limitations of using an oral thermometer? (i.e. what are we really trying to measure and what variables may influence this final reading?)

Oral thermometers tend to give us a more accurate central core temperature. However there are many variables that can influence the temperature reading such s drinking hot/cold liquids prior to the reading. Another factor would be the amount of time it takes to receive and accurate reading, removing the thermometer early can lead to a underestimation of the core temperature of your patient.

Please indicate which of the following descriptions related to Prothrombin time (PT time) or Partial Prothrombin time (PTT time)

PT Time: -Measures speed of blood clotting via extrinsic pathway -Typically gives an INR value which will indicate a tendency for bleeding PTT Time: -Measures the speed of blood clotting via intrinsic pathway

Do the parasympathetic or sympathetic nerves mediate accommodation to a near object? (Do the parasympathetic or sympathetic nerves trigger pupil constriction?)

Parasympathetic nerves.

What is Iron Deficiency Anemia (ida) and how frequently does it occur?

Iron Deficiency Anemia is a condition were the blood lacks a good or normal amount of red blood cells. Hemoglobin is the part of the red blood cell that can carry oxygen to body tissue because oxygen can bind to the Iron in hemoglobin. with less red blood cells present there is less iron to bind oxygen and you get iron deficient anemia. This type of anemia occurs often, it is very common effecting 50% pregnant women, 20% non pregnant women and 3% of men

Which of the following statements regarding acetylcholine at the neuromuscular junction is true?

It is broken down by acetylcholinesterase.

The botulinum toxin:

Produces muscle paralysis by inhibiting the release of acetylcholine from muscle endplates.

What is the process of action potential conduction along the axon called?

Propagation

What is proprioception? What receptors assist with this important sense

Proprioception is the perception or awareness of the position and movement of the body in space. Muscle spindles and GTOs assist with this important sense

What two laboratory measures are used to assess bleeding time in a clinical environment? Which typically assess the extrinsic vs intrinsic clotting pathways

Prothrombin time (PT): evaluates the extrinsic pathway of clotting - activation of tissue thromboplastin - measures rates of clotting factors VII, X and V, prothrombin and fibrinogen; partial prothrombin time (PPT): evaluates the intrinsic pathway - activation of cascade of clotting factors - measures rates of clotting factors XII, CI, IC, VIII, X, V, prothrombin and fibrinogen

Achilles reflex arc

Stretch caused by hit - muscle spindles - afferent (sensory) nerve - spinal cord - efferent (motor) nerve - gastrocnemius and soleus cause dorsiflexion of ankle

Patellar reflex arc

Stretch caused by hit - muscle spindles - afferent nerve (sensory) - spinal cord - efferent nerve (motor) - quadriceps cause knee extension

Explain how wet and wind can effect affect core and surface temperature

Surface and skin temp = the combination of water and air movement will result in evaporative water loss, which results in heat loss and will cause the surface temperature/central core temperature to decrease

Categorize the symptoms below into whether they are symptoms indicating autonomic dysfunction, associated with peripheral neurophathy.

Symptoms of autonomic dysfunction: -Abnormal blood pressure -Abnormal heart rate -Sexual dysfunction Not symptoms of autonomic dysfunction: -Increased sweating -Loss of balance -Muscle spasms

Which statement is not true from the beginning of the action potential?

It is impossible to stimulate the neuron again until the membrane potential returns to normal.

Compare a hot, dry climate with a hot, humid climate at the same temperature. In the humid climate, how effective is sweating at cooling the body?

It is less effective in cooling the body as it evaporates more slowly from the skin

In a nerve cell, which statement is not true regarding the Na-K-ATPase ("sodium pump")?

It is only active when removing the large quantities of sodium that enter the cell during an action potential.

Which describes the phenomenon of "coactivation"?

It is the weaker contraction of the antagonist muscle during the contraction of the agonist muscle.

You are in a room where the temperature is 10°C (50°F). You pick up two balls of the same size; one ball is made of steel and the other is made of wood. Why does one of the balls feel colder than the other?

It removes heat from your hand faster.

In skeletal muscle, ATP is not generated through:

Lactic acid metabolism

Pupillary light reflex arc

Light - photoreceptors - optic nerve - edinger westphal nucleus - oculomotor nerve - pupillary sphincter muscles - constricts pupil

Which of the choices below will always result in a net gain of heat by the body?

Metabolism

Coactivation is the phenomenon whereby the contraction of a muscle leads to what change?

More minor activity in the antagonist muscle.

Be able to describe the steps in the physiological process from nerve impulse to muscle contraction/relaxation.

Motor endplate conditions: 1. signal from motor neuron arrives at terminal. 2. Ca moves into endplate. 3. Ach is released into NMJ and binds to Ach receptors. 4. opened cation-selective channels allow for an influx of Na 5. Release of Ca from sarcoplasmic reticulum and initiates AP in the muscle fiber. 6. Muscle contraction

How would you define muscle fatigue. what strategies can be implemented to reduce fatigue of a muscle.

Muscle fatigue is the decline in ability of a muscle to generate force. Fatigue may be due to over work, poor sleep, wory, boredom or lack of exercise.Causes:Neural fatigue- limitations of a nerve's ability to generate a sustained signalMetabolic fatigue-reduced ability of the muscle fiber to contract. Accumulation of lactic acid results in fatigue.Lack of iron, magnesium, potassium, Vitamin B12 and folic acid contributes to muscle fatigue.Strategies to reduce muscle fatigue:-With sufficient exercise onset of muscle fatigue can be delayed- creatine,beta alanine, whey protein , glutamine can improve muscle functionOther ways:- stretch your muscles- ice and heat fatigued muscles- eat a recovery meal within 1 hour of exercise like legumes- replenish your body fluids during and after exercise that contain electrolytes- rest your muscles and a good night sleep is must

Which of the following is NOT considered a touch receptor?

Muscle spindles

Describe muscle spindles (size, location, response to stimulus)

Muscle spindles are stretch receptors that sense change in the length of the muscle body. Are wrapped around the intrafusal muscle fibers of the muscle body. They are small with an elongated shape

Categorize the labels by whether they apply to a motor endplate disease, myopathy, or a neurological disorder.

Myopathy: -Affects the muscle itself. -Includes Duchenne muscular dystrophy. Neurological disorder: -Affects the nerves. -Can result from damage to the myelin sheath. -Includes amyotrophic lateral sclerosis (ALS). Motor endplate disease: -Also known as NMJ disease. -Includes myasthenia gravis. -Includes botulism.

How might you calculate nerve conduction velocity

Nerve conduction velocity can be calculated as distance traveled (from elbow to wrist) divided by difference in latency at the two areas

Please place the following lipid panel values into the Typically Normal and Typically Abnormal categories.

Normal: -Triglycerides < 150 mg/dl -LDL less than 100 mg/dl Abnormal: -Glucose > 130 mg/dl fasted -Total Cholesterol > 240 mg/dl -HDL less than 40 mg /dl (female)

Which is true regarding the electrical potential called an evoked potential?

Occurs in response to a stimulus.

Be able to describe the physiological events that occur between the delivery of stimulus and recorded EMG response

Once the AP reaches the NMJ, a series of events will cause the release of a major neurotransmitter (namely ACh) into the synapse. This (Ach) will diffuse across the synapse (cleft) and bind to receptors on the muscle namely AChreceptors of the nicotinic type. These receptors will open ion channels which are cation selective (meaning positively charged ion channels for Na+ and K+). This allows an increase in the flux of these ions across the muscle fiber membrane, depolarizing the muscle end plate. The newly formed muscle AP will then initiate the release of calcium from the sarcoplasmic reticulum, and set off a series of events resulting in muscle contraction. In order to end this continued chemical communication between the motor nerve and the muscle fiber, the enzyme ACh esterase (Ache) will terminate the binding of Ach on the motor endplate. This will end excitation of the muscle fiber, enabling it to go back to resting state

What can you say about "simple" reflexes, given your results from the Jendrassik maneuver? In other words, how can reflexes be influenced by the higher level nervous system even though we say a reflex, is a spinal cord regulated response to a stimulus. How does the Jendrassik maneuver change this observed response (if at all)?

The latency period will be basically the same for simple reflexes, the time it takes to occur will not be changed by the Jendrassik maneuver. The amplitude/strength of the reflex changes and the Jendrassik maneuver makes the amplitude larger for simple relfexes, as seen by the data above. The Jendrassik maneuver serves as a distraction while testing the reflex so it increases the reflex. Knee Jerk reflex - Conduction Velocity

In everyday life, the classic stretch reflex assists with what?

The maintenance of an upright posture.

Which statement about sensory systems is false?

The more intense a stimulus, the greater the magnitude of each action potential fired by a sensory neuron.

Be able to describe the technique for attempting a Babinski reflex.What are the typical normal and abnormal observations in an adult?

Using a reflex hammer with the blunt end moderately stroke the lateral sole of the foot starting from the heel moving towards the toes and then across the base of the toes and observe the big toe response. Normal = plantarflexion, abnormal = dorsiflexion, can indicate damage to the central nervous system if get this result aka upper motor neuron lesion

What are the main structures involved with one's sense of balance and rotation? When a person's head is spinning, how you would explain the physiology of rotation?

Vestibular system can be found in the inner ear and its main structures are the semicircular canals and the cochlea. Rotation causes movement of the endolymph in the semicircular canals. Once you stop rotating, the endolymph is still spinning by its rotational momentum and pushes the cupula to spin in the direction you were spinning. This gives you the sensation of rapidly spinning in the opposite direction

You and a friend are waiting at a bus stop in strong winds. On the way to the bus stop your friend tripped and fell into a large puddle, and is now soaking wet. Which of you should be concerned about hypothermia and why?

Your friend because they are now wet and sitting in the wind. This is because on our readings wind and water was the coldest conditions therefore your friend would be losing heat due to heat removal from their body by the water and wind. (evaporative water loss used here)

Heat is _________________, while temperature is _________________.

a form of energy; a quantitative measurement

To test a 63-year-old man for possible nerve damage, his nerve conduction velocity was measured. Can you explain how this is done? (i.e. What is a typical setup for how nerve conduction velocity is measured?

a small electrical current is applied over his median nerves, and the contraction of a muscle measured. then the small electrical current can be applied more proximally over the same motor nerve. the distance between 2 separate stimulation sites is measured, and giving nerve conduction velocity in distance (m) per unit time (s). it is conventional to express the conduction velocity in m/s.

What are some benefits of interprofessionalism?

a. Improve education between professions.b. Improve patient outcomes.c. Decrease probability of "turf wars".

Be able to define terms such as Ethics, preconceived notions, collaboration, interprofessionalism.

a. Preconceived notion: A thought or a feeling gathered without appropriate evidence.b. Ethics: Provides professional control of behavior of medical professionals and indicates a commitment to act with integrity in extreme situations.c. Interprofessional collaboration: occurs when two or more professionals learn with, from, and about each other to improve collaboration and the quality of care.d. Interprofessionalism: Interprofessional is defined as a group of individuals from different disciplines working and communicating with each other individuals. In the interprofessional learning environment each member provides his/her knowledge, skills, and attitudes to augment and support the contributions of others

Please explain the "all or nothing" phenomena as it relates to generation of action potentials

action potentials are generated when a stimulus causes a graded potential that reas=ches threshold potential. once this threshold is achieved, a positive feedback cycle is started which then initiates the action potential. therefore, once threshold is received, the neuron will fire fully causing the action potential to propagate down the axon towards the effector.

mononeuropathy

affects only a single nerve

The rate of conduction of an action potential along a nerve fiber is affected by a range of things. Which of the following do you think affects the rate of conduction?

affects the rate of condition: drugs, myelin sheath, nerve diameter, temperature doesn't effect rate of conduction: nerve length

A spinal cord injury patient presents with upper motor neuron lesion signs of spastic paralysis in the upper limbs, but no signs of dysfunction in the lower limbs. Where has the injury occurred?

between T3-L3

What is meant by "binocular vision"? What benefit does having binocular vision provide us?

binocular vision means that you have 2 eyes with overlapping visual fields. this allows depth perception (stereo vision)

A stroke patient presents with vertigo, trouble breathing and difficulty swallowing. Where do you think the lesion has occurred?

brainstem

Taste and smell receptors are examples of

chemoreceptors

What are the possible ways the human body can lose heat to the environment? Explain how each of these effect heat loss

conduction: by direct contact between neighboring molecules flowing from warm area to cold convection: fluid flows over a surface, also occurs by the lungs breathing radiation: emission as rays or particles, ,emit heat as electromagnetic radiation in the infrared portion. of the spectrum (evaporation: small amount let off with the water removal)

symptoms of both hyperthermia and hypothermia

confusion, irritability, lack of coordination, nausea

Given a room temperature of 21°C (70°F), which of the following objects will feel coldest when you pick it up?

copper

An electrode is inserted into a chemosensory nerve fiber leading away from a taste bud in the mouth of a dog. A mild acid solution is then flushed continuously over the taste buds associated with this nerve. Initially the nerve responds to this stimulation but over time ceases to carry action potentials. This observation would best be explained by which of the following?

daptation of the sensory cells.

describe the role of hemoglobin as an oxygen carrier. how many O2 molecules are able to be carrier per hemoglobin? what is the normal range for hemoglobin in males/females? How is hemoglobin used to diagnose anemia?

each part of the 4 piece hemoglobin has an iron attached to the center that can bind to oxygen and carry it to the rest of the body. hemoglobin can cary 4 O2 molecules. normal range for men in 13.5-17.5g/dl and for women it is 12-15.5g/dl hemoglobin is an iron rich protein in the blood and if your hemoglobin levels are low it will indicate a lower than normal amount of iron in the blood which is anemia.

symptoms of hyperthermia

elevated HR, muscle cramps, rapid breathing, flushing of the skin

When the ambient temperature exceeds body temperature, heat can only be lost from the body by which of the following?

evaporation

Describe some confounding issues when taking oral temperature

exercising, drinking hot or cold liquids.

A patient has an upper motor neuron lesion due to having a stroke which has affected his left cerebral cortex. Which of the following symptoms may he exhibit and which is he unlikely to exhibit?

exhibit: -Paralysis of facial muscles on the right side. -Paralysis of arm muscles on the right side. unlikely to exhibit: -Paralysis of arm muscles on the left side. -Paralysis of facial muscles on the left side.

What do the terms hyperopia, presbyopia, and myopia mean?

hyperopia is far sighted meaning they are able to see things at a far distance but struggle with things up close presbyopia is also far sightedness that is caused by old age and the loss of elasticity in the lens myopia is near sightedness meaning that the person can see things clearly/sharply up close but not see well at a distance. Some people can see well at a distance but are unable to bring nearer objects into focus. This condition can be caused by hyperopia (farsightedness) or presbyopia (loss of focusing ability). Others can see items that are close but cannot see those far away. This condition may be caused by myopia (nearsightedness). (American Optometric Association). OK Check Answer Visual information - Activity

When someone is nearsighted, a far out object is focused?

in front of the retina

While recording the responses of a mechanoreceptor to stimulation of the skin, an investigator observes an increase in the number of action potentials. This increase usually signifies?

increased intensity of a stimulus

what does it mean to have a high PT-INR value? how might a high or low value predispose a patient to certain pathology?

it means that your blood clots more slowly than desired. High=serious liver damage or cirrhosis Low= at risk for dangerous blood clots (in heart)

What is the Babinski sign? In general, where does it indicate damage?

it's a test used to see if there are any upper motor neuron lesions and can indicate damage to the corticospinal tract.

When the ciliary muscles in the eye contract the

lens thickens (gets rounder or more convex)

What did you observe when you mechanically stimulated your retina? What is this phenomena called?

mechanical stimulation of the eye causes random firing of cells in the retina producing visual effects similar to light stimulating the retina. this is a type of ectopic phenomenon which is known as phosphene

what are the 4 components in sensory coding?

modality, time, intensity, and location.

Hyperpolarizing receptor potential makes the membrane potential ______ (more or less) negative and ______ (increases or decreases) the likelihood of action potentials occurring.

more; decreases

Those suffering from motor neuron disease experience dysfunction in which areas?

motor

A 37-year-old man has been admitted to the emergency room after a vehicle collision. The CT scan shows damage to the spinal column at the level of T8. Would you expect this man to have damage to the phrenic nerve resulting in breathing difficulties?

no

In which type of receptor, phasic or tonic, does the receptor potential fall below threshold, even as the stimulus continues?

phasic receptors

Drag and drop the statements below into the correct order for the pathway in a flexion withdrawal reflex arc.

receptor>sensory neuron>interneuron>motor neuron>muscle

What is the difference between observing a phosphene vs. an optical illusion? (i.e. which one occurs in the peripheral nervous system vs. the central nervous system?

the phosphene would be the central nervous system in the occipital lobe of the Brain and the optical illusion would be in the peripheral nerves of the eye.

Indirect response of the consensual pupillary reflex

the pupil of the other eye also constricts

What was the response of the pupil in the opposite eye? What is this called?

the response in the opposite eye is the same as what happens in the eye that is being looked at. it is called the Consensual Light reflex. if one eye has light shining in it and it contracts, the other eye will also contract

The action potential causes the release of calcium ions from ________________ in the muscle cell.

the sarcoplasmic reticulum

Was it easy to tell direction when: a) the chair had just started spinning, b) had been spinning for some time, and c) had stopped spinning? Explain your observations for these three scenarios how the physiology of the semicircular canals allows you to determine sensation of spinning vs stopping.

the sensation of rotating can be best felt when first starting and when rotating ends, in the middle of rotating it is harder to sense it. This can be observed by the semicircular canals because as the head moves with the body in rotation the fluid in the canals known as endolymph begins to move in response, this leads the cupula to get dragged in the direction of the fluids movement which causes the hair cells to move too. At first the hair cells will move in opposition of the rotation letting the person know they are rotating in that direction, then during the rotation the hair cells will catch up with the endolymph and remain even as if you were not spinning. Finally once the spinning stops the fluid will keep going and push the hair cells in the same direction as the spin allowing the individual to be aware of the direction they were just spinning.

Suggest why, for very small axon diameters, there is little benefit of myelination for conduction velocity? Please give one suggestion in your answer as to why larger diameter fibers can conduct action potentials faster? Why is bigger, better?

there is generally little ebenefit from continued myelination with regards to conduction velocity in smaller diameter fibers has after a point, the myelination can not speed up the rate of conduction. any further myelination is of no consequence. large diameter fibers offer less resistance to electrical conductive flow.

The direct light response is when the iris constricts to reduce the pupil aperture and the amount of light entering the eye.

true

The somatic nervous system is also known as the voluntary nervous system.

true

Categorize the following statements regarding evoked potentials.

true: -All muscle fibers contract simultaneously. -The EMG records the skeletal muscle action potentials. False: The strength of contraction is independent of the strength of the stimulus.

Which of these statements are true about nerve conduction velocity?

true: -Can be as high as 60 m/s. -Can be measured separately for motor and sensory nerves. -Is decreased by cold. -The range of normal conduction velocities in motor nerves will be approximately 100-120 meters per second. false: -Sensory nerve conduction velocities (SNAP) are too fast too be recorded. -Sensory nerve potentials are much larger than evoked potentials.

Which statements are true regarding conduction of an action potential along a nerve axon?

true: -It is an "all or none"phenomenon. -It is blocked by drugs that inhibit voltage-gated sodium channels in the nerve membrane. -It is decreased by cold. false: -It is faster the smaller the diameter of the fiber. -It is slowed by wrapping the fiber with layers of Schwann cell membrane.

Which of the following statements regarding the stretch reflex are true and which are false?

true: -It is involved in maintaining normal posture. -It results in contraction of fibers in the muscle that was initially stretched. -It uses muscle spindles to detect changes in the degree of muscle stretch. false: -It is seen only in the quadriceps muscles. -It involves neurons in the cerebral motor cortex. -It is multisynaptic.

Categorize the following statements about the recording above.

true: -The lower two tracings show the raw, unprocessed signal. -The upper RMS tracings provide a better illustration of the extent of muscle activity. False: -The recording of the biceps muscle activity demonstrates coactivation.

Which statements are true regarding compound nerve action potentials?

true: -change the shape as stimulus strength is altered -reflect the contributions of many nerve axons -are extracellular recordings false: -are recorded as the difference in potential between 2 electrodes -are displayed as a positive voltage when a wave of depolarization crosses the first recording electrode

Which of the following statements regarding convection are true, and which are false?

true: -heat cannot be lost from a colder body to a hotter body by convection -convection requires direct contact between a body and the surrounding fluid false: -the rate at which heat is transferred from a body to the environment is not influenced by the movement of the fluid over the surface of the body

Which statements are true and which are false?

true: -somatic nervous system is both sensory and motor -nerves carrying information traveling from the periphery to the spinal cord have their cell bodies in the dorsal ganglia false: -the automatic nervous system is part of the somatic nervosa system -there are 2 dividsions of the PNS, sensory and motor -nerves carrying information to skeletal muscles have their cell bodies in the dorsal ganglia

Which of the following statements regarding conduction are true, and which are false?

true: -the types of material that the bodies consists of affect the rate at which heat is transferred from one body to another -heat cannot be lost from a colder body to a hotter body by conduction - conduction requires direct contact between 2 bodies

Which of the following statements regarding radiation are true, and which are false?

true: all bodies both emit and receive radiant energy falce: - radiant heat cannot pass through a vaccum - radiation requires direct contact between a body and the surrounding fluids

Which of the following statements regarding evaporation are true, and which are false?

true: when the environmental temperature is higher Thant the body temperature, evaporation is the only way in which we can lose heat to the environment. False: -evaporation requires direct contact between a body and the surrounding fluid -the rate at which heat is lost by evaporation from a body to the environment is not influenced by the rate of movement of the air over the surface of the body

Which of the following statements regarding cold climates are true?

true: -loss of heat by convection is minimized by covering the body as completely as possible -sweating is reduced or absent -shivering assists metabolic heat production false: vasodilation of blood vessels beneath the skin moves blood away from the surface so that heat is conserved by the body

Where was your tactile discrimination best? What can you say about the density of tactile receptors on your arm vs. fingertips and how does this relate to tactile acuity?

typically, tactile discrimination is the best on the fingertips, the area that have the best tactile discrimination have the highest density of receptors and therefore the highest tactile acuity.

mononeuritis

usually begins in the limb extremities

In the knee-jerk reflex arc, the synapse between a sensory neuron and a motor neuron is found where?

within the spinal cord

can a person have high hematocrit but have a low hemoglobin? describe how this can be true.

yes, high hematocrit is more RBC's than normal but having a low hematocrit would be the lack of a crucial blood protein that carries O2 to the body.

In an infant of 4 months, or an individual who has suffered a stroke, in what direction would you expect the toe to move after this stimulus? What does this indicate?

you would expect them to show the babinski sign and the big toe would dorsi flex and the smaller toes fan outwards which would indicate upper motor neuron damage and possible tissue death (in a stroke patient) of the affected areas. Because of the tissue death, it inhibits the reflexes ability to synapse properly and there would be no muscle contraction

The two functional divisions of the PNS are:

Afferent and efferent

Select the best answer regarding the plantar reflex.

All of the above are true.: After infancy, a Babinski sign indicates some upper motor neuron damage. It requires full myelination of the corticospinal tracts. The Babinski sign is normally seen in an infant under 1-2 years of age. The plantar reflex indicates cerebral inhibition of the Babinski sign. When the sole of the foot is stroked and the big toe dorsiflexes, this is called the Babinski sign.

Give two differences between an evoked action potential and a single nerve impulse

An evoked AP is a depolarization of a nerve as a result of deliberate stimulation while a single nerve impulse is the movement of the AP along the nerve. 2. A nerve impulse does not look as prominent on a monitor whereas the evoked AP is a central feature of such a monitor picture

In a surface EMG, what does increasing strength of contraction demonstrate?

An increase in the number of motor units recruited.

why are muscles arranged in antagonistic pairs? be able to explain the concept of reciprocal inhibition.

Antagonistic pairs of muscles create movement when one (the prime mover) contracts and the other (the antagonist) relaxes. Reciprocal inhibition describes the process of muscles on one side of a joint relaxing to accommodate contraction on the other side of that joint. Joints are controlled by two opposing sets of muscles, extensors and flexors, which must work in synchrony for smooth movement.

In surface EMG:

At any time, the signal provides information about the relative number of motor units that are active at that time

Please match the appropriate fact with the corresponding blood type.

B blood type -Has B antigens -Has A antibodies O blood type -Has no antigens -Universal Donor -Highest prevalence in -US population -Contains both Antibodies A and B AB blood type -Universal Recipient -Lowest prevalence in US population

upper motor neuron lesion

Babinski sign Clasp-knife rigidity Hyper-reflexia Muscle weakness without wasting Spasticity

Be able to discern the various layerings in a microhematocrit tube after it has been centrifuged and identify how hematocrit is then determined

Bottom to top: clay stopper, RBCs, WBCs (buffy layer), plasma and air. Hematocrit can be determined by lining up and sliding the tube until the top of the RBC matches the column on the table

What is the most effective way to lose heat from the body?

By sweating plus convection

Sensory nerve classification responsible for detecting general pain, touch and pressure.

C fibers

In what ways can ATP be generated in skeletal muscle?

Can be generated by: -anaerobic glycolysis -aerobic glycolysis -breakdown of phosphocreatine Cant be generated by: lactate metabolism

Motor neurons:

Carry signals from the spinal cord to the muscles to produce movement.

describe the significance of motor units with respect increasing force output of a muscle.

A motor neuron and the skeletal muscle fibers supplied by that motor neuron's axon terminal constitutes a MOTOR UNIT.Group of motor units work together to co-ordinate the contractions of a single muscle. All the motor units within a muscle constitutes a MOTOR POOL.When a motor unit is activated, all of its fibres contract. The force of muscle contraction is controlled by the number of activated motor units. The number of muscle fibers in each unit car within a particular muscle like biceps brachii and also vary from muscle to muscle. The musclesame that act on the large body masses have motor units with more muscle fibers. However smaller muscles contain fewer muscle fibers in each unit. For example, gluteus maximus have thousand fibres in each unit while extraocular muscles have only ten. More the motor units more finely force output is controlled

Leaning on your elbow and your hand falls asleep could be an example of which of the following ?

A permanent polyneurapathy

Be able to explain the results of an ABO blood typing test. Which blood types contain which types of antibodies and antigens? what are implications of transfusing incorrect blood type?

ABO typing can figure out a person's blood type according to the ABO blood group. When blood is mized with a certain serum and agglutination occurs, this indicates the antibodies that have bound to the appropriate antigens (Type A blood have A antigens and B antibodies Type B blood have B antigens and A antibodies Type AB blood have A and B antigens and no antibodies Type O blood have no antigens and A and B antibodies) blood can lead to life threatening conditions as blood will react and cause agglutination in some cases which can result in fever, chills, shaking and aching

Be able to calculate a nerve conduction velocity if relevant information is provided

Distance traveled / difference in latencies of the two areas = nerve conduction velocity

What are some strategies that may enhance or improve one's reflex response of the patellar tendon? How might these be helpful when assessing a patient

Distraction can be used in the way of the Jendrassik maneuver. The method acts as a distraction for higher level brain structures, not "overthinking it". Also because this maneuver activates stretch receptors everywhere. The receptors are basically like rubber band that has been stretched and is now just waiting for something to happen - increase anticipatory actions = increase response time and magnitude

A child has recently been diagnosed with Duchenne muscular dystrophy, an X-linked, recessive condition. The parents are receiving genetic counseling prior to planning another pregnancy. Which of the following statements includes the most accurate information?

Duchenne muscular dystrophy is an X-linked recessive disorder, so daughters have a 50% chance of being carriers and sons a 50% chance of developing the disease

Explain the specific process for a typical nerve conduction velocity test.

During the test, your nerve is stimulated, usually with surface electrode patches attached to your skin. Two electrodes are placed on the skin over your nerve. One electrode stimulates your nerve with a very mild electrical impulse and the other electrode records it.

What does EMG record?

Electrical activity of the innervated muscle fibers

Unlike the discrete waveform from an ECG, the electromyogram waveform is irregular. Why is this? Explain the difference in the pattern of how the motor units depolarize in skeletal muscle vs. cardiac muscle....

Electromyogram waveform is irregular because it measures the unsynchronized electrical activity of the skeletal muscle motor units. Skeletal muscle motor units depolarize asynchronously whereas cardiac muscle motor units depolarize synchronously. The synchronous firing rate of cardiac muscle motor units shows a discrete waveform from an ECG.

Be able to define/explain what Evidence Based decision making means. How is it applied to healthcare/scientific decisions?

Evidence Based Decision-Making is a process for making decisions about a program, practice, or policy that is grounded in the best available research evidence and informed by experiential evidence from the field and relevant contextual evidence

lower motor neuron lesion

Fasciculation Fibrillation Hyporeflexia Hypotonia No Babinski sign Muscle wasting

For the above simulation at 1ms stimulus duration, what is the minimum stimulus strength needed to produce an action potential?

20 nA

What does 20/20 vision mean?

20/20 vision means normal visual acuity. a person with 20/20 vision can read something 100 feet away that someone with 20/100 vision can read at 20 feet away.

How much more oxygen is blood able to carry with hemoglobin than without?

40-50x more

Approximately, what is the conduction velocity of motor nerves?

50m/s

describe the major mechanistic differences between agglutination and coagulation? while they both can have a similar end result, how does the mechanism differ?

-Agglutination is a binding reaction whereby antibodies in the blood plasma of one individual, will recognize and eliminate the antigen group of particular foreign type cell. These foreign type cells will have a different surface antigen than is typically recognized in the organism thus causing the blood cells to form large clumps. These clumps will then block and damage small capillaries particularly in the kidneys. -coagulation involves activation and adhesion of platelets, as well as disposition and maturation of fibrin (main difference is agglutination refers to small particles coming together and coagulation refers to formation of a clump.)

Which of the following factors have been suggested as contributing to muscle fatigue?

-Loss of "central drive". -Reduction in calcium release in excitation-contraction coupling. -Reduction in muscle blood flow owing to compression of blood vessels.

Use only the correct statements to order the events of a nerve action potential:

-membrane permeability to NA+ ions increases initially - this increases the Na+ permeability is associated with membrane depolarization -later, the membrane permeability to K+ ions increases -at this time membrane permeability to Na+ ions returns to normal -The action potential finishes when both the Na+ and K+ ion membrane permeabilities return to normal values.

how might you determine visual field loss in a patient who experiences an optic nerve, optic chasm, or optic tract lesion?

....

Each gram of Hb combines with ~1.34 mL O2 Therefore if a person had a clinical measure of Hgb at 15g/Hb/dl. Then: 15 g Hgb/dl x 1.34 mL O2/g Hg = 20 mL O2 This indicates their oxygen carrying content If someone had a Hgb level of 9 g Hgb/dl. What would their oxygen content be?

12.06 ml O2 per dl of blood

Which of the following statements regarding coactivation is false?

Coactivation is associated with a smaller EMG recording from the agonist muscle compared to that in the antagonist muscle

Which statement is not true in saltatory conduction?

Conduction velocity is slower than is seen in an unmyelinated fiber.

Which of the following occurs when you shine light into an eye of a healthy person?

Constriction of that pupil with constriction of the other pupil.

Which factors are thought to contribute to muscle fatigue?

Contribute to fatigue: -Accumulation of muscle metabolites -Changes in the "sense of effort" -Decrease in neuromuscular transmission -Decreased muscle blood flow -Depletion of muscle energy reserves -Loss of central drive -Reduced release of calcium from sarcoplasmic reticulum Dont contribute to fatigue: -Prolonged muscle membrane depolarization

What is the significance of convergence of gaze? What is meant by binocular vision and what is its usefulness

Convergence of gaze is the coordinated movement and focus of our two eyes inward. It allows beings with two eyes to view things that are close up. Binocular vision is when using two eyes with overlapping fields of view which allows for good depth perception or stereo vision

What variables/nerve characteristics would change nerve conduction velocity

If the nerve is myelinated or not (if yes then faster conduction velocity), larger size = faster conduction velocity, shorter distance traveled = faster conductive velocity

If someone has a transfusion reaction, it can be considered immunological or nonimmunological. Please describe a typical immunological reaction which occurs from ABO incompatibility

In an ABO incompatibility the immune system attacks the new blood cells and destroys them. a clinical example is when the mother is blood type O and the baby is blood type A or B and the mothers immune system attacks the blood of the baby. The mothers immune system could react and make antibodies against the antigens on the baby's red blood cells. This is the process of agglutination, where by the mothers antibodies will recognize the antigen of the baby and eliminate the foreign cell type

Body temperatures for fever and hyperthermia often overlap (for example, > 38.8°C [100.9°F]). What makes these two temperature disturbances different?

In fever, the body's hypothalamic set point is reset.

Be able to describe the two primary mechanisms by which force production of a muscle can increase

Increasing the number of active motor units (recruitment) and stimulating motor units more frequently (shorter rest periods between stimulations)

Which receptor type, found in muscles, tendons, and ligaments, informs the central nervous system of the position of loads on parts of the body?

Stretch

Be able to describe in detail the signal transduction pathway for a typical sensory receptor. How is the stimulus received, transduced, and transmitted

Reception = the activation of sensory receptors by stimuli such as mechanical stimuli, chemicals or temperature. The receptor can then respond to the stimuli. Transduction occurs next in which the sensory signal is translated into an electrical signal in the nervous system which takes place in the sensory receptor. Stimuli causes a disturbance which opens gated ion channels in the sensory neuron, changing its electrical potential = depolarization of the neuron. A receptor potential (graded) is created and an AP is created. AP travels to the brain (integration center) via afferent neuron. The thalamus distinguishes sensory stimuli and decides which area of the brain to send the information to. That part of the brain decides what action needs to be taken and sends a nerve impulse down an efferent neuron to the effectors to perform whatever change.

be able to describe any receptors involved in muscle contraction / relaxation which includes voltage receptors, mechanical receptors, calcium receptors, and receptors for neurotransmitters (ligand receptors)

Receptors for ligands (muscle contractions): release of ACh into the motor end plate bind to ACh receptors on the muscle cell = the nicotinic acetylcholine receptors Calcium receptors (muscle contractions): once ACh is bound, open cation-selective ion channels = depolarizes the muscle end plate and leads to the release of calcium from the sarcoplasmic reticulum. mechanical receptors = those that are associated with the muscle spindles, that react to changes in muscle length Voltage gated channels (muscle contractions): Na+ and K+ channels that open and close with the onset and offset of an AP

Which one of the following statements about reflexes is true?

Reflexes require information to be detected by receptors.

How do you relieve tired and achy muscles after intense exercise?

Rest the muscles to allow blood flow to carry away the lactic acid, which needs to be broken down in the liver.

Under what conditions are rods and cones typically stimulated

Rods are active in low-light settings and can perceive shades of black but low spatial acuity. Cones are active in high light settings and can perceive color and have high spatial acuity

Vertebrates rely on information from which sensory structure to keep their balance?

Semicircular canal

How many muscle fibers may a single motor neuron innervate?

Several muscle fibers

Know the proper laboratory protocols for discarding waste with blood

Sharps: broken micropipette with blood or used lancets; biohazard: gazes with blood, alcohol swabs with blood, garbage: alcohol wipe packaging, plastic stopped of lancets

A patient who is brain dead may exhibit brief movement when their hand or foot is touched - why?

Spinal cord reflexes may still be able to occur.

Which is true regarding coactivation?

The antagonist muscle activity serves to control the rate of joint movement.

In a healthy adult, what happens when the sole of the foot is stroked?

The big toe flexes (curls downwards).

Which statement is not true in polyneuropathies?

The cell body of the neuron may remain functional but its axon is damaged.

The term gustation refers to which of the following?

The chemical sense of taste

Above is an EMG trace. What does an EMG record?

The electrical potential generated by skeletal muscle fiber activity.

How is acetylcholine removed from the synaptic cleft?

The enzyme acetylcholinesterase hydrolyzes the acetylcholine within the synaptic cleft.

How would you explain the physiological difference in two-point discrimination between the fingertips vs. the back of the forearm

The fingertips are very sensitive to two-point discrimination because of a higher density of tactile receptors on the fingertips than on the back of the forearm, for example. The smaller the distance you're able to tell, the higher the density of receptors

What are the advantages and disadvantages of digital vs. glass/mercury thermometers?

The glass thermometer was slower but gave us a more accurate central core temperature. A glass thermometer would give you a continuous measurement over time but this application is not practical there fore it is a disadvantage. However the digital thermometer was faster (instantaneous measurements) but gave us a less accurate reading.

What are the most common causes of ida?

The most common causes of ida include, menstruation, pregnancy, gastrointestinal blood loss, anti-inflammatory drugs, kidney disease, Mal absorption, and lack of iron in the diet.

In the pupillary reflex, what happens when light is focused on the eye?

The pupillary sphincter muscle in the iris of that eye constricts.

What receptors are primarily responsible for our proprioceptive sense?

The receptors primarily responsible for our proprioception sense are muscle spindles that inform the body of its surroundings based on an internal "spring" being stretched or compressed. This receptor allows you to detect your body position, balance, and cognition of the area you are in.

In a surface EMG, what is the recorded signal?

The skeletal muscle action potentials.

In an evoked EMG:

The stimulated muscle fibers all contract at the same time.

Name the anatomical structures involved in this ankle jerk reflex. (This should include the name of the tendon tapped, the distal attachment site (i.e. bone) of this tendon, the muscle group activated, the nerve which serves this muscle, which level of the spinal cord innervates this muscle, which muscle groups will eventually respond, and direction of response.

The tendon tapped is the achilles tendon while someone is dorsiflexing the patients ankle, it attaches to the calcaneus, and activates the gastrocnemius which allows the ankle to plantar flex. The nerve that serves the muscle is the tibial nerve is the one that serves the gastrocnemius and it is innervated by s1 and s2

The wood, paper towel, and aluminum foil are all at room temperature. From your results, explain why each of these appears to be a different temperature when you touch them

The three materials conduct heat differently at different rates, some of the materials like metal conduct heat away from the skin, and materials like paper conduct heat toward the skin. (need more detail)

The flexion withdraw reflex mediates what?

The withdrawal of a limb from a painful stimulus, such as a pinprick or the heat of a flame.

In a person with a motor endplate disease:

There are no sensory changes.

Which statement regarding evoked EMG is true?

There is synchronous excitation of the muscle fibers innervated by the stimulated nerve.

Which is true in an evoked EMG?

There is synchronous excitation of the muscles supplied by the stimulated nerve.

Which of the following regarding the use of drugs in hot climates to inhibit sweat production is true?

They may result in heat stroke.

How did your temperature rankings compare to the temperature probe recordings? Which combination of materials was the coldest, and why?

They were very accurate to our rankings compared with the probe readings. The water and wind was the coldest because of the evaporative water loss due to the wind.

Are these statements true or false in a peripheral nerve?

True: -As the stimulus strength is increased, the shape of the compound action potential remains the same. -As the strength of the stimulus increases, the nerve conduction velocity is unaffected. -Axons of different diameters exhibit different conduction velocities. false: -All fibers have the same threshold potential. -Large diameter axons are stimulated at lower voltages than smaller diameter axons.

Why is it important to clean the area with alcohol swabs and lightly abrade the skin prior to attaching EMG electrodes?

This reduces the electrical resistance of the skin.

Mr Smith, a 72-year-old man, has suffered a stroke that affects the left side of his body. Among the tests done is an assessment of his knee jerk reflex. How is this done (i.e. how is this performed procedurally)? What might you observe, using the same procedure, if the patient had an Upper Motor Neuron Lesion (lesion often means damage)? A Lower Motor Neuron Lesion?

To perform knee jerk test have the patient sit with legs hanging off the table, then lightly tap the patellar tendon located just below the knee cap and look to see if the knee extends (perform on his left leg to see if his left side was affected). In a lower motor neuron lesion, there could be a loss of the reflex but in an upper motor neuron lesion these effects could be exaggerated.

Why is it necessary to abrade and clean the skin before making a surface EMG recording?

To reduce the electrical resistance of the skin.

Sensory neurons:

Transmit sensory information to the central nervous system.

How is ida treated and prevented?

Treatment includes iron supplements, a change in diet to increase iron intake, or in worse case scenarios a blood transfusion may be necessary. for prevention an individual should maintain a diet with a healthy iron intake to keep ida at bay. Also for mothers of new born babies its advised they feed them breast milk or iron fortified formula to make sure the baby gets the right amount of iron in its system

Match the following labels as True or False regarding blood as a whole.

True: -Buffy coat layer consists of leukocytes and platelets -Hematocrit will typically increase with dehydration -Males typically have a higher Hgb content than females false: -Typical Hematocrit for males is 37-42% -The Oxygen carrying component of blood is erythropoeitin -The majority of blood consists of Red Blood Cells

Categorize the following statements regarding myasthenia gravis as true or false.

True: -Muscle fatigue develops during periods of muscle activity. -Thymus abnormalities are common. -Some 20% of the patients have antibodies to a protein involved in the formation of concentrated clusters of ACh receptors on the surface of the muscle cells. False: -There is an increased number of ACh receptors on the muscle cells at the NMJ. -There is increased activity of acetylcholinesterase. -Release of ACh from the motor nerve endplate is inhibited.

Why do we measure oral temperatures? Why don't we measure temperature anywhere on the body's surface? Where on the body (of each of the places measured) do you suppose would be less likely to reflect core body temperature?

We measure oral temperatures because it gives you a smaller temperature range within the central core temperature that you are trying to read. The temperature read is the average kinetic energy of the molecules within your mouth bouncing off the probe. The least likely part of the body to reflect the core body temperature would be your palm or elbow, more distal portions of the body. This is because it has a faster rate of change for temperature, like when you touch something hot or cold it takes on that temperature more quickly.

What happens to pupil diameter when the eye is focused for near vision? (In your answer, please indicate which division of the autonomic nervous system is responsible for this pupil diameter change). What is the advantage of this change in diameter?

When focusing on a near object the pupils becomes smaller, or constrict. It is not consciously controlled and would be part parasympathetic nervous system. The pupils contract to improve the focusing of the light on the fovea.

What occurs in the eye during accommodation of vision

When focusing to a far object, the ciliary muscles relax which increases tension in suspensory ligaments and stretches the lens to a thinner shape. When focusing on a close object, the ciliary muscles tighten which decreases the tension in suspensory ligaments and allows the lens to return to its usual rounded shape.

When do you think our body's metabolic rate would be at a minimum?

When the core temperature is within the thermoneutral zone

What is the response of the pupil when light is shone on it? What muscle is responsible for this response in the directly stimulated eye

When the light shines on the eye, the pupils constrict becoming smaller, when the light is taken away the pupils dilate and become larger. The pupils constrict to lessen the amount of light coming into the eye, and they dilate to let more light in. The pupillary sphincter muscles are the ones responsible for the contraction to occur

When is heat lost from the body by sweating? 1 / 1

When the sweat evaporates off the skin.

Almost all volunteers will show a declining force (pseudo-fatigue) while their eyes are shut that is very similar to actual fatigue. This is not true fatigue because the full 50% force can be exerted easily, as can be seen when the volunteer's eyes are opened again. What explanations can you think of for pseudo-fatigue?

Without the information on the actual force produced, the internal sensation of fatigue will be more present, leading to a decline in the force generated, this is Pseudo-fatigue, the idea that you are more tired than you really are.

List the physiological events that occur between delivery of a stimulus (action potential or electrical stimulus) through synaptic transmission (at the Neuromuscular junction) to initiation of a muscle contraction and a recorded response.

an action potential in the peripheral nerve is generated by the electrical stimulus. this action potential is conducted along the nerve axon and causes releases of Each into the synaptic cleft of the NMJ. the ACh diffuses through the junctional cleft and binds to the nicotinic ACH receptors on the motor end plate. the bound receptors open cation-selective ion channels, which depolarizes the muscle end plate. this sets up a muscle action potential that leads to the release of calcium from the sarcoplasmic reticulum. the increased cytosolic calcium sets in motion the biochemical events that underlie contraction. ACH is rapidly hydrolyzed by acetylcholine esterase that terminates the endplate potential.

The nasal part of the retina in the right eye, will be able to view which of the following visual fields?

temporal field on the right side

polyneuropathy

results from damage to several different nerves

Cutting which of the following, leads to total blindness in the right eye: optic chiasm, left optic tract, right optic tract, right optic nerve, left optic nerve?

right optic nerve

If the head is rotated to the right, which horizontal semicircular canal (right or left) is activated during the initial rotation? When the head stops rotating, which canal (right or left) is activated

right; left

The semicircular canals generally detect with of the following?

rotatory movements

does the tongue mapping theory truly exist? how do we explain the distribution of taste across the tongue regions?

sensitivity of taste receptors to different tastes may vary with region across the tongue. Although this observation has been refuted in literature, it does not exist it is a myth.

symptoms of hypothermia

shivering, skin feels cold to the touch, slowed breathing, HR and reflexes, drowsiness

In autonomic reflexes, which of the following are not activated?

skeletal muscle

This graph shows 4 different compound nerve action potentials. What do you think is causing the shape to change?

strength of stimulus

Describe your observations regarding the accommodation activity. How does the near point differ between people with normal vision and those who are nearsighted?

students who are nearsighted should have significantly shorter near point than those with normal vision.

what are the components of a SOAP note?

subjective- patient history (discussion of symptoms goes here), objective- physical exam and tests (tests and measurements goes here), assessment- asses the problem (2 diagnostic possibilities goes here), plan- how to solve the problem and a routine to do it (final diagnosis goes here)

Consider a hot climate, where the ambient temperature is greater than body temperature. What is the only way to lose heat?

sweating

The stretch reflex is a protective measure for the muscles, designed to prevent what?

tearing

What is the anatomical basis for the blind spot?

the blind spot is where the optic nerve exits the retina, there are no photoreceptors there.

Explain the existence of the blind spot in vision. I there an anatomical/ physiological reason for this?

the blind spot is where the optic nerve exits the retina, there are no photoreceptors there. (aka no rods or cones) it is an anatomical reason.

Look at the latency for the median nerve at the wrist and at the elbow. How do these latencies differ? Why do you suppose this is?

the distance traveled from the elbow to the adbuctor pollicis braves is greater than that from the wrist to the muscle. .the latency reflects the Tim eit takes for the nerve impulse to travel from the point of stimulation to the muscle and therefore is appreciably greater when writs and elbow latencies are compared.

When you change your focus from a near object to a far object, what occurs in the eye to allow you to focus on the object?

the muscle that control the curvature of the lens (ciliary muscles) relax, increasing the tension on the suspensory ligaments which stretches the lens to a thinner shape