Physio exam 3 labs and quizzes

When testing for SLE antibody, What chemical do you use to wash the wells?

0.1 ml of phosphate-buffered saline (PBS)

Indicate whether the following factors will INCREASE or DECREASE cardiac output (CO). 1. Increasing stroke volume 2. Increasing afterload 3. Sympathetic stimulation 4. Increasing contractility

1. Increasing stroke volume - Increases cardiac output 2. Increasing afterload - decreases cardiac output 3. Sympathetic stimulation - Increases cardiac output 4. Increasing contractility - Increases cardiac output

Describe the pathway of conduction from the atria to the ventricles and correlate this conduction with the ECG waves.

1. P-wave: SA node > AV node. This corresponds to atrial depolarization leading to atrial contraction. 2. QRS complex: AV node > AV bundle (of His) > Bundle branches > Purkinje fibers. This corresponds to ventricular depolarization leading to ventricular contraction. 3. T-wave: This corresponds to ventricular repolarization. (Atrial repolarization is not seen because it's masked by the QRS complex).

How does the heart compensate for aortic stenosis? 1. Preload (EDV) 2. Contractility 3. Afterload (resistance)

1. Preload (EDV) - Increase as the heart compensates for aortic stenosis 2. Contractility - Increase as the heart compensates for aortic stenosis 3. Afterload (resistance) - Decrease as the heart compensates for aortic stenosis

For how long do you incubate your ELISA plate?

15 minutes

If an artery is clogged by an atherosclerotic plaque, how does that affect radius? Therefore, how does this affect blood flow?

A clogged artery from an atherosclerotic plaque would reduce the radius of the vessel, resulting in more resistance to flow and reduced blood flow.

What effect does decreasing afterload have on cardiac output? Explain.

Afterload is the amount of pressure that the heart has to work against to pump/eject blood out of the ventricles. Decreasing afterload would lead to an increase in cardiac output. Decreasing the resistance or pressure that the left ventricle has to overcome, results in an increase in the stroke volume, and thus an increase in cardiac output.

In the Spirometry lab, What does the air flow tube simulate in the human body?

Air passageways such as the bronchi and bronchioles.

Which of the following could cause an increase in peripheral resistance in blood vessels? - Vasodilation - Atherosclerosis - decrease in flow rate - decrease in stroke volume

Atherosclerosis will cause an increase in peripheral resistance in blood vessels

Do fit people (e.g. athletes) tend to have fast or slow heart rates? Why?

Athletes tend to have a slower heart rate, which is known as athletes bradycardia. The reason for this is that athletes' hearts are stronger and are able to contract with more force, so they can maintain the same cardiac output at a lower heart rate.

What effect does aortic stenosis have on cardiac output? Explain.

Aortic stenosis is the narrowing of the aortic semilunar valve. It decreases cardiac output, which means less blood is ejected per beat (and per minute). This is due to the increase in total peripheral resistance and increase in afterload.

Describe the relationship between blood vessel length and blood flow. Explain.

Blood flow is inversely proportional to blood vessel length. Blood vessels of greater length contain more surface area which can interact with the formed elements, and these interactions create more resistance to flow.

When testing for SLE antibody, at what temperature do you incubate your ELISA plate? Why this temperature?

Because the antibody is produced in humans, and will only react with the antigen at body temperature, 37 celsius.

Systole occurs during the time between the ____.

Systole occurs during the time between the first and second heart sounds.

You measured a blood pressure of 100/90. Indicate the systolic and diastolic blood pressures.

Systolic blood pressure = 100 Diastolic blood pressure = 90

Intrapulmonary pressure _______________ as the diaphragm contracts.

Decreases

What effect does decreasing tube radius have on resistance and minute ventilation?

Decreasing tube radius increases resistance, decreases air flow, decreases minute ventilation

How would dehydration affect flow rate? Explain.

Dehydration would reduce flow rate by increasing the concentration of formed elements and proteins in the blood (increases plasma osmolality), which would make the blood more viscous.

Which ECG wave must occur before the ventricles can relax?

T-Wave (leads to repolarization of the ventricles)

How does exercise affect TV? Explain why the change occurs.

TV increases. The body will change its respiratory cycle to meet the increased metabolic demands. Specifically, the volume of normal breathing increases because when you exercise, your muscle cells require more oxygen and need to get rid of CO2.

Testing for SLE antibody, your ELISA plate has different wells. What chemical is coating the wells? Why?

The ELISA plate wells are coated with SLE antigens, which will stick to SLE antibody if the patient is positive for the disease.

Describe the Frank-Starling law of the heart

The Frank-Starling law of the heart states that the stroke volume is directly proportional to the preload; an increase in EDV results in an increase in Stroke volume. The EDV is the amount of blood in the ventricles directly before the ventricles begin to contract so it can be referred to as the preload. Stroke volume is also directly proportional to the contractility of the heart in that when the ventricles contract with more force, they pump more blood and thus increase the stroke volume.

What would happen to the MEA during exercise? Explain why.

The MEA would deviate more to the left (further than sitting up). It would increase because the heart pumps harder to deliver more oxygen to the body.

Why is hematocrit reduced in a person with aplastic anemia?

The bone marrow fails to produce adequate amounts of formed elements

With which ECG wave is the first heart sound correlated? Explain why.

The first heart sound is associated with the QRS complex. The closure of the atrioventricular valves, occurring right before systole to prevent back flow of blood from the ventricles to the atria, causes the first heart sound. Therefore, the first heart sound is heard at the beginning of systole. In terms of the electrical activity of the heart, systole is also preceded by depolarization of the ventricles, which is represented as the QRS complex. The first heart sound is heart slightly after the QRS complex is produced.

During which phase of the cardiac cycle (ventricular systole or diastole) does the first heart sound occur?

The first heart sound occurs at the beginning of ventricular systole. AV valves close causing the "lub" sound.

How does body position (lying down vs. upright) affect HR? Explain the reason.

The heart rate is slower while lying down, and increases when standing up. When you stand, gravity pulls blood towards the veins in the legs, causing a rapid decrease in blood pressure. To compensate, heart rate increases and the heart works harder to return blood to the heart (remember it has to pump against gravity). When lying down, there's no decrease in pressure (no effects of gravity). Blood is easily more able to return to the heart, and thus no increase in heart rate.

If your bone marrow is producing a high number of RBCs, what happens to hematocrit?

The hematocrit (percentage of RBCs in whole blood) would increase.

The individual with: ____: Characterized by chest pain caused by reduced blood flow to the heart due to blood vessel obstruction (i.e., atherosclerosis). Because RBCs are not damaged or affected, ESR does not change.

The individual with: Angina pectoris: Characterized by chest pain caused by reduced blood flow to the heart due to blood vessel obstruction (i.e., atherosclerosis). Because RBCs are not damaged or affected, ESR does not change.

What buffer do you add to the ELISA assay? Aside from diluting the sample, what is the purpose of that buffer?

Phosphate buffered Saline (PBS) to keep the solution from becoming too acidic or basic

What happened to the total minute ventilation right after exercise? What physiological mechanisms might account for this change?

The total minute ventilation (total minute volume) = Tidal volume (TV) x Respiratory rate (RR). It takes into account both the respiratory rate and depth of breathing. The total minute ventilation increases during and after exercise. Lactic acid released into the blood during exercise and the accumulation of CO2 decreases the pH of the blood. The decrease in pH is sensed by peripheral and central chemoreceptors, which then stimulates an increase in ventilation in order to breath out more CO2 until the blood pH increases back to the normal range.

How does the viscosity v. flow graph differ from the graphs for pressure and radius?

The viscosity flow graph shows an inverse relationship (negative slope), whereas the graphs for pressure and radius show a direct relationships (positive slopes).

How would polycythemia affect flow rate? Explain.

The viscosity of the blood is determined by the formed elements (e.g. RBCs, WBCs, and platelets) and plasma proteins, which tend to stick together when they come in contact. Polycythemia, referring to an increase in RBCs, increases the viscosity of the blood, which increases the resistance and reduces flow rate.

Positive control?

This will always produce a positive response if the reagents and conditions are correct.

True or False: Individuals with a decreased hematocrit would probably be anemic.

True

Sodium citrate is used as an anticoagulant. True or False

True, Sodium citrate is used as an anticoagulant.

What effect does tube radius have on air flow?

Tube radius is directly proportional the air flow. As the tube radius increases, air flow also increases due to a decrease in resistance.

What effect does tube radius have on resistance?

Tube radius is inversely proportional to resistance, whereby, a decrease in tube radius results in an increase in resistance.

In both the moderate and heavy exercisers, ERV and IRV decreased. Explain why.

VC = IRV + ERV + TV VC is constant because that is the maximum amount o fair that can be forcefully exhaled after maximum inhalation. Because TV increases with exercise, IRV and ERV decrease.

Which ECG wave must occur before the ventricles can contract?

QRS complex (depolarization of the ventricles)

Why is it only possible to induce an extrasystole during relaxation?

Extrasystole is only possible during relaxation because no new stimulation can take place during the absolute refractory period. Due to this wave summation tetanus can't be achieved and the extrasystole can't occur until relaxation.

Why are extrasystoles not observed during the contraction phase?

Extrasystoles are not observed during the contraction phase, due to the longer refractory period of the cardiac action potential. Sequential action potentials cannot induce another cardiac contraction during the refractory period.

When testing for SLE antibody, What animal is the source of the anti-human antibodies that you are adding to your wells?

Rabbit

Hydrostatic pressure is ________ and colloid osmotic pressure is ________ at the arterial end of a capillary.

Hydrostatic pressure is higher and colloid osmotic pressure is lower at the arterial end of a capillary.

Compare and contrast the following terms: hyperpnea and hyperventilation.

Hyperpnea: increase in total minute volume (TMV) during exercise. CO₂ values don't change because increased ventilation is matched to an increased metabolic rate. Hyperventilation: increase in ventilation resulting in a decrease in CO2 concentration below normal levels.

After you hyperventilate, what happens to respiratory rate and depth? Explain the physiology.

Hyperventilation causes respiratory alkalosis. After hyperventilation, respiratory rate decreases and you breathe more deeply to increase CO2 levels. As a result, pH will decrease back to normal.

After you hypoventilate, what happens to respiratory rate and depth? Explain the physiology.

Hypoventilation causes respiratory acidosis. After hypoventilation, respiratory rate increases to get rid of the excess CO2. This will in turn decrease H+ concentration and increase pH to bring it back to normal levels.

If someone is well hydrated, what happens to blood flow? How would this influence blood flow to organs such as the brain?

If a person is well hydrated, blood flow is increased because the increased water content in the blood reduces the concentration of formed elements and, thus, the viscosity of the blood. This would increase the blood flow to essential organs, such as the brain.

What effect does increasing stroke volume have on heart rate? Explain.

If cardiac output remains constant, increasing stroke volume would decrease heart rate (recall CO = HR x SV). Heart rate would decrease to allow more time for the ventricle to fill with blood. This results in a greater contraction and stroke volume due to the Frank Starling Law. In addition, with an increased stroke volume, fewer contractions are needed to transport blood through the systemic circulation.

Describe the different mechanisms that cause iron-deficiency versus aplastic anemia.

Iron deficiency anemia is caused by either a lack of iron intake from the diet or decreased ability to absorb iron and transport it to developing RBCs. Since less iron is available, fewer RBCs are produced. Aplastic anemia occurs due to damage to the bone marrow, the location of hematopoiesis, so less RBCs are produced (there will be less WBC and platelets as well).

Which two leads are used to determine MEA?

Leads I and III

How do gender and height affect VC? Why?

Lung capacity is dependent on lung size. The vital capacity is the maximum amount of air that can be breathed out after a maximum inhalation. People with larger lungs can hold more air in their lungs and breathe more air out. Males tend to have higher vital capacities compared to females because males tend to be larger, and thus, have larger lungs. Similarly, taller individuals, tend to have larger lungs as well.

MVV decreases with age. Why?

MVV decreases with age for the same reason that VC and FEV1 decreases with age--the elasticity of the lungs is decreased with age. This means that the total volume of air that we can breath in and out per unit time is reduced, so that the MVV would be reduced.

Males and taller individuals tend to have _______ lungs and thus, have _______ vital capacities.

Males and taller individuals tend to have Larger lungs and thus, have greater vital capacities

C5 through C9 from the ____________, creates a hole in the cell that permits fluid influx and lysis.

Membrane attack complex (MAC)

What advice about diet and exercise would you give to someone with borderline cholesterol?

My advice would be that reducing intake of food with high cholesterol content (e.g. meat and eggs) and exercising regularly would reduce cholesterol levels and associated risk for cardiovascular disease.

How does obesity affect blood vessel length? Would flow increase or decrease as a result? What effect would this have on the heart long term?

Obesity has been shown to increase blood vessel length. The increase in blood vessel length would provide more resistance to the flow of blood, thus reducing blood flow. This would be detrimental to the heart in the long term, because the heart would need to work harder to pump the blood throughout the vasculature against a greater resistance.

What effect does stimulating the vagus nerve have on heart rate? From which subdivision of the autonomic nervous system (ANS) does the vagus nerve carry motor fibers?

Stimulation of the vagus nerve decreases heart rate through the opening of potassium channels in the pacemaker cells. The vagus nerve supplies motor parasympathetic fibers to all organs (except the adrenal glands) from the neck down.

Why is it important that summation not occur in heart muscle?

Summation is not possible because relaxation must be complete before the next contraction. This is due to the long absolute refractory period. If summation occurred in heart muscle leading to tetany, this could result in muscle fatigue. In this case, the heart would not be able to pump blood and cardiac output would be severely reduced.

What effect does surfactant have on air flow? Explain.

Surfactant increases airflow, because surfactant reduces the surface tension within the water layer surrounding the inner surface of the alveolar, which allows for easier expansion of the alveoli and lungs (increases compliance). As the lungs expand, the airways are pulled open, which decreases resistance and increases airflow.

Venous return to the heart will directly affect the afterload or the preload?

Venous return to the heart will directly affect the preload

Ventricular diastole occurs during the time between the ____.

Ventricular diastole occurs during the time between the second and first heart sounds.

What happens to VC as you age? Why?

Vital capacity decreases with age. This is because, with age, the lungs lose elastin fibers and become more stiff and less compliant (i.e., less able to stretch). Older individuals with stiffer lungs cannot breath in or out as much air as younger individuals with more elastic lungs. Also, the rib cage becomes more stiff as well.

When testing for SLE antibody, To what color does the substrate change when it reacts with the enzyme?

Yellow

Is there a difference in hematocrit between males and females living in the same city? If so, explain why.

Yes, males generally tend to have greater values of hematocrit than females. This is because testosterone stimulates the production of RBCs.

Was there any difference in the PR interval between resting and exercise conditions? If so, explain.

Yes, the PR interval was shorter in the exercise condition than in the resting condition. A shorter PR interval infers that the heart rate was faster during exercise than resting.

Was blood pressure different when exercising compared to at rest? Which was higher and why?

Yes, the blood pressure was greater while exercising compared to rest. Exercising results in sympathetic stimulation to the heart, which causes the heart to contract with more force and the heart rate to increase, which increases the blood pressure. This ensures adequate supply of blood to muscles that are working during exercise.

Was blood pressure different when lying down compared to sitting? Which was higher and why?

Yes, the blood pressure was higher when sitting compared to lying down. When a person is sitting up, the heart needs to pump harder in order to pump blood against gravity to the brain. Therefore, the blood pressure is greater. When lying down, the gravitational force is no longer acting against blood flow to the head, so the blood does not need to pump as hard. Therefore, the blood pressure would be lower.

Is there a difference in loudness (p-p) between the first and second heart sounds? If so, which is louder and why?

Yes, the first heart sound is louder than the second heart sound. This is because the atrioventricular valves are stronger and close with more force in comparison to the semilunar values, which results in a louder heart sound.

Is there a difference in hematocrit between people (regardless of gender) that live in Boston (at sea level) versus Denver (one mile above sea level)? If so, explain why.

Yes, the samples from people living at higher altitude have a greater hematocrit than people living at lower altitude. This is because the hypoxia resulting from high altitude stimulates the production of more RBCs.

When testing for SLE antibody, With what is the secondary antibody reacting: the SLE antigen or the anti-SLE antibody?

anti-SLE antibody

Give an example of one way to naturally increase preload

increasing the pulmonary vein radius (increase blood flow from the lungs to the heart), led to an increase in preload. Preload can be naturally increased through sympathetic stimulation (i.e., increased skeletal muscle contraction through exercise) that increases venous return to the heart and thus, increased ventricular filling (EDV)

Describe how the heart alters stroke volume

it alters contractility or the preload

When testing for SLE antibody, What enzyme is tagged to the secondary antibody (give the whole name, not the abbreviation)?

Horse radish peroxidase (HRP). This is an enzyme used to stimulate the conversion of the colorless substrate into a colored product.

What happens to RV as you age? Why?

Residual volume increases with age. Since the lungs become less elastic with age (reduced elastic recoil), the capacity for individuals to breath air out is reduced, so that the residual air maintained inside the lungs, is increased. The total lung capacity remains the same with age (the lungs do not become smaller), and the vital capacity decreases with age. Since TLC = VC + RV, residual volume must then increase with age.

How does anemia (regardless of cause) affect hematocrit values?

Anemia decreases hematocrit values

What happens to the following as you age? Indicate whether there is an increase OR decrease. 1. Residual volume (RV) 2. FEV1% 3. Maximum voluntary ventilaiton (MVV)

1. Residual volume (RV) - Increase as we age 2. FEV1% - Decrease as we age 3. Maximum voluntary ventilaiton (MVV) - Decrease as we age

A person has type AB- blood. What antigens are present in their blood plasma?

A and B antigens

If the Anti-A antibody causes the blood to agglutinate, which antigen must be present on the blood cells?

A antigen

What effect would a fever have on heart rate?

A fever would increase heart rate. Fever induces an increase in heart rate to increase metabolism and it aids in hindering bacterial/viral activity. The increase in metabolism leads to an increase in heart rate.

How might a doctor stop the heart during surgery?

A physician stops the heart during surgery by infusing the heart in a solution high in potassium (cardioplegia; "heart" "paralysis"). The high extracellular potassium content does not allow for adequate repolarization (remember, potassium efflux occurs during repolarization). The end result, is diastolic cardiac arrest. This is often accompanied with decreasing body temperature (i.e., inducing hypothermia) to decrease the metabolic demands of the heart.

Which substance(s) do NOT inhibit platelet aggregation? A. von Willebrand factor B. Nitric Oxide C. Prostacyclin D. CD39

A. von Willebrand factor does not. Nitric Oxide, Prostacyclin, and CD39 all inhibit platelet aggregation

When testing for SLE antibody, What is the name of the substrate that reacts with the enzyme?

ABTS (2,2'-azinobis-3-ethylbenzothiazoleine-6-sulfonic acid)

Describe the relationship between blood vessel radius and blood flow. Explain.

According to Poiseuille's equation, blood flow is directly proportional to the fourth power of blood vessel radius. Increasing the blood vessel radius therefore would dramatically reduce the resistance to flow, which increases the blood flow.

Compared to the values during an asthma attack, what effect did the inhaler have on TV, ERV, IRV and FEV1%? How do inhalers relieve the symptoms of asthma attacks?

All values have increased. This is because inhalers induce bronchodilation and have anti-inflammatory mechanisms. Inhalers that contain anti-inflammatory agents act to relax smooth muscle or reduce the inflammation and reduce the mucus production that leads to a reduction in airway resistance.

If a patient had an atherosclerotic plaque in their aorta, what would be the long term effect on the patient's heart? Explain.

An atherosclerotic plaque would narrow the radius of the aorta, and this would increase the resistance, decrease blood flow, and increase blood pressure (i.e., hypertension). The long term effect that this would have on the patient's heart is that the left ventricle would need to pump blood with more strength to overcome the increased after load. The ventricle adapts by increasing in thickness, resulting in ventricular hypertrophy (which leads to a decrease in end diastolic volume).

What advantage is there to having an increased MVV? How might this benefit athletes?

An increased MVV is advantageous because it allows for a greater amount of oxygenated air to reach our cells per unit time, allowing them to sustain high levels of energy production. This benefits endurance athletes because, with a greater amount of aerobic respiration, athletes can maintain activity longer without becoming fatigued.

Lupus is not the result of an infection. Why would antibodies be present if the patient is sick?

Antibodies are present in a person infected with Lupus because their immune system thinks that the patient's own body proteins (antigens) are foreign, and mounts an immune response against the body.

Helper T lymphocytes bind to antigens present on the _________ to become activated.

Antigen presenting cell (APC)

Which type of leukocyte produces antibodies?

B lymphocytes

Describe the relationship between blood pressure and blood flow. Explain.

Blood flow is directly related to the pressure gradient, according to the Ohm's law equation delta P = flow * resistance. The pressure gradient drives the flow of blood. Without a pressure gradient, there would be no flow of blood.

What is serum?

Blood serum is a component of blood plasma without blood clotting factors (coagulants) and cells (i.e., no erythrocytes or leukocytes). It contains non-clotting factor proteins, electrolytes, antibodies, antigens, hormones and other exogenous substances (i.e., drugs, microorganisms, etc.)

In real life, what physiological processes lead to blood vessels dilating and constricting?

Blood vessels dilate and constrict due to the relaxation and constriction of the smooth muscle surrounding the blood vessels.

Describe the relationship between blood viscosity and blood flow. Explain.

Blood viscosity, referring to the cohesiveness or stickiness of the blood, is inversely proportional to blood flow. Highly viscous fluids (i.e., maple syrup), are much more resistant to flow than less viscous fluids (i.e., water), because the stickiness of the fluid, impedes forward motion.

What effect do emphysema and asthma have on ERV and IRV? Explain.

Both are obstructive disorders. Patients with emphysema have decreased ERV and decreased IRV. Exhalation is impaired due to loss of elasticity and more effort is required for each expiration. ERV is decreased because the airways collapse and pinch closed before forced expiration. IRV is decreased because air pockets obstruct air flow. Patients with asthma have a decreased ERV due to obstruction of airflow (because of inflammation). They also have low IRV.

What effect do emphysema and asthma have on RV? Explain.

Both emphysema and asthma have elevated RVs. The decrease in both ERV and IRV means that more air is retained in the lungs after forced expiration. The increases in obstruction and resistance makes exhalation difficult.

What effect do emphysema and asthma have on FEV1 and FEV1%? Explain.

Both patients have a problem getting the air out, so FEV1 volume will decrease. Asthma patient: The increase in resistance due to bronchoconstriction and excess mucus accumulation, makes it difficult to move air (i.e., difficult in expiration). Emphysema patient: Because the lungs cannot passively recoil and deflate due to the decrease in elasticity, they expire more slowly and cannot expire all the air.

Does bronchoconstriction increase or decrease air flow? Explain.

Bronchoconstriction is the constriction (decrease in radius) of the airways in the lungs. This results in a decrease in airflow due to the tightening of surrounding smooth muscle or inflammation.

During an asthma attack, does bronchodilation or bronchoconstriction occur? What happens to airway resistance?

Bronchoconstriction will occur which increases resistance to the airways. Epipen or inhalers might help to relax the smooth muscles of the bronchioles.

What effect does compensation (regardless of type) have on heart rate? Explain.

Compensation increases heart rate but the increase does not go up to the "normal" heart rate. When there is a greater afterload (due to the narrowing of systemic blood vessels), the heart compensates by increasing contractility and preload (EDV). The myocardium of the left ventricle thickens to increase contractility. This hypertrophy limits the increase in preload because the increased stiffness of the myocardium prevents normal filling. To maintain the same cardiac output through compensation, heart rate increases.

Identify which of the following would indicate that you can infer a "false positive" result for your ELISA experiment? A. Not observing a color change in any of your sample wells B. Observing a color change in all your patient sample wells C. Observing a color change in your positive control wells D. Observing a color change in your negative control wells

D. Observing a color change in your negative control wells

Atrial fibrillation occurs when the atria have very fast rates of contraction. Why would digitalis be used on a patient with this condition?

Digitalis is used for treatment of atrial fibrillation because it acts by increasing the refractory period and slowing conduction through the atrioventricular node. This reduces the rate of impulses being sent from the atria to the ventricles.

Which drug would best be used to treat atrial fibrillation? A. Digitalis B. Atropine C. Epinephrine D. Pilocarpine

Digitalis would be best to treat atrial fibrillation

During hypoventilation, does PCO2 increase OR decrease?

During hypoventilation, there is an increase in PCO2

ESV is equal to?

ESV = EDV - SV

Elevated levels of cholesterol are associated with increased risk of ____ diseases.

Elevated levels of cholesterol are associated with increased risk of cardiovascular diseases.

What effect did exercise have on pulse? Why?

Exercise increased the pulse rate. Exercise is associated with increased sympathetic activity to increase heart rate in order to increase cardiac output to muscles. Pulse rate corresponds of heart rate, because the blood compresses on the arteries at close to the same time and rate as the heart is contracting.

How does exercise affect the loudness of heart sounds? Why?

Exercise increases the loudness of the heart sounds. The heart pumps with more force during exercise. Increased force of contraction leads to greater pressure changes between the atria and ventricles (and arteries), which results in the valves closing with more force, and thus louder heart sounds.

What happens to FEV1% as we age? Why?

FEV1 decreases as we age. As we age, there is a reduction in accessory muscle function and the elasticity of our lungs are reduced as well. The total amount of air that we can breath out is less and we cannot breath out that air as quickly, compared to younger people with more elastic lungs - reduced elastic recoil ability.

Give examples of factors that can naturally increase contractility. Give examples of factors that can naturally decrease contractility.

Factors that can naturally increase contractility: positive ionotropic factors that can increase sympathetic stimulation (i.e., exercise). Factors that can naturally decrease contractility: negative ionotropic factors that can stimulate the parasympathetic nervous system (i.e., relaxation and meditation).

Internal respiration occurs in the respiratory zone. True or False

False

True or False: The oxygen content of arteries in the pulmonary circulation is high.

False

Why would increasing stroke volume result in a decrease in heart rate?

Fewer contractions are needed to transport blood through the systemic circulation

Explain the changes in heart rate between the resting and exercise conditions. Describe the physiological mechanisms causing these changes.

Heart rate is slower when resting, and increases during exercise. During exercise, blood pressure, heart rate, and respiration increases to meet the metabolic demand for oxygen and nutrients by the musculo-skeletal system. During exercise, stimulation of adrenergic receptors releases epinephrine and norepinephrine. This causes an increase in heart rate and force of contraction. The slowing of the heart rate during resting is caused by parasympathetic stimulation of the pacemaker cells while resting.

What effect does aplastic anemia have on %WBC? Why?

Hematopoiesis, the production of blood cells (i.e., RBCs, WBCs and platelets), occurs in the bone marrow, which is damaged in aplastic anemia. Therefore, the production of WBCs would also be decreased.

Explain why a positive diagnosis is indicated by a color change in the ELISA plate wells. In other words, explain how this ELISA worked.

If the patient has the disease, the patient's immune system will be producing SLE antibodies. The ELISA test is used to detect the presence of SLE antibodies in the blood. The wells are coated with the SLE antigen. If the patient produces the SLE antibody, the SLE antibody present in the patient's serum will bind to the SLE antigen. A secondary antibody (the rabbit anti-human antibody) is then added to detect for the presence of the SLE antibody. If the SLE antibody is present, bound to the SLE antigen, then the antihuman antibody will bind to the SLE antibody. The antihuman antibody contains the horseradish peroxidase enzyme, which will react with the substrate to produce a color change (from white to yellow), which indicates the presence of the SLE antigen-SLE antibody-antihuman antibody complex.

What is the type of resistance increased in Aortic Valve Stenosis?

In Aortic Valve Stenosis, there will be an increase in left-ventricular afterload

What effect does decreasing tube radius have on FEV1 %? Explain.

In obstructive diseases (i.e., chronic bronchitis and asthma), airway radius is decreased and the FEV1% will decrease proportionately. The FEV1% will decrease due to increasing resistance. In addition, there is a decrease in the amount of air that can be exhaled. Decrease VC (amount of air exhaled after max inhalation) = decreases FEV1%

What would happen to the pump rate of the heart if the stroke volume is increased?

In order to maintain the cardiac output, the pump rate would decrease

What effect does increasing the radius of the aorta have on heart rate? Explain.

Increasing the radius of the aorta also increases heart rate. Recall that delta P = HR x SV x R (where CO = HR x SV). Given that pressure and SV are constant, an increase in radius causes a decrease in resistance. To maintain a constant pressure, heart rate increases to compensate for the decrease in resistance.

How does the heart provide for an increase in stroke volume?

Increase contractility

What effect does increasing the radius of the aorta have on cardiac output? Explain.

Increasing the radius of the aorta increases cardiac output. The cardiac output is equal to the pressure difference (delta P) divided by the total peripheral resistance. Increasing the radius of the aorta decreases the total peripheral resistance. Since the pulse pressure remains the same, and the total peripheral resistance is decreased, there must be a corresponding increase in cardiac output.

Increased heart contractility will result in?

Increased end systolic volume

During isovolumetric ventricular contraction, ventricular pressure is ________.

Increasing

What effect does increasing contractility have on cardiac output and pressure? Explain

Increasing cardiac contractility increases the stroke volume, and consequently, would increase the cardiac output. When cardiac output is increased, the blood pressure would also be increased if total peripheral resistance remained the same.

What effect does increasing preload have on cardiac output? Explain

Increasing preload increases cardiac output. According to the Frank-Starling law, an increase in blood filling the ventricles leads to more myocardium stretching. This results to stronger contractions and increased stroke volume. The increase in stroke volume means an increase in cardiac output.

Why would increasing blood vessel radius lead to an increase in blood flow?

Increasing radius reduces resistance to blood flow

What was the effect of temperature on heart rate? Why?

Increasing temperature increases heart rate. The hypothalamus increases sympathetic stimulation in response to higher temperatures. Sympathetic stimulation increases heart rate and vasodilates blood vessels at the skin. This cools down the body by delivering more blood to the skin and dissipating heat at the skin surface.

Individual with: ____ anemia: RBCs are sickle shaped and tend to ____. This prevents RBS from stacking and as a result, ESR is reduced.

Individual with: Sickle cell anemia: RBCs are sickle shaped and tend to clump together. This prevents RBS from stacking and as a result, ESR is reduced.

Individuals with: Menstruating female: Menstruating females contain a high concentration of ____ which leads to an elevated ESR. ____ anemia: Low iron. This individual has a ____ than normal hematocrit which results in an elevated ESR. Myocardial infarction (heart attack): This individual has the highest ESR. ____ (tissue death) may cause ____ which then leads to elevated ESR.

Individuals with: Menstruating female: Menstruating females contain a high concentration of fibrinogen which leads to an elevated ESR. Iron deficiency anemia: Low iron. This individual has a lower than normal hematocrit which results in an elevated ESR. Myocardial infarction (heart attack): This individual has the highest ESR. Necrosis (tissue death) may cause inflammation which then leads to elevated ESR.

Define minute ventilation.

Minute ventilation is the amount of air that flows into and out of the lungs in a minute. Minute ventilation (ml/min) = TV (ml/breath) x RR (breaths/min)

Does iron-deficiency anemia have the same effect as aplastic anemia? Why or why not?

No, Iron-deficiency only affects the number of RBCs, because the development of RBCs requires iron, whereas the development of WBCs does not.

Do you see a normal breathing pattern with coughing or reading? Explain.

No. Coughing is an active event with deep inspiration followed by short, forceful exhalations. When reading aloud, the breathing cycle temporarily ceases as a person is talking (causing an increase in CO2 levels).

Which antibodies are present in the plasma of a person with type AB+ blood?

None.

The ability of antibodies and complements to enhance phagocytosis is called __________.

Opsonization

How does our body naturally decrease afterload?

Our body naturally decreases afterload by vasodilating blood vessels. This leads to a decrease in resistance (and thus, decrease in afterload).

If a patient is experiencing tachycardia (high heart rate), what drug would you administer?

Pilocarpine, which is an agonist for muscarinic receptors. This would stimulate muscarinic receptors in the heart, thus decreasing heart rate.

What effect do you think polycythemia would have on ESR? Explain your reasoning.

Polycythemia is a condition attributed to higher than normal RBC count. This causes an increase in blood viscosity and a reduction in the compactness of roulex formations. As a result, ESR will be reduced.

Why do you think the heart has a compensatory pause after extrasystoles?

The compensatory pause after extrasystoles allows the cardiac muscle time to recover.

In the lung puncture experiment, why did the lung on the right remain inflated?

The lung on the right remained inflated because the lungs, are each surrounded by a separate intrapleural space. Equilibration of the left lung's intrapleural pressure with the atmosphere does not affect the intrapleural pressure for the right lung. Each lung has its own pleural membranes.

Explain why the lung collapsed when you opened the valve during the spirometry lab.

The lungs collapsed when the valve was open because the intrapleural pressure became equilibrated with the atmospheric pressure, so that the subatmospheric intrapleural pressure was no longer exerting a negative force to maintain the expansion of the lungs.

Research has shown that in the absence of any neural or hormonal influences, resting heart rate is 100 bpm. However, average heart rate is 70 bpm. Explain this difference.

The natural periodicity of the pacemaker cells in the heart is around 100 bpm. However, under normal physiological conditions, there is a tonic parasympathetic stimulation of the vagus nerve to the heart, which decreases the heart rate to its normal rate of 70 bpm

negative control?

The negative control will always produce a negative result

How does the radius v. flow graph differ from the pressure v. flow graph?

The radius vs. flow graph is exponential (slope increases exponentially), because flow is proportional to the fourth power of radius, whereas the pressure vs. flow graph is linear (constant slope), because flow is proportional to the first power of the pressure gradient.

With which ECG wave is the second heart sound correlated? Explain why.

The second heart sounds is correlated with the T wave on the ECG. The second heart sound is associated with the closure of the semilunar valves, which occurs at the beginning of diastole. The beginning of diastole is also associated with repolarization of the ventricles, which is represented by the T wave on the ECG. The second heart sound is heard shortly after the T wave is produced.

The second heart sound occurs at the (beginning or end) of (systole or diastole).

The second heart sounds occurs at the beginning of ventricular diastole. The semilunar valves close, causing the "dub/dup" sound.

Describe the intrinsic factors that control stroke volume

The stroke volume is regulated by three variables: 1. EDV (volume of blood in the ventricles at the end of diastole) 2. Total Peripheral Resistance (the frictional resistance/impedance of blood flow in the arteries) 3. Contractility (the strength of ventricular contractions)

When testing for SLE antibody, why do you incubate your sample?

To allow time for the reaction to occur. In this case, it allows time for antibodies present in the sample to interact (bind) with the antigen.

Why do you change the pipette tip each time you remove fluid from the wells?

To prevent cross contamination. Each well has a different dilution and patient sample.

When testing for SLE antibody, Why do you wash the wells?

To remove the SLE antibodies (or any other molecules) if the reaction did not occur

Why did you centrifuge your samples in the ELISA assay?

To separate serum from formed elements. If any cells remain, it can interfere with the assay, possibly causing a false positive result to appear regardless of whether or not the SLE AB is present.

Describe the relationship required between intrapleural pressure and atmospheric pressure in order to draw air into the lungs.

Under normal conditions, the intrapleural pressure is less than the atmospheric pressure, which maintains the expansion of the lungs. During inspiration, the thoracic volume increases, which decreases the intrapleural pressure, and correspondingly, decreases the intrapulmonary pressure below atmospheric pressure, so that air follows a pressure gradient moving into the lungs. Conversely, during expiration, the thoracic volume decreases, causing an increase in the intrapleural pressure, and correspondingly, an increase in intrapulmonary pressure above atmospheric pressure, so that air follows a pressure gradient from the inside of the lungs towards the atmosphere.

Which blood type is considered the universal donor? What about the universal acceptor?

Universal donor: O- Universal recipient: AB+

When you are scared, what happens to blood pressure? How would this affect flow? What is the practical purpose of these physiological changes?

When a person is scared, there is an increase in blood pressure. The increase in blood pressure would provide a greater driving force for flow, resulting in a greater blood flow. The practical purpose of this is to increase blood flow to skeletal muscles and the brain, so that one is prepared to run from the danger (flight or fight response).

Explain the difference in mean electrical axis between the lying down and sitting up conditions. Toward which side of the heart did the axis deviate when the subject sat up? Why that side?

When lying down, the heart is in a more horizontal position. The MEA will deviate more towards the right (towards Lead III) or centered. When sitting down, the heart is in a more vertical position. The MEA will deviate to the left (towards Lead I). Recall that when a person sits up, the heart has to counteract the effect of gravity. The left ventricle works harder to return blood to the heart (and to the brain). Thus, there's a shift in electrical activity.

Describe the physiological process that occurs from the time the pathogen infects the body to the time an antibody is made.

When the pathogen enters the body: 1. Antigen presenting cells (APCs) phagocytizes the pathogen and presents the antigen on its cell surface. 2. A helper T cell recognizes the antigen on the APC which activates B cells and cytotoxic T cells (we'll focus on the B cells) 3. B cells divide to form clones: memory cells (for immunological memory) and plasma cells (that secrete antibodies) 4. Plasma cells secrete antibodies that bind to the pathogen. This can stimulate opsonization where phagocytic cells attack the pathogens.