penguin

Why do you think the diving response is considered advantageous? What other factors should be accounted for during a real dive that were not simulated in this experiment?

Advantages: reducing the heart rate to conserve body heat. Blood kept from the extremities prevents excess heat loss and directs o2 supply to the vital organs. Disadvantages: fxn of skeletal muscles is deminished due to the decrease in blood flow. Factors that weren't seen in this lab: a full body submersion would cause a different response (e.g. metabolic response to maintain homeostasis).

Select the statement that is not correct.

Drinking 800 ml of Sprite or similar sodas, results in glucose appearing in the urine in healthy people.

Describe any change in pulse amplitude you observed during and after the simulated dive.

During the dive pulse amplitude was smaller, because peripheral (extremeties) circulation decreases during the dive.

Select the statement about sodium that is not correct.

Excess sodium taken in the diet is rapidly (over an hour or so) excreted in the urine.

Select the statement about insulin that is NOT correct.

Insulin release can be stimulated by sympathetic nerves.

List the hormones that play a role in glucose metabolism. Of these, which is the most important in regulating blood glucose after absorption of a glucose load?

Insulin, Glucagon, Cortisol, Growth Hormone, Epinephrine, Thyroid Hormone. Insulin is the most important.The

What would happen if your water intake over sixty minutes significantly exceeded the maximal volume you could excrete in this period? Why could this be life threatening?

It can cause brain swelling which is very dangerous and can be life threatening.

Your "lub-dub" recordings probably show some differences from the correct timing of the heart sounds as judged by phonocardiography. How can you account for this difference?

It is difficult for a person to react correctly for every heart beat causing some human error and not matching the coreect timing of the heart sound.

Select the statement about gastric emptying that is NOT correct.

It is not affected by hormonal or nervous influences.

Select the statement about insulin that is NOT correct.

It is not needed for glucose entry into skeletal muscle cells.

Are the amplitudes and durations of the various waves in different individuals similar or very different

Most amplitudes and duration of waves in different individuals are different because no two people are identicle. Each person can have a different level of activity, could be in different body shape and can have faster or sower heart rates

Compare the effects of diving and breath-holding on pulse rate. Were they the same?

No. The effects of diving had a much greater decrease on pulse rate.

Stretch receptors in the lungs ________.

None of these answers are correct.

Do your results for leg volume suggest that peripheral circulation changes during a breath-hold?

Not appreciatively. Similar to resting levels.

Describe any change in pulse rate you observed during and after the simulated dive.

Pulse decreased, bradycardia was induced.

The _______________ act(s) as the pacemaker for the heart.

SA node

Which of these statements about stroke volume is not true for severe sustained exercise?

Stroke volume continues to increase as the intensity of exercise increases.

Which one of the following do you think would alter the most in conditions where heart rate is increased?

TP interval

What environmental factors could explain differences between breath-holding and a "dive"?

Temperature of the water, body position, and pressure on the face.

The P wave and the QRS complex represent depolarization of the atrial and ventricular muscle respectively. Why does the QRS complex have the largest amplitude

The QRS complex has a larger amplituide because it requires a higher pressure. Ventricles are bigger than atria and ventricular muscle is thicker than atria.

Compare the changes in heart rate during dives among the members of other groups. Is the effect between individuals similar?

Usually the heart rate will decline.Bradycardia is usually more pronounced in athletes.

The term bradycardia refers to ____________.

a decrease in heart rate

Select the statement that is NOT correct. After a meal _____.

about 1/3 of the absorbed glucose is metabolized by the gut epithelial cells

Water is _______.

absorbed most rapidly from very dilute intestinal fluid

During blood pressure measurements, the cardiomicrophone will be strapped in place over the [1] [2].

brachial artery

An athlete with a resting heart rate of 40 beats/min has a greater capacity to increase his ___________ during exercise than does a person with a resting heart rate of 90 beats/min.

cardiac output

Compare the effects of diving and breath-holding on pulse amplitude. Were they the same?

change in pulse amplitude was greater with the dive.

The dive response in adult humans and other land animals seems to have the greatest benefit by _____________.

conserving body heat

The terms systole and diastole usually refer to the _______ and _______, respectively, of the _______.

contraction; relaxation; ventricles

I would expect that, together with a sphygmomanometer, the finger pulse detector __________.

could not be used to determine diastolic pressure

Blood flows to the [1] and [2], which together normally account for 50% of the resting blood flow, decrease during exercise.

gut and kidneys

Heart murmurs result from defective ______________.

heart valves

Blood pressure is at its highest _______.

immediately after the ventricles contract

The QRS complex in the ECG occurs _______.

immediately before the first heart sound is heard

During exercise, blood flow in the skin and finger pulp is usually reduced by sympathetic vasoconstrictor nerve activity. After exercise, however, skin and finger blood flow may be increased. Why is the blood flow to extremities reduced during exercise? Why does it increase to higher than normal levels during recovery? What other factors may influence the supply of blood to the skin and fingers during and after exercise?

temperature

When the BP cuff is fully inflated no sound can be heard through the stethoscope because ______.

the artery has collapsed

In the auscultation method for blood pressure measurement, diastolic pressure is indicated by _________.

the disappearance of the sounds

In the auscultation method for blood pressure measurement, systolic pressure is indicated by _________.

the first detection of the sounds

What happened to the pulse amplitude during recovery from exercise?

the pulse amplitude increases.

Immediately after exercise, was the amplitude of the pulse smaller or larger than in the resting record

the pulse amplitude is smaller after exercise because all the blood is rushing to the muscle that needs oxygen.

What is the basis for the sounds referred to as Kortokoff sounds?

turbulent blood flow

Explain the differences in pressure with the arm in different positions. Hint: the pressure in a column of fluid depends on height. In a column of blood, a difference in height of one meter corresponds to a pressure difference of 10.3 kPa or 77 mmHg.

when your arm is raised pressure will decrease, when you lower your arm the pressure increase.

Glucose is absorbed from the gut lumen _________.

with sodium ions on an SGLUT transporter

Which of these factors would you assume to occur with reduced blood flow to the extremities?

• a. more blood is available to the heart and brain • b. increased stroke volume of the heart

The human diving reflex results in ____________.

• an increase in blood volume returning to the heart • increase in arterial blood pressure

Select the statement about ADH secretion that is not correct.

ADH is released into the blood directly from the supraoptic nuclei in the hypothalamus.

What hormone is involved in regulating renal water excretion? What normally inhibits the release of this hormone?

ADH, it is inhibited by the decrease in plasma osmolarity.

Which of the following statements is not correct?

About one-third of the body water is found in the plasma.

The ECG records electrical activity originating from ______________ at the body's surface.

specialized myocardial cells

In skeletal muscle, insulin __________.

stimulates glucose uptake

In the liver, insulin ________.

stimulates glycogen synthesis

The cardiac cycle has two phases, namely __________.

systole, in which the ventricles contract, and diastole, in which the ventricles relax

Explain the underlying cause of the Korotkoff Sounds that you detected with the Cardiomicrophone as the cuff pressure was decreased.

By inflating the blood pressure cuff you are stopping the blood flow, by slowly deflating the cuff the blood begins to flow again which causes the Korotkoff sound. "turbulent blood flow"

The BP cuff must initially be inflated to approximately _____ mmHg.

180

The heart rate in an adult human can rarely exceed about _______ beats per minute.

180

Water conducts heat away from the body _________.

24 times more efficiently than air

Of the total body weight of a male of average build about __________ is water.

60%

What is the osmolarity of the fluid in the interstitial space in the renal cortex? Is it the same throughout that space?

A lot of water and salt are being reabsorbed in the renal cortex causing the osmolarity to stay about the same since both of them are being reabsorbed at the same time. Remaing the same throughout the space. the osmolarity in the interstial fluid of the renal cortex is about 300 mOsm/L

From your data, estimate the maximum volume of water that you could drink over sixty minutes while still remaining in water balance?

1 L per hour

What is the osmolarity of the fluid in the interstitial space in the renal medulla? Is it the same throughout that space?

1200 mOsm/L and increases progressively

Provide a physiological explanation for the results for the hyperosmotic glucose solution and the hyposmotic solution (Protocol 4 - pink vs Protocol 2 - blue)?

Both decrease osmolarity, however water has a higher decrease than sprite.

In what regions of the body are carbohydrates digested? Of these, which region is the most important?

Carbohydrates are digested in the mouth, stomach and small intestine. The small intestine is the most important becasue this is where pancreatic enzymes break down dissaccurides into monosaccirides for absorption.

Immediately after hand exercise, was the amplitude of the pulse smaller or larger than in the resting record?

Change is very little

Which of the following is responsible for generating the first heart sound?

Closing of the AV valves

Which one of the following is responsible for generating the second heart sound?

Closing of the semilunar valves

What cellular mechanisms are involved in glucose absorption from the small intestine?

Glucose and Sodium are transported together into the cell using the SGLUT1 transporter. Sodium moves down the electrochemical gradient which provides the energy to move glucose against its own chemical gradient. Glucose then exits the cell into the interstial fluid down its chemical potential gradient via one of the GLUT family of transporters (GLUT 2). The sodium is then activley transported by the NA-K-ATPase into the interstual fluid.

Explain why ventricular relaxation (diastole) and the 'dub' sound occur after the T wave.

The blood pressure drops below that of the artery and the semilunar valve closes.

What factors influence the rate of gastric emptying?

The greater the liquid the greater the rate of gastric emptying

Provide a physiological explanation for the results for the isosmotic sodium chloride solution and the hyposmotic solution (Protocol 3 - green vs Protocol 2 - blue)?

The hyposmotic solution causes a dilution in body fluids since the solutes are staying unchanged and you are just adding water. Once the body fluids are diluited the plasma osmolarity decreases. This decrease inhibits osmoreceptors in the anterior hypothalmus.This decreases thirst and inhibits the secretion of ADH. Because the water is beig reabsorbed less water is being circulated, also the inhibition of thirst all causes the plasma osmolarity to increase again.In the isomotic solution the extracellular osmolarity remains the same, therefore there is no stimulus to supress ADH secretion.

Provide a physiological explanation for the blood glucose results of drinking the glucose solution (Protocol 2 - blue) compared to ingesting the white bread (Protocol 3 - green)?

The liquid is more quickly absorbed because of its form compared to white bread. This explains the boost in glucose after the liquid is drank

Explain why ventricular contraction (systole) and the 'lub' sound occur immediately after the QRS complex.

The lub sound after the QRS is comming from the closure of atrioventricular valves.

Provide a physiological explanation for the blood glucose results of ingesting the white bread (Protocol 3 - green) compared to ingesting the potato chips (Protocol 4 - pink)?

The potato chip digests slower because of the fat in the chips

What factors influence the rate of carbohydrate absorption from the small intestine?

The rate of carbohydrate absorption from the smaill intestine can be influenced by the amount of enzymes secreted by the pancreas and the nature of the material to be.

Changes in the cardiovascular system are only some of a number of changes that occur in the body during and after exercise. What other physical changes did you observe in the volunteer?

The volunteer was out of breath, fatigued, increased body temperature, and the volunteer began to sweat.

What can you say about the amplitude of the various waves in different cardiac cycles?

There is normally little difference between different cardiac cycles. The QRS amplitude is usually the greates and the P wave is normally the smallest amplitude in a normal cardiac cycle.

The range for a normal resting heart rate is 60 to 90 bpm. A trained athlete could have a resting heart rate of 45 to 60 bpm. Why might a very fit person have a slower heart rate than someone of average fitness?

They have a larger stroke volume.

During exercise, cardiac output increases. Which one of the factors below does not contribute to this increase?

Vasoconstriction in the exercising muscles

The R-R interval consists of the sum of QRS, S-T, T-P and P-R. Which of these became shorter when the heart rate increased?

When the heart rate increases the T-P shortens due to the complexes being in closer proximity.

Do your results for leg volume suggest that peripheral circulation changes during a "dive"?

Yes, it decreases during a dive.

Explain the relationship, shown in the graph above, between the urine flow rate and specific gravity.

dilute solvents have a high rate of urination and a low specific gravity.

What happened to the R-R interval and the heart rate after exercise?

increase in heart reate caused the R-R interval to shorten.

Glucose ________.

is rapidly removed from the portal circulation by the liver

What substances are absorbed from the stomach?

lipid soluble substances can be absorbed from the stomach, as well as alcohol.

Comment on how the systolic pressure determined by auscultation and by pulse detection compare for each of the subjects in your group.

lower pulse by pulse detection.

A carbohydrate is absorbed as a ________.

monosaccharide

Describe what happens to the glucose that is absorbed from the gut.

monosaccrides like glucose require no digestion and start to be absorbed immediatley.

Ingested carbohydrates are _____.

mostly digested in the small intestine

From your results, do you think that pulse measurement can replace the stethoscope in determining diastolic pressure

no, pressure exceeds diastolic pressure.

Given the variation in pressure with height, in clinical medicine human blood pressure is normally referenced to heart level. Does this usually affect the pressure recorded from the upper arm?

no, the pressure is normal level to the heart.

What happened to the pulse amplitude during recovery from hand exercise?

nothing changes

The most important determinant of thirst is the __________.

osmolarity of the plasma

At rest, the heart rate is most affected by __________.

parasympathetic (vagal) nervous innervation

Select the statement that is NOT correct. After a substantial carbohydrate meal _________.

plasma cortisol rises

The subject in this week's lab will be connected to the Powerlab as follows:

positive electrode to left arm, negative electrode to right arm, earth connection to right leg

What are some possible sources of error or variation in this technique of blood pressure measurement?

possible errors could be room noise and if it is released to fast.

In the electrocardiogram (ECG) of a normal cardiac cycle, the wave called T corresponds to __________.

repolarization of the ventricles

ADH causes the kidneys to __________.

retain water

Blood flows from _______________.

right atrium to right ventricle to lungs to left atrium to left ventricle

As water temperature decreases, ____________.

severity of bradycardia increases

During exercise, there is a marked increase in blood flow to the ________.

skeletal muscles (in total)