Unit Quizzes

Explain why a person who is blood type AB+ can receive blood from any blood type but can only donate to individuals who are also blood type AB+

AB+ blood has all three antigens but no antibodies to these antigens, which is why it is often called the universal recipient.

Another lab value that is monitored routinely is the total red blood cell (RBC) count. A normal RBC count is typically 4.2-5.9 million/mm3. Having a low RBC count is called anemia. Predict the possible effects of having anemia, considering the functions of erythrocytes.

Anemia is a condition in which the blood's oxygen-carrying capacity is too low to support normal metabolism. Anemic individuals are fatigued, often pale, short of breath, and chilled.

Skeletal muscle cells exhibit a phenomenon known as recruitment, in which the number of muscle cells recruited to contract is proportional to the strength of muscle contraction needed. In this way, we active a few fibers to produce a small contraction to pick up a piece of paper and we activate many fibers to produce a larger contraction to pick up a textbook. Would you expect to see recruitment in cardiac muscle tissue? Why or why not?

Because gap junctions electrically couple cardiac cells, the myocardium behaves as a single coordinated unit, or functional syncytium, therefore recruitment does not occur.

The poison ricin, derived from the castor bean plant, interferes with protein synthesis. Which formed elements of blood would ricin affect directly? Are there any formed elements in the blood that ricin would not affect? Explain.

Erythrocytes would most directly be affected because the RBC protein, hemoglobin functions as gas transportation. There are also other proteins present that allow RBC to deform and spring back into shape. No, all formed elements would be affected because leukocytes are true cells that can undergo protein synthesis. Platelets are affected mostly in their megakryocytes stage.

The condition known as an atrial septal defect is characterized by the presence of a hole in the interatrial septum. How would this condition impact the normal pattern of blood flow? What effect would this have on the oxygenation of the blood?

If there is a hole present in the interatrial septum, which connect the atria would cause the mixture of deoxygenated and oxygenated blood in the right atrium. This would result in the presences of deoxygenated blood in the atrial systemic circuit, reducing the amount of oxygen available to the cells.

When the pericardium fills with blood, it produces a condition called cardiac tamponade, which can be rapidly lethal. Why is this condition so dangerous?

In extreme cases, large amounts of inflammatory fluid leak into the pericardial cavity. This excess fluid compresses the heart and limits the ability to pump blood, called cardiac tamponade. It causes: decline in blood pressure, shortness of breath, fainting and lightheadedness.

What might i mean if a pulse were normal (grade 2/4) on the right limb, and absent (grade 0/4) on the left limb?

It could indicate a normal anatomical variation, a blocked artery, or vascular disease.

Your patient presents with severe abdominal pain. Your team orders a CT scan and discovers a large blood clot lodged in the celiac trunk. What organs could this blood clot potentially impact? Why do you think the clot is causing abdominal pain.

Organs that would affected would be: stomach, spleen, pancreas, and esophagus. Pain caused because clots block the supply of blood to various organs.

You come across a crime scene and find two samples of blood. Sample one reacts with anti-A and anit-Rh antiserum. Sample two reacts with only anti-B antiserum. What is the blood type for each of the samples. How do you know?

The blood type for sample one is A+ and the blood type for sample two is B-. When the blood, in sample one, reacted with anti-A antibody, the blood type is A and it reacted with the anti-Rh antibody, making it Rh positive. When the blood, in sample two, reacted with anti-B antibody, the blood type is B and since react with anti-Rh antibody it becomes negative.

One potential cause of valve dysfunction is rupture of the chordae tendineae. Why would this lead to valve dysfunction? Would this impact the atrioventricular valves, the semilunar valves, or both? Explain

The chordae tendineae (heart strings) are tendons that control the opening and closing of atrioventricular valves. If strings are ruptured the valves can't function. This would only affect AV valves and not semilunar valves because the semilunar valves do not contain chordae tendineae.

Your patient has been admitted to the emergency room with an occupational injury due to an industrial saw. He has lost significant volumes of blood. What effect has this blood loss likely had on this blood pressure, and why?

The patient would have a decrease in blood pressure due to hypovolemic shock. Less blood, less pressure.

High pressure in the systematic and pulmonary circuits often results in ventricular hypertrophy, in which the ventricle enlarges to pump against greater forces. Which side(s) of the heart would be affected by high pressure in the pulmonary circuit? Which side(s) of the heart would be affected by high pressure in the systemic circuit? Explain.

The right side of the heart pumps into the pulmonary circuit so the right side would be affected by pulmonary hypertension. The left side of the heart pumps into the systemic circuit so the left side would be affected by systemic hypertension.

In the surgical procedure called a bypass graft a vessel is removed from a patient and used to make a vascular bridge that bypasses one of that patient's blocked arteries. A common vessel that is used for this procedure is the great saphenous vein. Why do you think a surgeon might use the great saphenous vein instead of the femoral vein or a large artery?

The saphenous vein is a large superficial vein of the leg. The vein grafts are placed in a reversed position to allow free blood flow. It is used because it is easily accessible, superficial location, and redundancy of veins in the leg. The other veins can cause large amounts of bleeding and complications of rejection of graft.

Predict the effects of a drug that stimulates the SNS on blood pressure and heart rate. How would this drug affect the three factors that determine blood pressure?

This would increase cardiac output and peripheral resistance, which would increase blood pressure. Over a long period of time it may increase blood volume/ pressure.

In the heart dissection you perform, you saw the smooth texture of the valves and how the leaflets fit together. How do you think the function of the valves would be affected if the valves were tough and filled with calcium deposits? Explain.

Valves prevent backflow of blood in the heart. If they were less flexible they would not close properly and blood would flow backwards into the heart.

Predict what might happen if the elastic fibers in a blood vessel's wall were defective. Would such a condition be more problematic for arteries or for veins? Explain.

arteries are under higher pressure and need to be to expand, which is provided by the elastic fibers.

Would a blood clot lodged in one of the anterior or posterior communicating arteries of the cerebral arterial circle be likely to cause significant symptoms? Why or why not?

it would be unlikely to cause noticeable symptoms because the blood could flow along an alternate route to the brain

Predict the effects of a drug that stimulates the parasympathetic nervous system on blood pressure and heart rate. How would this drug affect the three factors that determine blood pressure?

it would decrease cardiac output, peripheral resistance and blood volume

The baroreceptor reflex can bu sued to our benefit in a procedure known as a carotid sinus massage, which is performed when the blood pressure or heart rate is high. Why would a "massage" of the carotid sinus help to treat these conditions?

massaging the carotid sinus decreases blood pressure in a controlled way by activating the baroreceptor reflex and allowing the PSNS to control heart rate

Certain drugs cannot be taken by mouth because the entire dose of the drug is destroyed in the liver before it ever reaches the general circulation. Explain why these same drugs can be given by injection, either intravenously or intramuscularly.

the drug given IV or IM reaches the tissues via capillary beds before it is destroyed in the hepatic portal system

Palpation of both carotid arteries at the same time initiates a reflex known as the baroreceptor reflex. If this reflex is initiated in a healthy person with normal blood pressure, the person may temporarily lose consciousness. Explain why this happens, considering the effects of the baroreceptor reflex.

the sudden, abnormal drop in blood pressure deprives the brain of blood temporarily, which results in a loss of consciousness

The diseases known as collagen vascular diseases are characterized by defects in the collagen in the tunica externa. What effects would you expect such diseases to have on blood vessels?

weakens the vessels and makes them prone to ballooning and potential rupture, particularly in the arteries under high pressure such as the aorta.