Question 1

The white blood cells that are important in leaving the blood vessels and phagocytizing large materials are

Accepted Answer

Monocytes are the white blood cells that leave the blood vessels and differentiate into macrophages, which phagocytize large materials such as bacteria and cellular debris. Neutrophils and eosinophils also have phagocytic properties but are primarily involved in destroying pathogens through the release of granules. Basophils are involved in allergic reactions and inflammation, and lymphocytes are involved in specific immune responses.

Question 2

Pus contains

Accepted Answer

Pus is a thick, yellowish or greenish fluid that forms at the site of infection. It comprises a mixture of leukocytes, bacteria, and damaged body cells, among other components. Platelets are not typically present in pus.

Question 3

The following is a list of the steps involved in the process of hemostasis and clot removal: 1. coagulation
2) fibrinolysis
3) vascular spasm
4) retraction
5) platelet phase
The correct sequence of these steps is

Accepted Answer

The correct sequence of the steps involved in the process of hemostasis and clot removal is as follows: 
1) Vascular spasm - to reduce blood flow and prevent further bleeding 
2) Platelet phase - platelets adhere to the damaged blood vessel and form a plug 
3) Coagulation - the formation of fibrin mesh that stabilizes the platelet plug 
4) Retraction - the clot tightens and pulls the edges of the damaged vessel together 
5) Fibrinolysis - the breakdown and removal of the clot once the damage is repaired. 
Therefore, the correct sequence is 3, 5, 1, 4, 2, which corresponds to choice letter B.

Question 4

The intrinsic pathway of coagulation is activated by

Accepted Answer

The intrinsic pathway of coagulation is activated by the activation of a proenzyme exposed to collagen, which sets off a chain reaction leading to the formation of a clot. This is in contrast to the extrinsic pathway, which is activated by the release of tissue factor by damaged endothelium.

Question 5

The main event of the coagulation phase is

Accepted Answer

The main event of the coagulation phase is the activation of fibrinogen, which leads to the formation of fibrin and the formation of a blood clot. Vascular spasm, clot retraction, the formation of a platelet plug, and the contraction of platelets are all important processes during coagulation, but they are not the main event.

Question 6

Platelets release ________, which causes local vasoconstriction.

Accepted Answer

Platelets release serotonin, which causes local vasoconstriction by narrowing the blood vessels in the area. This helps to stop bleeding and maintain a clot.

Question 7

Which of the following is a necessary cofactor in the formation of a blood clot?

Accepted Answer

Calcium is required for the conversion of prothrombin to thrombin, which is a necessary step in the formation of a blood clot. Fibrinogen and prothrombin are also involved in clotting, but they require calcium as a cofactor. Albumin is not directly involved in clotting, and while vitamin K is important for the production of several clotting factors, it is not a necessary cofactor in the formation of a blood clot.

Question 8

The least numerous white blood cells in peripheral circulation are the

Accepted Answer

Basophils are the least numerous white blood cells in peripheral circulation, typically making up less than 1% of total white blood cell count. Basophils are the least numerous white blood cells in peripheral circulation, making up only 0.5-1% of all white blood cells.

Question 9

During a viral infection, you would expect to see increased numbers of

Accepted Answer

During a viral infection, the body's immune response primarily involves the activity of lymphocytes, particularly T cells and B cells. Thus, an increase in lymphocyte numbers would be expected. Neutrophils, eosinophils, and basophils are all associated with different aspects of the immune response, but are generally not as involved in viral infections as lymphocytes. Thrombocytes (also called platelets) are not directly involved in the immune response, but are important for blood clotting.

Question 10

Platelets function in

Accepted Answer

Platelets perform all of the above functions. They transport chemicals important for clotting, form temporary patches in injured areas, undergo contraction after clot formation, and also initiate the clotting process.

Question 11

Which of the following is the MOST active phagocytically?

Accepted Answer

Neutrophils are the most active phagocytic cells among the given options. They are a type of white blood cell that can rapidly respond to an infection or injury by migrating from the bloodstream to the site of infection to engulf and destroy the invading microorganisms or foreign particles. Neutrophils also release chemicals that attract other immune cells to the area. Eosinophils are also phagocytic cells but are specialized to attack parasites rather than bacteria and viruses. Basophils primarily release histamine and other chemicals involved in inflammation and allergies. Lymphocytes are a type of immune cell that are involved in adaptive immunity and do not have phagocytic abilities. Erythrocytes, or red blood cells, do not have any immune function and are not involved in phagocytosis.

Question 12

Neutrophils

Accepted Answer

Neutrophils are granular leukocytes that have lobed nuclei and are phagocytic, meaning they engulf and destroy pathogens such as bacteria. Therefore, all options are correct.

Question 13

Platelets are

Accepted Answer

Platelets are small, irregularly shaped cell fragments that help to form blood clots by sticking together and plugging a damaged blood vessel.

Question 14

Thrombocytopenia is a deficiency of

Accepted Answer

Thrombocytopenia is a deficiency or decrease in the number of platelets in the blood. It does not affect the levels of antibodies, erythrocytes, or WBC. Therefore, the correct answer is C) platelets.

Question 15

A sample of tissue from an injury shows a large number of eosinophils. This would indicate that the tissue was

Accepted Answer

Eosinophils are white blood cells that are typically associated with an immune response to parasites, such as helminths (e.g. worms). Therefore, a large number of eosinophils in tissue would indicate an infection caused by parasites. Eosinophils are a type of white blood cell that are typically associated with an immune response to parasitic infections. Therefore, the presence of a large number of eosinophils in tissue suggests that the tissue is infected by parasites.

Question 16

Which of the following vitamins is needed for the formation of clotting factors?

Accepted Answer

Vitamin K is required for the formation of clotting factors in the liver that are necessary for normal blood clotting.

Question 17

Bill wants to determine his blood type, so he takes a few drops of blood from a puncture wound in his finger and mixes it with various antisera. His blood cells agglutinate when mixed with the anti-A sera and anti-Rh sera, but not with the anti-B sera. This means

Accepted Answer

The answer of Bill wants to determine his blood type,...

Question 18

________ are large phagocytic WBCs that are "transformed" into phagocytic macrophages at the site of an injury.

Accepted Answer

Monocytes are large phagocytic WBCs that can migrate into tissues and transform into macrophages at the site of an injury or infection. Neutrophils are also phagocytic WBCs but do not transform into macrophages. Eosinophils and basophils have important roles in the immune response, but they are not usually involved in phagocytosis. Lymphocytes, while important in immune defense, are not phagocytic cells.

Question 19

The basic event that causes a blood clot to form is the change of

Accepted Answer

The basic event that causes a blood clot to form is the change of fibrinogen to fibrin. Fibrinogen is a soluble protein in blood plasma, but upon activation by thrombin it is converted into fibrin, which forms a network of fibers that reinforces a blood clot.

Question 20

The common pathway of coagulation ends with

Accepted Answer

The common pathway of coagulation ends with the activation of a clotting factor that converts fibrinogen to fibrin, which results in the formation of a stable clot. Choices A, B, and C are all part of the initial steps of coagulation but do not represent the final step of the process. Choice D represents the conversion of prothrombin to thrombin, which is an earlier step in the coagulation pathway. The common pathway of coagulation ends with the activation of a clotting factor (Factor X) that ultimately converts fibrinogen to fibrin, resulting in the formation of a stable clot. Choices A, B, and C describe events that occur earlier in the coagulation process. Choice D describes the conversion of prothrombin to thrombin, which occurs in the final step of the previous pathway (the prothrombinase pathway) and is not part of the common pathway.

Quiz 11: The Cardiovascular System: Blood