25 Flashcards
- Normal hemostasis depends on all of the following except
A. an intact vascular system
B. inadequate numbers of platelets
C. appropriate coagulation factors
D. fibrinolysis
B. inadequate numbers of platelets
The sequence of events following injury to a small blood vessel is (2) ______ to (3) ______ to (4) ______ to (5) ______ to (6) ______.
A. contact between damaged blood vessel, blood platelets, and coagulation proteins
B. formation of a platelet plug
C. fibrinolysis and reestablishment of vascular integrity
D. development of a blood clot around the injury
E. blood vessel spasm (vasoconstriction)
- E. blood vessel spasm (vasoconstriction)
- B. formation of a platelet plug
- A. contact between damaged blood vessel, blood platelets, and coagulation proteins
- D. development of a blood clot around the injury
- C. fibrinolysis and reestablishment of vascular integrity
- Which blood vessels have the thickest walls?
A. Veins
B. Arteries
C. Capillaries
D. Arterioles
B. Arteries
- All blood and lymphatic vessels are lined with
A. endothelium
B. nerve endings
C. stratified epithelial cells
D. simple squamous epithelium
A. endothelium
- Blood passes from the arterial to the venous system via
A. arterioles
B. capillaries
C. veins
D. arteries
B. capillaries
The initiating stimulus to blood coagulation following injury to a blood vessel is
A. contact activation with collagen
B. vasoconstriction
C. stenosis
D. release of serotonin
A. contact activation with collagen
Endothelium is involved in the metabolism and clearance of molecules such as
A. serotonin
B. angiotensin
C. bradykinin
D. all of the above
D. all of the above
Which of the following is not correct?
A. Vasoconstriction reduces blood flow and promotes contact activation of platelets and coagulation factors.
B. Platelets adhere to exposed endothelial connective tissues.
C. Aggregation of platelets releases thromboxane A2 and vasoactive amines (serotonin and epinephrine).
D. None of the above.
D. None of the above.
Which of the following is (are) true of endoreduplication?
A. Duplicates DNA without cell division
B. Results in cells with ploidy values of 4n, 8n, 16n, and 32n
C. Is unique to the megakaryocytic type of blood cell
D. All of the above
D. All of the above
Which of the following is (are) true of thrombopoietin?
A. Thought to stimulate the production and maturation of megakaryocytes
B. Is influenced by various cytokines, which increase megakaryocyte size
C. Is influenced by various cytokines, which impact maturational stage and ploidy
D. All of the above
D. All of the above
Which of the following is not a characteristic of platelets?
A. The presence of a nucleus
B. Life span of 9 to 12 days.
C. Cytoplasm is light blue with fine red-purple granules.
D. A discoid shape as an inactive cell.
A. The presence of a nucleus
The cellular ultrastructural component unique to the platelet is the
A. cytoplasmic membrane
B. glycocalyx
C. mitochondrion
D. microtubule
B. glycocalyx
Choose the incorrect statement regarding storage granules related to hemostasis in the mature platelet.
A. Alpha-granules contain platelet factor 4, beta-thromboglobulin, and platelet-derived growth factor.
B. Alpha-granules contain platelet fibrinogen and von Willebrand factor.
C. Dense bodies contain serotonin and ADP.
D. Lysosomes contain actomyosin, myosin, and filamin.
D. Lysosomes contain actomyosin, myosin, and filamin.
- At all times, approximately ______ of the total number of platelets are in the systemic circulation.
A. one fourth
B. one third
C. one half
D. two thirds
D. two thirds
- The reference range of platelets in the systemic circulation is
A. 50 to 150 × 10^9/L
B. 100 to 200 × 10^9/L
C. 150 to 350 × 10^9/L
D. 150 to 400 × 10^9/L
D. 150 to 400 × 10^9/L