Lymph does not contain:
1. | proteins | 2. | microorganisms |
3. | red blood cells and platelets | 4. | minerals |
The lymph eventually enters the circulation by draining into two specific ___________.
1. arteries
2. arterioles
3. capillaries
4. veins
The fraction of an anticoagulated blood sample called the "buffy coat" contains
1. red blood cells
2. white blood cells
3. platelets
4. white blood cells and platelets
The cause of “aplastic anemia" would be:
1. lack of iron content or iron absorption from the diet
2. destruction of the bone marrow, perhaps by chemicals in the environment or chemotherapy
3. high altitude
4. inadequate vitamin B12 absorption from the diet because the intrinsic factor is absent
Thrombocytes:
1. have a life span of about 60 days
2. are also called megakaryocytes
3. release a chemical called serotonin that constricts blood vessels
4. are not involved in hemostasis
The rarest white blood cells are:
1. | neutrophils | 2. | eosinophils |
3. | basophils | 4. | lymphocytes |
What is true regarding pulmonic and aortic semilunar valves in the human heart?
1. They prevent the backflow of blood from the ventricles into the atria
2. They are open during the relaxation phase of the ventricles
3. They are held tightly closed by papillary muscles and chordae tendineae
4. They regulate the passage of blood from the ventricles into the pulmonary artery and the aorta
Which of the following causes the second heart sound [dub]?
1. opening of the AV valves at the start of diastole
2. closing of the AV valves at the start of systole
3. opening of the semilunar valves at the start of systole
4. closing of the semilunar valves at the start of diastole
The sinoatrial node is the normal pacemaker of the human heart because it:
1. | can form action potentials that can spread throughout the rest of the heart |
2. | depolarizes to its threshold potential before other pacemakers in the heart |
3. | is located in the top of right atrial wall |
4. | is most likely to form an ectopic focus |
What is the ejection fraction that is achieved by the left ventricle in a healthy heart?
1. 10(--)15%
2. 25(--)33%
3. 60(--)70%
4. 98(--)100%