Final Exam Flashcards
What is the composition of blood?
Blood is a liquid connective tissue comprised of formed elements suspended in a liquid matrix (plasma) and contains fibers (fibrin) which become visible during clotting.
Formed elements include red blood cells, white blood cells, and platelets.
What are the three formed elements of blood?
- Plasma
- White blood cells
- Red blood cells
- Platelets
- Thromboxane A
Which statement about erythrocytes (RBCs) is NOT true?
Erythropoiesis is triggered by EPO which is secreted by the bone marrow
Which structural characteristic does NOT contribute to erythrocyte oxygen transport?
Mitotically active
True or False: Hemoglobin is made up of the protein heme and the red pigment globin.
True
True or False: Each hemoglobin molecule can transport two molecules of oxygen.
False
Describe the general steps of erythropoiesis.
All cells are derived from a common hematopoietic cell; the myeloid cell line gives rise to RBCs, platelets, and various white blood cells, while the lymphoid cell line gives rise to lymphocytes.
What stimulates erythropoiesis?
Hypoxia of EPO-producing cells in the kidney
The process by which WBCs leave the bloodstream is called ___
diapedesis
Which statement about platelets is NOT true?
Platelets normally kept mobile in the blood stream by factors released from the endothelium
Indicate which cell types the following statements apply to: RBCs, WBCs, platelets.
- Complete cells: WBCs
- Make up 98% of all formed elements: RBCs
- Have a nucleus: WBCs
- Are cell fragments: Platelets
- Have no nuclei: RBCs
- Contain hemoglobin: RBCs
- Are involved in the immune response: WBCs
- Are involved in hemostasis: Platelets
What is the correct sequence for the events of coagulation?
- Formation of prothrombin activator
- Prothrombin → thrombin
- Fibrinogen → fibrin
- Clot retraction
- Fibrinolysis
Which statement about hemostasis is NOT true?
All are true statements
What mechanisms prevent undesirable clotting?
- Rapid dilution of clotting factors
- Anticoagulants in the blood
Which statement about the heart is NOT true?
The base of the heart points towards the left hip.
What is the function of the pericardial fluid?
Protects the heart from friction.
What structures line the heart chambers?
Simple squamous epithelium (endocardium)
Trace the pathway of blood through the heart starting with the right atrium.
From body (vena cavae) → Right atrium → Tricuspid valve → Right ventricle → Pulmonary semi-lunar valve → Pulmonary trunk → Lungs → Pulmonary veins → Left atrium → Mitral valve → Left ventricle → Aorta → Body
Indicate if the following statements about cardiac muscle cell physiology are true or false.
- Cardiac muscle cells are striated and interconnected: True
- Cardiac muscle cells are short and fat compared to skeletal muscle cells: True
- Cardiac muscle cells do not require innervation to contract: True
- Cardiac muscle cells do not contract via a sliding filament model: False
- Plasma membranes of cardiac muscle cells are connected via desmosomes: True
- Gap junctions allow electrical currents to pass: True
How does the action potential of cardiac contractile cells differ from skeletal muscle?
Very fast depolarization, presence of Ca++ channels causing a plateau phase, long refractory period allowing chambers to fill.
Put the components of the intrinsic conduction system of the heart in the correct order.
- SA node
- AV node
- AV bundle
- Bundle Branches
- Subendocardial conducting network (Purkinje Fibers)
How do the SA node, AV node, and AV bundle regulate heart activity?
The SA node generates impulses, which spread to the AV node and then through the AV bundle to depolarize the rest of the heart.
What would be the most likely outcome if the AV bundle of the heart were damaged?
The ventricles would not contract.
Which statement about the intrinsic conduction system of the heart is NOT true?
The pattern of ion channel opening and closing in pacemaker cells is identical to that seen in cardiac contractile cells.
