Quizlet final Flashcards
Buffy coat
A thin light colored layer of WBCs and platelets that lie between a top layer of plasma and RBCs in a centrifuged. Makes up less than 1% of the total volume of blood.
Erythrocytes
RBCs that transport oxygen from the lungs to the body cells and deliver carbon dioxide from the body cells to the lungs.
Hemopoiesis
Process where the formed elements of blood develop.
Before birth, this occurs in the yolk sac of an embryo and later in the liver spleen, thymus, and lymph nodes.
After birth and so on, red bone marrow is where this happens.
Thrombopoietin
The hormone produced by the liver that stimulates the formation of platelets from megakaryocytic
Neutrophils
A type of WBCs that engulfs invading microbes and contributes to the non specific defenses of the body against disease.
What cells secrete lysozymes?
Paneth cells/neutrophils
Intrinsic pathway
- Occurs slowly and most complex
- Activators are in direct contact with blood or contained within the blood
- If endothelial cells are roughened or damaged, blood comes in contact with collagen fibers in the connective tissue around endothelium of blood vessels.
- Activates clotting factor XII which begins sequence of reactions that then activate clotting factor x
- Clotting factor x then combines and form prothrombinase
Prothrombinase
The intrinsic and extrinsic pathways of blood clotting are identical after formation of this to produce thrombin and then fibrinogen
Extrinsic pathway
- Factors released by damaged tissues begin cascade, occurs rapidly if trauma is severe
- Thromboplastin leaks into blood from cells outside the blood vessels and initiates the formation of prothrombinase thromboplastin begins sequence of reactions that activate clotting factor x.
- Once factor x is activated, it combines with factor v in the presence of calcium to form prothrombinase
Thrombus
A formation of blood clot in an unbroken vein
Thrombosis
Clotting in an unbroken blood vessel
Agglutinins
Antibodies in the plasma that bring about transfusion mismatch
Agglutination
Clumping of RBCs in an incompatible blood transfusion, antibodies in the recipients plasma bind to the antigens on the antigens on the donated RBCs
Tricuspid valve
Valve between the right atrium and the right ventricles which allows blood to pass from the right atrium to the right ventricle and prevemt blood from flowing back into the right atrium as the heart pumps
Vena cava
The largest vein in the body, it carries blood from the body back to the heart
Atrioventricular (AV) valve
Bicuspid valves: has two cusps which allow blood to pass from the left atrium into the left ventricle, prevents backflow of blood from the ventricles into the atria during systole
Semilunar valve
Acts to prevent backflow of blood from the arteries to the ventricles during ventricular diastole and help maintain pressure on the major arteries
Pulmonary circulation
Flow of blood from the heart to the lungs and back to the heart; right side of the heart pumps deoxygenated blood into the pulmonary circulation to the air sacs
Pulmonary pathway
- Right atrium with deoxygenated blood
- Tricuspid valve
- Right ventricle
- Pulmonary valve
- Pulmonary trunk and pulmonary arteries
- Blood goes into pulmonary capillaries of the lung
- Blood looses co2 and gains o2.
Gap junctions
Allows muscle action potentials to conduct from one muscle fibers to its neighbours. Gap junctions allot the entire myocardium of the atria or the ventricles to contract as a single, coordinated unit
Auto rhythmic fibers
A network of specialized cardiac muscle fibers that are self-excitable; generate action potentials that trigger heart contractions that will continue even after the heart has been removed from the body.
Cardiac conduction system
A network of cardiac muscle fibers that provide path for each cycle of cardiac excitation; ensures that cardiac chambers become stimulated to contraction in a coordinated manner
Systole
The phase of contraction
ECG waves
Predicts the timing of atrial and ventricular systole and diastole
Ventricular systole event
- Cardiac action potential in SA node and propagates throughout the atrial muscle down to AV node, P wave appears in ECG
- After P wave atria contracts, action potential slows at AV node
- Action potential goes rapidly again after entering AV bundle, then goes through bundle branches, purkinje fibers, and ventricular myocardium. QRS complex
- Contraction of ventricular contractile fibers begins after QRS complex. Blood is squeezed upward toward semilunar valves
- Repolarization of ventricular contractile fibers begins and spread in myocardium and produces T wave
- After T wave begins, ventricles relax, contractile fibers relax, and repolarization ends.
T wave
In an ECG, this represents ventricular diastole which happens during ventricular repolarization
Stroke volume
Volume of blood in mL from each ventricle due to the contraction of the heart muscle which compresses ventricles. mL/beat
Cardiac output
The amount of blood the heart pumps through the circulatory system in a minute. mL/min
