Blood & Cardiovascular System Flashcards
What are the major functions of blood?
-transportation of nutrients/waste/hormones -regulation of body temperature/water volume/pH -defense against infections and bleeding
Differentiate between blood plasma and formed elements:
-plasma is the liquid portion of blood (55% of whole blood) - formed elements are WBCs/RBCs/platelets (45% of whole blood)
What substances are dissolved in plasma?
-proteins-hormones-ions-wastes-amino acids-carbs-vitamins
Plasma proteins:
Albumins: maintain osmotic balance with interstitial fluid Globulins: diverse group of proteins Beta Globulins: transport function/bind to lipid forming lipoproteins HDL- good cholesterol LDL- bad cholesterol Gamma Globulins: antibodies/body’s defense against infection
How are RBCs and WBCs made?
-from the continuous division of stem cells
Process of RBC production (erythropoiesis):
-the RBC number is maintained by negative feedback -special cells in the kidney monitor O2 availability and secrete the hormone erythropoietin if O2 levels are low - EPO stimulates stems cells in bone marrow and causes an increase in RBC production
What is the function of RBCs?
-transport oxygen to body tissues; transport carbon dioxide away from tissues
What is the function of WBCs?
-defend the body against invading organisms
What is hematocrit?
-percentage of whole blood that consists of RBCs
Difference between women’s and men’s hematocrit?
-women have a lower hematocrit than men due to menstruation
% of WBCs, RBCs and plasma in blood?
WBCs and platelets: 1% RBCs: 44% Plasma: 55%
What is blood typing? Why is it important?
blood typing: the type of blood you have (ABO) -it is important because you must receive/donate blood to/with someone who is compatible to your blood type
How is oxygen carried in blood?
- RBCs are packed with hemoglobin, a protein which transports oxygen
- hemoglobin is composed of four polypeptide chains which each contain a heme group of an iron atom that readily bonds with oxygen molecules
How is carbon dioxide carried in the blood?
- in tissues where carbon dioxide levels are high about 25% of the CO2 binds to hemoglobin
- in the lungs CO2 detaches from hemoglobin and is eliminated through respiration
What effect would CO have on the bloods ability to carry oxygen?
- carbon monoxide would impede on the blood’s ability to carry oxygen
- CO combines with hemoglobin producing carboxyhemoglobin which diminishes hemoglobin’s oxygen carrying capacity
What blood types can donate to what other types?
What is agglutination?
-the clumping together of foreign cells induced by cross-linking of antigen-antibody complexes
What are platelets?
-cell fragments that are important in blood clotting
Process of hemostasis:
- ) Vascular Spasm: constriction of blood vessels to reduce blood flow
- ) Platelet Plug Formation: sealing of the ruptured blood vessel
- ) Coagulation: formation of a blood clot/blood changes from liquid to gel/involves at least 12 different clotting proteins in plasma
What is the difference between an antigen and an antibody?
Antigen: non-self protein, foreign to body
Antibody(gamma globulin): a defensive protein directed against specific antigens
What is an Rh antigen and how can this affect a pregnant woman and her baby?
Rh antigen: proteins on the surface of RBCs that can cause a response from the immune system
-If a pregnant woman has the Rh- antigen and her child is Rh+ the mother will respond to the childs blood by producing anti-Rh antibodies which could cross the placenta and damage fetal red blood cells (hemolytic disease).
Blood Disorders:
Mononucleosis: Epstein Barr virus infection of lymphocytes “mono”
Blood Poisoning (septicemia): can develop from infected wounds, burns, major dental procedures/may be life threatening
Anemia: reduction in oxygen carrying capacity of blood
Leukemia: uncontrolled production of white blood cells
Multiple Myeloma: form of cancer/proliferation of plasma cells in the bone marrow
Thrombocytopenia: reduction in platelet number/unusual bruising and bleeding
The path of blood through the heart and body:
Rt Atrium–>Rt AV valve (tricuspid)–>Rt ventricle–>Pulm. S.L. valve–>Pulm. Trunk–>
Pulm. Veins–>Left Atrium–>Left AV valve (bicuspid/mitral)–>Left ventricle–>
Aortic S.L. valve–>Aorta–>Vena Cava
Arteries:
- transport blood away from the heart
- transport blood under high pressure
- thick walled
- 3 layers
- outer layer of connective tissue-middle layer of smooth muscle-inner layer of squamous epithelial cells
Veins:
- return blood to the heart
- larger lumen (hollow interior) than arteries
- high distensibility (able to swell)
- serve as blood volume reservoir
- 3 layers (same as arteries)
What controls the flow of blood through a capillary?
-The precapillary sphincters serve as gates that control blood flow into individual capillaries
Vasodilation: relaxation of vascular smooth muscle/increases blood flow to capillaries
Vasoconstriction: contraction of vascular smooth muscle/decreases blood flow to capillaries
What materials move back and forth between capillaries and tissues?
- fluid is filtered out of the vessel into the interstitial fluid, accompanied by oxygen, nutrients, and raw materials needed by the cell
- high concentration to low concentration
How is blood pumped through a vein?
- ) contraction of skeletal muscles
- ) one-way valves inside the veins
- ) movements associated with breathing
Systemic and Pulmonary Circulation:
Systemic Circulation (rest of body): O2 is used, CO2 waste is produced
Pulmonary Circulation (lungs): blood picks up O2, gets rid of CO2
Anatomy of Heart
The Pattern of Blood Flow Through the Cardiovascular System:
- blood passes through the heart twice for every one trip around the body
1. ) once as deoxygenated blood, through the right side of the heart
2. ) once as oxygenated blood, through the left side of the heart
How is blood supplied to the heart muscle(myocardium)?
- blood is supplied to the heart muscle by the coronary arteries which branch from the aorta
- from the surface the coronary arteries send branches inward to supply the myocardium
What happens if blood flow to the myocardium (coronary artery) is blocked?
-heart attack: sudden death of an area of the heart tissue due to oxygen starvation
Cardiac Systole & Diastole:
Cardiac Systole: ventricles or atria of the heart are contracting/AV valve open, semilumar valves are closed/ventricles fill
Cardiac Diastole: heart chamber is relaxed/both atria and ventricles relax/semilunar valves close
Path of the electrical conduction system of the heart:
- the stimulus that initiates contraction starts at the sinoatrial node (near rt. atrium & superior vena cava
- impulse travels from cell to cell across both atria
- impulse reaches atrioventricular node and travels to atrioventricular bundle (septum between the two ventricles)
- impulse is carried by the Purkinje fibers to cells in myocardium and ventricles
How is heart rate controlled intrinsically/extrinsically?
Atrial Systole: both atria contract forcing blood into ventricles/AV valves are open, S.L. valves are closed
Ventricular Systole: both ventricles contract/AV valves close, S.L valves open/blood ejected into pulmonary trunk and aorta/atria relax
Diastole: ventricles relax and fill with blood through open AV valves/S.L. valves are closed and atria are relaxed
How does pressure change from the arteries to arterioles to capillaries to venules and then to veins?
-Area of high pressure to an area of low pressure
Major arteries/veins of the body:
How do we measure blood pressure? What is normal blood pressure?
-blood pressure is measured with a sphygmomanometer (an inflatable cuff) that is places over the brachial artery/cuff is inflated to a pressure above systolic pressure and blood flow through brachial artery stops because the cuff pressure collapses the artery
Normal blood pressure: Systolic below 120 mm Hg /Diastolic below 80 mm Hg
What is hyper/hypotension?
Hypertension: high blood pressure/strain on cardiovascular system/blood vessels become hardened and scarred/no symptoms
Hypotension: low blood pressure/may cause dizziness or fainting/may result from excessive blood or fluid loss from burns
What is a baroreceptor/what does it do?
Baroreceptor: pressure receptors in aorta and carotid arteries
- )blood pressure rises, vessels are stretched
- )baroreceptors are activated/signal sent at increased rate
- )signals travel to cardiovascular center in brain
- )signals from cardiovascular center sent to hear to lower heart rate and force contraction(decreases cardiac output
- ) blood vessels signaled to reduce vascular resistance,increasing blood flow to tissues
- )combined effects lower blood pressure
Function of the lymphatic system:
- maintains blood volume
- returns excess interstitial fluid to circulatory system
- functions in immune defenses
What is a heart attack/coronary bypass?
Heart Attack: sudden death of an area of myocardium
Coronary Bypass: piece of blood vessel is removed from somewhere else in the body (often a leg vein) and grafted onto the blocked artery to bypass the damaged region
-heart attacks survival rate has risen with coronary artery bypass graft
Cardiovascular Disorders:
Embolism: blockage of a blood vessel by material floating in blood stream (pulmonary and cerebral)
Stroke: damage to part of brain cause by interruption of blood supply
Atherosclerosis: buildup of fatty deposits on and within the inner walls of arteries
Aneurysm: ballooning or bulging of the wall of an artery caused by dilation or weakening of the wall
Angina: narrowing of coronary arteries and diminished blood flow to coronary muscle
Congestive Hear Failure: weakness of heart causes fluid back-up in intersitial spaces
