Unit 7 Review Lesson 1: The Blood

Unit 7 Review Lesson 1: The Blood ● Outline the composition of the blood and discuss the function(s) of its components. - Whole blood can be separated into different parts - Plasma - Include plasma proteins: - Albumins: involved in osmolarity and transport - Globulins: part of immune response and antibodies (immunoglobulins) - Fibrinogen: blood clotting, helps form serum - Buffy coat - Platelets (thrombocytes) - Involved with forming blood clots - WBC (leukocytes) - Involved in the immune response - Hematocrit (erythrocytes) - The part with all the RBC ● Discuss the clinical significance of hematocrit value. - It indicates the total amount of RBC count - Provides information about someone's overall health and shows many conditions and disorders - Anemia: not enough RBC - Polycythemia: too many RBC - Dehydration: lots of hematocrit and very little plasma (liquid portion) - Blood doping: lots of hematocrit - Tissue hypoxia from lack of oxygen: low amounts of RBC b/c of lack of oxygen being carried around the body ● Describe the characteristic features of erythrocyte and hemoglobin. - RBC have no nucleus, no organelles, and no ribosomes, they contain hemoglobin - Hemoglobin is within the RBC and they are used to transport O2 and CO2 throughout the body. They are made of 4 heme groups and a globin portion ● Compare and contrast the five kinds of leukocytes and explain the significance of a differential white blood cell count. - Neutrophils - Most abundant WBC - First responders - Inflammatory response - granulocyte - Eosinophils - Involved in parasitic infections - Attacks things coated in antibodies by exocytosis - Increase in number during infection and allergy responses - Granulocytes - Basophils - Least numerous - Synthesizes and stores histamine and heparin (main inflammatory response) - Granulocyte - Monocytes - In bloodstream they are monocytes, in tissues they are macrophages - Macrophages are aggressive phagocytes - Agranulocytes - Leukocytes - T lymphocytes - Destroys cells by releasing cytotoxins that punch holes into the cell membrane - Cell mediated immunity - B lymphocytes - Antibody-mediated humoral immunity - Produces antibodies - Differential WBC count - Shows which WBC are active and can show the state of the infection you are in (if you have lots of neutrophils you are in early stages, but if there are lots of others it might indicate the type or later stage of the infection) ● Describe the characteristics and functions of platelets. - Also called thrombocytes - Thrombopoietin stimulates platelet creation (thrombopoiesis) - Platelets form in the bone marrow (myeloid tissue) - Megakaryocytes create the platelets - Platelet plug formation - hemostasis ● Define hemostasis and explain the stages involved in blood clotting. Consider the impacts of alterations in blood clotting (increased clotting vs increased bleeding). - Hemostasis is the formation of a blood clot - 1. Vascular Phase - Vascular spasm - Basically the blood vessels decrease in diameter to stop bleeding - 2. Platelet Phase - Platelets start to form a plug and release chemicals - 3. Coagulation Phase - Coagulation cascade - Extrinsic pathway activates Factor X due to tissue trauma - Intrinsic pathway activates Factor X due to damage inside the blood vessel - Factor X activates prothrombin activator - Prothrombin activator turns prothrombin into thrombin - Thrombin turns fibrinogen into fibrin - Fibrin forms the mesh that causes the clot - 4. Clot Retraction - The platelets in the clot contract and reduce the size of the damaged area - 5. Clot Destruction - The clot is removed through fibrinolysis to prevent restriction of blood flow ● Describe ABO and Rh blood grouping system and explain the clinical significance of the blood types. - Each type of blood has different antigens on the surface that correspond with their name (ie. A blood has A antigens and AB blood has A and B antigens) - However O blood simply means there is no antigens (A or B) - Each blood type also has antibodies to the antigens of other blood types so they don't mix (ie. A blood doesn’t like the B antigen of B blood and will coagulate if in contact) - RH factor is an antigen that determines the +/- factor of the blood type - The lack of Rh means you are negative (ie. O-) - You do not naturally have antibodies to the Rh factors in blood unless you come into contact with it from being introduced to someone else's blood with that antigen (HDN, transfusion reactions) - AB+ blood is a universal receiver because none of the other blood types will affect them - O- blood is a universal donor because they have literally no antigens and they won't affect other blood cells if they come into contact ● What is the significance of Rh factor and the effect of Rh incompatibility between mother and fetus? - Hemolytic Disease of the Newborn (HDN) - In the first pregnancy everything is fine and dandy because their blood does not come into contact with each other until birth - In the second pregnancy, the mother will develop antibodies to the RH factor of the babies blood and it will attack the fetus unless administered Rhogam - Also this happens when the mother is - and the baby is + Lesson 2: The Heart ● Describe the location of the heart in relation to other structures of the thoracic cavity and identify its borders. - The heart is located in the pericardial cavity in between the lungs, slightly offcentered to the left side of the body (in the mediastinal space) - The superior portion of the heart is where the great vessels attach - The inferior portion of the heart is the apex and its border is related to the right ventricle - The right side of the heart border is from the right atrium - The left side of the heart border is from the left atrium and left ventricle ● Describe the structure and functions of the pericardium and heart wall. - The pericardium is the outer portion of the heart wall - Parietal pericardium - - - - Dense fibrous layer - Areolar layer - mesothelium Visceral pericardium (epicardium) - Mesothelium - Areolar layer - External surface of the heart Myocardium - Internal section of the heart - Contains the heart muscles that contracts Endocardium - The innermost layer of the heart - Simple squamous epithelium ● Describe the internal anatomy of the chambers of the heart. - 4 chambers: RA, RV, LA, LV - Interatrial septum: separates the atria - Interventricular septum: separates the ventricles - 4 valves - 2 semilunar valves: pulmonary and aortic - 2 atrioventricular valves: tricuspid and mitral - Chordae tendinae: the heart strings, help keep valves in place - Papillary muscles: keep the heart strings attached - Trabeculae carnae: meshwork in the ventricles that help ventricles pump blood - Pectinate muscles: line the atria and help them contract - ● ● ● ● ● ● Ligmentum arteriosum: leftover from fetal development where the pulmonary and systemic circuits were attached Identify the major structures of the heart and trace the flow of blood through the pulmonary and systemic circulations. - Pulmonary circuit - Blood goes to the lungs to be oxygenated - Goes through RA, tricuspid valve, into RV, then through pulmonary valve and to the lungs - Systemic circuit - Blood comes from the lungs and goes out to the rest of the body - Comes in through LA, mitral valve, into LV, then through the aortic valve to the rest of the body Discuss the route of blood in coronary (cardiac) circulation. - Coronary circulation is the flow of blood that is used to oxygenated the heart - Coronary arteries supply the blood through different parts of the heart - Right coronary artery: RA, RV, interatrial septum, (parts of LA, LV, and interventricular septum) - Left coronary artery: LA, LV, (parts of RA, RV, and interventricular septum) - Coronary veins then take the used blood and dump it into the coronary sinus which then dumps it into the RA to go through the cycle again Describe the location of parts of the conduction system of the heart and trace the pathway of impulse initiation and conduction. - The conduction of the heart begins at the SA node (a pacemaker cell) and then travels to the internodal pathway to the AV node (another pacemaker cell) - Then it goes to the bundle of his (which contains contractile cells), and travels down the left and right bundle branches - From there it goes to purkinje fibers that push the impulse throughout the whole heart Describe the cycle of contraction and relaxation of the atria and ventricles (cardiac cycle). - 1. Atrial systole, the atria fills with blood and contracts it and pushes it into the ventricles - 2. Ventricular systole, the ventricles fill with blood and push it out - 3. Ventricular diastole, the ventricles relax - 4. The cycle starts again State the events that produce heart sounds. - S1 (lubb) is heard when the atrioventricular valves close (tricuspid and mitral) - S2 (dubb) is heard when the semilunar valves close (pulmonary and aortic) Discuss the factors affecting heart rate and stroke volume that control cardiac output. - Preload - The degree of stretch in the ventricles at the end of diastole - The volume of the blood in the ventricle at the end of diastole determines preload - Afterload - The amount of resistance that the heart must pump against to eject the blood from the ventricles - Contractility - The force produced during contraction - Increased contractility leads to increased stroke volume ● State the events that produce the ECG waves and correlate the ECG waves with the events of the cardiac cycle. - P wave: atrial depolarization - PR segment: AV nodal delay - QRS complex: ventricular depolarization - ST segment: ventricles contract and eject blood - T wave: ventricular repolarization - QT interval: ventricular depolarization and repolarization - TP interval: ventricles are relaxing and filling Lesson 3: Blood Vessels & Circulation ● Contrast the structure and function of arteries, arterioles, capillaries, venules and veins. ○ Arteries ■ Moves blood AWAY from the heart to peripheral capillaries ■ Big → small ■ High pressure vessels since they are closest to the heart ○ Arterioles ■ A smaller artery that delivers blood to a capillary branch ■ Less pressure than large arteries since it's a little farther away from the heart ○ Capillaries ■ A small blood vessel located between an arteriole and a venule ■ It has thin walls for diffusion of gasses, nutrients, and wastes between the plasma and interstitial fluid ○ Venules ■ A smaller vein that receives blood from the capillaries ■ Unites to form larger veins ○ Veins ■ Moves blood TOWARDS the heart from a capillary bed ■ Small → big ● Identify the arterial branches of the head, neck, chest and abdomen. ○ Head and Neck ■ Internal carotid: brain ■ External carotid: face and neck ○ Chest ■ Aorta ■ Coronary arteries: the heart ■ Thoracic aorta: thoracic cavity ■ Bronchial arteries: lungs ■ Esophageal arteries: esophagus ○ Abdomen ■ Abdominal aorta ■ Celiac trunk: → hepatic artery → left gastric artery → splenic artery ■ Superior mesenteric artery: small intestine and large intestine ■ Inferior mesenteric artery: lower part of large intestine ■ Renal arteries: kidneys ■ Common iliac arteries: → internal and external iliac arteries ● Define blood pressure and discuss the factors affecting blood pressure. ○ Blood pressure: the pressure exerted by the blood against the walls of the arteries as the heart pumps it around the body (usually refers to arterial pressure) ○ Nervous system ■ ANS ● Parasympathetic ↓BP ● Sympathetic ↑BP ■ Vasomotor center ● Adrenergic neurons secrete NE/E causing smooth muscle constriction ● Ach at neuromuscular junction stimulates NO synthesis causing dilation of vessels in skeletal muscles ■ Reflexes ● Chemoreceptors ○ Senses Increased CO2, decreased O2, decreased pH, and then communicates with medulla and vasomotor centers ● Baroreceptors ○ Activity increases and lowers BP ○ Activity decreases and raises BP ○ Endocrine control ■ Adrenal medulla ● Stimulated by NE/E ● Increases HR, CO, and vasoconstriction ● ↑ BP ■ Aldosterone ● Stimulated by low NA or high angiotensin 2 ● Conservation of NA → water retention → increased BP ■ Erythropoietin ● Stimulated by low BP or low O2 ● Vasoconstriction, RBC production, increased BP ■ ADH ● Stimulated by decreased BP, increased solute concentration, or increased angiotensin 2 ● Conservation of water by kidneys → raises BP ■ Angiotensin 2 ● Stimulated by decreased blood flow to kidneys ● Renin → angiotensin → angiotensin 1 + (ACE)→ angiotensin 2 ● Aldosterone secretion, ADH secretion, increased CO, vasoconstriction → increases BP ■ Natriuretic peptides ● Stimulated by excessive cardiac stretch ● Na and water loss, inhibits hormones that increase BP, vasodilation → decreases BP ○ Resistance ■ Blood vessel length ● Short blood vessel: less area to flow through, decreases resistance, lower BP ● Long blood vessel: more area to go through, increases resistance, higher BP ■ Blood viscosity ● Thick blood: more resistance, higher BP ● Thin blood: less resistance, lower BP ■ Blood vessel diameter ● Vasoconstriction: decreases diameter of blood vessels and increases pressure ● Vasodilation: increases diameter of blood vessels and decreases pressure ● Explain the following: pulse pressure, mean arterial pressure, peripheral resistance, and venous return. ○ Pulse pressure: the difference between systolic and diastolic pressures ○ Mean arterial pressure (MAP): the average arterial pressure through one cardiac cycle ○ Peripheral resistance: resistance to the flow of blood through small vessels ○ Venous return: the flow of blood from the periphery to the right atrium ● Describe the mechanisms that aid in returning venous blood to the heart ○ Venous valves ○ Vasoconstriction and vasodilation ● Discuss the structure and functions of capillaries and the pathophysiology of edema. ○ Capillaries are very small exchange vessels that are present in capillary beds. They are used for chemical and gaseous exchange to maintain homeostasis ■ Continuous: complete endothelial lining (no gaps) to allow for simple diffusion and bulk transport ■ Fenestrated: have pores for rapid exchange between blood and interstitial fluid ■ Sinusoid: have a discontinuous endothelial lining, permitting free movement of water and solutes (including large plasma proteins) ○ Edema ■ An abnormal increase in interstitial fluid that can occur when filtration exceeds absorption ● Hydrostatic pressure > osmotic pressure ■ Excess filtration may be due to hypertension, or leaky capillaries ■ Inadequate reabsorption may be due to decreased plasma proteins ● Define hypertension, listing the risk factors and explaining the classification of hypertension according to the etiology. ○ Hypertension is when BP is over 140/90 ○ Primary hypertension ■ Cause is typically unknown but it may be due to environmental factors, genetics, diet, family history, lifestyle, behaviors etc. ○ Secondary hypertension ■ Usually occurs secondary to a known primary problem, or due to medications ○ Eg. renal hypertension, endocrine hypertension ○ High BP can damage your arteries by making them less elastic, which decreases the flow of blood through the heart and leads to heart disease ■ It can also cause chest pain (angina)