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BIOS255 EXAM – Q/A – 100% CORRECT
WEEK1: Cardiovascular System (The Blood) ✔Ans -_________________________ Blood Functions ✔Ans -> transportation (oxygen, carbon dioxide, nutrients, hormones, heat, and waste) > regulation (homeostasis of bodily fluids, pH, blood temp, and water content) > protection (clotting and fighting infections) Blood Properties ✔Ans -> mean fraction of body weight = 8% > volume = 4-6L (based on body size/composition) > viscosity = thicker, higher BP > pH = 7.35-7.45 (below - acidosis) > mean salinity = 0.9% (isotonic, same, to blood) Blood Composition ✔Ans -> whole blood = what you naturally draw out > plasma = semi-fluid matrix acting as transport for molecules and cells > RBC = carries oxygen throughout body for respiration towards energy > platelets = proteins responsible for blood clotting during injuries > WBC = immune cell that helps fight infection Centrifuged Blood Composition ✔Ans -> Plasma = 55% (water, dissolved gasses, nutrients, waste products, proteins) > Buffy Coat = less than 1% (WBCs and Platelets)
> Hematocrit (Erythrocyte) = 45% (RBC - blood covering layer/viscosity/amount) Major Proteins of Blood Plasma ✔Ans -> albumin = responsible for colloid osmotic pressure from influencing viscosity while transporting lipids, hormones, and calcium + buffers blood pH > globulins = transport and defense functions > fibrinogen = becomes fibrin when in contact with thrombin as the major component of blood clots Blood Formed Elements ✔Ans -"cells"; RBCs (Erythrocytes), WBCs (Leukocytes), Platelets Erythrocytes (Red Blood Cells) ✔Ans -> lack a nucleus (cannot perform mitosis), biconcave disc shape, bags of hemoglobin, carry oxygen and some carbon dioxide > Formed in the red bone marrow from the hematopoietic stem cell, myeloid stem cell, erythroblast, reticulocyte, mature RBC Erythrocytes (Red Blood Cells): Composition ✔Ans -> hemoglobin = protein that carries four oxygen to cells and some carbon dioxide (potentially hydrogen) to lungs > erythropoietin = hormone responsible for RCB production by ejecting the nucleus from proerythroblasts released by the kidneys Erythropoiesis (Red Blood Cell Production) ✔Ans - require: reticulocytes, EPO, iron, protein, vitamin B > red blood cell death and phagocytosis for macrophage to react in spleen, liver, or red bone marrow > hemoglobin = globin - breaks down into protein monomer (amino acids) and reused for protein synthesis, heme - releases
> basophils = secrete histamine during allergy (increasing blood flow to tissue) and heparin (prevent clotting acting as a blood thinner) + nuclei that look like pellets/obscured from view Leukocytes: Agranulocytes ✔Ans -clear looking cytoplasm > monocytes = turn into macrophages to phagocytize pathogens/dead neutrophils in presenting antigens to activate immune system cells + continuous, elongated, and folded nucleus > lymphocytes = adaptive immune system in secreting antibodies and killing cancer cells + one large nucleus w/ thin cytoplasm (halo effect) Thrombocytes ✔Ans -> platelets = fragments of cells w/out nucleus that can be responsible for clotting > thrombopotein = hormone responsible for production of platelets (megakaryocytes) > megakaryocytes = cells made by the liver broken up into fragments aka platelets Lymphoid vs Myeloid Stem Cells ✔Ans -give rise to B-cell lymphocytes, T-cell lymphocytes, and Natural Killer cells vs give rise to RBCs, platelet, Monocytes, Neutrophils, Eosinophils, and Basophils Hemostasis ✔Ans -process to stop bleeding > vascular spasm (throbbing) = blood vessel constricts so neutrophils/white blood cells to arrive > platelet plug formation = platelets stick to injury site/collagen fibers so framework of scab to form
> coagulation = (blood clotting/wound healing utilizing vitamin K) converts inactive proteins to active form in forming fibrin strands allowing time for cells to mature and move scab out the way once healed > clot retraction = activated platelets transduce contractile forces onto the fibrin network of a thrombus (increases clot density and decreases clot size) for maintaining blood vessel patency Coagulation Factors ✔Ans -1 = fibrinogen; liver; common 2 = prothrombin; liver; common 3 = thromboplastin (tissue factor); damaged tissues and activated platelets; extrinsic 4 = calcium ions (needed to guide clotting); diet, bones, and platelets; all 5 = proaccerlerin (accelerator globulin); liver and platelets; extrinsic and intrinsic 7 = stable factor; liver; extrinsic 8 = anti hemophilic factor A; liver; intrinsic 9 = anti hemophilic factor B; liver; intrinsic 10 = stuart/power factor; liver; extrinsic and intrinsic 11 = anti hemophilic factor C; liver; intrinsic 12 = anti hemophilic factor D; liver; intrinsic 13 = fibrin stabilizing factor; liver and platelets; common Intrinsic vs Extrinsic ✔Ans -vascular spasm with factor 7 as tissue is damaged vs working with calcium and factors 8, 9, 11, and 12 to form platelet clots Common Pathway ✔Ans -> release clotting factors involving intrinsic and extrinsic > activation of prothrombin factor > conversion of prothrombin to thrombin > conversion of fibrinogen (in the plasma) to fibrin (when in contact with thrombin)
Pericardium ✔Ans -consists of an outer fibrous pericardium and inner serous pericardium separating visceral and parietal > visceral (touches organs) > parietal (facing to walls) Layers to the Heart Wall ✔Ans -> epicardium = visceral pericardium; give the heart's shape and structure in being the outermost layer; produces pericardial fluid and Composed of elastic fibers and adipose tissue > myocardium = pulls on cardiac muscular tissue disc/striations; generates force to pump blood > endocardium = innermost layer that regulates contractility Basic Anatomy of the Heart ✔Ans -> atria = upper chambers of the heart > ventricles = lower chambers of the heart > AV Valves = separates atria from ventricles (R - Tricuspid, L - Bicsupid/Mitral) > semilunar valves = separates ventricles from major vessels (R - pulmonary - separates RV from pulmonary vein, L - aortic - separates LV from aorta) Right Atrium vs Ventricle ✔Ans -receives blood from superior (drains blood from above the heart) and inferior (drains blood from below the heart) vena cava + coronary sinus (drains blood around the heart) vs receives blood from the right atrium and sends blood to the lungs through the pulmonary artery Left Atrium vs Ventricle ✔Ans -receives blood from the pulmonary veins vs
receives blood from the left atrium and sends blood all over the body via the aorta (thickest since it sends blood against gravity to the brain) Fibrous Skeleton ✔Ans -> foundation of the heart valves attachment to prevent overstretching of the valves > point of intersection for cardiac muscle bundles acting as an electrical insulator > chordaetendinae = heart string fibers held by papillary muscles of the tri- and bi- cuspid valves (reduces back flow) Heart Valves ✔Ans -> atrioventricular = prevents back flow from the ventricles into the atria > semilunar valves = prevent back flow from the arteries into the ventricles Nervous System Regulation of the Heart: Input (cardiovascular center) ✔Ans -> higher brain centers: cerebral cortex, limbic system, and hypothalamus > sensory receptors = proprioceptors (monitor movements), chemoreceptors (monitor blood chemistry), baroreceptors (monitor blood pressure) Nervous System Regulation of the Heart: Output (heart) ✔Ans -> cardiac accelerator nerves (sympathetic) = increased rate of spontaneous depolarization in SA/AV node increasing contractility of atria/ventricles/stroke volume > vagus (X) nerves (parasympathetic) = decreased rate of spontaneous depolarization in SA/AV node decreasing heart rate Cardiac Output ✔Ans -CO (mL/min) = SV (mL/beat) x HR (beats/min) Stroke Volume (volume changes) ✔Ans -> end- diastolic volume = amount of blood in ventricles during diastolic
Electrocardiogram ✔Ans -measures levels of electricity within the heart Electrocardiogram: Interpretation ✔Ans -> P wave = atrial depolarization > qrs complex = ventricular depolarization > t wave = ventricular repolarization > pr interval = signal conduction through AV node before activating ventricles > qt interval = duration of ventricular depolarization > qrs interval = atrial depolarization and diastolei > pq segment = signal conduction from SA to AV node initiating systole > st segment = ventricular systole and ejection of blood Action Potential in a Ventricular Fiber ✔Ans -> voltage gated Na+ channels open > Na+ inflow depolarizes membrane, opening sodium channels (positive feedback cycle and rapidly depolarize membrane) > Na+ channels close at voltage peak of +30mV > Ca2+ enters prolonging depolarization creating a plateau > Ca2+ channels close and K+ channels open Other Terms ✔Ans -> Preload = stretch of the atria during ventricular filling. > Afterload = The pressure required to overcome the vascular resistance. > Venous return = The amount of blood returned to the heart via the veins. > Contractility = The intrinsic strength of the contractions of the cardiac muscle. Conduction System ✔Ans -> SA node squeezes atrium
> AV node breakup pace maker making average ~40 beats per minute > AV bundle to R/L bundle branches squeeze ventricles > purkinje fibers help contract as one big unit
