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HSF II Cardio I
Cardiovascular I - Vasculature and Cells
Term | Definition |
---|---|
Cardiovascular System consists of: | 1) a conducting system (blood vessels or vasculature) 2) a fluid tissue (the blood) 3) a pump (the heart) |
Closed Circulation | blood is contained within the heart and elements of the blood vasculature |
Closed Circulation and Pressure/Volume | Changes in blood volume will cause changes in pressure inside the system, thus system volume will cause changes in pressure |
Direction of Blood (artery vs vein) | arteries carry blood away from the heart, veins toward it. This is independent of blood oxygenation. E.G. pulmonary and system circulations |
Vascular Tree | Heart => tissues in arteries => distribution of nutrients in capillaries => from tissues => heart via veins. Arteries diverge, veins converge |
Vascular Structure | Tunica intima, tunica media, tunica adventitia (externa). Artery thick media, Vein thick adventitia |
Types of Vessels | 1) elastic arteries 2) muscular arteries 3) arterioles 4) capillaries 5) small, medium, and large veins |
Aorta | it and its initial branches are elastic arteries. They experience recoil |
Elastic Recoil | maintains blood pressure and blood flow during ventricular diatole. Pressure reservoir as they accept new blood from the heart |
Muscular Arteries | include most named arteries. they are the poster child for a typical blood vessel |
Arterioles | smallest branches of the arterial tree. They have a single layer of circular smooth muscle in the media. Able to produce the biggest diameter change of the lumen |
Arteriole Function | 1) regulate access to discrete capillary beds depending on physiological need 2) determine peripheral resistance, determining how hard the heart has to work |
Capillaries | Exchanging vessels. Whole purpose of the CV system is to deliver blood to and from these vessels for exchange with the cells of the body's tissues |
Capillary Function | Diffusion of oxygen, CO2 , nutrients, and re-absorption of waste. They require a concentration gradient |
Capillary Walls | endothelium only and basal lamina. No tunica media or externa. Large surface area slow blood flow for diffusion |
Capillary Types | Continuous, fenestrated, discontinuous (sinusoidal) |
Continuous Capillaries | have complete endothelial lining and basement membrane, permit diffusion of water, small solutes, and lipid-soluble materials |
Fenestrated Capillaries | Have pores/fenestrae in endothelial lining, complete basement membrane. Permit more rapid exchange of H2O and somewhat larger solutes between plasma and instersitial fluid |
Sinusoidal Capillaries (sinusoids/discontinuous) | Have gaps between adjacent endothelial cells. Discontinuous basement membrane. Permit free exchange of H2O, large plasma proteins, and formed elements between blood and interstitial fluid. Phagocytic cells monitor blood at sinusoids |
Venules | converge to form medium veins, and medium veins form large veins e.g. venae cavae |
Blood Development | from mesoderm, in the embryonic yolk sac. Perinataly and adult made in red bone marrow |
Average Adult Blood Volume | about 5.5 liters, or a little more than 5.5 quarts. About 7% of lean body weight, not sex dependent |
Blood Characteristics | Red, temp around 38C or 100.4F (internal temp, slightly alkaline, pH 7.35-7.45, 3-5X more viscous than water |
Blood Functions | 1) Transport dissolved subs.: hormones, O2/CO2, Nutrients, Waste 2) Thermoregulation 3) Regulation of pH 4) hemostasis |
Hemostasis | a property of blood that ensures small holes don't leak anymore, temporary clotting |
Whole Blood | suspension of formed elements in plasma (all cells and solids) |
Plasma | fluid including water, dissolved plasma proteins and other solutes, makes up about 50% of blood volume and is mostly water. |
Formed Elements | all cells and solids, causes the viscosity of blood. RBCs, WBCs, and platelets |
Bilirubin | makes plasma pale yellow, from a breakdown product of hemoglobin |
Plasma Proteins | Clotting factors (most abundant), globulins, albumins (least abundant). can only pass through sinusoids |
Albumins | important in maintaining partitioning of water between plasm and interstitial fluid. restricted to outside the vessels, balance water out in the body. Made in liver |
alpha and beta-globulins | have enzymatic activity and/or are transport proteins. Made in liver |
gamma globulins | antibodies and are a part of the body's soluble immune response. made by lymphocytes |
Clotting Factors | important in homeostasis |
Origins of Plasma Proteins | 90% made in liver, but antibodies are made by plasma cells |
Heredity Spherocytosis | mutations that disrupt RBC cytoskeleton proteins which cause RBC spherical configuration |
Spherocytes | unusually fragile and are rapidly removed from circulation, spherical blood cells |
RBC Cytoskeleton | proteins that form the RBC biconcave shape and allow them to bend through tiny blood vessels |
Differentiation of RBCs | involves extrusion of the nucleus and the elaboration of a single protein, hemoglobin |
Mature RBCs | lack organelles |
Hemoglobin | molecule consists of 4 polypeptide chains and 4 heme groups. globin consists of 2 alpha chains and 2 beta chains: a2b2 |
Hb Saturation Curve | logarithmic graph in which the origin is 100% deoxyhemoglobin or 0% oxyhemoglobin |
Myoglobin | red protein containing heme that carries and stores oxygen in muscle cells |
Primary Polycythemia | due to factors intrinsic to red cell precursors e.g. when excess RBCs are produced as a result of an abnormality of the bone marrow |
Secondary Polycythemia | due to increased erythropoietin (EPO) production either in response to chronic hypoxia (low blood O2 level) or from an erythropoietin secreting tumor |
Agglutination | not the same thing as clotting, when RBC antigens and plasma antibodies complex |
Acute Transfusion Reaction | when donor cells agglutinate and target recipient's pre-existing antibodies |
Hematopoietic Tissue | contains hematopoietic stem cells and make formed elements |
Red Bone Marrow | form all formed elements after birth, contain pluripotent stem cells as well as the differentiating RBCs, WBCs, and platelets |
Lymphoid Lineage | Pluripotent hematopoietic stem cells produces lymphocytes |
Myeloid Lineage | pluripotent hematopoietic stem cells produce all other blood cells |
Reticulocytes | young erythrocytes with granular or reticular filamentous structures, 0.5-2% of all RBCs |
Erythropoietin (EPO) | renal hormone made by peritubular fibroblasts in the renal cortex. Causes myeloid stem cells to turn into RBCs |
Stimulation of Erythropoietin | anything that decreases O2 content of blood: RBC numbers, O2 availability, increased O2 demand, insufficient hemoglobin, etc. |
RBC Lifespan | 120 days |
Bilirubin | sourced by non-iron heme, causes a yellow pigment and jaundice, also makes urine yellow |
Bile | incorporates bilirubin, and is essential for proper absorption of dietary lipids, some lost to intestines coloring feces |
Leukocytes (WBCs) | least numerous of the formed elements, the effector cells of the immune system |
5 Characteristics of WBCs | 1) contain nuclei and some have apparent granules 2) diapedesis 3) varying degrees of mobility 4) varying degrees of phagocytic 5) formed in red bone marrow |
Positively Chemotaxic | they can crawl toward the site |
Diapedesis | process where WBCs are able to leave blood vasculature by passing between and through the endothelium |
Antigen Presentation | WBC shows the immune system that there is an antigen |
Granulocytes vs Agranulocytes | WBCs with visible cytoplasmic granules, vs not, but all WBCs have granules |
Neutrophils | first responders in bacterial infection. granules contain antimicrobial or cytotoxic substances, neutral proteinases, acid hydrolases, and a pool of cytoplasmic membrane receptors |
Eosinphils | directed against multicellular parasites but also have roles in allergies and asthma |
Basophils | granules contain histamine and heparin, function in allergic inflam. and some kinda of parasitic infestation. Bilobed nucleus |
Lymphocytes | T and B lymphocytes, most common and effector cells in many types of immunity |
Monocytes | precursors to the members of the MPS, including macrophages |