Blood and lymphatic system Flashcards
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what is Blood?
Blood: A vital bodily fluid composed of plasma, red blood cells, white blood cells, and platelets, circulating throughout the body via the cardiovascular system, responsible for transporting oxygen, nutrients, hormones, and waste products, regulating body temperature, pH balance, and immune responses, with functions including gas exchange, clotting, and immune defense.
cardiovascular system
The cardiovascular system: An intricate network of organs, vessels, and cells responsible for circulating blood and essential nutrients throughout the body, comprising the heart, blood vessels (arteries, veins, and capillaries), and blood. It facilitates the transportation of oxygen, nutrients, hormones, and metabolic waste products to and from cells, regulates blood pressure, body temperature, and pH balance, and plays a crucial role in immune responses and homeostasis. The heart acts as the central pump, propelling oxygen-rich blood from the lungs to the body’s tissues via arteries and returning oxygen-depleted blood to the lungs for oxygenation via veins. Capillaries facilitate nutrient and gas exchange between blood and tissues. The cardiovascular system is vital for sustaining life and supporting the functions of all organs and tissues in the body.
Cellular Components Of Blood
Cellular Components of Blood: Red blood cells (erythrocytes) are specialized for oxygen transport, while white blood cells (leukocytes) play roles in immune defense against pathogens, and platelets (thrombocytes) contribute to clotting mechanisms. These components, suspended in plasma, form a complex system facilitating nutrient delivery, waste removal, and immune responses crucial for maintaining homeostasis and overall health.
Diagnostic Blood Tests
Diagnostic Blood Tests: Hematology tests assess blood cell counts and characteristics, including complete blood count (CBC), white blood cell differential, and red blood cell indices; coagulation tests evaluate blood clotting function, such as prothrombin time (PT), activated partial thromboplastin time (aPTT), and international normalized ratio (INR); biochemical tests measure levels of specific substances in blood, such as glucose (blood sugar), electrolytes, enzymes (e.g., liver enzymes), lipids (cholesterol, triglycerides), and proteins (albumin, globulins); immunological tests detect antibodies or antigens related to infectious diseases or autoimmune disorders, including serological tests (e.g., ELISA, Western blot) and autoimmune panels; genetic tests analyze DNA or RNA to identify genetic mutations or predispositions to inherited disorders, such as chromosomal analysis, polymerase chain reaction (PCR), or genetic sequencing techniques.
Hematopoiesis
Hematopoiesis: The process of blood cell formation occurring primarily in the bone marrow, involving the differentiation and maturation of hematopoietic stem cells into various blood cell types, including erythrocytes (red blood cells), leukocytes (white blood cells), and platelets. Hematopoietic stem cells undergo self-renewal and differentiation into committed progenitor cells, which further differentiate into mature blood cells under the influence of specific growth factors and cytokines. Erythropoiesis produces red blood cells, which transport oxygen; leukopoiesis generates white blood cells, which play roles in immune defense; and thrombopoiesis forms platelets, essential for blood clotting. Hematopoiesis is tightly regulated by complex signaling pathways and microenvironmental factors within the bone marrow, ensuring the continuous production and replenishment of functional blood cells to maintain homeostasis and respond to physiological demands.
Erythropoiesis
Erythropoiesis: The process of red blood cell (erythrocyte) formation occurring primarily in the bone marrow, regulated by erythropoietin (EPO), a hormone produced by the kidneys in response to low oxygen levels. Erythropoiesis begins with hematopoietic stem cells differentiating into erythroid progenitor cells, which undergo multiple stages of maturation and specialization. During erythropoiesis, these progenitor cells progressively acquire hemoglobin, the oxygen-carrying protein, and undergo nuclear condensation and expulsion to become mature erythrocytes. The mature red blood cells are released into circulation, where they transport oxygen from the lungs to tissues and carbon dioxide from tissues to the lungs for elimination. Erythropoiesis is finely regulated to maintain the balance between oxygen supply and demand, with disruptions in this process leading to disorders such as anemia or polycythemia.
Thrombopoiesis
Thrombopoiesis: The process of platelet (thrombocyte) formation that occurs primarily in the bone marrow, specifically in the megakaryocytes. Thrombopoiesis begins with hematopoietic stem cells differentiating into megakaryocyte progenitor cells, which undergo maturation and development into large, multinucleated megakaryocytes. These megakaryocytes undergo a process known as cytoplasmic fragmentation, where they shed cytoplasmic fragments called platelets into the bloodstream. Platelets play a crucial role in hemostasis and blood clotting by adhering to damaged blood vessel walls, aggregating at the site of injury, and initiating the formation of blood clots to prevent excessive bleeding. Thrombopoiesis is regulated by various cytokines and growth factors, including thrombopoietin (TPO), which stimulates megakaryocyte production and platelet release in response to physiological demands. Disruptions in thrombopoiesis can lead to thrombocytopenia (low platelet count) or thrombocytosis (high platelet count), affecting the body’s ability to regulate blood clotting and hemostasis.
Leukopoiesis
Leukopoiesis: The intricate process of white blood cell formation occurring primarily in the bone marrow and lymphoid tissues, characterized by the differentiation and maturation of hematopoietic stem cells into various types of white blood cells essential for immune function. Granulopoiesis involves the sequential development of myeloblasts into promyelocytes, myelocytes, metamyelocytes, band cells, and finally mature granulocytes (neutrophils, eosinophils, and basophils). Lymphopoiesis encompasses the differentiation of lymphoid progenitor cells into T cells, B cells, and natural killer cells, crucial for adaptive and innate immunity. Monopoiesis leads to the production of monocytes, which can differentiate into tissue macrophages or dendritic cells, playing roles in phagocytosis and antigen presentation. Leukopoiesis is tightly regulated by a complex network of cytokines, growth factors, and transcription factors, including colony-stimulating factors (CSFs) and interleukins, which respond to various stimuli to maintain immune homeostasis and mount effective immune responses against pathogens. Dysregulation of leukopoiesis can result in disorders such as leukopenia or leukocytosis, affecting the body’s ability to combat infections and maintain immune function.
Red blood Cell
Red Blood Cell (Erythrocyte): The most abundant type of blood cell responsible for transporting oxygen from the lungs to tissues and carbon dioxide from tissues to the lungs. Erythrocytes are biconcave disc-shaped cells devoid of a nucleus, containing hemoglobin, a protein that binds and carries oxygen. Hemoglobin molecules within erythrocytes give blood its red color. Produced through erythropoiesis in the bone marrow under the regulation of erythropoietin (EPO), erythrocytes have a lifespan of approximately 120 days before being removed by the spleen and liver. The shape and flexibility of erythrocytes allow them to squeeze through narrow capillaries and deliver oxygen efficiently. Anemia, characterized by low red blood cell count or hemoglobin levels, can result in symptoms such as fatigue, weakness, and shortness of breath, while conditions such as polycythemia involve an excess of red blood cells, potentially leading to complications such as blood clot formation. Erythrocytes play a crucial role in maintaining tissue oxygenation and overall physiological function.
Extravascular Hemolysis (destruction of RBC’s)
Extravascular Hemolysis: Destruction of red blood cells (RBCs) outside the bloodstream primarily within the reticuloendothelial system by macrophages, triggered by structural changes or opsonization, leading to their breakdown and recycling; occurs physiologically and in conditions like autoimmune hemolytic anemia or hereditary hemolytic disorders, presenting with symptoms like anemia, jaundice, and splenomegaly, managed based on underlying causes and may involve supportive care or surgical interventions.
Intravascular Hemolysis
Intravascular Hemolysis: Rupture or lysis of red blood cells (RBCs) within the bloodstream, triggered by various factors, leading to release of hemoglobin into plasma, potentially causing hemoglobinuria, hemoglobinemia, or hemosiderinuria, contributing to anemia, hemolytic jaundice, or hemolytic uremic syndrome, managed based on underlying causes with supportive measures and specific therapies to prevent complications.
Packed Cell Volume = Hematocrit
Packed Cell Volume (PCV), also known as Hematocrit (HCT), represents the volume percentage of red blood cells (erythrocytes) in whole blood after centrifugation. During the centrifugation process, blood components separate based on their density, with red blood cells settling at the bottom of the tube. PCV/HCT measurement is obtained by comparing the volume of packed red blood cells to the total volume of whole blood in the tube.
Platelets
Platelets, or thrombocytes, are small cell fragments vital for hemostasis, forming temporary plugs at injury sites and contributing to blood clot formation; produced in bone marrow through thrombopoiesis; release bioactive substances aiding in inflammation, wound healing, and tissue repair; abnormalities can lead to bleeding disorders or thrombotic conditions; platelet count measured in blood tests to assess health and diagnose conditions, managed with specific treatments targeting platelet function or count.
White blood cells/Leukocytes/WBC’s
White blood cells (WBCs), or leukocytes, are key components of the immune system, produced in the bone marrow through leukopoiesis; include neutrophils, lymphocytes, monocytes, eosinophils, and basophils, each with specific functions in combating infections and foreign substances; abnormalities in WBC count or function can indicate various medical conditions, diagnosed through blood tests; treatment depends on the underlying cause and may include medications or therapies targeting immune function or specific diseases.
Lymphatic System
The lymphatic system, a key component of the immune system, comprises lymphatic vessels, nodes, and organs; responsible for fluid balance, immune surveillance, and defense against pathogens; transports lymph containing white blood cells and waste products; disorders include lymphedema, lymphadenopathy, and lymphoma; treated with various modalities such as drainage techniques, compression therapy, medications, or surgery.
spleen
The spleen, integral in veterinary medicine, functions as a blood reservoir, immune organ, and site for red blood cell recycling; composed of white pulp rich in lymphocytes for immune responses and red pulp containing sinuses for blood filtration and removal of old erythrocytes; plays a role in blood storage and release during times of increased demand; disorders encompass splenomegaly (enlargement), splenic torsion (twisting), or neoplasia; treatment options include medications, splenectomy, or supportive care, depending on the underlying condition and clinical presentation.
thymus
The thymus, located in the thoracic cavity of animals in veterinary medicine, is crucial for T lymphocyte development, maturation, and self-tolerance; provides a microenvironment for differentiation and selection of T cells; involutes with age but continues to contribute to immune function; disorders include thymomas, hyperplasia, or aplasia, managed with surgical excision, chemotherapy, or supportive care.
tonsils
Tonsils, part of the lymphoid system in veterinary medicine, are clusters of lymphoid tissue located in the oral and pharyngeal regions, serving as a first-line defense against pathogens entering through the respiratory and digestive tracts; involved in immune surveillance and response, helping to trap and destroy pathogens and antigens; may become inflamed (tonsillitis) due to infections or other factors, managed with medications or, in severe cases, surgical removal (tonsillectomy).
gut associated lymph tissue (GALT)
Gut Associated Lymphoid Tissue (GALT) in veterinary medicine, encompasses lymphoid structures located throughout the gastrointestinal tract, including Peyer’s patches, mesenteric lymph nodes, and diffuse lymphoid aggregates; plays a crucial role in immune surveillance, response, and tolerance within the gut mucosa, protecting against pathogens while maintaining tolerance to commensal bacteria and dietary antigens; involved in the production of antibodies, regulation of immune cell trafficking, and induction of oral tolerance; abnormalities in GALT function may contribute to gastrointestinal diseases or immune disorders, managed through dietary interventions, medications, or immunomodulatory therapies.
Lymph nodes
Lymph nodes, essential in veterinary medicine, are small, bean-shaped organs distributed throughout the body along the lymphatic vessels; serve as sites for filtration and processing of lymph fluid, trapping and destroying pathogens, abnormal cells, and foreign substances; play a crucial role in immune surveillance, activation, and response, containing specialized immune cells such as lymphocytes, macrophages, and dendritic cells; enlargement (lymphadenopathy) may occur in response to infections, inflammation, or neoplastic processes; managed through diagnostic evaluation, treatment of underlying conditions, or, in some cases, surgical intervention.
Lymphatic Vessels
Lymphatic vessels, integral in veterinary medicine, form a network that transports lymph fluid from tissues to lymph nodes and eventually back to the bloodstream; consist of thin-walled vessels with valves that prevent backward flow, facilitating one-way movement of lymph; serve to drain interstitial fluid, transport immune cells, and absorb dietary fats from the intestines; abnormalities may lead to lymphedema or impaired immune function; managed through supportive care, compression therapy, or surgical interventions depending on the underlying cause.
Lymphatic Organs
Lymphatic organs, vital in veterinary medicine, include lymph nodes, spleen, thymus, tonsils, and Peyer’s patches; serve as sites for immune cell development, maturation, and activation; involved in immune surveillance, response, and tolerance; abnormalities in lymphatic organs may lead to immune dysfunction or susceptibility to infections; managed through diagnostic evaluation, medical treatment, or surgical interventions based on the specific condition.
Lymphocytes
Lymphocytes, key components of the immune system in veterinary medicine, are a type of white blood cell involved in adaptive immunity; include T cells, B cells, and natural killer (NK) cells; T cells coordinate immune responses, B cells produce antibodies, and NK cells target infected or abnormal cells; play crucial roles in immune surveillance, defense against pathogens, and maintenance of immune memory; abnormalities in lymphocytes can lead to immunodeficiency or autoimmune diseases; managed through diagnostic testing, immunomodulatory therapies, or supportive care depending on the underlying condition.
Fluid Balance
Fluid balance, critical in veterinary medicine, refers to the equilibrium between fluid intake and output, ensuring the body maintains adequate hydration and electrolyte levels; regulated by various physiological processes including thirst sensation, renal function, and hormonal mechanisms such as antidiuretic hormone (ADH) and aldosterone; disruptions in fluid balance can lead to dehydration or overhydration, causing symptoms such as altered mentation, weakness, or edema; managed through fluid therapy, dietary adjustments, or addressing underlying medical conditions.
Immune Response
Immune response, pivotal in veterinary medicine, refers to the coordinated reaction of the immune system to defend against pathogens, foreign substances, or abnormal cells; involves recognition, activation, and effector phases mediated by various immune cells, cytokines, and antibodies; encompasses innate and adaptive immunity, providing immediate and long-term protection; dysregulation of immune responses can lead to immune-mediated diseases or susceptibility to infections; managed through vaccination, immunomodulatory therapies, or supportive care tailored to the specific condition.
Absorption of Fats
Absorption of fats, crucial in veterinary medicine, occurs primarily in the small intestine, particularly the jejunum and ileum; involves emulsification of dietary fats by bile acids, facilitated by pancreatic lipase and colipase enzymes; results in the formation of micelles, which transport fat-soluble vitamins, cholesterol, and fatty acids across the intestinal epithelium; absorbed fats are then reassembled into triglycerides within enterocytes and packaged into chylomicrons for transport via lymphatic vessels into the bloodstream; disruptions in fat absorption can lead to malnutrition or deficiencies in fat-soluble vitamins; managed through dietary adjustments, supplementation, or addressing underlying gastrointestinal conditions.
Lymph Circulation
Lymph circulation, vital in veterinary medicine, involves the movement of lymphatic fluid through lymphatic vessels, lymph nodes, and lymphoid organs; serves to drain interstitial fluid from tissues, transport immune cells, and absorb dietary fats from the intestines; propelled by skeletal muscle contractions, respiratory movements, and intrinsic smooth muscle contractions within lymphatic vessels; abnormalities in lymph circulation can lead to lymphedema, impaired immune function, or compromised fat absorption; managed through supportive care, compression therapy, or surgical interventions depending on the underlying cause.
Bursa of Fibricius
The Bursa of Fabricius, significant in avian veterinary medicine, is a specialized lymphoid organ located at the junction of the cloaca and rectum in birds; serves as the primary site for B cell maturation, proliferation, and differentiation, playing a crucial role in humoral immune responses; regresses with age, disappearing in mature birds; abnormalities in the bursa, such as inflammation or atrophy, can impact immune function and susceptibility to infections; managed through supportive care or immunomodulatory therapies depending on the specific condition.
Peyer’s Patches
Peyer’s patches, relevant in veterinary medicine, are lymphoid nodules located in the mucosa of the small intestine, particularly prominent in the ileum; serve as specialized sites for immune surveillance and response in the gastrointestinal tract; contain lymphocytes, macrophages, and dendritic cells involved in antigen sampling, immune activation, and tolerance induction; play a role in mucosal immunity, protecting against pathogens while maintaining tolerance to commensal bacteria and dietary antigens; abnormalities in Peyer’s patches can contribute to gastrointestinal diseases or immune disorders; managed through dietary interventions, medications, or immunomodulatory therapies depending on the underlying condition.
Secondary Lymphatic Organs
Secondary lymphatic organs, significant in veterinary medicine, include lymph nodes, spleen, and mucosa-associated lymphoid tissues (MALT) such as Peyer’s patches; serve as sites for immune cell activation, proliferation, and interaction following antigen encounter in primary lymphoid organs; facilitate immune surveillance, response, and memory formation; abnormalities in secondary lymphatic organs can impair immune function and predispose animals to infections or immune-mediated diseases; managed through diagnostic evaluation, medical treatment, or surgical interventions based on the specific condition.
Lymphatic Organs
Lymphatic organs, essential in veterinary medicine, encompass primary organs like the thymus and bone marrow, and secondary organs including lymph nodes, spleen, and mucosa-associated lymphoid tissues (MALT); play key roles in immune cell development, maturation, activation, and response; involved in immune surveillance, antigen presentation, and antibody production; abnormalities in lymphatic organs can lead to immune dysfunction or increased susceptibility to infections; managed through diagnostic evaluation, medical treatment, or surgical interventions tailored to the underlying condition.
Trabeculae
Trabeculae, pertinent in veterinary anatomy, are thin, fibrous partitions or bands of connective tissue that extend inward from the capsule of various organs, such as the spleen, lymph nodes, or liver; serve to support and compartmentalize the parenchyma of these organs, providing structural integrity and organization; contain blood vessels, lymphatic vessels, and nerves that supply nutrients and regulate function within the organ; abnormalities in trabeculae can affect organ architecture and function, contributing to diseases or disorders; managed through diagnostic imaging, surgical intervention, or medical treatment depending on the specific condition.
Peripheral Lymph Nodes
Peripheral lymph nodes, crucial in veterinary medicine, are small, bean-shaped structures located throughout the body along the lymphatic vessels, excluding the primary lymphoid organs; serve as sites for filtration, processing, and immune response activation; contain lymphocytes, macrophages, and dendritic cells that trap and destroy pathogens, abnormal cells, and foreign substances; play a key role in immune surveillance, response, and memory formation; enlargement (lymphadenopathy) may occur in response to infections, inflammation, or neoplastic processes; managed through diagnostic evaluation, treatment of underlying conditions, or surgical intervention depending on the specific situation.
Plasma
Plasma, a key component of blood, is a straw-colored, liquid portion of blood constituting approximately 55% of its volume; primarily composed of water (approximately 90%), electrolytes, proteins, hormones, nutrients, waste products, and gases; serves as a medium for transporting blood cells, nutrients, and waste products throughout the body; contains various proteins, including albumin, globulins, and fibrinogen, contributing to osmotic pressure, immune function, and blood clotting; plays a crucial role in maintaining blood volume, pH balance, and temperature regulation; abnormalities in plasma composition can lead to various disorders, including hypoalbuminemia, hyperproteinemia, or coagulopathies; managed through diagnostic evaluation and targeted treatment depending on the underlying condition.
Serum
Serum, a component of blood, is the liquid portion remaining after blood coagulation and removal of clotting factors; similar to plasma but lacks fibrinogen and other clotting proteins; contains electrolytes, antibodies, hormones, enzymes, and metabolic waste products; used in diagnostic tests to assess various aspects of health, such as liver function, kidney function, and immune status; abnormalities in serum composition can indicate underlying medical conditions, including liver disease, kidney disease, or autoimmune disorders; managed through diagnostic evaluation and targeted treatment depending on the specific condition.
Blood vessels
Blood vessels, comprising arteries, veins, and capillaries, form a network facilitating blood circulation; arteries carry oxygen-rich blood away from the heart, while veins return deoxygenated blood to the heart; capillaries enable exchange of gases and nutrients with tissues; lined with endothelial cells, regulated by smooth muscle; disorders include atherosclerosis, hypertension, or thrombosis, managed through lifestyle changes, medications, or surgery.
Blood clotting
Blood clotting, or coagulation, is a multifaceted process essential for hemostasis, involving vascular spasm, platelet plug formation, coagulation cascade, and fibrinolysis; vascular spasm initiates vasoconstriction to reduce blood flow; platelets adhere to injured vessels, activating and forming a plug; the coagulation cascade leads to fibrin clot formation, reinforcing the plug; fibrinolysis breaks down the clot once healing occurs; disorders like hemophilia or thrombophilia can disrupt clotting, resulting in bleeding disorders or abnormal clot formation; management includes anticoagulants, clotting factor replacement, and lifestyle modifications.
Fibrin
Fibrin, a key component of blood clotting, is a fibrous protein formed during the coagulation cascade from soluble fibrinogen; it polymerizes into insoluble fibrin strands, meshing with platelets to create a stable blood clot; fibrin provides structural support to the clot, reinforcing the platelet plug and sealing the damaged vessel; abnormalities in fibrin formation or degradation can lead to clotting disorders or excessive bleeding; managed through anticoagulant therapy or clotting factor replacement depending on the specific condition.
Thrombus
Thrombus: A thrombus is a blood clot that forms within a blood vessel or the heart. It typically develops due to abnormalities in the coagulation cascade, vascular injury, or alterations in blood flow dynamics. Thrombi can partially or completely obstruct blood flow, leading to ischemia or infarction in the affected tissue. Management involves anticoagulant therapy or thrombolytic agents to prevent further clot growth or dissolve existing clots.
Embolus
Embolus: An embolus is a detached fragment of a thrombus or other material that travels through the bloodstream and lodges in a smaller blood vessel, causing obstruction. Common sources of emboli include thrombi, air bubbles, or fat globules. Depending on its size and location, an embolus can lead to tissue ischemia, infarction, or organ dysfunction. Treatment aims to prevent embolization through anticoagulant therapy or surgical interventions such as embolectomy.
