University:
Texas A&M University
Course:
BIOL 319 | Integrated Human Anatomy and Physiology I
Academic year:

2024
Views:

280

Pages:

75
Author:

Madelyn Bradshaw

Peripheral Blood Objectives Gross description and general properties of blood The structure and function of red blood cells, white blood cells, and platelets Blood Diagnostic value = most examined Types of information: 1) Identify nature of disease Viral – T lymphocytes Bacterial – neutrophils Parasitic – eosinophils 2) Follows the course of disease 3) Allows method to evaluate the effectiveness of treatment Blood - connective tissue Like CT Has abundant extracellular matrix (fluid). Maintains logistic support and communication between tissues and organs. Unlike CT Blood has no rigid physical connection among cells. Blood Composition Blood plasma (liquid component of blood) Buffy coat (White blood cells) Packed red blood cells (Hematocrit) Blood Plasma Liquid part of blood - 55% of whole blood Composition – • • • • • • Water Albumin: Osmotic pressure and neutralizes proteases Globulin: antibodies (IgG, IgE, ETC.) Transferrin: iron, copper, zinc Chylomicrons: lipids from intestine Low-density lipoprotein: cholesterol removal Blood plasma Composition con’t: • Plasma clotting factors o Fibrinogen o Prothrombin o Thromboplastin o Thrombin • Hormones - direct activity of cells • Chemotaxis factors – attract immune cells Blood serum Serum – yellow liquid from clotted blood (e.g., plasma minus clotting factors) Blood (definition and function) Blood - fluid tissue composed of erythrocytes (RBC), leukocytes (WBC), and platelets suspended in blood plasma. Function of blood is the transportation of cells and fluid. RBC carry O2 to and CO2 from tissues. Function of blood is transportation of cells and fluid. WBC Immune defense for body. Plasma Nutrients to tissues. Waste from tissues. Proteins to hold water in plasma. Hormones and other informational mediators. Platelets Prevent loss of transportation. Blood Volume 5-6 L = 12-13 pints/person Travel/day 172,000 miles (960 trips/day at 179 miles of blood vessels/trip and trip/6090 sec.) • http://www.youtube.com/watch?v=q0s1MC1hcE&feature=related Size of human blood cells Cell/platelet 1. Erythrocytes 2. Leukocytes (WBC) size 6.5-8 µm % of WBC a) Neutrophil 12-15 µm 60-70% b) Eosinophil 12-15 µm 2-4% c) Basophil 12-15 µm 0-1% d) Lymphocyte 6-18 µm 25% e) Monocyte 12-20 µm 5% 3. Platelets 2-4 µm Formed elements (non-fluid, cellular) and functions in blood Cell type Erythrocytes Main functions CO2 and O2 transport Neutrophils phagocytosis of bacteria Eosinophils parasitic infections, inflammatory processes release of histamine and other inflammation mediators Basophils Monocytes Mononuclear-phagocyte system become macrophages Formed elements (non-fluid, cellular) and functions in blood con’t Cell type B lymphocytes main functions generation of antibodyproducing plasma cells T lymphocytes killing of virus-infected cells Natural killer (cytotoxic T cell) killing of some tumor and virus-infected cells Platelets clotting of blood Erythrocytes Minute corpuscles - red color of blood (iron) Bone marrow derived Anucleate cells (mammals) – Nonfunctional nuclei in birds, reptiles, amphibian, and fish 4.8 to 5.4 x 106/MM3 = 1µl of blood, 45% of blood 25-30 x 1012/person (larger at high elevation) Erythrocytes Total surface area 3,800 m2 = 2,000 times total body surface area Rouleaux - aggregate like stacked coins Crenation – spines due to hypertonicity Descriptive terms for erythrocytes (RBC) Term Anisocytosis – Microcyte – Macrocyte variation size < 6µm >9µm Poikilocytosis shape Chromasia shade/color (due to – hypochromic amount of hemoglobin) Biconcave shape of erythrocytes Erythrocytes Biconcave shape is important: Surface area increased by 20-30% for greater diffusion of O2 and CO2 It facilitates passage through the smallest (<6 µm) of capillaries Hemoglobin - 65,000 MW protein with 4 polypeptide globin chains, each has an iron- containing heme group to attach O2 or CO2. Case study: Globins • Myoglobin – heart and skeletal muscle – functions as O2 reservoir & transport within muscle cells – single polypeptide chain – 1 heme in hydrophobic pocket – 8 -helices, 153 AA • Hemoglobin – red blood cells – O2 reservoir & transport from lungs to capillaries – 4 polypeptide chains – 4 hemes – each chain is similar in sequence and structure to myoglobin – 2 -chains (141 AA), 2 chains (146 AA) – chains held together by noncovalent forces Erythrocytes Sickle cell anemia - valine substituted for glutamic acid (one out of 514 AA) on the beta chain of the tetramer Reduces solubility of O2, causing crystals to form In the shape of long tactoids or sickles Prone to hemolysis and to block capillaries Homozygous carriers of the HbS gene Consequences of mutation • Severity of disease – Depends on nature of substitution – Radical or conservative physicochemically • Hb missense mutations – Sickle cell anemia Glu6Val substitution (charged to non-polar) arises from GAA codon mutated to GUA – Sickle cell Hb polymerizes in low oxygen conditions – Cell ‘sickles’ Erythrocytes Reticulocytes – released from bone marrow, matures (looses ribonucleoprotein) in 24 hours to become a mature RBC or Erythrocyte – lifespan of 120 days then removed in spleen 5th month of pregnancy Erythropoiesis Erythrocytes No nucleus and red cytoplasm Reticulocytes No nucleus and blue - grey cytoplasm Orthochromatophilic erythroblasts Polychromatophilic erythroblasts Dark, small, spherical nucleus blue – grey cytoplasm Darkening, fractured ,spherical nucleus and mixed pools of grey and blue cytoplasm Basophilic erythroblasts Fractured, spherical nucleus and thin rim of dark blue cytoplasm Proerythroblasts Uniformly light, spherical nucleus with thin rim of medium to dark blue cytoplasm Nucleus is removed creating the reticulocyte Orthochromatophilic erythroblasts reticulocyte McGraw-Hill Companies Erythropoiesis Erythrocytes Proerythroblasts Reticulocytes Orthochromatophilic erythroblasts Basophilic erythroblasts Polychromatophilic erythroblasts Erythropoiesis Bone marrow Reticulocyte entering blood vessel Blood vessel 32583 Granular leukocytes* * Neutrophilic granulocyte* Eosinophilic granulocyte* * * * * * * Basophilic granulocyte* Lymphocyte* Nongranular leukocytes* Monocyte* Monocyte* Granulopoiesis Neutrophils Lobulated, dark nucleus, mature grey cytoplasm with small granules Neutrophilic band or stab cells Horse-shoe shaped, darkening nucleus, grey mature cytoplasm Neutrophilic metamyelocytes Oval to kidney bean-shaped, indented nucleus, grey mature cytoplasm with a weak blue tent Neutrophilic myelocytes Large, oval, non-indented nucleus, large amount of cytoplasm with specific and non-specific granules Promyelocytes Large, oval, non-indented nucleus, large amount of sky blue cytoplasm with non-specific granules 32583 ` Bone marrow Developing granulocytes Granulopoiesis Neutrophils Promyelocytes Neutrophilic band cells Neutrophilic myelocytes Neutrophilic metamyelocytes Bone marrow 32583 White blood cell entering a blood vessel Blood vessel Blood vessel Types of Leukocytes Granular leukocytes • Neutrophils (polymorphs, PMNs) • Eosinophils • Basophils Neutrophilic granulocyte Basophilic granulocyte Eosinophilic granulocyte Lymphocyte Nongranular leukocytes • Lymphocytes • Monocytes Monocyte Monocyte Neutophils (PMN) 20 to 30 billion in circulation at any time 55-65% of WBC 5,000 to 9,000 /µl whole blood 40,000 /µl (e.g., 5 times higher) with acute infection Segmented lobes of condensed nucleus – drumstick (Barr body in women) Neutrophilic granulocyte Neutrophils (granules) Azurophilic granules Acid phosphatase (Hydrolytic enzymes) Primary lysosomes Specific granules Basic protein (Phagocytins, anti-bacterial action) Neutrophilic granulocyte Neutophils (PMN) Band cells – immature release of cells indicative of infection Phagocytosis • Opsin enhanced • Nonspecific Basic cellular functions – random motility, chemotaxis, phagocytosis, and killing bacteria Neutrophilic granulocyte Eosinophils 8-12 day life span Transient component of blood - 3 to 4 hrs Specific granules - red/orange, large crystalloids • Major basic protein (kills parasitic worms) Histo 60x 3 Common in lamina propria (CT under lining epithelium) • Alimentary tract • Respiratory tract Attracted by chemotactic factors given off by mast cells and basophils. Role • Parasitic diseases • Allergy Eosinophilic granulocyte Eosinophil EOSINOPHIL BASOPHIL Basophils Least numerous WBC Specific granules (blue, large, histamine) – Metachromasia (Heparin in several varied colors) May be induced to degranulation (like mast cells) Specific receptors for IgE immunoglobulin – IgE usually dilutes in blood – 20 fold in persons with hay fever, asthma, or allergic dermatitis Basophils Histamine - itching and increased vascular permeability – edema Cutaneous basophil hypersensitivity - rebuck window – (Basophils migrate to dermis - cell mediated Immunity) Note granules above nucleus Basophilic granulocyte A Lymphocyte Types and Functions Type B Function Plasma cells Antibodies (Memory B cells) T lymphocyte T cell receptors specialized to recognize surface antigens of cells 1) Memory Sensitive to previous antigens 2) Cytotoxic cells Destroys transplants 3) Helper cells Secretes substances - help T & B respond 4) Suppressor cells Dampens response to foreign antigens, self antigens Plasma cells Lymphocytes, Summary Humoral immune response B cells → plasma cells → Immunoglobins (antibodies) Lymphocytes, Summary Cell mediated immune response T cells • Memory - specific receptors for predisposed antigens/mount quick second response • Helper - stimulates immune response • Suppressor - inhibits immune response Interact with macrophages - cytotoxic and phagocytic mechanism Interferon - produced by T cells • Capable of inhibiting replication of certain viruses • Capable of reducing multiplication of some intracellular parasites Platelets megakaryocyte 32585 29250 Platelet function - blood clotting 1.Primary aggregation of platelet plug attachment to damaged tissue 2.Secondary aggregation • Alpha and delta granules – induce further aggregation 3.Blood coagulation - cascade of plasma proteins to form blood clot or thrombus 4.Clot retraction - platelet actin, myosin and ATP 5.Clot removal - plasmin (proteolytic enzyme) and platelet enzyme containing granules Platelet’s role in stopping bleeding Production of Serotonin – vasoconstriction to stop blood flow Produce thromboplastin THROMBOPLASTIN PROTHROMBIN THROMBIN FIBRINOGEN FIBRIN Fibrin polymerizes and produces the hemostatic plug Summary of Platelets - Thromboplastins Have many metabolic function of whole cells When exposed to damaged cells, sticky aggregation - Stick to each other Release ADP (from ATP inside platelets) which attaches to other platelets Produce thromboplastic which catalyzes prothrombin to thrombin which catalyzes fibrinogen to fibrin, forms net to catch RBC and other platelets (basis of the blood clot). Summary of Platelets Thromboplastins Hemophilia - bleeding disease – Inherited single deficiencies of any and/or many of the 12 plasma clotting factors Summary of Platelets Thromboplastins Anucleate (mammals) Zones • Hyalomere – microtubules and small vesicles • Granulomere - azurophilic granules Granules - some contain serotonin for vasoconstriction Platelets produced by megakaryocytes (bone marrow) Last 8 to 11 days

Peripheral Blood

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