Cardiovascular (connective tissue)

Transcription

1 Cardiovascular (connective tissue) Blood Connective tissue Blood Proteins 7% Plasma 55% Other solutes 2% Water 91% Erythrocytes ~5.2 million per cubic mm Formed elements 45% Leukocytes ~7 thousand per cubic mm Platelets ~325 thousand per cubic mm Albumins 60% Electrolytes Globulins 35% Organic nutrients Organic wastes Agranular Leukocytes Granular Leukocytes Fibrinogen 4% Reg. proteins<1% T-cells 80% of lymphocytes Lymphocytes 20-30% of leukocytes B-cells 15% of lymphocytes Monocytes 2-8% Basophils inflammation <1% Eosinophils parasites 2-4% Neutrophils bacteria 50-70%

2 Connective tissue mesodermal cells occupy only small volume. Matrix =plasma; non-fibrous and nongranular 3 Plasma becomes fibrous by clotting. Clotting; fibers : fibrin monomer polymer fibrin; from fibrinogen in plasma fibrin threads form a mesh. Hemostasis: maintaining normal blood volume, blood pressure; minimizing hemorrhage Remaining liquid after the formation fibers is the ground substance; called serum. 4

3 Plasma; aqueous solution ; inorganic and organic solutes proteins other than fibrinogen albumins, globulins slightly yellowish bilirubin; waste molecule from hemoglobin breakdown. Humans plasma occupies 52% to 60% of the volume of the blood Denver; male adults; 51%: female adults; 56% 5 Cells ERYTHROCYTES Erythrocytes = red cell; red blood cells: RBC's most common blood cell Denver; adult males; 48%; adult females ; 43% Hematocrit; percentage of the blood volume occupied by RBCs Erythrocytes are red in life contain the red molecule hemoglobin; cytoplasm; eosinophilic. 6

4 7 Hemoglobin: tetramer of a proteinnonprotein complex; protein; globin nonprotein ; heme; red. Heme; complex of porphyrin ring + iron ion porphyrin ring is red ferrous ion is bound in the center of the porphyrin ring. 8

5 Heme binds to globin and Fe 2+ Fe 2+ of hemoglobin,loosely bind 0 2 ; Hemoglobin main function; 0 2 transport from lungs to tissues; aerobic respiration ATP synthesis. 9 Mammals; nonnucleated, biconcave, and disc-shaped; smallest in mammals. Shape allows RBCs to exchange O 2 efficiently. 10

6 RBCs are produced mainly in red marrow tissue Lymphoid-like tissue filling the marrow spaces of some bones RBCs enter sinusoids of lymphoid tissue when they are mature RBCs circulate in the blood ; about 4 months in humans RBCs are destroyed in the liver, spleen, and red marrow. 11 Red marrow; stem cells for production of all blood cells Hemocytoblasts hemocytoblasts ; derived from mesenchymocytes hemocytoblasts undergo several mitotic cell divisions and differentiations form mature erythrocytes hemoglobin synthesis loss of the nucleus biconcave-disc shape. 12

7 Biconcave-disc RBC is very plastic cone shape as it moves through capillaries RBCs are tiny, diameter of 8.5 µm thickness of 1.5 µm most capillaries - 6 µm to 10 µm in diameter RBCs pass in single file. Abundance of erythrocytes in blood related to O 2 -demand by tissues 13 LEUCOCYTES (leuc: white, bright; cyt: cell) Leucocytes = white blood cells produced in red marrow and lymphoid tissue function in loose C.T., lymphoid tissue, or dense interwoven C.T. whitish in color Granulocytic leucocytes produced in red marrow tissue only cytoplasmic granules nucleus tends to become bi-or multi-lobed. 14

8 Neutrophil (polymorphonuclear leucocyte) Neutrophil: cytoplasmic granules; neutral to slightly eosinophilic Most common granulocytes; Phagocytic, destroys infecting; bacteria, viruses, cell fragments, in the blood; in loose, dense, or lymphoid CT after the cell leaves circulation squeezing between endothelial cells of capillary wall: diapedesis. 15 Neutrophil (polymorphonuclear leucocyte) Mature neutrophil nucleus divided into a several lobes connected by thin threads Diameter = 1.5 x RBC 16

9 Eosinophil Distinct eosinophilic granules large and densely-packed pink to red granules. Less common than neutrophil In loose to dense interwoven CT. lumenal epithelium of digestive and respiratory tract. 17 Eosinophil Defense against substances entering body in air and food increase in eosinophils during parasitic infections. Nucleus ; two large lobes. Diameter= 2 x RBCs. 18

10 Basophil Basophilic cytoplasmic granules. Not densely packed Vary in size and stain density. Tend to be more purplish than nucleus Restricted to cortical cytoplasm Obscures nucleus Substances that promote blood flow: histamine, heparin (anticoagulant) 19 Basophil 0.5% of total white cells Nucleus divided into lobes difficult to see because of the cytoplasmic granules. Diameter = 1.5 x RBC 20

11 Agranulocytic leucocytes: some produced in lymphoid tissue, others in red marrow tissue NO cytoplasmic granules; intact nucleus. Two types: lymphocytes and monocytes Lymphocyte 25% of total circulating leukocyte populations. 21 Three general types of lymphocytes T and B-cells and Null (natural killer) cells Structurally indistinguishable. Very small, little cytoplasmic volume; nucleus spherical almost all of cells volume diameter = 1 x RBC 22

12 Lymphocytes are the most common of the three types of agranulocytes (others; monocytes and macrophages) Similar abundance as the neutrophil. B-cells (15% of lymphocytes) Some are produced in red marrow tissue ; most in lymphoid tissue Inactive form of the plasma cell (plasmocyte) Plasmocyte is found in lymphoid tissue, and produces immunoglobulins for circulation. 23 T-cells (80% of lymphocytes) Produced in the marrow. Responsible for specific immune response and immunologic memory. Null cells (inc. NK cells) Ignore these 24

13 Monocyte Rare; 8% of leukocyte pop µm in dia. "mononuclear leucocyte Nucleus occupies about half of cell s volume Nucleus not as dark as other leucocytes Flattened, indented on one side;no lobes. 25 Monocyte Remain in circulation briefly migrate to CT transform into a macrophage. Unusually abundant in mononucleosis; disease named mono. 26

14 Leukocyte type comparison 27 Platelet Abundant: more than leucocytes. Platelets diameter < 10% of RBC basophilic purplish in blood smears. Platelets have no nucleus sacs of cytoplasm produced in marrow by budding Megakaryocytes of the hemopoietic tissue; bud-off tiny bits of themselves 28

15 29 Platelets ; hemostasis ; contact with traumatized tissues; collagen aggregate; release procoaggulants trigger chemical events in the plasma concludes with formation of a fibrin clot traps erythrocytes, leucocytes, and platelets 30

16 Blood Next few hours trapped platelets produce extensions contact /attach to adjacent fibrin threads of clot Actin and myosin-like molecules in the cytoplasm pull threads toward the platelet's center clot becomes smaller,denser: clot retraction seals off broken blood vessels. 31 smear slide Very thin film (monolayer) of blood Film dries and stained Wright's and Giemsa stain and combinations of these two include eosin Y and methylene blue. 32