760 likes | 1.02k Views
BLOOD. William Harvey- father of physiology: discovered that blood circulated through the body in 1628. Blood..a liquid “tissue”???. How are Tissue Classified ?(AGAIN). Epithelial - lining or covering and glandular tissue. Muscle - highly specialized to contract
E N D
William Harvey- father of physiology: discovered that blood circulated through the body in 1628.
How are Tissue Classified ?(AGAIN) Epithelial- lining or covering and glandular tissue. Muscle- highly specialized to contract Nervous- irritability and conductivity Connective-Connects body parts; Must be living cells surrounded by a matrix. Example: Bone (cells sitting in lacunae in hardened matrix of calcium salts in Collagen fibers)
Bloodis considered to be a type of connective tissue. Even though it has a different function in comparison to other connective tissues it does have an extracellular matrix. • The matrix is the plasma and erythrocytes, leukocytes and platelets are suspended in the plasma.
Blood • The only fluid tissue in the human body • Classified as a connective tissue • Living cells = formed elements • Non-living matrix = plasma
1. Appearance of Blood Samples during Recovery of WBCs Whole blood in the collection tube Blood after centrifugation WBCs and RBCs after plasma removal Top view of the WBCs (buffy coat) Top view of sample after WBC removal
These are the Functions of Blood. Can You Elaborate? • Transport- • Protection. • Regulation
Physical Characteristics of Blood • Color range • Oxygen-rich blood is scarlet red • Oxygen-poor blood is dull red • pH must remain between 7.35–7.45 • Blood temperature is slightly higher than body temperature
Blood Plasma • Composed of approximately 90 percent water • Includes many dissolved substances • Nutrients • Salts (metal ions) • Respiratory gases • Hormones • Proteins • Waste products
Plasma Proteins • Albumin – regulates osmotic pressure • Clotting proteins – help to stem blood loss when a blood vessel is injured • Antibodies – help protect the body from antigens
Formed Elements • Erythrocytes = red blood cells • Leukocytes = white blood cells • Platelets = cell fragments
Photomicrograph of a Blood Smear Figure 10.2
Embryonic Stem Cells • Stem Cells-are undifferentiated cells and remain that way for a long period of time. They have ability to specialize into any type of tissue thus have “plasticity”. They can be used to generated any kind of tissue and have great therapeutic potential.Embryonic Stems cells- have much greater degree of plasticity than adult stems.
Blastocyst 5-6 day old embryo; about 120 cells big; ES cells derived from its inner mass. Embryonic Stem cells are TotipotentTheir differentiation abililty has no limits.
Hemopoiesis • Adult produces 400 billion platelets, 200 billion RBCs and 10 billion WBCs every day • Hemopoietic tissues produce blood cells • yolk sac produces stem cells • colonize fetal bone marrow, liver, spleen and thymus • liver stops producing blood cells at birth • spleen remains involved with WBC production • lymphoid hemopoiesis occurs in widely distributed lymphoid tissues (thymus, tonsils, lymph nodes, spleen and peyers patches in intestines) • red bone marrow • pluripotent stem cells • myeloid hemopoiesis produces RBCs, WBCs and platelets
Hematopoiesis • Occurs in red bone marrow from • All blood cells are derived from a common stem cell (hemocytoblast) Pleuripotent • Hemocytoblast differentiation • Lymphoid stem cell produces lymphocytes • Myeloid stem cell produces other formed elements
Leukocyte Terms • Leukocytosis- A rise in production of WBC count, usually due to response to infection. • Leukopenia- Abnormally Low WBC count • Leukemia-.bone marrow becomes cancerous. WBCs abnormally high.
Leukocytes (White Blood Cells) • Crucial in the body’s defense against disease • These are complete cells, with a nucleus and organelles • Able to move into and out of blood vessels (diapedesis) • Can move by ameboid motion • Can respond to chemicals released by damaged tissues
Types of Leukocytes • Granulocytes • Granules in their cytoplasm can be stained • Include neutrophils, eosinophils, and basophils Figure 10.4
Eosinophiles • Function: Phagocytosis of antigen-antibody complexes; allergens • Release enzymes to weaken or destroy parasites such as worms. • Appearance: Nuceus has 2 large lobes
Basophil • Appearance: • Function: Secretes Histamine,( a vasodilator) • Secretes heparin ( an anticoagulant)
Neutrophils Appearance • Nucleus usually with 3-5 lobes in S-C shaped array Functions: Phagocytosis of bacteria Release of antimicrobial chemicals
Agranulocytes • Lymphocytes • Nucleus fills most of the cell • Play an important role in the immune response • Monocytes • Largest of the white blood cells • Function as macrophages • Important in fighting chronic infection
Lymphocytes • These are cells involved in the….. IMMUNE RESPONSE There are: B-Lymphocytes and T-Lymphocytes
Monocytes • Largest of the WBCs • They resemble lymphocytes however they contain much more cytoplasm. • They are macrophages.
Order of Leukocyte Abundance? • Never Let Monkeys Eat Bananas • Neutrophils, Lymphocytes, Monocytes, Epsonophils, Basophils
Granulocyte Functions • Neutrophils ( in bacterial infections) • phagocytosis of bacteria • release antimicrobial chemicals • Eosinophils ( in parasitic infections or allergies) • phagocytosis of antigen-antibody complexes, allergens and inflammatory chemicals • release enzymes to destroy parasites • Basophils ( in chicken pox, sinusitis, diabetes) • secrete histamine (vasodilator) • secrete heparin (anticoagulant)
Red Blood Cells: Erythrocytes FUNCTION: Carry Oxygen to all cells in body. So specialized for this function that they lose their nucleus when mature and lose other organelles RBCs carry oxygen as Oxyhemoglobin; 1 molecule of hemoglobin binds to 4 molecules of oxygen.
About Red Blood Cells • The main function is to carry oxygen • Anatomy of circulating erythrocytes • Biconcave disks • Essentially bags of hemoglobin • Anucleate (no nucleus) • Contain very few organelles • Outnumber white blood cells 1000:1
Control of Erythrocyte Production • Rate is controlled by a hormone (erythropoietin) • Kidneys produce most erythropoietin as a response to reduced oxygen levels in the blood • Homeostasis is maintained by negative feedback from blood oxygen levels
Stages Of Erythropoiesis (3-5days) • PluripotentStem Cell ( Has organelles including nucleus) • Colony- Forming Unit- Has receptors for erythropoietin (EPO)….which stimulates it into blast. • Erythroblast- multiplies synthesizs hemoglobin…then when this is done…shrivel ( loses organelles) and become… • Reticulocyte-a cluster of polyribosomes within shriveled cell when these leave the bone marrow in a day or two… • Erythrocyte-the mature blood cell ..polysomes disintegrate ; RBCs enter the circulate the bloodstream.
Control of Erythrocyte Production: Homeostasis Figure 10.5
Hemoglobin • Iron-containing protein • Binds strongly, but reversibly, to oxygen • Each hemoglobin molecule has four oxygen binding sites • Each erythrocyte has 250 million hemoglobin molecules
Your RBC Count is low: ANEMIA? • Hemoglobin, that pigment that carries oxygen, is a molecule made up of various elements……in the middle is Fe…IRON. • So when your iron level is insufficient….so is your RBC level… • Symptoms of ANEMIA: Tired, listless, lack of energy.
Fate of Erythrocytes • Unable to divide, grow, or synthesize proteins • Wear out in 100 to 120 days • When worn out, are eliminated by phagocytes in the spleen or liver • Lost cells are replaced by division of hemocytoblasts
Destruction of RBCs • Macrophages phagocytize and destroy damaged RBCs primarily in the liver and the spleen. • Subunits are HEME, the iron-containing portion and globin, the protein. • The hemo further decomposes into biliverdin which decomposes into bilirubin (orange)---excreted in Bile. • Fe returns to hematopoietic tissue for reuse.
For WBCs • Leukopenia- low white blood cell count • Leukocytosis- White blood cell count above 10,000 WBC/uL ( indicates infection) • Leukemia- Cancer of the hematopoietic tissues ( UNUSUALLY high WBCs ??) • Myeloid—granulocytes • Lymphoid-lymphocyte or monocytes
Sickle Cell Anemia A genetic disease in which a SUBSTITUTION mutation exits.
Different Amino Acid Results in Different Blood Protein Structure Valine instead of Glutamine
Hematocrit When analyzing blood the 3 most important measurements are RBC count, hemoglobin concentration and Hematocrit. Hematocrit stands for total blood volume. Usually 4.6 -6.2 million RBCs / uL in men 4.2 -5.2 million RBCs / uL in women Why the difference?