Unit 6: Circulatory System. 6.1 Blood

Transcription

1 Unit 6: Circulatory System 6.1 Blood

2 Blood Function Function Nutritive Respiratory Excretory Regulatory Protective Effects on Body Transporting nutrient molecules (glucose, amino acids, fatty acids and glycerol) from small intestine or storage sites to tissues Transporting oxygen from the lungs to the tissues and carbon dioxide from the tissue to the lungs Transporting waste products (lactic acid, urea and creatinine) from cells to excretory organs Transporting hormones and other chemical substances that control the proper functioning of many organs. Circulating excess heat to the body surfaces and to the lungs, through which it is lost (controls body temperature). Maintains water balance and a constant environment for tissue cells. Circulating antibodies and defensive cells throughout the body to combat infection and disease

3 Blood Composition Blood is made up of the following major components: Plasma Cellular Elements: Erythrocytes Leukocytes Thrombocytes

4 Blood Plasma Composes about half of blood volume Made up of the following substances in solution: 1. Water makes up about 90% of plasma 2. Blood proteins hemoglobin (oxygen) 3. Plasma proteins fibrinogen (blood clotting), serum albumin (osmotic pressure), serum globulin (antibodies and coagulation)

5 Blood Plasma Composes about half of blood volume Made up of the following substances in solution: 4. Nutrients absorbed from digestive tract (glucose, fatty acids, cholesterol, amino acids) 5. Electrolytes come from food (sodium chloride and potassium) 6. Hormones, vitamins, enzymes control chemical reactions (very small amounts) 7. Metabolic waste products come from cellular functions to go to excretory organs

6 Erythrocytes Erythrocytes are commonly known as red blood cells (RBCs) Only live about 120 days due to the lack of a nucleus Hemoglobin pigment in erythrocytes gives the red color A single erythrocyte contains several million molecules of hemoglobin Vital in carrying oxygen to tissues and some carbon dioxide away from tissues. Normal hemoglobin count (per 100cc): Males: gm Females: gm

7 Erythrocyte Function In lungs, erythrocytes pick up oxygen from air breathed in Oxygen combines with hemoglobin to form the molecule oxyhemoglobin The oxygen-rich erythrocytes travel to the tissues and the oxygen is released In tissues, erythrocytes pick up carbon dioxide Erythrocytes circle back to the lungs to release carbon dioxide and pick up more oxygen

8 Erythropoiesis Creation of red blood cells Occurs in bone marrow of all bones, until adolescence. As one grows older, red blood cells are formed in short and flat bones Erythrocytes come from stem cells in red bone marrow (hemocytoblasts) As hemocytoblasts develop, they lose their nucleus and cytoplasmic organelles. Becomes smaller and gains hemoglobin.

9 Hemolysis Rupturing (bursting) of red blood cells Can occur due to a blood transfusion or other disease process

10 Leukocytes Leukocytes are commonly known as white blood cells (WBCs) Larger than erythrocytes Have a granular, agranular, translucent and ameboid shape Manufactured in red bone marrow and lymphatic tissue

11 Types of Leukocytes Granulocytes (granular leukocytes): synthesized in red bone marrow by myeloblasts; destroyed as they age (from bacterial destruction); most only live a few days Neutrophils (polymorphonuclear leukocytes): phagocytize bacteria with lysosomal enzymes Eosinophils: phagocytize antibody-antigen reactions; increase greatly in allergic reactions, malaria and worm infestations Basophils: perform phagocytosis; increases during chronic inflammation and healing from infection; produce histamine (vasodilator) and heparin (coagulant)

12 Types of Leukocytes Agranulocytes: Lymphocytes: life spans a few days to several years; help body by synthesizing and releasing antibody molecules and protect against cancer cell formation B-lymphocytes: synthesized in bone marrow T-lymphocytes: synthesized in thymus gland Others are formed in lymph nodes and spleen Monocytes: formed in bone marrow and spleen; assist in phagocytosis; can leave blood and attach to tissues

13 Inflammation Occurs when tissues are subjected to a chemical (heat) or physical (cut) trauma Invasion of pathogens (bacteria, fungi, protozoa, viruses) can also cause inflammation Characteristics are redness, local heat, swelling and pain

14 Inflammation Reaction 1. Histamine released from basophils increases blood flow to the injured area 2. Neutrophils begin phagocytosis of pathogen In most inflammations, a cream-colored liquid (pus) forms. Pus is a combination of dead tissue, dead and living bacteria, dead leukocytes and blood plasma. If the damaged area is below the epidermis, an abcess (pus-filled cavity) forms. If it is on the skin or mucous surface, it is called an ulcer.

15 Thrombocytes Thrombocytes are commonly called blood platelets. Ovoid-shaped structures synthesized by megakaryocytes in red bone marrow. Thrombocytes are NOT cells but fragments of the megakaryocytes cytoplasm. Function in the initiation of the blood clotting process (coagulation). Thrombocytes produce sticky projecting structures when introduced to a wounded area. Release serotonin which causes blood vessel to spasm and narrow decreasing the amount of blood flow to the area.

16 Coagulation Blood clotting When a blood vessel or tissue is injured, platelets and tissue release thromboplastin (plasma protein). Converts prothrombin to thrombin Thrombin changes fibrinogen into fibrin Traps RBC, platelets and plasma creating a blood clot As serum oozes out of cut, it dries and a crust (scab) forms. In order for coagulation to occur properly: Two anticoagulants must be neutralized to allow coagulation The clotting time for humans is from 5-15 minutes.

17 Once Upon a Time The Tiny Platelets Part 1 Part 2 Part 3

18 Blood Types Four types of blood: A, B, AB, O Inherited from parents and determined by the presence (or absence) of blood protein antigens on the surface of the red blood cell Type A: presence of A antigen Type B: presence of B antigen Type AB: presence of A and B antigen Type O: absence of A and B antigen

19 Rh Factor in Blood Human red blood cells also contain Rh antigen (found in the Rhesus monkey) Found on the surface of red blood cells Someone containing the Rh antigen is said to be Rh positive (Rh+) Someone not containing the Rh antigen is said to be Rh negative (Rh-)

20 Blood Types

21 Blood Type Compatibility

22 Blood Typing Problems Handout

23 Concept Map: Blood Handout WORD BANK: Red blood cells Homeostasis Albumins biconcave disc bone marrow transport nutrients Hemoglobin Monocytes defend against diseases Plasma Leukocytes Spleen Phagocytes inflammatory reaction Water Platelets Hematopoeisis Eosinophils Oxygen Nucleus Hemostasis Globulins Antibodies

24 Blood Disorders Sickle cell anemia Causes: genetic disorder that causes blood cells to become sickle shaped instead of oval shaped Symptoms: pain, lethargy, lifelong anemia (low RBC count), organ failure, stroke Treatment: bone marrow transplant, medication to reduce pain and prevent complications, blood transfusions

25 Blood Disorders Hemophilia Causes: disorder that causes the blood not to clot Symptoms: unexplained/excessive bleeding, large/deep bruises, blood in urine/stool, nosebleeds without a cause Treatment: blood transfusions, gene replacement for clotting factor Believed that Queen Victoria was the original carrier of the disease

26 Blood Disorders Leukemia Causes: cancer of the blood due to the overproduction of WBC Symptoms: fatigue/weakness, frequent infections, losing weight without trying, swollen lymph nodes, easy bleeding/bruising Treatment: bone marrow transplants, chemotherapy, radiation

27 Blood Disorders Mononucleosis: mono or kissing disease Causes: infection caused by Epstein-Barr virus (EBV); increase in lymphocytes in the bloodstream Symptoms: fatigue, loss of appetite, headache, sore and red throat, chills, fever, aches, swollen and red tonsils, swollen lymph nodes, cough Treatment: bed rest, good nutrition, fluids (antibiotics don t work against viruses)

28 Blood Disorders Septicemia: sepsis or blood poisoning Causes: infection in the bloodstream Symptoms: body temperature above 101 F or below 96.8 F, heart rate greater than 90 beats per minute, respiratory rate higher than 20 breaths per minute Treatment: antibiotics

29 Blood Crossword Handout

30 Blood Feedback Loop Handout