Chapter 14 Blood. Functions Transportation –Food and oxygen to cells –Waste from cells...
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Transcript of Chapter 14 Blood. Functions Transportation –Food and oxygen to cells –Waste from cells...
Chapter 14
Blood
Functions
• Transportation – Food and oxygen to cells– Waste from cells– Hormones– Heat from the core to the surface
Blood Characteristics
• Plasma = fluid portion of blood. – 55% of the blood’s volume – 90% water, 8% proteins,
and 2% acids and salts.
• Blood Cells:– Erythrocytes – red blood
cells (rbc) (99%)– Leukocytes – white blood
cells (.2%)– Thrombocytes – platelets
(.6 – 1%)
Blood Characteristics Continued
• Blood volume – Varies with age, body type, and sex– Body Fat
• decrease in body fat = increase blood volume. • More oxygen to cells = increase energy
– About 10-12 pints of blood
Blood Cells
• Erythrocytes (Red blood cells)– Appearance
• No nucleus or organelles• Concave shape (donut)• Large surface area to carry oxygen• Great elasticity
– Abnormalities• Sickle cells – crescent shaped RBC’s
– Hemoglobin – molecule in RBC• Contains 4 iron atoms – which allows
oxygen to bind• Men carry more than women• Color of blood depends on
hemoglobin content
Blood Cells Continued• Erythrocytes
– Anemia – the state of having a deficiency of hemoglobin content in RBC’s
– Blood doping – increases RBC’s = increase in hemoglobin = more oxygen to cells
– Formation of RBC’s – Erythoropoiesis• Mature in red bone marrow• Contain reticulocytes – help doctors diagnose how
much blood is being made
– Destruction of RBC’s• Live 3-4 months• Cells lining blood vessels phagocytose RBC’s• Iron is recycled in the liver• Bilirubin is formed = yellow pigment = jaundice
Homeostatic Mechanism – Keeps RBC’s Constant
Normal Red Blood Count
Some Factor (Car Wreck)
Tissue Hypoxia
Increased secretion of erythroprotein by kidney and liver
Decreased # of RBC’s
Hormone
Increased erythropoiesis (rbc production) by red bone marrow
Increased # of RBC’s
Tends to restore
Blood Cells Continued• Leukocytes (White
blood cells)– Appearance
• Five types in body – lymphocytes, neutrophils, eosinophils, monocytes, and basophils
– Function• Fight infection• Phagocytosis – ingest and
digest microbes– Formation
• In red bone marrow or lymphatic tissue
• Life span not known (3-12 days or 3-6 months)
Blood Cells Continued• Platlets
– Appearance• Colorless, irregular
spindles or oval disks– Function
• Hemostasis – stopping of blood flow to area
• Clotting – plugging up ruptured vessels
– Formation• In red bone marrow, lungs,
and spleen• About a 10 day life span
Blood Types• A person’s blood type
depends on the type of antigen on the RBC membrane – Type A – antigen A on RBC– Type B – antigen B on RBC– Type AB – antigen A and B
on RBC (universal recipient)
– Type O – no antigen A or B on RBC (universal donor)
– Rh-factor = Rh antigen on RBC
• Rh-positive = Rh antigen present
• Rh-negative = Rh antigen not present
Blood Types Continued• Antigen – stimulates the formation of
antibodies (identify and neutralize foreign objects) that combine with antigen to clump cells– Danger in blood transfusions– Plasma never contains antibodies against the
antigen present on RBC’s
Blood Types Continued• Anti-Rh antibodies
– No blood usually contains this antibody– Can show up in blood of an Rh-negative
type comes into contact with an Rh-positive type• Transfusions• Pregnant women with Rh-negative blood
– Fetus is Rh-positive (gene from dad)– Blood mixes at birth – mother’s body makes anti-
Rh antibodies (no harm to mother)– During the 2nd pregnancy the antibodies could
attack the fetus and destroy = erythroblastosis fetalis
Blood Types Continued
Blood Coagulation• Mechanism
– Vessel is cut– Bleeding occurs– Platelets aggregate at the site of injury– Formation of a chemical with chemical
fibrinogen– Insoluble fibrin is made and tangles with
RBC which forms the clot– RBC’s give scab a red/brown color
Blood Coagulation Continued
• Opposition of Clotting Mechanism– Smooth surface of blood vessel– Antithrombins – heparin
• No thrombin made – no clot
Blood Coagulation Continued
• Factors that Hasten Clotting– Rough spot on blood vessel lining– Slow blood flow to area – atherosclerosis
• Bed patients must be moved frequently
– Clots seem to grow once started– Clinical method
• Apply gauze – rough surface• Heat massage
http://nobelprize.org/educational/medicine/landsteiner/index.html
Blood Transfusion Game