Title: Blood
1Blood
2Functions of blood
- Transportation
- Oxygen
- Carbon dioxide
- Nutrients Hormones
- Wastes
- Regulation
- Fluid balance Thermoregulation
- pH Electrolytes
- Protection
- Immune System bodies defenses
- Clotting and wound repair
3Physical characteristics of Blood
- Yes, it is thicker than water
- pH between 7.35 (venous) and 7.45 (arterial)
- Volume
- 5 to 6 liters in an average male (1.5 gal or 12
pints) - 4 to 6 liters in an average female (1.2 gal or 10
pints) - About 20 of the extracellular fluid
- About 8 of the body mass
4Composition of Blood
- Whole blood is divided into plasma and formed
elements - Plasma
- 55 of whole blood volume
- 91.5 water
- 7 soluble proteins
- Albumin 54 (osmotic balance, buffering,
transport of steroid hormones and fatty acids) - Globulins 38 (antibodies, etc)
- Fibrinogen 7 (produced by liver, for clotting)
- 1 other
- Other solutes
- Electrolytes, gases, nutrients, wastes, hormones
5Fig.19.01
6Formed Elements
- Erythrocytes (a.k.a. red blood cells)
- 4 to 6 million per mm3 (mL)
- About 7 - 8 mm in diameter
- Anucleate
- Amitotic at maturity
- No mitochondria, centrioles, or much else in the
way of cytoplasm. Mostly hemoglobin. - Live about 90 120 days
- Hematocrit The total volume of blood occupied
by erythrocytes. - 38 46 for females, average 42
- 40 54 for males, average 47
7Formed elements
Fig.19.02
8Hemopoiesis formation of blood cells
- Also known as hematopoiesis
- Occurs in the red marrow
- In adults, mostly in the proximal epiphysis of
femur and bodies of the lumbar vertebrae - Originally from pluripotent stem cells from
mesenchyme - In the fetus, hematopoiesis occurs in the liver,
spleen, thymus, lymph nodes and yolk sac - Red marrow is found in the spaces of spongy bone
- Erythropoietin from the kidneys stimulates
hematopoiesis
9Development of blood cells
Fig. 19.03
10The anatomy of an erythrocyte the hemoglobin
molecule
11Hemoglobin (Hb)
- Each RBC contains an average of 250 million Hb
molecules - Each Hb molecule has 4 oxygen binding sites
- Thats about 1 billion oxygen molecules per RBC!
- CO (carbon monoxide) has approximately 200 times
the affinity for Hb than oxygen and it fool O2
saturation detectors
12Erythrocyte catabolism
- After roughly 120 days red blood cells are worn
out and must be recycled - This occurs in the spleen and liver
- Iron (Fe)
- The Fe is removed from the heme group and
bound to transferrin - It is stored in the liver, muscle and spleen by
transferring it to ferritin - It can be transported on demand to the bone
marrow where it can be reincorporated into new Hb
13RBC catabolism continued
- The rest of the heme molecule
- First converted to biliverdin (it is green)
- Then to bilirubin (it is yellow-orange)
- Its carried in the blood to the liver where it
is secreted into bile - Bile is stored in the gall bladder (if you have
one) and then into the small intestine - When it reaches the large intestine it is
converted by bacteria into urobilinogen - Some is reabsorbed and excreted in the urine
(urobilin or urochrome). The rest is in the feces
(stercobilin)
14RBC life cycle
Fig. 19.05
15Erythrocyte disorders
16Anemia Insufficient Erythrocytes
- Hemorrhagic anemia result of acute or chronic
loss of blood - Hemolytic anemia prematurely ruptured
erythrocytes - Aplastic anemia destruction or inhibition of
red bone marrow
17Anemia Decreased Hemoglobin Content
- Iron-deficiency anemia results from
- A secondary result of hemorrhagic anemia
- Inadequate intake of iron-containing foods
- Impaired iron absorption
- Pernicious anemia results from
- Deficiency of vitamin B12
- Lack of intrinsic factor needed for absorption of
B12 - Treatment is intramuscular injection of B12
18Anemia Abnormal Hemoglobin
- Thalassemias absent or faulty globin chain in
hemoglobin - Erythrocytes are thin, delicate, and deficient in
hemoglobin - Sickle-cell anemia results from a defective
gene coding for an abnormal hemoglobin called
hemoglobin S (HbS) - HbS has a single amino acid substitution in the
beta chain - This defect causes RBCs to become sickle-shaped
in low oxygen situations
19Polycythemia
- Polycythemia excess RBCs that increase blood
viscosity - Three main polycythemias are
- Polycythemia vera
- Secondary polycythemia
- Blood doping
20Sickle Cell Disease
21RBC homeostasis
22Leukocytes
- White blood cells are important for bodily
defenses and immunity - 2 General categories
- Granulocytes
- Neutrophils
- Eosinophils
- Basophils
- Agranulocytes
- Lymphocytes
- Monocytes
23Granulocytes
- Granulocytes neutrophils, eosinophils, and
basophils - Contain cytoplasmic granules that stain
specifically (acidic, basic, or both) with
Wrights stain - Are larger and usually shorter-lived than RBCs
- Have lobed nuclei
- Are all phagocytic cells
24Neutrophils
- Neutrophils have two types of granules that
- Take up both acidic and basic dyes
- Give the cytoplasm a lilac color
- Contain peroxidases, hydrolytic enzymes, and
defensins (antibiotic-like proteins) - Neutrophils are our bodys bacteria slayers
25Eosinophils
- Eosinophils account for 14 of WBCs
- Have red-staining, bilobed nuclei connected via a
broad band of nuclear material - Have red to crimson (acidophilic) large, coarse,
lysosome-like granules - Lead the bodys counterattack against parasitic
worms - Lessen the severity of allergies by phagocytizing
immune complexes
26Basophils
- Account for 0.5 of WBCs and
- Have U- or S-shaped nuclei with two or three
conspicuous constrictions - Are functionally similar to mast cells
- Have large, purplish-black (basophilic) granules
that contain histamine - Histamine inflammatory chemical that acts as a
vasodilator and attracts other WBCs
(antihistamines counter this effect)
27Agranulocytes
- Agranulocytes lymphocytes and monocytes
- Lack visible cytoplasmic granules
- Are similar structurally, but are functionally
distinct and unrelated cell types - Have spherical (lymphocytes) or kidney-shaped
(monocytes) nuclei
28Lymphocytes
- Account for 25 or more of WBCs and
- Have large, dark-purple, circular nuclei with a
thin rim of blue cytoplasm - Are found mostly enmeshed in lymphoid tissue
(some circulate in the blood) - There are two types of lymphocytes T cells and B
cells - T cells function in the immune response
- B cells give rise to plasma cells, which produce
antibodies
29Monocytes
- Monocytes account for 48 of leukocytes
- They are the largest leukocytes
- They have abundant pale-blue cytoplasms
- They have purple-staining, U- or kidney-shaped
nuclei - They leave the circulation, enter tissue, and
differentiate into macrophages
30Monocytes
- Macrophages
- Are highly mobile and actively phagocytic
- Activate lymphocytes to mount an immune response
31Leukocytes
32Chemotaxis of neutrophils
33Leukocyte Disorders
- Leukemia
- Acute uncontrolled production of immature WBCs.
- Chronic accumulation of mature WBCs in the blood
34Leukocytes Disorders Leukemias
- Leukemia refers to cancerous conditions involving
white blood cells - Leukemias are named according to the abnormal
white blood cells involved - Myelocytic leukemia involves myeloblasts
- Lymphocytic leukemia involves lymphocytes
- Acute leukemia involves blast-type cells and
primarily affects children - Chronic leukemia is more prevalent in older people
35Leukemia
- Immature white blood cells are found in the
bloodstream in all leukemias - Bone marrow becomes totally occupied with
cancerous leukocytes - The white blood cells produced, though numerous,
are not functional - Death is caused by internal hemorrhage and
overwhelming infections - Treatments include irradiation, antileukemic
drugs, and bone marrow transplants
36Hemostasis clotting
- Involves
- platelets (fragments of megakaryocytes)
- Proteins Fibers (Thrombin Fibrin)
- Clotting factors
37Platelet plug formation
38Plug formation
39Clotting
40Hemostasis DisordersThromboembolytic Conditions
- Thrombus a clot that develops and persists in
an unbroken blood vessel - Thrombi can block circulation, resulting in
tissue death - Coronary thrombosis thrombus in blood vessel of
the heart
41Hemostasis DisordersThromboembolytic Conditions
- Embolus a thrombus freely floating in the blood
stream - Pulmonary emboli can impair the ability of the
body to obtain oxygen - Cerebral emboli can cause strokes
42Prevention of Undesirable Clots
- Substances used to prevent undesirable clots
include - Aspirin an antiprostaglandin that inhibits
thromboxane A2 - Heparin an anticoagulant used clinically for
pre- and postoperative cardiac care - Warfarin used for those prone to atrial
fibrillation
43Hemostasis Disorders Bleeding Disorders
- Thrombocytopenia condition where the number of
circulating platelets is deficient - Patients show petechiae (small purple blotches on
the skin) due to spontaneous, widespread
hemorrhage - Caused by suppression or destruction of bone
marrow (e.g., malignancy, radiation) - Platelet counts less than 50,000/mm3 is
diagnostic for this condition - Treated with whole blood transfusions
44Hemostasis Disorders Bleeding Disorders
- Inability to synthesize procoagulants by the
liver results in severe bleeding disorders - Causes can range from vitamin K deficiency to
hepatitis and cirrhosis - Inability to absorb fat can lead to vitamin K
deficiencies as it is a fat-soluble substance and
is absorbed along with fat - Liver disease can also prevent the liver from
producing bile, which is required for fat and
vitamin K absorption
45Hemostasis Disorders Bleeding Disorders
- Hemophilias hereditary bleeding disorders
caused by lack of clotting factors - Hemophilia A most common type (83 of all
cases) due to a deficiency of factor VIII - Hemophilia B results from a deficiency of
factor IX - Hemophilia C mild type, caused by a deficiency
of factor XI
46Hemostasis Disorders Bleeding Disorders
- Symptoms include prolonged bleeding and painful
and disabled joints - Treatment is with blood transfusions and the
injection of missing factors
47Blood typing ABO groups
48ABO groups by frequency in US population
49Rh factor
50Blood Transfusions
- Whole blood transfusions are used
- When blood loss is substantial
- In treating thrombocytopenia
- Packed red cells (cells with plasma removed) are
used to treat anemia