Unformatted text preview: Blood
Blood BLOOD: actually is a specialized CT with intercellular material comprised entirely of fluid. formed from undifferentiated mesenchyme of embryos (similar to other CT)
contains formed elements (blood cells) and plasma 1. In average human blood formed elements comprise 46% of blood volume, plasma 54% (hematocrit or pcv packed cell volume) Men: 4050% (56 million RBC's/mm3)
Women: 3545% (45 million RBC's/mm3) 2. Blood volume in average human about 5 L (8% 2. Blood volume in average human about 5 L (8% of body weight)
3. Formed elements include: erythrocytes (RBC), leukocytes (WBC), platelets (thrombocytes which are cell fragments from megakaryocyte
Origin of blood: Blood cells originate in red bone marrow
from hematopoietic stem cells (pluripotent or hematocytoblasts). These in turn will differentiate (progenitor cells) into the specialized blood cells. Erythrocytes (RBC’s)
Erythropoiesis: begin as immature
proerythroblasts which in turn mature to a reticulocytes and ultimately an erythryocyte.
Adult RBC production is approximately 200 billion RBC's /day. This means that RBC's are produced at the astonishing rate of 2 million/sec in healthy adults. RBC's outnumber WBC's about 800 to 1
RBC's outnumber WBC's about 800 to 1
Female: RBC count is 45 million/mm3
Male: RBC count is about 56 million/mm3
Characteristics: anucleate 7.5 micrometers in diameter lacks other subcellular organelles as well biconcave shaped (allows a 2030% increase in surface area which increases efficiency of O2 and CO2 transport) life span of 120 days The protein spectrin allows cell to flex and change shape to squeeze through capillaries.
Ability to carry O2 and CO2 hemoglobin
Protein found in rbc’s that bind O2. Imparts reddish color to rbc.
Hemoglobin (Hb) in g/100 mL of blood 1318 g of hemoglobin/100 mL of blood in adult males 1216 g of hemoglobin/100 mL of blood in adult females
Hb contains a structure called the porphyrin ring Hb contains a structure called the porphyrin ring (also called heme) that is bound to a centrally located Fe molecule.
Each Hb can carry 4 O2's. One RBC contains 250 million Hb molecules (ie. 1 RBC can carry as many as 1 billion molecules of O2). O2 is picked up in the lungs and binds to Hb along with H+. Hb is now called oxyhemoglobin (bright red arterial blood).
When O2 is dumped off in the tissues it is called deoxyhemoglobin.
When Hb picks up CO2 from tissues it binds to the protein portions of the Hb. Hb carrying CO2 is called carbaminohemoglobin. This gives venous blood its bluish color. Venous blood is not blue due to the decrease in O2 in the blood. Life cycle of an RBC
1 Nutrients (folic acid, Fe and Vit. B12) are absorbed in the small intestine.
2 Nutrients go to red bone marrow
3 RBC’s develop from progenitor cells
4 RBC’s released in bloodstream and circulate for approx. 120 days
5 After 120 days, RBC’s are broken down by macrophages in the liver and spleen
6 Hb is broken down into heme and globin
7 Heme decomposes into Fe and a greenish substance called biliverdin 8 Iron binds to a protein called transferrin 8 Iron binds to a protein called transferrin which ultimately travels to the red bone marrow to be recycled. (80% of Fe in the body is stored in the liver as ferritin)
9 Some biliverdin is converted to bilirubin, as yellowish/orange pigment found in bile –gallbladder.
10 Bilirubin travels into small intestine and 10 % is metabolized to urobilinogen (urochromes filtered in the liver)
11 90% of bilirubin exits in the feces giving fecal matter its brown color (stercobilin) RBC’s do not have mitochondria so they obtain their energy from anaerobic glycloysis (produce ATP)
primary component in this pathway is
2,3 diphosphoglycerate (2,3 DPG)
assists in unloading O2 in the tissues from the Hg in the RBC Leukocytes (WBC’):
Contain a nucleus plus all common organelles
5,00010,000/mm3 lab values
Have the ability to move once outside the blood (diapedesis) through fenestrations (holes) in the capillaries
Ability to be attracted to chemicals (chemotaxis)
Grouped according to the presence of granules in their cytoplasm
Granular leukocytes/ granulocytes/ myeloblast series cells/ polymorphonuclear cells (PMN’s)
Eosinophils Agranular leukocytes (agranulocytes):
Agranular leukocytes (agranulocytes):
WBC’s are involved in immune functions and are primarily active outside the blood stream.
To remember granulocytic and agranulocytic
“Every Boy Needs Mommies Love”
To remember percentage of proportion
“Never Let Monkeys Eat Bananas” NEVER: neutrophils (60%)
LET: lymphocytes (30%) MONKEYS: monocytes (5%) EAT: eosinophils (4%) BANANAS: basophils (1%) Neutrophil (lobed)
Neutrophil (lobed) Neutrophils:
25 lobes that are interconnected by fine strands (sometimes called “segs”)
acute inflammatory response and phagocytize bacteria, fungi and some viruses
circulate in blood for short period of time (10 hrs.) before migrating into tissues (5 days).
first white cell on the scene of an infection
Neutropenia: too few neutrophils
Neutrophilia: too many neutrophils Basophil
Nucleus is typically bilobed
Granules contain histamine and heparin
Little ameboid and no phagocytic activity
when basophil stimulated by an antigen or by tissue injury, responds by
breaking open granulations causing histamine release. Histamine release initiates inflammatory
reaction causing vasodilation and increasing permeability of blood vessels.
plasma release Eosinophil
nucleus usually bilobed High number present in an allergic reaction.
Phagocytize and kill larval stage of parasitic worms.
Phagocytosis of the Ab/Ag complex found in an immune response Lymphocytes:
30% of WBC population
Large dark purple nucleus
Small, medium and large
Majority are not found in circulating blood but in lymphoid tissue (nodes, spleen, marrow etc..)
Smallest WBC slightly larger than RBC
T lymphocytes (immune response)
B lymphocytes (antibodiesimmunoglobins)
We will cover these two lymphocytes in much detail under immunology Lymphocyte
Largest of the WBC’s
Nucleus is indented
monocytes are phagocytic
when monocytes leave bloodstream they rapidly
transform to macrophages that are very active in ingesting bacteria, dead
cells, tissue debris (“wandering macrophages”)
Uses filopodia to search for things to eat
stimulate antibody production by lymphocytes. Monocyte
Not cells but cell fragments
Hemocytoblast Megakaryoblast Megakaryocyte
200,000 to 300,000/mm3 Anucleated
Aid in blood clotting
Arise from megakaryocytes in red bone marrow
granulated: granules contain serotonin that aid in vasoconstriction
Form a temporary plug when vessel is damaged.
Formation is regulated by a hormone called thrombopoietin Platelets Platelets Plasma vs. serum:
Plasma is an aqueous (92% water), straw colored solution containing proteins, lipids (digested nutrient), blood gases (O2, CO2 and N2), amino
acids, vitamins, hormones, and electrolytes (i.e. Na and Cl). The main plasma proteins are: 1 gamma globulins (immunoglobulins or antibodies) lymphoid tissue
2 albumins (maintains osmotic pressure of blood) liver
3 fibrinogen (clotting agent) liver
To obtain plasma, blood sample is spun down with an anticoagulant in the tube Serum:
If blood is allowed to clot, the clear yellow liquid that separates out is called serum. Serum is similar to plasma but lacks fibrinogen and other clotting agents.
To obtain serum, blood sample is spun down with no anticoagulant in the tube. Normal lab values of common substances dissolved in blood plasma/serum.
Glucose: 60100 mg/dl (fasting)
Sodium (Na): 135 147 mEq/L Calcium (Ca): 8.8 10.3 mg/dL Chloride (Cl): 95 107 mEq/L
Potassium (K): 3.5 5.2 mEq/L Hemostasis blood stoppage
Initial goal is to turn liquid (blood) into gel (coagulation).
1 smooth muscle in blood vessel wall contracts when vessel is damaged (vasospasm) decrease blood loss, may seal off opening slower flow of blood also helps platelets & coagulation. 2 attracted & stick to damaged vessel walls & to 2 attracted & stick to damaged vessel walls & to other sticky platelets platelets release attractant chemicals that attracts other platelets platelets release thrombospondins that aid platelet adhesion platelet plug
3 Blood coagulation: Cascade of blood clotting chemicals.
To form a blood clot a soluble plasma protein, fibrinogen (factor I), must be converted to insoluble threads called fibrin. Prothrombin (factor II) is a protein made in the liver Prothrombin (factor II) is a protein made in the liver and is a normal part of blood plasma. a. Prothrombin is converted to thrombin (factor II a).
b. Thrombin fragments fibrinogen.
c. Fibrinogen joins to form long slender threads of fibrin.
d. Fibrin threads attach to the damaged blood vessels and more blood cells and platelets will stick. This mesh will form a blood clot.
Under normal conditions clotting of blood in the body should only occur if blood remains stationary. Embolus vs. thrombus Blood typing (ABO):
Discovered in 1900 by Dr. Karl Landsteiner A – antigen A (40%)
B – antigen B (10%)
AB – antigen A & B (universal recipient 5%) O – no antigens (universal donor 45%) In the plasma:
In the plasma:
A: Antigen A in RBC
Plasma: antiB type antibodies B: Antigen B Plasma: antiA type antibodies
AB: antigen A&B
Plasma: no antiA or antiB antibodies
O: no antigens Plasma: both antiA and antiB antibodies Type O 45% Type A Type B 42% Type AB 3% 10% Rh factor
Rh factor Rh + = Rh factor antigen (marker) on RBC (85%)
Rh = no Rh antigen
Rh mother and Rh+ father: If baby inherits Rh+ from dad, mom’s blood will recognize baby’s blood as foreign and will attack it.
Erythroblastosis fetalis ...
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- Winter '11
- white blood cell