Studied by 8 peopleBlood
connective tissue made of cellular elements (formed elements) and an extracellular matrix (plasma).
What is an erythrocyte?
red blood cell
What is a leukocyte?
white blood cell
The 3 functions of blood
Transportation
Defense
Homeostasis
What does blood transport?
Blood transports oxygen, carbon dioxide, nutrients, hormones, and metabolic waste products
How does blood protect?
Prevents blood loss (clots), prevents infection (antibodies, WBC's)
How does blood perform homeostasis?
Regulation of pH in the body and fluid balance in cells
Distributing heat
Is blood temperature higher than body temperature?
Yes, Blood is 1º C higher than body temp
What is a centrifuge?
Machine used to separate blood by spinning it
Whole blood
plasma and formed elements
hematocrit
percentage of blood volume occupied by erythrocytes (RBCs)
Composition of blood
55% plasma, 45% RBCs, <1 WBC and platelets
Normal range of hematocrit in adults?
Adult Males: 42-52%
Adult Females: 37-47%
What is condition called when an individual has low hematocrit?
Anemia
What is condition called when an individual has high hematocrit?
Polycythemia
Bright scarlet red blood indicates...?
Well oxygenated blood
Dark red blood indicates...?
Poorly oxygenated blood
Blood is:
Slightly acidic
OR
Slightly alkaline
Slightly alkaline
What is the pH of blood?
Blood is slightly alkaline, with a pH of 7.35-7.45
Volume of blood in adults
Adult males: 5-6 liters
Adult females: 4-5 liters
Viscosity of blood
5x thicker than water
what does blood plasma look like when centrifuged?
yellow liquid portion of blood
What does blood plasma consist of?
It contains mostly water but also contains many dissolved materials
What percent of blood plasma is water?
92%
Where are plasma proteins produced?
in the liver
What are the 3 types of plasma proteins?
albumins, globulins, fibrinogen
Albumins
Transports fatty acids and steroid hormones within the blood
Why do lipids need assistance for transport in the blood?
Lipids are hydrophobic
The most abundant plasma protein
albumin (54%)
What are the 3 groups of globulins?
alpha, beta, gamma
What do alpha and beta globulins do?
Transport iron, lipids, and vitamins A, D, E, K; maintain proper [H2O] in blood
What does the gamma globulin do?
Helps antibody formation and attacks invaders
Fibrinogen
essential for blood clotting
Fibrin
a long, thread-like fiber created by the combination of thrombin and fibrinogen used to forms a blood clots
What do erythrocytes do?
transport oxygen and carbon dioxide
Most abundant cell in the body?
erythrocytes (RBCs)
Do erythrocytes have a nucleus?
No, they are anucleate
What is the shape of an erythrocyte?
biconcave disc
Where do erythrocytes form?
red bone marrow
Hemoglobin
oxygen-carrying compound in erythrocytes
What is globin?
four polypeptides, two "alpha" chains and two "beta" chains
Heme
red, iron-containing pigment to which oxygen binds in hemoglobin
How many oxygens can a heme bind to?
Up to 4 oxygens
Oxyhemoglobin
hemoglobin bound to oxygen (bright red)
deoxyhemoglobin
hemoglobin without oxygen (dark red)
What is percent saturation("percent sat")?
The percent of hemoglobin oxygen sites occupied by oxygens
Hypoxia/Hypoxemia
too little oxygen in the blood
What is the lifespan of an erythrocyte?
120 days
Life cycle of erythrocytes
-form in red bone marrow
-circulate in the bloodstream for up to 120 days
-aged erythrocytes are phagocytized in the liver, spleen, and bone marrow by macrophages
-most parts of old erythrocytes are broken down and reused to make new ones:
the heme --> bilirubin-> bile-> stercobilin/urobilin
iron-> stored in liver( must attach to hemosiderin or ferritin) or recycled(transported by transferrin)
globin-> amino acids-> back to bone marrow
Jaundice
excess of bilirubin, inability of the liver to excrete products of heme breakdown
hemoglobinuria
excess hemoglobin in urine, from excess breakdown of RBCs
What are the five different types of leukocytes?
Granular leukocytes: neutrophil, basophil, eosinophil
Agranular leukocytes: monocyte, and lymphocyte
Are there more erythrocytes of leukocytes?
erythrocytes
Whats another name for neutrophils?
polymorphonuclear leukocytes (PMNs)
Neutrophils
Most abundant leukocyte, phagocytic, rapid responders to the site of infection
Eosinophils
phagocytic, respond to infections by multicellular parasites
basophils
least numerous, migrate to injury sites where they release histamine and heparin
lymphocyte
T cells, B cells, and natural killer cells.
monocyte
enters the tissues and becomes macrophages and phagocytize any pathogens
What do platelets do?
release chemicals required for blood clotting
formation of temporary patch in damaged blood vessel
Active contraction after clot formation
Thrombocytopenia
insufficient amount of platelets
What can thrombocytopenia lead to?
Excessive bleeding and inability to clot
Hemopoiesis (Hematopoiesis)
production of the formed elements of blood
What are the different sites of hemopoiesis?
red bone marrow
Hemocytoblast
stem cells that give rise to all the formed elements of the blood
Where are hemocytoblasts located?
red bone marrow
How do hemocytoblasts give rise to all different formed elements
By cytokinesis, they divide over and over and form many daughter cells
A daughter cell can become which two stem cells?
Lymphoid stem cell or myeloid stem cell
Lymphoid stem cell
give rise to lymphocytes
Myeloid stem cells
give rise to all other blood cells
Thrombosis
Myeloid Stem Cell-> megakaryocytes-> platelets
leukopoiesis
msc-> basophils, neutrophils, eosinophils, monocytes
Erythropoiesis
msc-> proerythroblasts-> erythroblast-> reticulocytes-> erythrocytes
Erythropoietin(EPO)
peptide hormone that controls the production of erythrocytes
When EPO is in bone marrow, what is produced?
Red Blood cells
What stimulated the production of EPO in kidneys and periphery?
Hypoxia
Cytokines
promote the development of leukocytes
What stimulates the production of platelets?
Thrombopoietin
Hyopxia
Oxygen deprivation
Hemostasis
clotting of blood to heal damaged blood vessels
What are the 3 phases of hemostasis?
vascular spasm, platelet plug, coagulation
How long does a vascular spasm last?
30 minutes
Vascular Spasm
contraction of the smooth muscle in the wall of a damaged blood vessel to prevent blood loss, blood vessel becomes sticky
platelet plug formation
platelets stick together to form a temporary seal to cover the break in the vessel wall
platelet adhesion
the attachment of platelets to exposed surfaces
platelet aggregation
The attachment of platelets to one another
Coagulation
process of blood clotting
What are the two pathways of coagulation?
intrinsic and extrinsic
intrinsic coagulation
Damage to the inside of the vessel
When does the coagulation phase begin?
30 seconds after injury
Fibrinolysis
gradual degradation of a blood clot
Clot retraction
the stabilization of blood clots
Antithrombin
prevents thrombokinase
Heparin
accelerates the activation of antithrombin
T cells and B cells are responsible for the body's specific immune response.
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