ch. 17 (blood) Flashcards
What is blood referred to as?
The ‘River of Life’
What is the vital force carried by blood?
Life-sustaining fluid
What was a common practice involving blood in early medicine?
Draining ‘bad blood’ from people
What did people historically believe about hereditary traits and blood?
‘I got farming in my blood’ - traits transmitted through blood
What is the internal transport system of the body?
Blood
What is the life-sustaining transport vehicle of the cardiovascular system?
Blood
Name the parts of blood circulation.
Heart, arteries, arterioles, capillaries, venules, veins, IVC and SVC
What are the three main functions of blood?
Transportation, regulation, protection
What does blood transport to body cells?
Oxygen (O₂) and nutrients
What waste products does blood transport for elimination?
Nitrogenous waste, CO₂
How does blood help in hormonal transportation?
Transports hormones from endocrine organs to target organs
How does blood regulate body temperature?
By absorbing and distributing heat
What pH range does blood maintain?
7.35-7.45
What role do plasma proteins play in blood regulation?
Create osmotic pressure to prevent fluid loss from vessels
How does blood prevent infection?
By carrying WBCs, antibodies, and complement proteins
What are the components of blood?
Plasma and formed elements
What type of tissue is blood?
Connective tissue
What are the formed elements in blood?
RBCs, WBCs, and platelets
What is the fluid matrix in blood called?
Plasma
What percentage of whole blood is made up of erythrocytes?
~45%
What is hematocrit?
The percent of blood volume that is RBCs
What is the normal hematocrit value for males?
~47%
What is the normal hematocrit value for females?
~42%
What condition results from too few RBCs?
Anemia
What condition results from too many RBCs?
Polycythemia
What percentage of blood is plasma?
~55%
What is the color of blood with high O₂ levels?
Scarlet red
What is the color of blood with low O₂ levels?
Dark red
What is the pH range of blood?
7.35-7.45
What is the volume of blood in males?
5-6 liters
What is the volume of blood in females?
4-5 liters
What percentage of plasma is water?
92%
What are plasma proteins primarily responsible for?
Osmotic pressure and transport of substances
What is the most abundant plasma protein?
Albumin
Where are most plasma proteins produced?
Liver
What percentage of plasma proteins does albumin account for?
60%
What contributes to the osmotic pressure in blood?
Albumins, electrolytes, RBCs
What are the only complete cells in blood?
White blood cells (WBCs)
Do RBCs and platelets have nuclei?
No
Where do all formed elements in blood originate?
Red bone marrow
How does the biconcave shape of RBCs help?
It offers a large surface area for gas exchange
What is hemoglobin?
A protein in RBCs that binds oxygen and carbon dioxide
How many O₂ molecules can one hemoglobin molecule carry?
Four
What happens when O₂ binds to hemoglobin?
It forms oxyhemoglobin (ruby red)
What happens during O₂ unloading in tissues?
Deoxyhemoglobin (dark red) is formed
Where does CO₂ bind in hemoglobin?
To the globin chains
What is hematopoiesis?
The formation of all blood cells
Where does hematopoiesis occur?
Red bone marrow
What are hemocytoblasts?
Stem cells that give rise to all formed elements
What hormone regulates RBC production?
Erythropoietin (EPO)
What is erythropoiesis?
Formation of RBCs
What is the lifespan of RBCs?
100-120 days
What is anemia?
A condition where the blood’s O₂-carrying capacity is too low
What is sickle-cell anemia?
A genetic disorder where RBCs are crescent-shaped due to mutated hemoglobin
What is leukocytosis?
An increase in WBC count in response to infection
What are the two categories of leukocytes?
Granulocytes and agranulocytes
What mnemonic helps remember leukocytes in order of abundance?
Never Let Monkeys Eat Bananas (Neutrophils, Lymphocytes, Monocytes, Eosinophils, Basophils)
What are neutrophils known for?
Being ‘bacteria slayers’
What do eosinophils do?
Attack parasitic worms and play a role in allergies and asthma
What do basophils secrete?
Histamine and heparin
What are lymphocytes?
B cells and T cells
What do B cells give rise to?
Plasma cells that produce antibodies
What do T cells target?
Virus-infected and cancerous cells
What is leukopoiesis?
The production of WBCs
What stimulates leukopoiesis?
Interleukins and colony-stimulating factors (CSFs)
What are platelets?
Cell fragments essential for blood clotting
What hormone regulates platelet production?
Thrombopoietin
What is hemostasis?
The process of stopping bleeding
What are the three steps of hemostasis?
Vascular spasm, platelet plug formation, coagulation
What is coagulation?
Blood clotting, where fibrinogen is converted to fibrin
What is a thrombus?
A clot that develops in an unbroken blood vessel
What is an embolus?
A thrombus that breaks away and moves freely in the bloodstream
What is an embolism?
An embolus that becomes lodged in a narrow blood vessel
What are some anticoagulant drugs?
Aspirin, heparin, warfarin
What is thrombocytopenia?
A condition with a low number of circulating platelets
What are some blood transfusion options for restoring blood volume?
Normal saline solution, Ringer’s solution
What are the main human blood groups?
ABO and Rh
What is type A blood?
Has antigen A and anti-B antibodies in plasma
What is type B blood?
Has antigen B and anti-A antibodies in plasma
What is type AB blood?
Has both antigen A and B, no antibodies in plasma
What is type O blood?
Has no antigens, both anti-A and anti-B antibodies
What is Rh factor?
An antigen, with Rh+ indicating its presence
What is hemolytic disease of the newborn?
Occurs when an Rh- mother carries an Rh+ fetus, leading to antibody attack on fetal RBCs
What is a transfusion reaction?
Occurs when mismatched blood is transfused, causing agglutination of donor RBCs
What is erythropoiesis regulated by?
Hormones and growth factors
What is the main dietary requirement for erythropoiesis?
Iron
What condition results from insufficient hemoglobin per RBC?
Iron-deficiency anemia
What is pernicious anemia?
Lack of intrinsic factor leading to B₁₂ deficiency
What is hemolytic anemia?
RBCs are destroyed faster than they are produced
What is polycythemia?
An excess of RBCs causing increased blood viscosity
What are granulocytes?
White blood cells with visible granules
What are agranulocytes?
White blood cells without visible granules
What is the function of neutrophils?
Phagocytosis of bacteria
What is respiratory burst?
A process by neutrophils that produces germ-killing substances
Where are eosinophils mainly located?
In the lining of the digestive and respiratory tracts
What do eosinophils release to combat parasitic worms?
Hydrolytic enzymes
What does histamine do?
Causes vasodilation and attracts WBCs to inflamed sites
What are mast cells?
Cells that secrete histamine and heparin, similar to basophils
Where are lymphocytes mainly found?
Lymphoid tissue, such as lymph nodes and spleen
What are monocytes called when they enter tissues?
Macrophages
What do macrophages do?
Phagocytize pathogens and dead cells
What are antigen-presenting cells?
Cells that present antigens to T cells, like macrophages
What is the lifespan of WBCs?
Typically a few days due to fighting infections
What is thrombopoiesis?
The production of platelets
How long do platelets last in the bloodstream?
About 10 days
What is platelet plug formation?
The aggregation of platelets to seal small blood vessel tears
What is fibrinolysis?
The process of removing a clot after a blood vessel has healed
What is plasmin?
An enzyme that digests fibrin and breaks down clots
What are anticoagulants?
Substances that prevent blood clotting
What role does heparin play in blood?
It enhances the activity of antithrombin III to inhibit clotting
What is a pulmonary embolism?
An embolus that blocks blood flow in the lungs
What is warfarin used for?
To interfere with vitamin K and prevent clot formation
What is hemophilia?
A hereditary disorder where blood cannot clot properly
What is disseminated intravascular coagulation (DIC)?
A condition involving widespread clotting and bleeding
What is the purpose of blood transfusions?
To restore oxygen-carrying capacity of the blood
What are packed red blood cells (PRBCs)?
A blood product used in transfusions to restore oxygen capacity
What determines ABO blood groups?
The presence or absence of antigens A and B on RBCs
Which blood type is the universal recipient?
Type AB
Which blood type is the universal donor?
Type O
What is Rh incompatibility?
A condition where Rh- individuals produce anti-Rh antibodies after exposure to Rh+ blood
What is RhoGAM?
A treatment given to Rh- mothers to prevent the formation of anti-Rh antibodies
What are the main components of plasma?
Water, electrolytes, nutrients, hormones, waste products
What role does calcium play in blood clotting?
It acts as a cofactor in the coagulation process
What is serum?
Plasma without the clotting proteins
What is the role of vitamin K in coagulation?
It is necessary for the synthesis of clotting factors
What is the ‘intrinsic pathway’ of coagulation?
A clotting mechanism initiated by factors within the blood
What is the ‘extrinsic pathway’ of coagulation?
A clotting mechanism triggered by external trauma to blood vessels
What is prothrombin activator?
An enzyme complex that converts prothrombin to thrombin
What does thrombin do?
Converts fibrinogen to fibrin during coagulation
What is clot retraction?
The contraction of platelets to pull a wound together
What happens during hypoxia?
Tissues are deprived of adequate oxygen
What triggers the release of erythropoietin?
Low oxygen levels in the kidneys
What is hemoglobin made of?
Heme (iron-containing pigment) and globin (protein)
What is oxyhemoglobin?
Hemoglobin bound to oxygen
What happens in the spleen during erythrocyte destruction?
Old RBCs are broken down by macrophages
What is bilirubin?
A yellow pigment formed from the breakdown of heme
Where is bilirubin processed?
In the liver, where it becomes part of bile
What is the main function of leukocytes?
To defend the body against infection and disease
What happens during positive chemotaxis?
WBCs follow chemical signals to sites of infection or injury
What are megakaryocytes?
Large bone marrow cells that produce platelets
How do platelets remain inactive?
By the secretion of nitric oxide and prostacyclin from endothelial cells
What does thromboxane A₂ do?
Promotes platelet aggregation during clot formation
What is hemolysis?
The rupture or destruction of red blood cells
What is the lifespan of platelets?
10 days in the bloodstream
What happens in vasoconstriction during hemostasis?
Blood vessels constrict to reduce blood flow and limit bleeding
What is petechiae?
Small red or purple spots caused by bleeding into the skin
What is the most abundant electrolyte in plasma?
Sodium (Na⁺)
What is the role of plasma proteins?
To maintain osmotic pressure and transport substances
What is globulin?
A plasma protein involved in immune responses and transport
What are the key nutrients in plasma?
Glucose, amino acids, fatty acids, vitamins, and minerals
What are the waste products in plasma?
Carbon dioxide, urea, creatinine, and bilirubin
What are colony-stimulating factors (CSFs)?
Proteins that stimulate the production of white blood cells
What is the function of fibrin?
To form a mesh that traps blood cells during clot formation
What is the role of interleukins?
To regulate the immune response and stimulate white blood cell production
