ch 17- Blood Flashcards
What is the internal transport system of the body?
Blood
Blood is responsible for transporting oxygen, nutrients, hormones, and metabolic wastes.
List the three main functions of blood.
- Transport
- Regulation
- Protection
What does blood transport to cells?
Oxygen (O2) and nutrients
How does blood help in regulation?
- Maintains body temperature
- Maintains normal pH
- Maintains fluid volume
What are the protective functions of blood?
- Prevents blood loss
- Prevents infection
What are the formed elements in blood?
- Red blood cells (RBCs or erythrocytes)
- White blood cells (WBCs or leukocytes)
- Platelets
What is the color of blood when it is oxygen-rich?
Scarlet (bright) red
What is the color of blood when it is oxygen-poor?
Dark red
What is the average blood volume in men?
5-6 liters
What is the average blood volume in women?
4-5 liters
What is the pH range of blood?
7.35–7.45
What percentage of blood plasma is water?
90%
What are the main components of blood plasma?
- Nutrients
- Gases
- Hormones
- Wastes
- Proteins
- Inorganic ions
What is the most abundant plasma protein?
Albumin
What are the major functions of albumin?
- Blood buffer
- Carrier for certain molecules
- Contributes to plasma osmotic pressure
What are the two major categories of leukocytes?
- Granulocytes
- Agranulocytes
What are the types of granulocytes?
- Neutrophils
- Eosinophils
- Basophils
What are the types of agranulocytes?
- Lymphocytes
- Monocytes
What mnemonic helps remember the order of leukocyte abundance?
Never let monkeys eat bananas
What is hematopoiesis?
Formation of blood cells
Where does hematopoiesis occur?
Red bone marrow
What hormone stimulates erythropoiesis?
Erythropoietin (EPO)
What dietary requirements are essential for erythropoiesis?
- Iron
- Amino acids
- Certain B vitamins
What is the life span of red blood cells (RBCs)?
100–120 days
What is anemia?
Blood’s oxygen-carrying capacity too low to support normal metabolism
What are the three groups of causes for anemia?
- Blood loss
- Not enough RBCs produced
- Too many RBCs being destroyed
What is polycythemia?
Abnormal excess of RBCs
What is the treatment for polycythemia vera?
Therapeutic phlebotomy
What condition results from a lack of EPO?
Renal anemia
What is the primary function of leukocytes?
Defend the body against disease
What are the five types of leukocytes?
Neutrophils, Lymphocytes, Monocytes, Eosinophils, Basophils
What are granulocytes?
Include neutrophils, eosinophils, and basophils
What is the shape of granulocyte nuclei?
Lobed, rather than circular
How do granulocytes compare in size and lifespan to red blood cells?
Larger and shorter-lived than RBCs
What do granulocytes contain when stained with Wright’s stain?
Visible cytoplasmic granules
What percentage of WBCs do neutrophils account for?
50–70%
What enzymes do neutrophils’ granules contain?
Hydrolytic enzymes (lysosomes) and antimicrobial proteins called defensins
What is the primary function of neutrophils?
Highly phagocytic ‘bacteria slayers’
What is the appearance of eosinophils’ nucleus?
Two lobes connected by a broad band
What do eosinophils primarily destroy?
Parasitic worms
What chemical do basophils release?
Histamine
What is the function of histamine released by basophils?
Vasodilates and attracts WBCs to inflamed sites
What type of cells do lymphocytes include?
T lymphocytes (T cells) and B lymphocytes (B cells)
What role do T lymphocytes play?
Act against virus-infected cells and tumor cells
What do B lymphocytes give rise to?
Plasma cells that produce antibodies
What do monocytes differentiate into after leaving circulation?
Macrophages
What stimulates leukopoiesis?
Two groups of chemical messengers: interleukins and colony-stimulating factors (CSFs)
What is the precursor to lymphocytes?
Lymphoid stem cells
What is leukopenia?
An abnormally low WBC count
What are leukemias?
Group of cancerous conditions involving overproduction of abnormal WBCs
What are the two types of leukemia based on progression?
Acute and Chronic
What is the primary cause of death in untreated leukemias?
Internal hemorrhage or overwhelming infections
What is infectious mononucleosis commonly known as?
The ‘kissing disease’
What are the primary functions of platelets?
Form temporary platelet plug to seal breaks in blood vessel walls
What is thrombopoiesis?
The formation of platelets
What regulates thrombopoiesis?
Thrombopoietin
Where are platelets formed?
Bone marrow
What is hemostasis?
The rapid series of reactions that stop bleeding
What are the three steps involved in hemostasis?
Step 1: Vascular spasm, Step 2: Platelet plug formation, Step 3: Coagulation
What triggers vascular spasm?
Direct injury to vascular smooth muscle, chemicals from endothelial cells, pain reflexes
What is the role of von Willebrand factor in platelet plug formation?
Stabilizes bound platelets by forming a bridge between collagen and platelets
What is the end point of coagulation?
A fibrin mesh that traps blood cells and seals the hole
What is the common pathway in coagulation?
Involves factor I (fibrinogen) and factor II (prothrombin)
What are the two pathways of coagulation?
Intrinsic pathway and extrinsic pathway
What is the primary function of thrombin in coagulation?
Converts fibrinogen to fibrin
What vitamin is needed for the synthesis of clotting factors?
Vitamin K
What is the function of calcium ions in coagulation?
Needed for essentially all stages of the coagulation process
What are platelets?
Cell fragments involved in blood clotting
Also known as thrombocytes.
What is the common pathway in blood clotting?
Both extrinsic and intrinsic pathways converge to form a clot
It is essential for the final stages of coagulation.
How many clotting factors are there?
Thirteen
Each factor has a specific function in the coagulation process.
What is Proconvertin?
Factor VII; a plasma protein synthesized in the liver
It is part of the extrinsic pathway.
What is the function of Antihemophilic factor (AHF)?
Factor VIII; deficiency results in hemophilia A
It is synthesized in the liver and lung capillaries.
What does deficiency of Factor IX lead to?
Hemophilia B
Factor IX is also known as plasma thromboplastin component (PTC).
What is the Stuart factor?
Factor X; a plasma protein synthesized in the liver
It is involved in the common pathway of coagulation.
What is the role of Fibrin stabilizing factor (FSF)?
Cross-links fibrin, forming a strong, stable clot
It is also known as Factor XIII.
What is clot retraction?
Contraction of actin and myosin in platelets pulls on fibrin strands
This process helps to draw ruptured blood vessel edges together.
What initiates fibrinolysis?
Plasminogen becomes plasmin, a fibrin-digesting enzyme
Activation occurs through tissue plasminogen activator (tPA).
True or False: Clot growth is limited by the swift removal and dilution of clotting factors.
True
Inhibition of activated clotting factors also plays a role.
What are thromboembolic disorders?
Disorders resulting in undesirable clot formation
They can lead to conditions like thrombosis.
What is thrombocytopenia?
Deficient number of circulating platelets
It can cause spontaneous bleeding, known as petechiae.
What is the most common type of hemophilia?
Hemophilia A
It is due to a deficiency of factor VIII.
What is the universal donor blood type?
Type O
It has no A or B antigens.
What is the Rh factor?
Presence of D antigen on red blood cells
Rh+ indicates the presence of this antigen.
What happens during a transfusion reaction?
Recipient’s plasma antibodies attack donor’s RBCs
This can lead to hemolysis and renal failure.
What is blood typing?
Determining blood groups of both donor and recipient
It involves mixing blood with antibodies against common antigens.
What is prothrombin time (PT)?
A test that assesses hemostasis
PT is compared to control values and reported as international normalized ratio (INR).
What does a complete blood count (CBC) check?
Formed elements, hematocrit, hemoglobin
It provides a comprehensive overview of blood health.
