Comprehensive Blood, Immune System, and Hemostasis Overview for Students

What are the primary functions of blood?

Transports gases, nutrients, hormones, and metabolic wastes; regulates interstitial fluid composition, restricts fluid loss at injury sites, defends against toxins and pathogens, and regulates body temperature.

What is hematocrit?

The percentage of total blood volume occupied by packed red blood cells.

What is the normal range of hematocrit for males?

40-54%

What is the normal range of hematocrit for females?

37-47%

What is the main component of plasma?

Water (92%)

What are the functions of albumins in plasma?

Generate colloid osmotic pressure and act as carriers.

What is the role of fibrinogen in blood?

It is cleaved to form fibrin during blood clotting.

Where are blood cells produced in adults?

In the bone marrow, specifically in the pelvis, spine, ribs, cranium, and proximal ends of long bones.

What is erythropoiesis?

The production of red blood cells.

What hormone promotes erythropoiesis?

Erythropoietin, produced primarily by kidney cells.

What is the lifespan of a red blood cell?

About 120 days.

What is anemia?

A condition characterized by a reduced ability of blood to carry oxygen due to low red blood cell count or low hemoglobin.

What are common symptoms of anemia?

Tiredness, weakness, pale skin, headaches, and dizziness.

What is polycythemia?

A condition where hematocrit is too high, leading to increased blood viscosity.

What are the three phases of hemostasis?

Vascular phase, platelet phase, and coagulation phase.

What initiates the vascular phase of hemostasis?

Neurogenic and myogenic control leading to vasoconstriction.

What role do platelets play in hemostasis?

They aggregate to form a plug and release factors that attract more platelets.

What is the coagulation cascade?

A series of events where inactive plasma clotting factors are converted to active enzymes to form a blood clot.

What is the function of tissue plasminogen activator (tPA)?

It activates plasminogen to break down fibrin and remove clots.

What is the role of anticoagulants?

They prevent blood clotting by blocking the action of thrombin or inhibiting clotting factor synthesis.

What is the significance of vitamin K in coagulation?

It is necessary for the synthesis of several clotting factors including thrombin.

What is the cell-based theory of coagulation?

It describes the initiation, amplification, and propagation phases of coagulation.

What are the two main types of blood cells?

Erythrocytes (red blood cells) and leukocytes (white blood cells).

What is the primary role of hemoglobin in red blood cells?

To transport oxygen and carbon dioxide.

What causes jaundice in relation to red blood cells?

High turnover of red blood cells leading to increased bilirubin levels.

What are the causes of low production anemia?

Destruction of stem cells, inadequate nutrients (iron, folic acid, Vitamin B12), and low erythropoietin.

What can lead to high removal anemia?

Hemolytic conditions, genetic defects in RBC proteins, parasitic infections, autoimmune reactions, and excessive blood loss.

What are the two main types of immunity?

Innate immunity (rapid, non-specific) and adaptive immunity (slower, specific).

What is the role of T cell receptors?

T cell receptors bind to antigens that are presented by MHC molecules.

What activates helper T cells?

Helper T cells are activated by MHC class II molecules presenting exogenous antigens.

What is the function of cytotoxic T cells?

Cytotoxic T cells are activated by MHC class I molecules and destroy infected or cancerous cells.

What is immediate hypersensitivity?

An exaggerated immune response to an allergen that can lead to rapid reactions such as anaphylaxis.

What are the four features of adaptive immunity?

Specificity, versatility, memory, and tolerance.

How do B cells get activated?

B cells are activated when an antigen binds to their specific receptors, leading to internalization and processing with MHC.

Why is knowing your blood type important?

To prevent cross-reactions during blood transfusions, which can occur if donor antigens react with recipient antibodies.

What is the connection between Rh factor and pregnancy?

Rh- mothers can develop anti-D antibodies if exposed to Rh+ blood, which can lead to hemolytic disease of the newborn.

How do doctors prevent hemolytic disease of the newborn?

By injecting anti-D antibodies into Rh- mothers during and after pregnancy to prevent an immune response.

What is the role of memory B cells?

Memory B cells provide a rapid and strong response upon re-exposure to the same antigen.

What types of cells are classified as phagocytes?

Monocytes, macrophages, and neutrophils.

What are the two types of hypersensitivity?

Immediate hypersensitivity and delayed hypersensitivity.

What happens during clonal selection of B and T cells?

B and T cells that recognize specific antigens are selected for proliferation and differentiation.

What is the primary function of antibodies?

To bind to antigens and neutralize pathogens or mark them for destruction.

What is the significance of MHC class I molecules?

They present endogenous antigens and are crucial for the activation of cytotoxic T cells.

What is the significance of MHC class II molecules?

They present exogenous antigens and are essential for the activation of helper T cells.

What is an antigen-presenting cell?

A cell that displays antigen on its surface via MHC molecules to activate T cells.

What is the role of cytokines in T cell activation?

Cytokines stimulate the activation and proliferation of helper T cells, cytotoxic T cells, and B cells.

What is tolerance in the context of adaptive immunity?

Tolerance refers to the immune system's ability to ignore normal tissues while responding to foreign substances.

What is the primary function of dendritic cells?

To capture and present antigens to T cells, initiating an immune response.

What is the role of plasma cells?

Plasma cells are differentiated B cells that produce large quantities of antibodies.

What is the function of natural killer cells?

Natural killer cells destroy infected or cancerous cells without prior sensitization.

What is the role of eosinophils?

Eosinophils are involved in combating multicellular parasites and allergic reactions.

What is the significance of memory T cells?

Memory T cells provide a quicker and more effective response upon re-exposure to the same antigen.

What is the role of basophils in the immune response?

Basophils release histamines and other chemicals that mediate inflammation and allergic responses.

What is the difference between innate and adaptive immunity?

Innate immunity is rapid and non-specific, while adaptive immunity is slower and specific to particular antigens.

What activates a specific helper T cell?

Recognition of an antigen presented on MHC class II by a B cell.

What do activated B cells divide into?

Plasma cells that secrete antibodies and memory B cells.

What is the role of cytokines in the immune response?

Cytokines, such as IL-4, IL-5, and IL-6, are secreted by activated T cells to regulate immune responses.

What is the most common type of circulating antibody?

IgG, which is transferred across the placenta from mother to baby.

What is the function of IgA antibodies?

IgA protects epithelial surfaces and is present in breast milk.

What type of immune response is characterized by rapid and non-specific action?

Innate immunity.

What is the primary function of phagocytes?

To engulf, ingest, and breakdown pathogens.

What are the main types of pathogens recognized by the immune system?

Parasitic worms, fungi, protozoa, bacteria, and viruses.

What is the role of natural killer (NK) cells?

To kill infected or cancerous cells that lack MHC class I expression.

What triggers the inflammatory response?

Injury to tissues, leading to swelling, redness, heat, and pain.

What is the function of complement proteins in the immune system?

To destroy target cell membranes, stimulate inflammation, and attract phagocytes.

What is the role of fever in the immune response?

To speed up metabolic activity of the host and inhibit some pathogens.

What are pathogen-associated molecular patterns (PAMPs)?

Molecules associated with groups of pathogens that are recognized by the immune system.

What is opsonization?

The process of coating a pathogen with opsonins to enhance phagocytosis.

What are the primary lymphoid tissues involved in immune cell production?

Bone marrow and thymus.

What is the function of dendritic cells?

To present antigens to T cells and initiate an immune response.

What is the role of mast cells in the immune response?

To release chemicals that contribute to inflammation and allergic reactions.

What is the significance of memory B and T cells?

They provide long-lasting immunity by remembering past infections.

What are the effects of pyrogens on the body?

They change the thermoregulatory set point in the hypothalamus, causing fever.

How do antibodies protect the body?

By binding to antigens, blocking their action, and activating the immune system.

What is the main function of leukocytes in the immune system?

To detect and destroy pathogens and abnormal cells.

What is the role of chemotaxis in the immune response?

To guide immune cells to the site of infection or injury.

What is the function of neutrophils?

To act as phagocytes that circulate in the blood and migrate into tissues.

What is the role of the spleen in the immune system?

To monitor blood for pathogens and initiate immune responses.

What is the function of the thymus?

To produce T lymphocytes, which are essential for adaptive immunity.

What is the role of the lymphatic system in immunity?

To return excess tissue fluid to the blood and transport pathogens to lymph nodes.

What is the role of eosinophils in the immune system?

To defend against parasites and participate in allergic reactions.