Untitled Quiz

Plasminogen is a protein that is converted to plasmin, an enzyme that breaks down fibrin clots. This process helps to dissolve blood clots and prevent them from growing too large.

The endothelium, the inner lining of blood vessels, actively prevents blood clots by shielding collagen, releasing nitric oxide, degrading ADP, altering thrombin, shielding tissue factor, competing with thrombomodulin, producing heparin and antithrombin III, and activating fibrinolysis by producing tissue plasminogen activator (tPA).

Vitamin K deficiency can be caused by a lack of bacteria in the intestine, which are responsible for producing Vitamin K. It can also be caused by an inability to absorb Vitamin K, which can occur with conditions like bile duct obstruction.

Hemophilia is a genetic disorder that impairs blood clotting due to a deficiency in certain clotting factors. The most common type, Hemophilia A, is due to a lack of factor VIII. Hemophilia B is due to a lack of factor IX.

Thrombocytopenia is a condition characterized by a low platelet count in the blood, making it difficult for the blood to clot properly.

A pulmonary embolism occurs when a blood clot (embolus) from a deep vein in the leg travels to the lungs and blocks an artery, potentially leading to serious respiratory complications.

DIC is a life-threatening condition where widespread clotting occurs within small blood vessels. It often arises due to underlying infections, trauma, or cancer, and leads to a deficiency of clotting factors, which paradoxically leads to excessive bleeding.

The prothrombin time test measures the time it takes for blood plasma to clot after adding calcium and tissue factor. It assesses the function of the extrinsic and common pathways of the coagulation cascade.

INR stands for International Normalized Ratio. It is a standardized way to measure the prothrombin time, allowing for consistent results across different laboratories. A normal INR value typically falls between 1.0 and 2.0. Higher INR indicates increased bleeding risk.

The three main types of WBCs are granulocytes, monocytes, and lymphocytes. Granulocytes include neutrophils, eosinophils, and basophils. Monocytes develop into macrophages. Lymphocytes include T cells and B cells.

Part of the innate immune system that directly kills infected or cancerous cells without prior sensitization. They recognize cells with low or abnormal MHC-1 expression, suggesting viral infection or malignancy.

NK cells detect the absence or decrease of MHC-1 molecules on the surface of target cells, indicating potential infection or transformation. They also recognize stress-induced molecules expressed by infected or cancerous cells.

Antigen-presenting cells (APCs) that link the innate and adaptive immune systems. They engulf pathogens, process their antigens, and present them to T cells in lymph nodes.

A highly specific and long-lasting immune response that involves lymphocytes (B cells and T cells) and antibodies. It targets specific pathogens and remembers them for future encounters.

Substances that elicit an immune response, specifically by binding to antibodies or T cell receptors.

The mechanism by which adaptive immune cells (lymphocytes) are selected and activated based on their specific antigen-binding receptors. When a lymphocyte encounters its specific antigen, it proliferates and differentiates, generating many copies of itself and effector cells.

The ability of the adaptive immune system to remember past encounters with specific pathogens. This allows for a faster and stronger response upon re-exposure to the same pathogen.

B cells are a type of lymphocyte that produce antibodies. Antibodies are proteins that bind to specific antigens and neutralize pathogens, recruit other immune cells, and trigger complement activation.

Type of lymphocytes that require antigen presentation by APCs (like dendritic cells) for activation. They act in a short range and have different types, including cytotoxic T cells and helper T cells.

Major Histocompatibility Complex proteins are markers on cells that identify them as 'self. They play a critical role in antigen presentation to T cells.

IgE antibodies bind to mast cells and basophils. When an allergen binds to IgE, it triggers the release of histamine and other inflammatory mediators.

These immune cells are responsible for releasing histamine and other inflammatory mediators during allergic reactions.

A condition where the body has a low white blood cell count, making it more susceptible to infections.

A type of cancer where abnormal white blood cells are produced in the bone marrow. These cells can't fight infections effectively.

The body's first line of defense against infection, including physical barriers, antimicrobial substances, and phagocytes.

Pathogen-associated molecular patterns (PAMPs) are molecules found on pathogens that are recognized by the immune system.

Pattern recognition receptors (PRRs) are receptors on immune cells that detect PAMPs, initiating an immune response.

The process by which immune cells engulf and destroy pathogens.

A complex system of proteins that assists in the immune response by tagging pathogens for destruction, activating inflammation, and directly killing invaders.

The volume of plasma cleared of a substance per unit time. It represents the removal rate of a substance from the body.

It can be calculated by dividing the excretion rate of a substance by its arterial plasma concentration.

The volume of fluid filtered from the blood into Bowman's capsule per unit time. It's a measure of kidney function.

A substance used to measure GFR because it is freely filtered, not reabsorbed or secreted by the kidneys.

A measure of the glomerular wall's permeability and surface area to water. It reflects how easily fluid can pass through the filter.

The difference between the hydrostatic pressure in glomerular capillaries and Bowman's capsule, and the colloid osmotic pressure in the capillaries.

It decreases GFR because it increases the pressure opposing filtration.

It decreases GFR because it increases the pressure opposing filtration.

The volume of blood flowing through the kidneys per unit time.

The ability of the kidneys to maintain a steady RBF and GFR despite changes in systemic blood pressure.

The constriction of blood vessels in response to increased blood pressure, which helps maintain a steady RBF.

A mechanism where the macula densa cells monitor the concentration of sodium in the filtrate and adjust the GFR.

It constricts both afferent and efferent arterioles, lowering GFR and RBF.

Low levels primarily constrict efferent arterioles (raising GFR, lowering RBF), while high levels constrict both (lowering GFR and RBF).

Slow waves are rhythmic fluctuations in membrane potential that occur at a fixed frequency but variable amplitude. They are not true action potentials and are generated by specialized pacemaker cells in the gut wall.

Spike potentials are true action potentials triggered when slow waves reach threshold. They are caused by the opening of voltage-dependent calcium channels.

Electrical activity (slow waves and spike potentials) slightly precedes mechanical activity (muscle contraction).

Swallowing involves three phases: oral (voluntary), pharyngeal (involuntary), and esophageal (involuntary).

The UES opens to allow food into the esophagus and closes to prevent food from going back up into the pharynx.

The LES opens to allow food into the stomach and closes to prevent stomach contents from refluxing back into the esophagus.

Receptive relaxation is the relaxation of the orad (upper) part of the stomach to accommodate incoming food.

The caudad part of the stomach mixes food with gastric juice (propulsion/retropulsion) and propels chyme into the duodenum (antral pump).

Factors that increase gastric emptying include: higher tone of the orad region, stronger peristaltic contractions, lower pylorus tone, and absence of segmental contractions in the intestine.

Factors that decrease gastric emptying are the opposite of those that increase it. These are triggered by receptors in the intestinal mucosa when food enters the small intestine.

Enterogastric reflexes are neural and hormonal signals that originate in the small intestine and inhibit gastric emptying. This is triggered by receptors in the intestinal mucosa that are activated by osmolarity, acid, fat, or protein.

CCK is a hormone released by the small intestine in response to fat and proteins. It slows gastric emptying by inhibiting the antral pump and promoting relaxation of the orad region.

The small intestine mixes chyme with enzymes and other digestive secretions, circulates it to expose it to the mucosa, and propels it forward.

Haustral contractions are segmental contractions of the large intestine that occur in the haustra (pouches) of the colon. They serve to mix and propel fecal matter.

The gastrocolic reflex is a reflex that increases colonic motility (mass movements) in response to distension of the stomach by food.

The most abundant type of white blood cell, specializing in quickly attacking and killing bacteria.

Larger phagocytes that engulf pathogens, debris, and old cells, playing a crucial role in wound healing and immune response.

White blood cells involved in allergic reactions, releasing histamine to trigger inflammation.

White blood cells that target parasites and modulate allergic reactions.

The body's first line of defense against pathogens, involving physical barriers, antimicrobial substances, and phagocytes.

The body's targeted and long-lasting immune response that specifically targets pathogens and remembers them for future encounters.

A type of T cell that orchestrates the immune response, activating other immune cells to fight specific pathogens.

A protein complex on the surface of antigen-presenting cells (APCs) that presents antigen fragments to T-helper cells.

The final stage of the coagulation cascade where the extrinsic and intrinsic pathways converge to activate thrombin.

Red blood cells responsible for oxygen transport throughout the body.

The protein in red blood cells that binds to oxygen, giving blood its red color.

The process of stopping bleeding by forming a clot to seal the damaged blood vessel.