Biology And Epidemiology Test Quiz!

Atherosclerosis is the correct answer because it refers to the accumulation of cholesterol within the intimal layer of the aorta and large arteries. This condition occurs when fatty deposits, known as plaques, build up on the inner walls of the arteries, leading to narrowing and hardening of the arteries. Atherosclerosis is a common cause of various cardiovascular diseases, including heart attacks and strokes.

Antithrombin is a substance that inhibits the activity of thrombin, a protein involved in blood clotting, as well as other serine proteases. By inhibiting these enzymes, antithrombin helps to regulate the clotting process and prevent excessive blood clot formation.

Metastatic calcification occurs when calcium is deposited in tissues due to an underlying condition that disrupts calcium metabolism, leading to hypercalcemia. This can happen in various diseases such as hyperparathyroidism or kidney failure. The statement is true because it accurately describes the process of metastatic calcification.

Prostacyclin inhibits platelet aggregation. It is a prostaglandin produced by endothelial cells and acts as a potent vasodilator and inhibitor of platelet aggregation. It prevents platelets from clumping together and forming blood clots, thus helping to maintain normal blood flow.

The formula for negative predictive value is True Negatives / (True Negatives and False Negatives). This formula calculates the proportion of true negative results among all the negative results, including both the true negatives and the false negatives. It is a measure of the accuracy of a test in correctly identifying individuals who do not have a condition or disease.

Hyperaemia is an active process resulting from arteriolar dilation, which leads to an increased blood flow to a particular area. This increased blood flow can cause erythema, which is the redness of the skin due to increased blood flow. On the other hand, congestion is a passive process resulting from decreased venous outflow, which leads to a buildup of blood in the tissue. This buildup of blood can cause cyanosis, which is the bluish discoloration of the skin due to poor oxygenation. Therefore, the correct answer is 1. Hyperaemia → erythema, 2. Congestion → cyanosis.

Dystrophic calcification refers to the local deposition of calcium in dying tissues without any disturbances in calcium metabolism. This type of calcification occurs as a result of tissue injury or damage, such as in areas of necrosis or inflammation. It is a common occurrence in various pathological conditions, including atherosclerosis, chronic kidney disease, and certain types of cancer. Dystrophic calcification is different from metastatic calcification, which is characterized by calcium deposition in otherwise healthy tissues due to systemic metabolic imbalances.

In the hypophosphorylated state, RB prevents cells from replicating by forming a tight inactive complex with the transcription factor E2F.

The formula (True Positives + True Negatives) / Total number of patients represents test efficiency because it calculates the percentage of times that the test gives the correct answer (True Positives and True Negatives) compared to the total number of tests (Total number of patients).

Cyclin-dependent kinases play a crucial role in regulating the cell cycle by phosphorylating target proteins. Phosphorylation is the process of adding a phosphate group to a protein, which can change its structure and function. In the context of the cell cycle, phosphorylation by cyclin-dependent kinases helps to activate or inactivate specific target proteins, allowing cells to progress to the next stage of the cell cycle. Therefore, phosphorylating critical target proteins is essential for driving the cell cycle forward.

The sensitivity of a test is the percentage of all patients with the disease present who have a positive test. This means that the formula that represents sensitivity is True Positives / (True Positives + False Negatives). This formula calculates the proportion of true positive results (patients with the disease who test positive) out of all the patients with the disease present.

The formula True Negatives / (True Negatives and False Positives) represents SPECIFICITY. This formula calculates the percentage of patients without the disease who have a negative test result. True Negatives represent the number of patients without the disease who are correctly identified as negative. The denominator, True Negatives and False Positives, represents the total number of patients without the disease. Therefore, dividing True Negatives by the total number of patients without the disease gives the specificity of the test.

Xanthoma is the correct answer because it refers to the accumulation of cholesterol within the subepithelial connective tissue. Xanthomas are typically yellowish nodules or plaques that develop due to the buildup of cholesterol in certain areas of the body, such as tendons, skin, and blood vessels. They can be a sign of underlying lipid disorders or conditions like familial hypercholesterolemia. Therefore, xanthoma accurately describes the accumulation of cholesterol within the subepithelial connective tissue.

Laminin is the most abundant glycoprotein found in the basement membrane. It is a major component of the extracellular matrix and plays a crucial role in providing structural support and stability to tissues. Laminin is involved in various cellular processes including cell adhesion, migration, and differentiation. Its abundance in the basement membrane makes it an essential protein for maintaining tissue integrity and function.

Leukotrienes are created by the lipoxygenase pathway and are known to be potent vasoconstrictors. They also cause bronchospasm and increased vascular permeability. Therefore, they fit the description given in the question.

The positive predictive value is a measure of the proportion of positive test results that are true positives. It is calculated by dividing the number of true positives by the sum of true positives and false positives. This formula represents the positive predictive value because it calculates the ratio of true positives to the sum of true positives and false positives.

TNF, or tumor necrosis factor, can induce apoptosis, which is a programmed cell death process, and it can also promote cell survival. TNF is a cytokine that plays a role in regulating immune responses and inflammation. It can activate signaling pathways that lead to apoptosis in certain cells, such as cancer cells or infected cells. However, TNF can also promote cell survival by activating other signaling pathways that promote cell growth and proliferation. Therefore, TNF can have both pro-apoptotic and pro-survival effects depending on the context and the specific cells involved.

Non-inflammatory edema is usually transudate due to hydrodynamic derrangements. Inflammatory oedema is often an exudate = protein rich, due to increased vascular permeability.

Glucocerebrosidase cleaves glucose residue from ceramide.

IFN-γ is the major macrophage activating cytokine. It plays a crucial role in activating macrophages, which are important immune cells involved in the defense against pathogens. IFN-γ enhances the ability of macrophages to kill and eliminate invading microorganisms, as well as stimulates the production of inflammatory mediators. This cytokine is produced by various immune cells, including T cells and natural killer cells, in response to infection or inflammation. Its activation of macrophages is essential for the immune response against pathogens and the regulation of inflammation.

There are 3 types of natural anticoagulants: 1. Antithrombins: inhibits thrombin and other serine proteases 2. Proteins C and S: Vitamin K dependent proteins that inactivate factors V and VIII 3. Tissue factor pathway inhibitor: forms complexes with clotting factors that inhibits them.

Lipoxins inhibit leukocyte recruitment. Leukocyte recruitment is a process in which white blood cells are attracted to and accumulate at the site of inflammation or infection. Lipoxins are anti-inflammatory molecules derived from arachidonic acid metabolism. They play a crucial role in resolving inflammation by inhibiting the recruitment of leukocytes to the site of inflammation. By reducing leukocyte recruitment, lipoxins help to dampen the inflammatory response and promote the resolution of inflammation.

Smoking cigarettes is the principal preventable risk factor for bladder cancer in both men and women.

In order to maintain long-term immunity, some vaccines require multiple doses followed by booster doses. Administering doses at intervals less than the minimum interval can result in a suboptimal immune response. However, in clinical practice, it is recommended that vaccine doses administered within a certain number of days before the minimum interval may still be considered valid. The correct answer is 4, indicating that vaccine doses administered within 4 days before the minimum interval may be counted as valid.

Sites of fatty change are liver, heart, mucle, kidney. Causes of fatty change include toxins, protein malnutrition, diabetes mellitus, obesity, anoxia.

Phospholipases are enzymes that break down phospholipids. They are activated by increased intracellular calcium levels and are inhibited by steroids. Steroids are known to have anti-inflammatory effects and can suppress the activity of phospholipases. Therefore, the statement "Inhibited by steroids" is true. Additionally, the statement "Activated by increased intracellular calcium" is also true because phospholipases require calcium ions for their activation. Lastly, the statement "Breaks down phospholipids" is true because that is the primary function of phospholipases.