Which chamber of the heart endures the highest pressures?

Atherosclerosis is a disease in which fatty deposits (plaques) build up in the walls of arteries, leading to narrowing and reduced blood flow. Elevated levels of certain lipids, including low density lipoprotein (LDL) cholesterol and triglycerides, are well-established risk factors for the development of atherosclerosis.

In contrast, high density lipoprotein (HDL) cholesterol has been shown to have a protective effect against atherosclerosis. HDL is often referred to as "good cholesterol" because it helps to transport excess cholesterol from peripheral tissues (including the walls of arteries) back to the liver for processing and excretion. HDL also has anti-inflammatory and antioxidant properties that may help to reduce the risk of atherosclerosis.

In general, higher levels of HDL cholesterol are associated with a lower risk of cardiovascular disease and atherosclerosis. However, the protective effect of HDL may vary depending on other factors such as smoking, obesity, and diabetes. It is important to maintain a healthy balance of lipids in the bloodstream, including a high level of HDL and low levels of LDL and triglycerides, in order to reduce the risk of atherosclerosis and other cardiovascular diseases.

Croup is a common respiratory illness in young children, characterized by inflammation of the upper airways (including the larynx and trachea) that leads to a characteristic barking cough and difficulty breathing. Croup is most commonly caused by viral infections, particularly parainfluenza virus, although other viruses such as respiratory syncytial virus (RSV) and influenza virus can also be responsible.

Bacterial croup is rare and usually occurs in children who have an underlying condition that makes them more susceptible to bacterial infections, such as immunodeficiency or a history of recurrent respiratory infections. Fungal croup is also rare and usually occurs in children with a weakened immune system or a history of exposure to contaminated soil or other environmental sources of fungi.

Autoimmune croup is not a recognized medical condition. While some autoimmune disorders can affect the respiratory system (such as systemic lupus erythematosus), they do not typically cause croup-like symptoms.