What are the lipids in tears?

What are the lipids in tears?

Three lipids have been analyzed as an equimolar mixture: a wax ester behenyl oleate [m/z 535.6, (M + H)+], tristearin [m/z 607.6, (M – FA + H)+ and m/z 908.6, (M + NH4)+], and cholesteryl oleate (only one ion is visible, m/z 369 (M – FA +H)+].

What can lipids be broken into?

Triglycerides are broken down to fatty acids, monoglycerides (glycerol backbone with one fatty acid still attached), and some free glycerol. Cholesterol and fat-soluble vitamins do not need to be enzymatically digested (see Fig.

What is a plaque rupture?

Plaque rupture is defined as “an area of fibrous cap disruption whereby the overlying thrombus is in continuity with the lipid core”. 3. Intraplaque hemorrhage is defined as the deposition of blood products inside the plaque and is not necessarily associated with atherosclerotic plaque rupture.

What is the nickname for lipids?

fats
Although the term “lipid” is sometimes used as a synonym for fats, fats are a subgroup of lipids called triglycerides. Lipids also encompass molecules such as fatty acids and their derivatives (including tri-, di-, monoglycerides, and phospholipids), as well as other sterol-containing metabolites such as cholesterol.

What produces the lipid layer of tear?

The outer lipid layer is secreted principally by the sebaceous (meibomian) glands of the eyelid margins, although lipid tear elements also are contributed by the Harderian glands, particularly in rabbits.

What is tear film made of?

The traditional description of the tear film divides it into three layers: lipid, aqueous and mucin. The role of each layer depends on the composition of it. Tear production, evaporation, absorption and drainage concur to dynamic balance of the tear film and leads to its integrity and stability.

What are proteins broken down to?

The digestion of protein entails breaking the complex molecule first into peptides, each having a number of amino acids, and second into individual amino acids. The pepsins are enzymes secreted by the stomach in the presence of acid that breaks down proteins (proteolysis).

How are triglycerides broken down?

To obtain energy from fat, triglycerides must first be broken down by hydrolysis into their two principal components, fatty acids and glycerol. This process, called lipolysis, takes place in the cytoplasm. The resulting fatty acids are oxidized by β-oxidation into acetyl CoA, which is used by the Krebs cycle.

What happens to the contents of a ruptured plaque?

6.2. Coronary atherosclerotic plaque rupture or erosion is the most common cause of MI. Plaque rupture results in circulatory exposure of its thrombogenic contents (e.g., tissue factor, collagens, and lipids) leading to thrombus formation and MI [312,313].

How does plaque rupture lead to thrombosis?

Plaque rupture Thrombosis occurs when platelets and inflammatory cells in the circulating blood come into contact with the thrombogenic necrotic core. Previously, the necrotic core was thought to be the major source of tissue factor.

How are lipids named?

Lipid nomenclature. The nomenclature of lipids falls into two main categories: systematic names and common or trivial names. The latter includes abbreviations which are a convenient way to define acyl/alkyl chains in glycerolipids, sphingolipids and glycerophospholipids.

What are types of lipids?

The three main types of lipids are triacylglycerols (also known as triglycerides), phospholipids, and sterols.

• 1) Triglycerides make up more than 95 percent of lipids in the diet and are commonly found in fried foods, butter, milk, cheese, and some meats.
• 2) Phospholipids make up only about 2 percent of dietary lipids.

What is another name for tear film?

Syn. lacrimal layer; preocular tear film; tear film; tear layer.

Where is the lipid layer of the tear film produced?

Where are fats broken down?

Fat digestion begins in the stomach. Some of the byproducts of fat digestion can be directly absorbed in the stomach. When the fat enters the small intestine, the gallbladder and pancreas secrete substances to further break down the fat.

How are lipids digested and absorbed?

In the small intestines bile emulsifies fats while enzymes digest them. The intestinal cells absorb the fats. Long-chain fatty acids form a large lipoprotein structure called a chylomicron that transports fats through the lymph system.

Why does a thrombus form when plaque ruptures?

Matrix Metalloproteinases in Coronary Artery Disease Plaque rupture results in circulatory exposure of its thrombogenic contents (e.g., tissue factor, collagens, and lipids) leading to thrombus formation and MI [312,313].

What happens when an atherosclerotic plaque ruptures?

Myocardial infarction and unstable angina are caused by rupture or erosion of an atherosclerotic plaque, with subsequent thrombus formation and occlusion of the artery. The plaque that causes a patient’s heart attack is not necessarily the one that is identified at angiography.