Human Digestive System

A brush border (striated border or brush border membrane) is the microvilli-covered surface of simple cuboidal epithelium and simple columnar epithelium cells found in certain locations of the body. It increases absorption.

Chlorine helps in manufacturing of HCL for gastric secretion. 

This is the correct order as first, the stored glycogen is used, then fats and lastly protein stores are digested by the starving person.

Only cattles can digest cellulose with the help of gut protozoa.

This option is correct because streptokinase (SK) is an enzyme secreted by Streptococcus equisimilis that can bind and activate human plasminogen.

Villi are finger-like projections in small intestine that massively increase surface area for absorption of nutrients like amino acids, monosaccharides and fatty acids. Digestion occurs primarily via enzymes in lumen; assimilation refers to cellular utilization; egestion is elimination of waste.

Crypts of Lieberkuhn are intestinal glands located between the villi that secrete succus entericus (intestinal juice). This juice contains enzymes like maltase, lipase, and peptidases that complete digestion in the small intestine.

Villi are finger-like projections that massively increase the surface area of the small intestine for absorption. The stomach lacks villi, having instead gastric folds (rugae). This structural difference is key to their different functions.

Trypsinogen is secreted by pancreas.

Fatty acids and glycerol are absorbed through lacteals, which are lymphatic vessels located within the intestinal villi. They enter the lymphatic system first before reaching bloodstream. Blood capillaries absorb water-soluble nutrients like amino acids and sugars, not fats.

Secretin is a hormone produced by the small intestine in response to acidic chyme. It stimulates the pancreas to release bicarbonate-rich secretions to neutralize stomach acid. While it aids digestion, it is not an enzyme itself - enzymes are biological catalysts, whereas hormones are signaling molecules.

Amino acids are water-soluble molecules absorbed directly into blood capillaries within the intestinal villi. Lacteals are specialized lymphatic vessels that absorb fats, not amino acids. The rectum is the final portion of the colon for waste storage, not absorption.

Respiration - The process by which digested food is broken down with the help of oxygen to release energy.

The process of removal of waste products from the body is called excretion. This step not included in holozoic nutrition.

The process of digestion does not take place in this region. It simply secretes mucus, which serves as a lubricant for easy passage of the undigested matter in the form of faeces.