It also serves as a base of attachment for the cytoskeleton in some organisms and the cell wall in others. Thus the cell membrane also serves to help support the cell and help maintain its shape. The cell membrane is primarily composed of a mix of proteins and lipids.While lipids help to give membranes their flexibility, proteins monitor and maintain the cell's chemical climate and assist in the transfer of molecules across the membrane.t also serves as a base of attachment for the cytoskeleton in some organisms and the cell wall in others. Thus the cell membrane also serves to help support the cell and help maintain its shape. The cell membrane is primarily composed of a mix of proteins and lipids.
Endocrine gland is a gland whose secretions (called hormones) are collected by the blood and reach the tissues through the circulation. The hypophysis (pituitary) and the adrenals are examples of endocrine glands. Exocrine gland is a gland whose secretions are released externally through ducts (into the skin, intestinal lumen, mouth, etc.). The sebaceous glands and the salivary glands are examples of exocrine glands.
The liver and pancreas are both exocrine and endocrine glands; they are exocrine glands because they secrete productsâ bile and pancreatic juice âinto the gastrointestinal tract through a series of ducts, and endocrine because they secrete other substances directly into the bloodstream.he liver and pancreas are both exocrine and endocrine glands; they are exocrine glands because they secrete productsâ bile and pancreatic juice âinto the gastrointestinal tract through a series of ducts, and endocrine because they secrete other substances directly into the bloodstream.