Glandular epithelium

Glandular epithelium is a type of epithelial tissue that specializes in the secretion of various substances. It forms glands that can be either part of organs or independent structures. The glandular epithelium is involved in the production and release of enzymesEnzymes are proteins that accelerate chemical reactions in the body. They ensure the occurrence of metabolic processes such as food digestion, energy release, cell formation, and many others., hormonesHormones are biologically active substances that are produced by specialized cells or glands (such as endocrine glands) and regulate various physiological processes in the body. They act as chemical signals that are transmitted through the bloodstream to organs and tissues to control and coordinate a wide range of functions, including metabolism, growth and development, reproduction, mood, and more. Examples include insulin, testosterone, estrogen, and adrenaline., mucus, sweat, saliva and other biologically active substances necessary for the functioning of the body.

Main characteristics of glandular epithelium:

1. Cellular structure: Glandular epithelial cells are usually cubic or cylindrical in shape and contain well-developed organelles, such as the endoplasmic reticulum and Golgi apparatus, which are essential for the synthesis and secretion of substances.
2. Secretory function: Cells can secrete substances in various ways:
   • Merocrine type: The secret is released without destroying the cell (for example, salivary glands).
   • Apocrine type: Part of the cell is rejected along with the secret (for example, mammary glands).
   • Holocrine type: The cell is completely destroyed, releasing a secret (for example, sebaceous glands).

Types of glands:

1. Exocrine glands: Secrete a secret on the surface of the body or in the cavities of organs through ducts. Examples:
   • Sweat glands (secrete sweat).
   • Salivary glands (secrete saliva).
   • The pancreas (secretes digestive enzymes).
2. Endocrine glands: Secrete hormones directly into the blood or lymph, without having ducts. Examples:
   • The thyroid gland (secretes thyroxine).
   • The adrenal glands (which secrete epinephrine and cortisol).
   • Pituitary gland (secretes hormones that regulate other glands).

Glandular epithelial functions:

• Regulation of metabolism: Hormones secreted by the endocrine glands regulate metabolism, growth, and development.
• Digestion: Enzymes secreted by the exocrine glands are involved in the digestion of food.
• Protection: Mucus secreted by the glands protects the mucous membranes from damage and infection.
• Thermoregulation: The sweat glands help cool the body.

Glandular epithelium plays an important role in maintaining homeostasis and adapting the body to changing environmental conditions.