Question

Are you able to describe and classify the structural and functional properties if exocrine and endocrine glands??

Answer 1

Structure Of Exocrine gland:

Exocrine glands consists of a glandular portion and a duct portion, the structures of which can be used to classify the gland.

1)The duct portion may be branched (called compound) or unbranched (called simple).

2)The glandular portion may be tubular or acinar, or may be a mix of the two (called tubuloacinar). If the glandular portion branches, then the gland is called a branched gland.

Based on Method of secretion:

Exocrine glands are named apocrine glands, holocrine glands, or merocrine glands based on how their products are secreted.

1) Merocrine secretion – cells excrete their substances by exocytosis; for example, pancreatic acinar cells.

2) Apocrine secretion – a portion of the cell membrane that contains the excretion buds off.

3) Holocrine secretion – the entire cell disintegrates to excrete its substance; for example, sebaceous glands of the skin and nose.

Based on the Product secreted :

1) Serous cells secrete proteins, often enzymes. Examples include gastric chief cells and Paneth cells

2)Mucous cells secrete mucus. Examples include Brunner's glands, esophageal glands, and pyloric glands

3)Mixed glands secrete both protein and mucus. Examples include the salivary glands: although the parotid gland 20%is predominantly serous, the sublingual gland 5% mainly mucous gland, and the submandibular gland 70%is a mixed, mainly serous gland.

4)Sebaceous glands secrete Sebum, a lipid product. These glands are also known as oil glands, e.g. Fordyce spots and Meibomian glands.

Endocrine glands :

The endocrine system is a chemical messenger system consisting of hormones, the group of glands of an organism that secrete those hormones directly into the circulatory system to regulate the function of distant target organs, and the feedback loops which modulate hormone release so that homeostasis is maintained.

Endocrine glands are glands of the endocrine system that secrete their products, hormones, directly into interstitial spaces and then absorbed into blood rather than through a duct. The major glands of the endocrine system include the pineal gland, pituitary gland, pancreas, ovaries, testes, thyroid gland, parathyroid gland, hypothalamus and adrenal glands. The hypothalamus and pituitary gland are neuroendocrine organs.