Membranes are thin sheets of tissue  that cover surfaces, line body cavities, and form protective sheets around organs Types: Epithelial membranes Connective tissue membranes 1. Epithelial membranes: Cutaneous membranes Mucous membranes Serous membranes 1. Epithelial membranes: Cutaneous: skin - epidermis, dermis Mucous: mucous membrane or mucosa is a membrane that lines various cavities in the body and covers the surface of internal organs. Ex - Stomach Serous membranes: membranes lining closed internal body cavities. Ex - pleura, pericardium and peritoneum 2. Connective tissue membranes: formed by connective tissue, cover the kidneys, and line our movable joints. Synovial membrane is a type of connective tissue membrane that lines the cavity of a freely movable joint Functions: Line or cover body surfaces Protect body surfaces Lubricate body surfaces Definition: A gland is an organ which produces and releases substances that perform a specific function in the body.  Classification of glands: Exocrine glands Endocrine glands (ductless glands) Mixed variety Exocrine glands produce enzymes and release through a duct e.g. the salivary glands. Endocrine glands (ductless glands) produce hormones release directly into the blood stream, e.g. thyroid gland. Mixed variety: some glands possess both exocrine and endocrine function e.g. Pancreas. Exocrine glands: A gland that makes substances such as sweat, tears, saliva, milk, and digestive juices, and releases them through a duct or opening to a body surface. Examples of exocrine glands include sweat glands, lacrimal glands, salivary glands, mammary glands, and digestive glands in the stomach, pancreas, and intestines. These can be classified according to the no. of cells: Unicellular glands: example goblet cell (in GIT & certain passages of respiratory tract). Multicellular glands: are composed of many cells. Example - salivary glands Structure of the Exocrine Glands Divided into two parts: Ductal portion Glandular portion Ductal portion: The ductal portion is tubular in shape. It is a single, thick, cuboidal cell wall that helps in the movement of the secretion. The duct may be branched or unbranched. Glandular portion:  The glandular portion is responsible for the production of the secreted substance. It is a circular or elongated cluster of cells. Functions Of Exocrine Glands Regulate body temperature Lubrication Lactation Helps in digestion Helps in reproduction Endocrine glands: An organ that makes hormones that are released directly into the blood and travel to tissues and organs all over the body. Endocrine glands help control many body functions, including growth & development, metabolism, and fertility. Major endocrine glands are: Pituitary gland Thyroid gland Parathyroid glands Pancreas Adrenal glands Ovaries Testes 

1. Membranes
and
Glands
By,
M. Thiru murugan

2. • Membranes are thin sheets of tissue that cover surfaces,
line body cavities, and form protective sheets around organs
• Types:
1. Epithelial membranes
2. Connective tissue membranes
1. Epithelial membranes:
• Cutaneous membranes
• Mucous membranes
• Serous membranes
Membranes

3. 1. Epithelial membranes:
Cutaneous: skin - epidermis, dermis
Mucous: mucous membrane or mucosa is a membrane
that lines various cavities in the body and covers the
surface of internal organs. Ex - Stomach
Serous membranes: membranes lining closed
internal body cavities. Ex - pleura, pericardium and
peritoneum
2. Connective tissue membranes: formed by connective
tissue, cover the kidneys, and line our movable joints.
Synovial membrane is a type of connective tissue
membrane that lines the cavity of a freely movable joint

4. Functions:
1. Line or cover body
surfaces
2. Protect body surfaces
3. Lubricate body surfaces

5. • Definition: A gland is an organ which produces and releases substances
that perform a specific function in the body.
• Classification of glands:
• Exocrine glands
• Endocrine glands (ductless glands)
• Mixed variety
• Exocrine glands produce enzymes and release through a duct e.g. the
salivary glands.
• Endocrine glands (ductless glands) produce hormones release
directly into the blood stream, e.g. thyroid gland.
• Mixed variety: some glands possess both exocrine and endocrine
function e.g. Pancreas.
Glands

6. • Exocrine glands:
• A gland that makes substances such as sweat, tears, saliva,
milk, and digestive juices, and releases them through a duct or
opening to a body surface.
• Examples of exocrine glands include sweat glands, lacrimal
glands, salivary glands, mammary glands, and digestive glands
in the stomach, pancreas, and intestines.
• These can be classified according to the no. of cells:
1. Unicellular glands: example goblet cell (in GIT & certain
passages of respiratory tract).
2. Multicellular glands: are composed of many cells. Example
- salivary glands

7. • Structure of the Exocrine Glands
• Divided into two parts:
1. Ductal portion
2. Glandular portion
Ductal portion:
• The ductal portion is tubular in shape.
• It is a single, thick, cuboidal cell wall that helps in the movement of the
secretion.
• The duct may be branched or unbranched.
Glandular portion:
• The glandular portion is responsible for the production of the secreted
substance.
• It is a circular or elongated cluster of cells.

8. • Functions Of Exocrine Glands
• Regulate body temperature
• Lubrication
• Lactation
• Helps in digestion
• Helps in reproduction

9. Endocrine glands:
• An organ that makes hormones that are released directly into the
blood and travel to tissues and organs all over the body.
• Endocrine glands help control many body functions, including
growth & development, metabolism, and fertility.
 Major endocrine glands are:
 Pituitary gland
 Thyroid gland
 Parathyroid glands
 Pancreas
 Adrenal glands
 Ovaries
 Testes