The Various Tissues Of The Human Body

Function Of Connective, Epithelial, Muscular & Nervous System Tissue

Jun 10, 2009

A layer or group of cells that collectively perform a specific function forms tissues. These are the main types of tissues found in the human body and their functions.

Tissues are composed of groups or layers of cells, which collectively perform a specific function. Different types of tissues have different structures that are specific to their function. Tissues can be held together by a sticky coating called an ‘extracellular matrix’ or the matrix may weave the cells of tissues together. The Latin word for tissue is derived from the verb texere, “to weave”.

These are the major tissue types in the human body:

Connective
Epithelial
Muscular
Nervous system
Lymphatic

Connective Tissue

Connective tissue is made up of cells and protein fibers and provides support for other body tissues. The main proteins in connective tissue are collagen and elastin. There are five types of connective tissue. They are:

Loose connective tissue: including adipose tissue (fat storage)
Dense connective tissue
Blood
Bone
Cartilage

Epithelial Tissue

Epithelial tissue, often called epithelium, is comprised of tightly packed cells, arranged to form layers. Epithelium provides many functions, including absorption, excretion, protection, reproduction, secretion and sensory reception.

Epithelial cells are constantly renewing and replacing the dead or inactive cells. The two main epithelial tissue types are:

Glandular: found in exocrine and endocrine glands
Lining epithelium: forms the outer layer of the skin and in some internal organs

Muscular Tissue

Muscle tissue provides stability to the skeleton and internal organs and allows body movement. Muscle tissue makes up approximately 60% of the body’s mass and there are three types of muscle tissue. These are:

Cardiac: found in the heart
Skeletal: usually attached to bone
Smooth: found in walls of blood vessels in digestive system, respiratory system and the eye.

Nervous System Tissue

The nervous system is made up of the Central Nervous System (CNS) and the Peripheral Nervous System (PNS). Comprised of neural and nervous tissue, the CNS and PNS transmit signals from the brain to the body parts (muscles, glands, sense organs) to activate a response.

Lymphatic Tissue

Lymphatic, or lymphoid tissue is found at the entrance of the digestive system, respiratory system and urogenital tracts. The lymphoid tissue provides protection as a first line of defense for these areas.

Membranes

Membranes are thin layers of tissue that provide a surface lining or protective surface to organs or body structures. There are four types of membranes. They are:

Cutaneous: pertaining to the skin
Mucous: the lubricating membrane lining an internal surface or organ. An example of mucous membrane would be the gums.
Serous: thin membranes that line cavities that secrete serous fluid. An example would be the peritoneum.
Synovial: dense connective tissue membrane that secretes synovial fluid.

Resource and further reading:

Campbell and Reece, 2002, 'An Introduction to Animal Structure and Function', in Biology 6th edition, ed. Benjamin Cummings, San Francisco, chap 40.