The human body is made up of limitless cells as essential components of various tissues. The entire lot of these cells traces their origin from the ovum, typical cell and the egg cell. The egg cell or ovum is made up of protoplasm and contains nucleus. Immediately after the fertilization, the cell multiplies to form an embryo that differentiates to form the body tissues required to form body parts and essentially organs. Clark, (1999) defines a tissue as an aggregation compost of cells of a unique size and shape destined to perform a specialized task. The particular function of a body tissue is governed by biological functions and the nervous system. The four elementary tissues in the body are connective tissue, epithelial tissue, nervous tissue and the muscular tissue.
These tissues occur in the body as linings of the inside of organs, coverings of the outside of organs and glands. The linings and coverings of the epithelial tissue are all found on the free surface of the body. For instance, lining and dipping into the open cavities of the respiratory system and digestive track, outer skin layer, covering the walls of organs of closed central body cavity, and lining the heart and blood vessels. The high specialization of the epithelial tissues enables the accomplishment of various functions such as absorption, excretion, protection, secretion, and filtration. The epithelial cells have various traits that specializes their functions. Firstly, they are attached to one another for the formation of a protective barrier, and they have no blood vessels, however, can soak up nutrients from the blood vessels to the connective tissues that lie underneath (Byrne & Kosta, 2001). Besides, the epithelial tissue can have lots of nerves and excellent regeneration. Classifications of the epithelial tissues depend on the cell arrangement and by shape. By cell arrangement, there are simple and stratified epitheliums that are made of single layer cells and stacked up call layers respectively.
These tissues contain various types of cells including the macrophages, adipocytes, fibroblasts, and mast cells. Chittenden and Blake, (2005) explains that the matrix of connective tissue has two materials: polysaccharides and proteins. They compost the reticular, fiber, elastic and collagen. The connective tissues are classified as dense, loose and cartilage connective tissues. Loose connective tissues are made of fibers and numerous cells in a gelatinous matrix found in the surrounding of the blood vessels, skin, organs and nerves. The dense connective tissues are formed by bundles of parallel fibroblasts, collagen fibers that are found in ligaments and tendon. Finally, the cartilage connective tissues have subtypes of elastic, hyaline and fibrous cartilage. The major functions of connective tissues are to store nutrient, wrap, protect and cushion organs, strengthens the skin and also form tendons and ligaments that attached to bone and muscle and each other.
The muscles tissues are responsible for body movement, mechanical digestion and moving of food, blood and waste through the organs of the body. Muscles tissues are made up of smooth tissues found in blood vessel walls, organ walls, involuntary and are spindle-shaped. The cardiac muscles fund in the heart that provides synchronization of the contractions during a heart beat (Byrne & Kosta, 2001). Finally, the skeletal muscles that are voluntary striated and mainly attached to bones.
The nervous tissue is composting of two types namely; peripheral nervous system (PNS) and central nervous system (CNS). The nervous tissues have neurons made up of axon, cell body and dendrites. Neurons are further classified into motor neuron that carries impulses from CNS to glands and muscles, sensory neuron that receive information from the environment and transmit to the CNS, and interneuron that interpret sensory and end responses from motor neurons.
Line body organs and is vascular
has a nerve supply
Closely attached to each other
Has no blood vessels
Has lots of nerves
Very good at fixing itself
Has blood and nerve supply
Has collagen fibers and stores nutrients
Majorly form ligaments and tendons
Specialized to form cartilage, born adipose, and blood walls
Bind, reinforce, support and protect other tissues
Generate heat, stabilize posture and provides movement
Responsible for movement of blood, waste and mechanical digestion
Can be voluntary or involuntary
Made up of cardiac, connective and smooth muscles
Convert stimuli into nerve impulses
The elements are brain, spinal cord and nerves
Conducts impulses to a from body organs through neurons
Byrne, A. R., & Kosta, L. (January 01, 2001). Vanadium in foods and human body fluids and tissues. Science of the Total Environment, 10, 17-30.
Chittenden, R. H., & Blake, J. A. (January 01, 2005). The relative distribution of antimony in the organs and tissues of the body, under varying conditions. Transactions, 7.Clark, W. E. L. G. (1999). The tissues of the body. Oxford: Clarendon Press.