(http://en.wikipedia.org)
The next tissue that I am going to be talking about is the muscle tissue. The muscle tissue is a specialised tissue that has the ability to conduct electrical impulses and to contract. There are three types of muscles and these are called:
- Striated (also called voluntary or skeletal muscle),
- Non-striated (also called involuntary, plain or smooth)
- The cardiac muscle.
Striated muscles main function is to create movement of the skeleton by applying force to joints and bones by contradictions. It also maintains the body’s posture.
They generally contract voluntarily (by nerve stimulation), although they can contract involuntarily through reflexes and their cells lie in order of pattern and have elongated cells. Finally they are also known to be striated with light and dark bonds. (http://en.wikipedia.org)
Non striated muscles are types of tissues which have elongated cells as well, however they do not lie in an ordered pattern and therefore they do not produce the same characteristics of the striated muscle. The non- striated muscle is involuntary, which means that the brain can’t control it, it just behaves naturally. For example, the heart beating and pumping blood. This type of muscle is found around the hollow internal organs such as the stomach, intestines, eye, bladder and uterus. (Richard Walker, 2002)
The stomach is an example of where the non-striated muscles can be found. This means that the stomach is able to form involuntarily as part of the autonomic nervous system which does not require conscious thought. As it does not attach to the bones, it will be found inside internal organs and nowhere else in the body. Also this kind of muscle also gives the stomach its smooth appearance as it does not lie in an ordered pattern. This muscle also provides the stomach with its layered wall, which helps to cushion the stomach and prevents injury.
The cardiac muscle can only be found in the four chambers of the heart. It is a type of involuntary muscle which means that it can not be controlled. Cardiac muscle shares similarities in the structure of the skeletal muscle due to its striated appearance and contraction. Each cell consists of a central nucleus and is both horizontally and vertically striped. (http://en.wikipedia.org)
The next tissue that I am going to be talking about is the connective tissue. These types of tissues are widely distributed throughout the body and they lie beneath the epithelial tissue, connecting and binding together all types of tissue. Connective tissue has fairly few cells which are separated from each other by intercellular ground substance (matrix) which is secreted by the cells. The matrix is made up of liquid, solid, or connective tissue. Inside the matrix are different sorts of connecting fibre e.g. collagen and elastic fibre. The function of the connective tissues is supporting, binding, covering and protecting other tissues. (http://www.geocities.com)
There are many kinds of connective tissues such as, the bone, cartilage, areolar, adipose and blood. These are seen as types of connective tissue, because they support the body and they also hold together its various structures. (Richard Walker, 2002)
Cartilage tissues are made up of smooth, firm substance that protects bone ends from frictions during movement and they can be found at the bone ends in mobile joints, the front ends of the ribs and parts of the nose and ears. (Richard Walker, 2002)
The bone tissues are a much harder substance than the cartilage, but they can be worn away by friction. They are tough on the outside, but on the inside they have a sponge-like design that helps to reduce the weight while retaining strength. They are designed to maintain the body’s structure and support the body’s movement and are used to protect weaker tissues, such as the brain, lungs and heart. (http://www.geocities.com)
The areolar tissues are the most common tissue within the body. It is a sticky, white material that binds the muscle groups, blood vessels and nerves together. As well as being found throughout the body, you can also find the areolar tissue on meat. Its main purpose is to support the tissues that it surrounds. (Richard Walker, 2002)
The adipose tissue consists of a bundle of fat cells and its technical term is fatty tissue. This tissue can be found under the skin and around the different organs, such as the heart, kidneys, and parts of the digestive tract. Its main function is to insulate against any temperature change within the body and it also cushions/supports the organs. (http://www.geocities.com)
The skin is an example of where the adipose tissue is found. This tissue provides insulation for the stomach which prevents any variation of the homeostasis processes.
It absorbs shock to prevent damage to the stomach due to injury and its spongy texture allows it to do this and it stores high levels of energy. (Richard Walker, 2002)
The blood tissue consists of straw-coloured plasma (the matrix) in which several types of blood cells are carried. The main function of this tissue is to transport materials around the body. (B.Stretch, 2007)
Epithelial tissue covers the whole surface of the body. It is made up of cells closely packed and ranged in one or more layers. This tissue is specialised to form the covering of body lining of all internal and external body surfaces. These kinds of tissues can be divided into two groups depending on the number of layers that it has. An Epithelial tissue which is only one cell thick is known as Simple epithelia. If it consists of several layers then it is known as Compound Epithelia. (Richard Walker, 2002)
Simple epithelia tissues have three types and these are squamous, cuboidal and columnar. (Richard Walker, 2002)
Squamous cells consist of a single layer of flat cells. It allows materials to pass through it via osmosis and diffusion and it can be found in walls of lung alveoli and blood capillaries. (Richard Walker, 2002)
Cuboidal cells consist of cube-shaped cells that secrete and absorb substances and they can be found in the kidneys, sweat ducts, thyroid glands and breast tissue.
Columnar cells are tall cells with slightly oval nuclei. They secrete mucus, traps unwanted particles like carbon and the cilia helps to move substances towards the exterior. These cells can be found in the lining of the trachea, bronchi and the villi in the small intestines. (Richard Walker, 2002)
Compound epithelia tissues consist of several layers of cells, which vary in shape.
The deepest layers are column-shaped and the surface area layers are flattened.
This tissue forms the layer of the mouth, tongue and oesophagus (the tube which transports food from the mouth to the stomach). (Richard Walker, 2002)