Biology Assignment 1. Tissue types and their properties! Body tissues! The four core types of tissues in the body are; epithelial, connective, muscle and nervous.
Each is designed for specific functions. Epithelial Tissues! Epithelial tissues are spread out all over the body. They cover all surfaces and also line body cavities and hollow organs. These tissues are also the major tissue in glands. Epithelial tissues have many functions including secretion, protection, excretion, diffusion, absorption, filtration and sensory reception.
Epithelial tissues have one surface free which is not connected to other cells; this is because the epithelial cells form linings and surfaces. The opposite side of the tissue is attached to connective tissue. Between these two surfaces are cells packed tightly together. The shapes that the epithelial cells may be are: -, or columnar they can also be arranged in either singular or multiple layers. Simple cuboid al - found in glandular tissue and kidney tubules.
Simple columnar - line stomach and intestines. Pseudo stratified columnar - lines some of the respiratory tract and some of the male reproductive tract. Muscle Tissue. Muscle tissues include cells which boast the ability to shorten or contract to permit body parts to move. This type of cellular tissue also has a vast supply of blood vessels. Like the epithelial tissue the muscle tissue is also surrounded by connective tissue.
Muscle tissue contains contractile proteins called actin and myosin. There are three categories of muscle tissue. The muscle fibres in muscle tissue are cylindrical, multi nucleated, striated, and work under voluntary control. The cells in smooth muscle tissues are spindle shaped. They have a centrally located nucleus.
They also don't have striations. These are involuntary muscles. Cardiac muscle contains branching fibres. The cells each have one nucleus. This tissue has striations and disks that are intercalated. The contractions are not under voluntary control.
Connective Tissue. Connective tissue has many functions. They hold structures together. They give support and build a framework for organs and the body.
These tissues also store fat, they move substances from parts of the body, help repair tissue damage and protect against disease. They are all around the body. They have fairly few cells. Some connective tissues have a bloody supply but others don't. There are a lot of cell types in connective tissue.
Three of the most common are: - Fibroblast, Macrophage and Mast cell. Some types of connective tissue are: -Nervous Tissue. The nervous tissue controls most main body activities. It is found in the brain, spinal cord and nerves. It has a lot of functions for example; it plays a huge part in controlling emotions and the memory. Nerve cells communicate by using electrical nerve impulses.
Parts of the nervous cells which produce impulses are called neurons. These are a greyish / reddish granular cell with special processes which is the basic function of the nervous tissue. There are three main parts to the neuron cells these are dendrites, the cell body, and one axon. The dendrites are the stemming protoplasmic processes which send impulses to the main body of a nerve cell.
The axon is a long singular cell process which takes impulses away from the cell body.