Nervous tissue
Structure and functions
One of the main classes of vertebrate tissues is the nervous tissue. It is the main component of the nervous system. Nervous tissue comprise of neurons and neuralgia which are the support cells. Human brain contain a number of neuron around one hundred billion in number. Neurons are classified into three categories based on their functions. The categories mainly include, motor, sensory and interneurons. Sensory neurons facilitate in transmission of impulses from sensory organs to the central nervous system. On the other hand, motor neurons transfer impulses from the central nervous system to the intended organ in the body. Interneuron is a linkage between the sensory neurons and the motor..Neuralgias are supportive and defensive constitution of the nervous tissue. They are found in groups and surround the neurons. In case of damage, they are capable of regenerating. They supply the neurons with nutrients and offer them immunity (Sandhyarani para. 1-5). Glial cells are responsible for development of myelin sheath and preservation of homeostasis in the neurons.
Structure and functions of muscular tissue
Muscular tissue is divided into three groups which include cardiac muscle tissue, smooth muscle tissue and skeletal muscle tissue. Functioning of the tissues basically depends on their type and location in the body. Skeletal muscle is also referred to as striated due to it containing dark and light bands that are observable through the help of a microscope. A unit skeletal muscle cell is cylindrical in shape and long. The cells contain numerous nuclei positioned at their peripheries. Skeletal tissue is responsible for movement of the skeleton (IvyRose Ltd para. 2). It is also responsible for movement of tissues of facial gestures such as frown and smile.
The cardiac muscles are joined at their ends to adjoining fibers by solid plasma membrane, and main function o is pumping blood across the heart.
Different from cardiac and skeletal tissues, smooth muscle tissues are not striated. They are small and pointed with their edges reducing in size. Smooth muscle tissues are responsible for digestion process in the body. They facilitate in movement of food along the intestines. They help in food breakdown (IvyRose Ltd para. 3-7). They also aid in elimination of waste products from the intestines.
Epithelial tissues
Structure and functions
Epithelia tissue is located on the surface of the body and consists of intimately packed cells which are separated in one or more layers. It is structured in a way that it covers all exterior and interior body surfaces. The interior surface has cells that are tightly packed to an extent that there are limited intercellular substances. Some of the functions of epithelial tissues include protection of interior body tissues from bacteria attack, injuries and excessive water loss. In glands, epithelia tissue is responsible for filtering certain chemical substances like hormones and enzymes. In small intestines, epithelia tissue helps in absorption (Bailey para. 1-5). Other functions of epithelial tissue are excretion, diffusion and friction reduction.
Structure and functions of connective tissue
Just as its name proposes connective tissue is found between cells and it is the material that facilitate in holding varied tissues together. It consists of non-cellular fibers and proteins. The cellular components of the tissue are comparatively light and estranged from other cells by extracellular medium. Connective tissues are responsible for connecting and holding cells together (Currey para. 2-6). This helps body tissues overcome mechanical stress. They also protect entry of microorganisms into the body. They provide the body with immunity and help in wound healing.
Works Cited
Bailey, Regina. “Animal Tissues: Epithelial Tissue.” 2009. Web.
Currey, Charles. “Connective Tissue.” 2005. Web.
IvyRose Ltd. “Structure and Functions of Muscular Tissue.” 2010. Web.
Sandhyarani, Ninqthoujam. “Nervous Tissues: Structure and Function of Nervous Tissue.” 2009. Web.