Infectious Diseases

• Meningoencephalitis is an inflammation of the brain and meninges.
• Human diseases fall into many different categories, including: Degenerative diseases, Immune disorders, Infectious diseases, Metabolic disorders, Neoplasms (cancers and other types of tumors), Nutritional disorders, and Psychiatric disorders.
• Infectious diseases are caused by microbes and are the only category of diseases caused by pathogens.
• Pathogens cause two general categories of diseases: microbial intoxications and infectious diseases.
• Microbial intoxications follow ingestion of a toxin produced outside the body by a pathogen.
• Infectious diseases, or infections, follow colonization of some body site by a pathogen.
• Intact skin is a type of nonspecific host defense mechanism, serving as a physical barrier.
• Lysozyme and sebum serve to prevent colonization of the skin by pathogens.
• Very few pathogens can penetrate the intact skin.
• The superficial portion of the skin is known as the epidermis, while the inner layer of the skin, containing blood and lymphatic vessels, nerves, nerve endings, glands, and hair follicles, is known as the dermis.
• Dermatitis is the inflammation of the skin, while sebaceous glands are glands in the dermis that usually open into hair follicles and secrete an oily substance known as sebum.
• Folliculitis is the inflammation of a hair follicle, the sac that contains a hair shaft.
• Sty or styee is the inflammation of a sebaceous gland that opens into a follicle of an eyelash.
• Furuncle is a localized pyogenic (pus-producing) infection of the skin, usually resulting from folliculitis; also known as a boil.
• Carbuncle is a deep-seated pyogenic infection of the skin, usually arising from a coalescence of furuncles.
• Macule is a surface lesion that is neither raised nor depressed such as the lesions of measles.
• Papule is a surface lesion that is firm and raised, such as the lesions of a chicken pox.
• Vesicle is a blister or small fluid-filled sac, such as is seen in chicken pox and shingles.
• Pustules are pus-filled surface lesions.
• Conjunctiva is the thin tough lining that covers the inner wall of the eyelid and the sclera (the white of the eye).
• Conjunctivitis is an infection or inflammation of the conjunctiva.
• Keratitis is an infection or inflammation of the cornea – the domed covering over the iris and lens.
• Keratoconjunctivitis is an infection that involves both the cornea and the conjunctiva.
• Retinitis is inflammation that involves the retina, often caused by viral infection.
• Gastroenteritis is an inflammation of the mucosal lining of the stomach and intestines.
• Enteritis is an inflammation of the mucosal lining of the small intestine.
• Gastritis is an inflammation of the mucosal lining of the stomach.
• Pericarditis is an inflammation of the pericardium – the membranous sac around the heart.
• Encephalitis is an inflammation of the brain.
• Pneumonia is an inflammation of one or both lungs.
• RS is composed of Upper Respiratory Tract (URT) and Lower Respiratory Tract (LRT).
• The most common cause of tooth decay is S. mutans, which produces lactic acid as an end product in the fermentation of glucose.
• Dysentery is frequent watery stools, accompanied by abdominal pain, fever, and dehydration.
• Hepatitis is an inflammation of the liver, usually the result of viral infection.
• Myocarditis is an inflammation of the myocardium – the muscular walls of the heart.
• Epiglottitis is an inflammation of the epiglottis.
• Pharyngitis, also referred to as sore throat, is an inflammation of the pharynx.
• Sinusitis is an inflammation of the lining of one or more of the paranasal sinuses.
• LRT includes trachea, bronchial tubes and alveoli of the lungs.
• Meningitis is an inflammation of the membranes (meninges) that surround the brain and spinal cord.