Oropharynx Health Dictionary

The passage that connects the back of the mouth and nose to the oesophagus.

The upper part, or nasopharynx, connects the nasal cavity to the area behind the soft palate.

The middle part, the oropharynx, runs from the nasopharynx to below the tongue.

The lower part, called the laryngopharynx, lies behind and to each side of the larynx.... pharynx

(Singular: bacterium.) Simple, single-celled, primitive organisms which are widely distributed throughout the world in air, water, soil, plants and animals including humans. Many are bene?cial to the environment and other living organisms, but some cause harm to their hosts and can be lethal.

Bacteria are classi?ed according to their shape: BACILLUS (rod-like), coccus (spherical – see COCCI), SPIROCHAETE (corkscrew and spiral-shaped), VIBRIO (comma-shaped), and pleomorphic (variable shapes). Some are mobile, possessing slender hairs (?agellae) on the surfaces. As well as having characteristic shapes, the arrangement of the organisms is signi?cant: some occur in chains (streptococci) and some in pairs (see DIPLOCOCCUS), while a few have a ?lamentous grouping. The size of bacteria ranges from around 0.2 to 5 µm and the smallest (MYCOPLASMA) are roughly the same size as the largest viruses (poxviruses – see VIRUS). They are the smallest organisms capable of existing outside their hosts. The longest, rod-shaped bacilli are slightly smaller than the human erythrocyte blood cell (7 µm).

Bacterial cells are surrounded by an outer capsule within which lie the cell wall and plasma membrane; cytoplasm ?lls much of the interior and this contains genetic nucleoid structures containing DNA, mesosomes (invaginations of the cell wall) and ribosomes, containing RNA and proteins. (See illustration.)

Reproduction is usually asexual, each cell dividing into two, these two into four, and so on. In favourable conditions reproduction can be very rapid, with one bacterium multiplying to 250,000 within six hours. This means that bacteria can change their characteristics by evolution relatively quickly, and many bacteria, including Mycobacterium tuberculosis and Staphylococcus aureus, have developed resistance to successive generations of antibiotics produced by man. (METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS (MRSA)) is a serious hazard in some hospitals.

Bacteria may live as single organisms or congregate in colonies. In arduous conditions some bacteria can convert to an inert, cystic state, remaining in their resting form until the environment becomes more favourable. Bacteria have recently been discovered in an inert state in ice estimated to have been formed 250 million years ago.

Bacteria were ?rst discovered by Antonj van Leewenhoek in the 17th century, but it was not until the middle of the 19th century that Louis Pasteur, the famous French scientist, identi?ed bacteria as the cause of many diseases. Some act as harmful PATHOGENS as soon as they enter a host; others may have a neutral or benign e?ect on the host unless the host’s natural immune defence system is damaged (see IMMUNOLOGY) so that it becomes vulnerable to any previously well-behaved parasites. Various benign bacteria that permanently reside in the human body are called normal ?ora and are found at certain sites, especially the SKIN, OROPHARYNX, COLON and VAGINA. The body’s internal organs are usually sterile, as are the blood and cerebrospinal ?uid.

Bacteria are responsible for many human diseases ranging from the relatively minor – for example, a boil or infected ?nger – to the potentially lethal such as CHOLERA, PLAGUE or TUBERCULOSIS. Infectious bacteria enter the body through broken skin or by its ori?ces: by nose and mouth into the lungs or intestinal tract; by the URETHRA into the URINARY TRACT and KIDNEYS; by the vagina into the UTERUS and FALLOPIAN TUBES. Harmful bacteria then cause disease by producing poisonous endotoxins or exotoxins, and by provoking INFLAMMATION in the tissues – for example, abscess or cellulitis. Many, but not all, bacterial infections are communicable – namely, spread from host to host. For example, tuberculosis is spread by airborne droplets, produced by coughing.

Infections caused by bacteria are commonly treated with antibiotics, which were widely introduced in the 1950s. However, the con?ict between science and harmful bacteria remains unresolved, with the overuse and misuse of antibiotics in medicine, veterinary medicine and the animal food industry contributing to the evolution of bacteria that are resistant to antibiotics. (See also MICROBIOLOGY.)... bacteria

A mechanism for administering a drug in the form of a powder or aerosol. mainly used by patients with ASTHMA. Inhalers are basically of two types: aerosol, and dry-powder inhaler. The former delivers the drug as an aerosol spray when the patient presses the top of the canister containing the drug; the latter works by putting a drug capsule in the end of the chamber and, when the patient presses the top, the capsule is pierced and the drug released. A variety of ‘spacing devices’ are available to use with pressurised (aerosol) inhalers, providing metered doses. The space introduced between the inhaler and the mouth reduces the velocity of the aerosol and thus the impact it has on the oropharynx. More time is therefore allowed for evaporation of the propellant, with a greater concentration of drug particles being inhaled. Inhalers with larger spacing devices and a one-way valve are very e?ective and particularly useful for children and patients needing higher doses of the drug. (See INHALANTS; NEBULISERS.)... inhaler

n. difficulty in swallowing secondary to either mechanical obstruction or neurological disease. It can be caused by obstruction of the oropharynx or oesophagus by disease (for example, oesophageal carcinoma) or by neurological impairment of the coordination of the muscles involved in swallowing. Such disorders include motor neuron disease, multiple sclerosis, and stroke. A patient may describe food sticking at the level of the sternum in oesophageal dysphagia (compare odynophagia).... dysphagia

(postnasal space, rhinopharynx) n. the part of the *pharynx that lies above the level of the junction of the hard and soft palates. It connects the *nasal cavity to the *oropharynx. —nasopharyngeal adj.... nasopharynx

n. an instrument with a blunt blade used to spread ointments or plasters and, particularly in dentistry, to mix materials. A flat spatula is used to depress the tongue during examination of the oropharynx.... spatula

A cancerous tumour of the pharynx. Pharyngeal cancer usually develops in the mucous membrane lining. In the West, almost all cases of pharyngeal cancer are related to smoking and to drinking alcohol. The incidence rises with age, and the disorder is more common in men.

Cancerous tumours of the oropharynx (the middle section of the pharynx) usually cause difficulty swallowing, often with a sore throat and earache. Bloodstained sputum may be coughed up. Sometimes there is only the feeling of a lump in the throat or a visible enlarged lymph node in the neck. Cancer of the laryngopharynx (the lowermost part of the pharynx) initially causes a sensation of incomplete swallowing, then a muffled voice, hoarseness, and increased difficulty in swallowing. Tumours of the nasopharynx have different causes.Diagnosis of cancer of the pharynx is made by biopsy, often in conjunction with laryngoscopy, bronchoscopy, or oesophagoscopy.

The growth may be removed surgically or treated with radiotherapy.

Anticancer drugs may also be given.... pharynx, cancer of

pl. n. masses of *lymphoid tissue around the pharynx, usually referring to the palatine tonsils on either side of the *oropharynx. However, there is more tonsil tissue below the palatine tonsils, on the back of the tongue (the lingual tonsils), and small deposits around the openings of the *Eustachian tubes in the nasopharynx (the tubal tonsils). The tonsils are concerned with protection against infection. Together with the *adenoids, they form *Waldeyer’s ring.... tonsils