WORLD HEALTH ORGANIZATION

World Health Organization (WHO) was founded in April 7, 1948 when twenty-six United Nations member states, including Ukraine, ratified its Constitution. Now there are 192 member states, including all United Nations Member States except Liechtenstein.

WHO's objective is the attainment by all peoples of the highest possible level of health. Health is defined in WHO's Constitution as a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity. WHO activities has many forms, they are: strengthening national health services; preparing more and better health workers; controlling or eradicating epidemic diseases; protecting mother and child health; improving sanitation and water supply; and making all other efforts to raise health level.

One of the main services carried by WHO is the service of epidemic warnings. The five main world epidemics of history as plague, cholera, smallpox, typhus, and yellow fever are still a great danger in our time. WHO also informs national health services about outbreaks of viral diseases as influenza and poliomyelitis.

Besides an epidemic information WHO provides services, which are needed by all the countries, such as an international quarantine measures, world health statistics, international standardization of medicines and vaccines, and development of medical research.

The daily work of WHO is carried out by a medical and administrative staff of about 2.400 international officers from different countries. These officers are stationed at headquarters in Geneva, in Regional Offices, or with special centers working on every continent.

WHO's work is focused on four interrelated strategic directions.Strategic Direction 1: reducing

excess mortality, morbidity, and disability. Strategic Direction 2: promoting healthy lifestyles and reducing risk factors to human health.Strategic Direction 3: developing health systems.Strategic Direction 4: framing an enabling policy and creating an institutional environment for the health sector.

HEAD

The head is divided into the cranial and the facial parts. The skull is composed of 28 separate bones organized into the following groups: the cranial vault, the auditory ossicles, and the facial bones. The cranial vault consists of 8 bones that surround and protect the brain. They include the parietal, temporal, frontal, occipital, sphenoid, and ethmoid bones.

The six auditory ossicles, which function in the hearing, are located inside cavities of the temporal bones and cannot be observed unless the temporal bones are cut open.

The facial bones form the structure of the face in the anterior skull but do not contribute to the cranial vault. They are the maxilla (two), mandible (one), zygomatic (two), palatine (two), nasal (two), lacrimal (two), vomer (one), and inferior nasal concha (two) bones. The frontal and ethmoid bones, which are the part of the cranial vault, also contribute to the face. The forehead, the temples, eyes,eyebrows, the cheeks, the cheekbones, nose, oral cavity and chin compose the face.

The oral cavity is bounded by the lips anteriorly, the fauces posteriorly, the cheeks laterally, the palate superiorly, and a muscular floor inferiorly. In the oral cavity of an adult there are 32 permanent teeth, hard and soft palates, palatine tonsils, salivary glands, and a tongue. The types of the teeth are incisors, canines, premolars, and molars. Every tooth consists of a crown, a neck, and a root. The root is composed of dentine. Within the dentine of the root is the pulp cavity, which is filled with blood vessels and nerves. The crown is dentine covered by enamel. The hard and soft palates are the roofs of the oral cavity. Salivary glands produce serous and mucous secretions. The three pairs of large salivary glands are the parotid, submandibular, and sublingual.

The facial bones provide protection for major sensory organs located in the face such as the eyes, nose, and tongue. The person sees with eyes, breathes and smells with nose, taste with tongue, and hear with ears.

The skeletal muscles of the face are cutaneous muscles attached to the skin. In humans in whom facial expressions are important components of nonverbal communication, cutaneous muscles are confined primarily to the face and neck. Several muscles act on the skin around the eyes and eyebrows and furrow the skin of the forehead. They are: the occipitofrontal muscles, the orbicular muscles of eyes, the elevator muscles of the upper eyelids, the corrugator muscles and others. Several muscles function in moving the lips and the skin surrounding the mouth. The muscles of mastication (the masseter, temporal, medial pterygoid, and lateral pterygoid muscles) and the hyoid muscles move the mandible. The tongue consists of a mass of intrinsic muscles and extrinsic muscles, which change the shape of the tongue and move it. Hyoid muscles can depress the jaw and assist in swallowing. Six muscles with their origins on the orbital bones insert on the eyeball and cause it to move within the orbit.

The Skull From the Front

CELL

A cell is the structural and functional unit of living organism. Trillions of cells and the substances between them compose the human body. Every cell contains water, protein, carbohydrates, acids, fats, and minerals. All human cells originate from a single fertilized egg, and as differentiation proceeds during embryonic development. Cells specialize and give rise to a wide variety of cell types such as nerve, muscle, bone, fat, and blood cells.

The plasma membrane, nucleus and cytoplasm compose the cell.

The plasma or cell membrane is the outer component of a cell. The plasma membrane consists primarily of lipids and proteins and small amounts of carbohydrates. Substances outside the plasma membrane are extracellular or intercellular, and substances inside it are intracellular. The functions of the plasma membrane are to enclose and support the cell contents and to determine what moves into and out of the cell.

The nucleus is a large membrane-bound structure usually located near the center of the cell. All cells of the body have a nucleus at some point in their life cycle, although some cells such as red blood cells lose their nuclei as they develop. Other cells, such as osteoclasts and skeletal muscle cells, contain more than one nucleus. The nucleus is surrounded by a nuclear envelope composed of two membranes separated by a space. At many points on the surface of the nuclear envelope the inner and outer membranes fuse to form pore-like structures, the nuclear pores. Deoxyribonucleic acid (DNA) and associated proteins are dispersed throughout the nucleus as thin strands (23 pairs of chromosomes) approximately 4 to 5 nm in diameter. DNA is the hereditary material of the cell. It controls the activities of the cell through ribonucleic acid (RNA). The nucleus directs the cell’s activities.

Cytoplasm, the cellular material outside the nucleus but inside the plasma membrane, is approximately half cytosol and half organelles. Cytosol consists of a fluid portion, a cytoskeleton, and cytoplasmic inclusions. The cytoskeleton supports the cell and enables cell movements. It consists of protein fibers. Organelles are small structures within cells and are specialized for particular functions such as manufacturing proteins or producing adenosine triphosphate (ATP). Most organelles have membranes that are similar to the plasma membrane. The membranes separate the organelles from the rest of the cytoplasm, creating a subcellular compartment with its own enzymes and capable of carrying out its own unique chemical reactions. The nucleus is an example of an organelle. Mitochondria are small bodies, produce energy in the cell. Endoplasmic reticulum is a series of canals within the cell. Some canals contain small bodies called ribosomes. They help make substances for the cell.

Diagram of a Typical Cell.

Organelles: (1) nucleolus; (2) nucleus; (3) ribosome; (4) vesicle; (5) rough endoplasmic reticulum (ER); (6) Golgi apparatus; (7) Cytoskeleton; (8) smooth ER; (9) mitochondria; (10) vacuole; (11) cytoplasm; (12) lysosome; (13) centrioles