Life Cycle, Processes & Properties, MOR-OPT
None of us are born looking exactly the way that we do today; this is because humans, like other species, undergo a series of changes as they mature and age, in accordance with their biological life cycle. This process can look very different across different species. In many simple organisms and in higher animals, the life cycle is completed within a single generation, while in most plants, the life cycle is multigenerational.
Life Cycle, Processes & Properties Encyclopedia Articles By Title
morula, solid mass of blastomeres resulting from a number of cleavages of a zygote, or fertilized egg. Its name......
mosaic, plant disease caused by various strains of several hundred viruses. A number of economically important......
motion sickness, sickness induced by motion and characterized by nausea. The term motion sickness was proposed......
mouth, in human anatomy, orifice through which food and air enter the body. The mouth opens to the outside at the......
mouth fungus, fish disease caused by bacteria that attack the fish’s mouth and produce a fuzzy cottonlike growth,......
mpox, viral disease of animals, particularly certain rodents and primates, including monkeys and humans, that causes......
MRSA, bacterium in the genus Staphylococcus that is characterized by its resistance to the antibiotic methicillin......
multiple birth, the delivery of more than one offspring in a single birth event. In most mammals the litter size......
multiple endocrine neoplasia (MEN), any of a group of rare hereditary disorders in which tumours occur in multiple......
multiple myeloma, malignant proliferation of cells within the bone marrow that usually occurs during middle age......
multiple sclerosis (MS), progressive autoimmune disease of the central nervous system characterized by destruction......
mumps , acute contagious disease caused by a virus and characterized by inflammatory swelling of the salivary glands.......
muscle disease, any of the diseases and disorders that affect the human muscle system. Diseases and disorders that......
muscle tumour, abnormal tissue growth located in or originating from muscle tissue. Tumours may either arise in......
muscular dystrophy, hereditary disease that causes progressive weakness and degeneration of the skeletal muscles.......
mushroom poisoning, toxic, sometimes fatal, effect of eating poisonous mushrooms (toadstools). There are some 70......
Eadweard Muybridge was an English photographer important for his pioneering work in photographic studies of motion......
myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), condition characterized by persistent debilitating......
myasthenia gravis, chronic autoimmune disorder characterized by muscle weakness and chronic fatigue that is caused......
mycetoma, fungal infection, usually localized in the foot but occurring occasionally elsewhere on the body, apparently......
mycosis, in humans and other animals, an infection caused by any fungus that invades the tissues, causing superficial,......
mycotoxin, naturally occurring metabolite produced by certain microfungi (i.e., molds) that is toxic to humans......
myiasis, infestation of the body of humans and other animals with the larvae (maggots) of certain species of flies.......
myocardial infarction, death of a section of the heart muscle, caused by an interruption of blood flow to the area.......
myocarditis, inflammation of the heart muscle, or myocardium. Myocarditis is caused by a variety of infectious......
myopathy, any skeletal muscle disorder that directly affects the muscle fibres and does not arise secondarily from......
myopia, visual abnormality in which the resting eye focuses the image of a distant object at a point in front of......
myositis, inflammation, and frequently infection, of muscle tissue; it may be caused by any of a number of bacteria,......
myositis ossificans, disorder of unknown cause in which connective tissue and muscle are replaced by bone. In the......
myotonia, any of several muscular disorders characterized by difficulty in relaxing voluntary muscles after contraction.......
myxedema, physiological reaction to lack of sufficient thyroid hormone (hypothyroidism) in the adult. It can be......
myxomatosis, a highly fatal infectious viral disease of rabbits. It is characterized by fever, swelling of the......
Ménière disease, recurrent and generally progressive group of symptoms that include loss of hearing, ringing in......
Müllerian mimicry, a form of biological resemblance in which two or more unrelated noxious, or dangerous, organisms......
nagana, a form of the disease trypanosomiasis (q.v.), occurring chiefly in cattle and horses and caused by several......
nail-patella syndrome, rare hereditary (autosomal dominant) disorder characterized by small fingernails and toenails......
narcissism, pathological self-absorption, first identified as a mental disorder by the British essayist and physician......
narcolepsy, a sleep disturbance that is characterized by sudden, uncontrollable spells of sleep during the day,......
nasal polyp, lump of tissue that protrudes into the nasal cavity and sometimes obstructs it. Polyps can form as......
nasal tumour, abnormal growth in the nose. Tumours may be malignant or may remain localized and nonrecurrent. The......
natural childbirth, any of the systems of managing parturition in which the need for anesthesia, sedation, or surgery......
nausea, (from Greek nausia, “seasickness”), feeling of discomfort in the pit of the stomach that is associated......
navel, in anatomy, a small depression in the abdominal wall at the point of attachment of the umbilical cord (q.v.).......
necrosis, death of a circumscribed area of plant or animal tissue as a result of disease or injury. Necrosis is......
necrotizing fasciitis, rapidly spreading infection of the underlying skin and adipose (fat) layers caused by a......
Joseph Needham was an English biochemist, embryologist, and historian of science who wrote and edited the landmark......
neonatal hypothyroidism, condition characterized by the absence, lack, or dysfunction of thyroid hormone production......
nephroblastoma, malignant renal (kidney) tumour of early childhood. In 75 percent of the cases, the tumour grows......
nephrosclerosis, hardening of the walls of the small arteries and arterioles (small arteries that convey blood......
nephrotic syndrome, group of signs of kidney malfunction, including a low level of albumin (a protein) and a high......
nervous system disease, any of the diseases or disorders that affect the functioning of the human nervous system.......
- Introduction
- Emotional Disturbances
- Motor Disorders, Symptoms, Treatments
- EEG, Diagnosis, Treatment
- Localization, Symptoms, Diagnosis
- Cerebellar Dysfunction, Ataxia, Tremors
- Infections, Symptoms, Causes
- Disorders, Symptoms, Treatment
- Meninges, CSF, Symptoms
- Motor Neuron, Symptoms, Treatment
- Muscle Diseases
- Tumors, Symptoms, Treatment
- Optic Nerve, Vision Loss, Blindness
- Sleep Disorders
- Dystonias, Muscle Spasms, Treatment
- Dementia, Alzheimer's, Parkinson's
- Tension Headaches, Migraines, Neuropathy
- Prions, Symptoms, Treatment
- Stroke, Symptoms, Treatment
- Unlocalized, Multifocal, Disorders
- Fluid, Mineral, Electrolyte Disorders
- Demyelinating, Autoimmune, Neuropathy
nest, structure created by an animal to house its eggs, its young, or, in some cases, itself. Nests are built by......
neural crest, group of embryonic cells that are pinched off during the formation of the neural tube (the precursor......
neural tube defect, any congenital defect of the brain and spinal cord as a result of abnormal development of the......
neuralgia, cyclic attacks of acute pain occurring in a peripheral sensory nerve; the cause of the pain is unknown,......
neurasthenia, a syndrome marked by physical and mental fatigue accompanied by withdrawal and...
neuritis, inflammation of one or more nerves. Neuritis can be caused by injury, infection, or autoimmune disease.......
neuroblastoma, a tumour of the sympathetic nervous system (the branch of the autonomic nervous system that is best......
neurofibromatosis, either of two hereditary disorders characterized by distinctive skin lesions and by benign,......
neurogenic arthropathy, condition characterized by the destruction of a stress-bearing joint, with development......
neuropathy, disorder of the peripheral nervous system. It may be genetic or acquired, progress quickly or slowly,......
neurosis, generally outmoded term used to refer to mental disorders characterized by anxiety, depression, or other......
neurotoxin, substance that alters the structure or function of the nervous system. More than 1,000 chemicals are......
nevus, congenital skin lesion, or birthmark, caused by abnormal pigmentation or by proliferation of blood vessels......
Newcastle disease, a serious viral disease of birds caused by a paramyxovirus and marked by respiratory and nervous......
Niemann-Pick disease, inherited metabolic disorder in which a deficiency of the enzyme sphingomyelinase impairs......
night blindness, failure of the eye to adapt promptly from light to darkness that is characterized by a reduced......
nitrogen narcosis, reversible change in consciousness produced by nitrogen gas when it is breathed under increased......
nocardiosis, chronic systemic bacterial disease of humans and many other animals originating in the respiratory......
nosebleed, an attack of bleeding from the nose. It is a common and usually unimportant disorder but may also result......
notifiable disease, any of various health conditions that, upon detection, are required to be reported to public......
notochord, flexible rodlike structure of mesodermal cells that is the principal longitudinal structural element......
NREM sleep, one of two phases in the sleep cycle, considered the restful or quiet sleep phase. The other phase......
nut, in botany, dry hard fruit that does not split open at maturity to release its single seed. A nut resembles......
nutrient, substance that an organism must obtain from its surroundings for growth and the sustenance of life. So-called......
nutrition, the assimilation by living organisms of food materials that enable them to grow, maintain themselves,......
human nutrition, process by which substances in food are transformed into body tissues and provide energy for the......
- Introduction
- BMR, REE, Energy Balance
- Vitamins, Minerals, Proteins
- Lipids, Fats, Cholesterol
- Proteins, Amino Acids, Diets
- Vitamins, Minerals, Macronutrients
- Macronutrients, Vitamins, Minerals
- Protein, Vitamins, Minerals
- Dairy, Calcium, Vitamins
- Fats, Oils, Diet
- Dietary, Nutrient, Recommendations
- Cultural Adaptation, Dietary Habits, Nutrition Education
- Life Cycle, Macronutrients, Micronutrients
nutritional disease, any of the nutrient-related diseases and conditions that cause illness in humans. They may......
- Introduction
- Carbohydrates, Deficiencies, Malnutrition
- Vitamin K Deficiency, Causes, Symptoms
- Vitamin B12 Deficiency, Anemia, Symptoms
- Iodine Deficiency, Goiter, Hypothyroidism
- Dehydration, Water Deficiency, Electrolyte Imbalance
- Deficiency, Malnutrition, Absorption
- Alcoholism, Deficiencies, Malnutrition
- Dietary Fat, Deficiencies, Malnutrition
- Hypertension, Diet, Risk Factors
- Diabetes, Metabolic Disorders, Nutrition
- Obesity, Weight Control, Diet
- Food-Drug Interactions
- Foodborne Illnesses
nutritional supplement, in foods, any vitamin or mineral added during processing to improve nutritive value and......
nymph, in entomology, sexually immature insect that is usually similar to the adult form. Nymphs are found in such......
nystagmus, involuntary back and forth, up and down, or circular movements of the eyes that are often described......
obesity, excessive accumulation of body fat, usually caused by the consumption of more calories than the body can......
obsessive-compulsive disorder (OCD), type of mental disorder in which an individual experiences obsessions or compulsions......
obstetric fistula, abnormal duct or passageway that forms between the vagina and a nearby organ. This type of fistula......
occupational disease, any illness associated with a particular occupation or industry. Such diseases result from......
occupational injury, any health problem or bodily damage resulting directly from activities undertaken at the workplace.......
odour, the property of certain substances, in very small concentrations, to stimulate chemical sense receptors......
Oedipus complex, in psychoanalytic theory, a desire for sexual involvement with the parent of the opposite sex......
oidium, in fungi (kingdom Fungi), a single-celled asexual spore (arthrospore) produced by fragmentation of fungal......
old age, in human beings, the final stage of the normal life span. Definitions of old age are not consistent from......
olfactory receptor, protein capable of binding odour molecules that plays a central role in the sense of smell......
olfactory system, the bodily structures that serve the sense of smell. The system consists of the nose and the......
oligomenorrhea, prolonged intervals between menstrual cycles. Menstruation is the normal cyclic bleeding from the......
ommochrome, any of a group of biological pigments (biochromes) conspicuous in the eyes of insects and crustaceans......
omnivore, animal with wide food preferences, which can eat both plant and animal matter. Many small birds and mammals......
onchocerciasis, filarial disease caused by the helminth Onchocerca volvulus, which is transmitted to humans by......
ontogeny, all the developmental events that occur during the existence of a living organism. Ontogeny begins with......
oogenesis, in the human female reproductive system, growth process in which the primary egg cell (or ovum) becomes......
ophthalmoplegia, paralysis of the extraocular muscles that control the movements of the eye. Ophthalmoplegia usually......
optic ataxia, condition in which some or all aspects of visual guidance over reaching with the hand and arm are......