Life Cycle, Processes & Properties, NEU-PAR
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
neuroblastoma
neuroblastoma, a tumour of the sympathetic nervous system (the branch of the autonomic nervous system that is best......
neurofibromatosis
neurofibromatosis, either of two hereditary disorders characterized by distinctive skin lesions and by benign,......
neurogenic arthropathy
neurogenic arthropathy, condition characterized by the destruction of a stress-bearing joint, with development......
neuropathy
neuropathy, disorder of the peripheral nervous system. It may be genetic or acquired, progress quickly or slowly,......
neurosis
neurosis, generally outmoded term used to refer to mental disorders characterized by anxiety, depression, or other......
neurotoxin
neurotoxin, substance that alters the structure or function of the nervous system. More than 1,000 chemicals are......
nevus
nevus, congenital skin lesion, or birthmark, caused by abnormal pigmentation or by proliferation of blood vessels......
Newcastle disease
Newcastle disease, a serious viral disease of birds caused by a paramyxovirus and marked by respiratory and nervous......
Niemann-Pick disease
Niemann-Pick disease, inherited metabolic disorder in which a deficiency of the enzyme sphingomyelinase impairs......
night blindness
night blindness, failure of the eye to adapt promptly from light to darkness that is characterized by a reduced......
nitrogen narcosis
nitrogen narcosis, reversible change in consciousness produced by nitrogen gas when it is breathed under increased......
nocardiosis
nocardiosis, chronic systemic bacterial disease of humans and many other animals originating in the respiratory......
nonverbal learning disorder
nonverbal learning disorder (NVLD), a neurological condition characterized by cognitive, and occasionally social,......
nosebleed
nosebleed, an attack of bleeding from the nose. It is a common and usually unimportant disorder but may also result......
notifiable disease
notifiable disease, any of various health conditions that, upon detection, are required to be reported to public......
notochord
notochord, flexible rodlike structure of mesodermal cells that is the principal longitudinal structural element......
NREM sleep
NREM sleep, one of two phases in the sleep cycle, considered the restful or quiet sleep phase. The other phase......
nut
nut, in botany, dry hard fruit that does not split open at maturity to release its single seed. A nut resembles......
nutrient
nutrient, substance that an organism must obtain from its surroundings for growth and the sustenance of life. So-called......
nutrition
nutrition, the assimilation by living organisms of food materials that enable them to grow, maintain themselves,......
nutrition, human
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
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 Powerhouses: 8 Foods That Pack a Nutritional Punch
Sure, we all know that we’re supposed eat a balanced diet to contribute to optimal health. But all foods are not......
nutritional supplement
nutritional supplement, in foods, any vitamin or mineral added during processing to improve nutritive value and......
nymph
nymph, in entomology, sexually immature insect that is usually similar to the adult form. Nymphs are found in such......
nystagmus
nystagmus, involuntary back and forth, up and down, or circular movements of the eyes that are often described......
obesity
obesity, excessive accumulation of body fat, usually caused by the consumption of more calories than the body can......
obsessive-compulsive disorder
obsessive-compulsive disorder (OCD), type of mental disorder in which an individual experiences obsessions or compulsions......
obstetric fistula
obstetric fistula, abnormal duct or passageway that forms between the vagina and a nearby organ. This type of fistula......
occupational disease
occupational disease, any illness associated with a particular occupation or industry. Such diseases result from......
occupational injury
occupational injury, any health problem or bodily damage resulting directly from activities undertaken at the workplace.......
Odour
Odour, the property of certain substances, in very small concentrations, to stimulate chemical sense receptors......
Oedipus complex
Oedipus complex, in psychoanalytic theory, a desire for sexual involvement with the parent of the opposite sex......
oidium
oidium, in fungi (kingdom Fungi), a single-celled asexual spore (arthrospore) produced by fragmentation of fungal......
old age
old age, in human beings, the final stage of the normal life span. Definitions of old age are not consistent from......
olfactory receptor
olfactory receptor, protein capable of binding odour molecules that plays a central role in the sense of smell......
olfactory system
olfactory system, the bodily structures that serve the sense of smell. The system consists of the nose and the......
oligomenorrhea
oligomenorrhea, prolonged intervals between menstrual cycles. Menstruation is the normal cyclic bleeding from the......
Olympics: A Survey of Banned Substances
The use of performance-enhancing drugs among athletes competing in the Olympic Games is not new—as early as 1904,......
Ommochrome
Ommochrome, any of a group of biological pigments (biochromes) conspicuous in the eyes of insects and crustaceans......
omnivore
omnivore, animal with wide food preferences, which can eat both plant and animal matter. Many small birds and mammals......
onchocerciasis
onchocerciasis, filarial disease caused by the helminth Onchocerca volvulus, which is transmitted to humans by......
Ontogeny
Ontogeny, all the developmental events that occur during the existence of a living organism. Ontogeny begins with......
oogenesis
oogenesis, in the human female reproductive system, growth process in which the primary egg cell (or ovum) becomes......
ophthalmoplegia
ophthalmoplegia, paralysis of the extraocular muscles that control the movements of the eye. Ophthalmoplegia usually......
optic ataxia
optic ataxia, condition in which some or all aspects of visual guidance over reaching with the hand and arm are......
optic atrophy
optic atrophy, degeneration of the optic nerve (the second cranial nerve) due to direct or indirect damage to a......
optic nerve
optic nerve, second cranial nerve, which carries sensory nerve impulses from the more than one million ganglion......
optic neuritis
optic neuritis, inflammation of the optic nerve (the second cranial nerve). The inflammation causes a fairly rapid......
oral cancer
oral cancer, disease characterized by the growth of cancerous cells in the mouth, including the lips. Oral cancer......
orchitis
orchitis, inflammation and swelling of the testes as a result of infection or physical injury. The testes are a......
organogenesis
organogenesis, in embryology, the series of organized integrated processes that transforms an amorphous mass of......
orgasm
orgasm, climactic physiological state of heightened sexual excitement and gratification that is followed by relaxation......
orotic aciduria
orotic aciduria, hereditary metabolic disorder characterized by an anemia with many large immature red blood cells,......
Osler-Rendu-Weber disease
Osler-Rendu-Weber disease, hereditary disorder characterized by bleeding from local capillary malformations. In......
osteoarthritis
osteoarthritis, disorder of the joints characterized by progressive deterioration of the articular cartilage or......
osteochondroma
osteochondroma, solitary benign tumour that consists partly of cartilage and partly of bone. Osteochondromas are......
osteochondrosis
osteochondrosis, relatively common temporary orthopedic disorder of children in which the epiphysis (growing end)......
osteoclastoma
osteoclastoma, bone tumour found predominantly at the end of long bones in the knee region, but also occurring......
osteogenesis imperfecta
osteogenesis imperfecta (OI), rare hereditary disease of connective tissue characterized by brittle bones that......
osteoma
osteoma, small, often solitary bone tumour found mainly on bones of the skull. Osteomas usually appear in late......
osteomalacia
osteomalacia, condition in which the bones of an adult progressively soften because of inadequate mineralization......
osteomyelitis
osteomyelitis, infection of bone tissue. The condition is most commonly caused by the infectious organism Staphylococcus......
osteonecrosis
osteonecrosis, death of bone tissue that may result from infection, as in osteomyelitis, or deprivation of blood......
osteoporosis
osteoporosis, disease characterized by the thinning of bones, with a consequent tendency to sustain fractures from......
osteosarcoma
osteosarcoma, most common bone cancer, primarily affecting the long bones, particularly those in the knee, hip,......
otitis
otitis, Inflammation of the ear. Otitis externa is dermatitis, usually bacterial, of the auditory canal and sometimes......
otitis externa
otitis externa, dermatitis of the external auditory canal and sometimes also of the exposed ear. The skin on these......
otitis media
otitis media, inflammation of the lining of the middle ear. Otitis media is one of the most common infections in......
otosclerosis
otosclerosis, ear disorder characterized by abnormal bone growth in the middle ear, typically affecting the stapes......
ovarian cancer
ovarian cancer, disease characterized by the abnormal growth of cells in the ovaries, the internal reproductive......
ovary
ovary, in zoology, female reproductive organ in which sex cells (eggs, or ova) are produced. The usually paired......
overhydration
overhydration, condition characterized by an excessive volume of water in the body. Overhydration occurs when the......
overweight
overweight, Body weight greater than the optimum. If moderate, it is not necessarily obesity, particularly in muscular......
ovum
ovum, in human physiology, single cell released from either of the female reproductive organs, the ovaries, which......
Paedogenesis
Paedogenesis, reproduction by sexually mature larvae, usually without fertilization. The young may be eggs, such......
Paedomorphosis
Paedomorphosis, retention by an organism of juvenile or even larval traits into later life. There are two aspects......
Paget disease of bone
Paget disease of bone, chronic disease of middle age, characterized by excessive breakdown and formation of bone......
pain
pain, complex experience consisting of a physiological and a psychological response to a noxious stimulus. Pain......
palate
palate, in vertebrate anatomy, the roof of the mouth, separating the oral and nasal cavities. It consists of an......
Paleo diet
Paleo diet, dietary regime based on foods humans presumably would have consumed during the Paleolithic Period (2.6......
Panama disease
Panama disease, a devastating disease of bananas caused by the soil-inhabiting fungus species Fusarium oxysporum......
pancreas
pancreas, compound gland that discharges digestive enzymes into the gut and secretes the hormones insulin and glucagon,......
pancreatic cancer
pancreatic cancer, a disease characterized by abnormal growth of cells in the pancreas, a gland located behind......
pancreatitis
pancreatitis, inflammation of the pancreas, either acute or chronic. The disorder is most commonly caused by excessive......
pandemic
pandemic, outbreak of infectious disease that occurs over a wide geographical area and that is of high prevalence,......
panic attack
panic attack, sudden onset of intense apprehension, fear, or terror that occurs without apparent cause. A panic......
panic disorder
panic disorder, anxiety disorder characterized by repeated panic attacks that leads to persistent worry and avoidance......
Panting
Panting, a method of cooling, used by many mammals, most birds, and some reptiles, accomplished by means of the......
pappataci fever
pappataci fever, acute infectious febrile disease caused by a phlebovirus (family Bunyaviridae) and producing temporary......
paragonimiasis
paragonimiasis, infection caused by parasitic trematodes of the genus Paragonimus. Infection most commonly is with......
paralysis
paralysis, loss or impairment of voluntary muscular movement caused by structural abnormalities of nervous or muscular......
paranoia
paranoia, the central theme of a group of psychotic disorders characterized by systematic delusions and of the......
paraplegia
paraplegia, paralysis of the legs and lower part of the body. Paraplegia often involves loss of sensation (of pain,......
parasitic disease
parasitic disease, in humans, any illness that is caused by a parasite, an organism that lives in or on another......
parathyroid adenoma
parathyroid adenoma, disorder characterized by loss of mineral materials from the skeleton, the development of......
paratyphoid fever
paratyphoid fever, infectious disease caused by any of several organisms: Salmonella paratyphi (paratyphi A), S.......
paresis
paresis, psychosis caused by widespread destruction of brain tissue occurring in some cases of late syphilis. Mental......
Parkinson disease
Parkinson disease, a degenerative neurological disorder that is characterized by the onset of tremor, muscle rigidity,......
parkinsonism
parkinsonism, a group of chronic neurological disorders characterized by progressive loss of motor function resulting......