Biology, NEP-OVU
How do plants feed themselves? How did dogs evolve from wolves? What good is the appendix in humans, anyway? Such questions fall within the domain of biology, which seeks to understand living organisms and their vital processes (although the jury’s still out on what our appendixes are for). Biology’s diverse fields include botany, ecology, evolution, genetics, medicine, physiology, and zoology.
Biology Encyclopedia Articles By Title
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......
nerve, in anatomy, a glistening white cordlike bundle of fibres, surrounded by a sheath, that connects the nervous......
nerve net, primitive nerve arrangement forming the entire nervous system of many cnidarians and a part of more......
nervous system, organized group of cells specialized for the conduction of electrochemical stimuli from sensory......
- Introduction
- Organelles, Cells, Functions
- Neurons, Signals, Reflexes
- Axon, Signals, Neurotransmitters
- Astrocytes, Oligodendrocytes, Microglia
- Ionic Signals, Neurons, Synapses
- Neurons, Membrane, Signals
- Signaling, Neurons, Impulses
- Sodium-Potassium Pump, Active Transport, Neurotransmission
- Neurotransmitters, Neuromodulators
- Neurotransmitter, Dopamine, Signaling
- Evolution, Development, Structure
- Autonomic, Reflexes, Sensory
- Annelids, Reflexes, Sensory
- Arthropods, Reflexes, Sensory
- Brain, Spinal Cord, Neurons
- Brain, Control, Communication
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
human nervous system, system that conducts stimuli from sensory receptors to the brain and spinal cord and conducts......
- Introduction
- Morphology, Development, Anatomy
- Brain, Spinal Cord, Neurons
- Cerebrum, Brainstem, Cortex
- Brain Lobes, Cortex, Neurons
- Brainstem, Reflexes, Cranial Nerves
- Medulla, Brainstem, Reflexes
- Cerebellum, Motor Control, Coordination
- Spinal Cord, Reflexes, Sensory-Motor
- Descending Tracts, Motor Control, Sensory Input
- Peripheral Nerves, Sensory-Motor Pathways, Reflexes
- Cervical Plexus, Nerve Fibers, Nerve Impulses
- Cranial Nerves, Anatomy, Function
- Ophthalmic Nerve, Brain, Spinal Cord
- Vestibulocochlear, CN VIII, 8
- Autonomic, Neurotransmitters, Anatomy
- Parasympathetic, Autonomic, Reflexes
- Functions, Anatomy, Control
- Receptors, Signals, Pathways
- Reflex Actions, Motor Pathways, Sensory Pathways
- Motor, Sensory, Reflex
- Motor, Sensory, Reflex
- Motor Control, Reflexes, Movement
- Vestibular, Sensory, Motor
- Vestibular, Balance, Coordination
- Eye, Optic Nerve, Visual Cortex
- Reproduction, Anatomy, Physiology
- Pain, Sensory Receptors, Nerve Impulses
- Pain Pathways, Neurotransmitters, Sensory Receptors
- Perception, Sensory Organs, Signals
- Emotion, Behaviour, Control
- Urination, Defecation, Control
- Circadian Rhythms, Neurotransmitters, Anatomy
- Brain Functions, Neurons, Signals
- Brain, Neurons, Signals
- Memory, Brain, Neurons
neural crest, group of embryonic cells that are pinched off during the formation of the neural tube (the precursor......
neural oscillation, synchronized rhythmic patterns of electrical activity produced by neurons in the brain, spinal......
neural stem cell, largely undifferentiated cell originating in the central nervous system. Neural stem cells (NSCs)......
neural tube defect, any congenital defect of the brain and spinal cord as a result of abnormal development of the......
neurasthenia, a syndrome marked by physical and mental fatigue accompanied by withdrawal and...
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,......
neuroglia, any of several types of cell that function primarily to support neurons. The term neuroglia means “nerve......
neurohormone, any of a group of substances that are produced by specialized neurosecretory cells of the nervous......
neurolinguistics, the study of the neurological mechanisms underlying the storage and processing of language. Although......
neurology, medical specialty concerned with the nervous system and its functional or organic disorders. Neurologists......
neuron, basic cell of the nervous system in vertebrates and most invertebrates from the level of the cnidarians......
neuropathy, disorder of the peripheral nervous system. It may be genetic or acquired, progress quickly or slowly,......
neuroplasticity, capacity of neurons and neural networks in the brain to change their connections and behaviour......
neuropsychology, science concerned with the integration of psychological observations on behaviour with neurological......
neurosecretory cell, a type of neuron, or nerve cell, whose function is to translate neural signals into chemical......
neurosis, generally outmoded term used to refer to mental disorders characterized by anxiety, depression, or other......
neurotransmitter, any of a group of chemical agents released by neurons (nerve cells) to stimulate neighbouring......
neurotransmitter release, discharge of chemical substances known as neurotransmitters from a neuron in response......
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......
Nitophyllum, genus of red algae in the family Delesseriaceae, consisting of about 25 marine species distributed......
nitrifying bacterium, any of a small group of aerobic bacteria (family Nitrobacteraceae) that use inorganic chemicals......
nitrogen-fixing bacteria, microorganisms capable of transforming atmospheric nitrogen into fixed nitrogen (inorganic......
Noctiluca, genus of marine dinoflagellate in the family Noctilucaceae, consisting of a single species, Noctiluca......
node of Ranvier, periodic gap in the insulating sheath (myelin) on the axon of certain neurons that serves to facilitate......
nomenclature, in biological classification, system of naming organisms. The species to which the organism belongs......
normoblast, nucleated normal cell occurring in red marrow as a stage or stages in the development of the red blood......
norovirus, (genus Norovirus), genus consisting of one species of virus, known as Norwalk virus (family Caliciviridae),......
nose, the prominent structure between the eyes that serves as the entrance to the respiratory tract and contains......
nosebleed, an attack of bleeding from the nose. It is a common and usually unimportant disorder but may also result......
Nosema, genus of spore-forming parasitic single-celled organisms, of the phylum Microsporidia, found in host cells......
Nostoc, genus of blue-green algae with cells arranged in beadlike chains that are grouped together in a gelatinous......
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......
nucleolus, spherical body within the nucleus of most eukaryotic cells, involved in the synthesis of ribosomal RNA......
nucleus, in biology, a specialized structure occurring in most cells (except bacteria and blue-green algae) and......
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......
occupational disease, any illness associated with a particular occupation or industry. Such diseases result from......
oceanarium, saltwater aquarium for displaying marine animals and plants, particularly oceanic, or pelagic, fishes......
oidium, in fungi (kingdom Fungi), a single-celled asexual spore (arthrospore) produced by fragmentation of fungal......
oil gland, any of a variety of skin structures that secrete oily or greasy substances of various functions. In......
old age, in human beings, the final stage of the normal life span. Definitions of old age are not consistent from......
olfactory bulb, structure located in the forebrain of vertebrates that receives neural input about odours detected......
olfactory system, the bodily structures that serve the sense of smell. The system consists of the nose and the......
oligodendrocyte, a type of neuroglia found in the central nervous system of invertebrates and vertebrates that......
omics, any of several areas of biological study defined by the investigation of the entire complement of a specific......
one gene–one enzyme hypothesis, idea advanced in the early 1940s that each gene controls the synthesis or activity......
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......
opalinid, (subphylum Opalinata), any of about 150 protozoans found in the intestinal tracts of amphibians and some......
Oparin-Haldane theory, idea that organic molecules could be formed from abiogenic materials in the presence of......
ophthalmoplegia, paralysis of the extraocular muscles that control the movements of the eye. Ophthalmoplegia usually......
optic nerve, second cranial nerve, which carries sensory nerve impulses from the more than one million ganglion......
oral cancer, disease characterized by the growth of cancerous cells in the mouth, including the lips. Oral cancer......
Ordovician radiation, an interval of intense diversification of marine animal life that unfolded over tens of millions......
Ordovician-Silurian extinction, global mass extinction event occurring during the Hirnantian Age (445.2 million......
organ, in biology, a group of tissues in a living organism that have been adapted to perform a specific function.......
organelle, any of the specialized structures within a cell that perform a specific function (e.g., mitochondria,......
organogenesis, in embryology, the series of organized integrated processes that transforms an amorphous mass of......
According to nearly all ornithologists, birds are not only the descendants of ancient dinosaurs, they are, in fact,......
ornithology, a branch of zoology dealing with the study of birds. Most of the early writings on birds are more......
orthogenesis, theory that successive members of an evolutionary series become increasingly modified in a single......
orthomyxovirus, any virus belonging to the family Orthomyxoviridae. Orthomyxoviruses have enveloped virions (virus......
Osler-Rendu-Weber disease, hereditary disorder characterized by bleeding from local capillary malformations. In......
osmoregulation, in biology, maintenance by an organism of an internal balance between water and dissolved materials......
osteoarthritis, disorder of the joints characterized by progressive deterioration of the articular cartilage or......
osteoblast, large cell responsible for the synthesis and mineralization of bone during both initial bone formation......
osteoclast, large multinucleated cell responsible for the dissolution and absorption of bone. Bone is a dynamic......
osteoclastoma, bone tumour found predominantly at the end of long bones in the knee region, but also occurring......
osteocyte, a cell that lies within the substance of fully formed bone. It occupies a small chamber called a lacuna,......
osteogenesis imperfecta (OI), rare hereditary disease of connective tissue characterized by brittle bones that......
osteoma, small, often solitary bone tumour found mainly on bones of the skull. Osteomas usually appear in late......
osteomyelitis, infection of bone tissue. The condition is most commonly caused by the infectious organism Staphylococcus......
osteonecrosis, death of bone tissue that may result from infection, as in osteomyelitis, or deprivation of blood......
osteoporosis, disease characterized by the thinning of bones, with a consequent tendency to sustain fractures from......
otitis, Inflammation of the ear. Otitis externa is dermatitis, usually bacterial, of the auditory canal and sometimes......
otosclerosis, ear disorder characterized by abnormal bone growth in the middle ear, typically affecting the stapes......
ovary, in zoology, female reproductive organ in which sex cells (eggs, or ova) are produced. The usually paired......
overhydration, condition characterized by an excessive volume of water in the body. Overhydration occurs when the......
overweight, Body weight greater than the optimum. If moderate, it is not necessarily obesity, particularly in muscular......
oviparity, expulsion of undeveloped eggs rather than live young. The eggs may have been fertilized before release,......
ovum, in human physiology, single cell released from either of the female reproductive organs, the ovaries, which......
