Anatomy & Physiology, NER-PHO

Human beings have long been curious about the way that things work, and that curiosity includes wondering about how we ourselves work. The fields of anatomy and physiology involve studying the structures of bodies and the way that those structures and bodies function.
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Anatomy & Physiology Encyclopedia Articles By Title

nerve net
nerve net, primitive nerve arrangement forming the entire nervous system of many cnidarians and a part of more......
neural crest
neural crest, group of embryonic cells that are pinched off during the formation of the neural tube (the precursor......
neural oscillation
neural oscillation, synchronized rhythmic patterns of electrical activity produced by neurons in the brain, spinal......
neural stem cell
neural stem cell, largely undifferentiated cell originating in the central nervous system. Neural stem cells (NSCs)......
neuroglia
neuroglia, any of several types of cell that function primarily to support neurons. The term neuroglia means “nerve......
neurohormone
neurohormone, any of a group of substances that are produced by specialized neurosecretory cells of the nervous......
neurolinguistics
neurolinguistics, the study of the neurological mechanisms underlying the storage and processing of language. Although......
neuromuscular junction
neuromuscular junction, site of chemical communication between a nerve fibre and a muscle cell. The neuromuscular......
neuron
neuron, basic cell of the nervous system in vertebrates and most invertebrates from the level of the cnidarians......
neuroplasticity
neuroplasticity, capacity of neurons and neural networks in the brain to change their connections and behaviour......
neurosecretory cell
neurosecretory cell, a type of neuron, or nerve cell, whose function is to translate neural signals into chemical......
neurotransmitter
neurotransmitter, any of a group of chemical agents released by neurons (nerve cells) to stimulate neighbouring......
neurotransmitter release
neurotransmitter release, discharge of chemical substances known as neurotransmitters from a neuron in response......
neutrophil
neutrophil, type of white blood cell (leukocyte) that is characterized histologically by its ability to be stained......
night blindness
night blindness, failure of the eye to adapt promptly from light to darkness that is characterized by a reduced......
nightmare
nightmare, disturbing dream that provokes a strong negative emotional reaction. Nightmares differ from other dreams......
node of Ranvier
node of Ranvier, periodic gap in the insulating sheath (myelin) on the axon of certain neurons that serves to facilitate......
nonverbal learning disorder
What is nonverbal learning disorder (NVLD)? NVLD is a neurological condition characterized by cognitive and social......
normoblast
normoblast, nucleated normal cell occurring in red marrow as a stage or stages in the development of the red blood......
nose
nose, the prominent structure between the eyes that serves as the entrance to the respiratory tract and contains......
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......
nucleic acid
nucleic acid, naturally occurring chemical compound that serves as the main information-carrying molecule of the......
nucleoprotein
nucleoprotein, molecule consisting of a protein linked to a nucleic acid, either DNA (deoxyribonucleic acid) or......
nucleoside
nucleoside, a structural subunit of nucleic acids, the heredity-controlling components of all living cells, consisting......
nucleotide
nucleotide, any member of a class of organic compounds in which the molecular structure comprises a nitrogen-containing......
nystagmus
nystagmus, involuntary back and forth, up and down, or circular movements of the eyes that are often described......
obstetric fistula
obstetric fistula, abnormal duct or passageway that forms between the vagina and a nearby organ. This type of fistula......
occipital
occipital, bone forming the back and back part of the base of the cranium, the part of the skull that encloses......
odour
odour, the property of certain substances, in very small concentrations, to stimulate chemical sense receptors......
oil gland
oil gland, any of a variety of skin structures that secrete oily or greasy substances of various functions. In......
old age
old age, in human beings, the final stage of the normal life span. Definitions of old age are not consistent from......
olfactory bulb
olfactory bulb, structure located in the forebrain of vertebrates that receives neural input about odours detected......
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......
oligodendrocyte
oligodendrocyte, a type of neuroglia found in the central nervous system of invertebrates and vertebrates that......
oligonucleotide
oligonucleotide, a short chain of nucleotides (nitrogen-containing units linked to a sugar and a phosphate group)......
oligosaccharide
oligosaccharide, any carbohydrate of from three to six units of simple sugars (monosaccharides). A large number......
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 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......
orchitis
orchitis, inflammation and swelling of the testes as a result of infection or physical injury. The testes are a......
organ
organ, in biology, a group of tissues in a living organism that have been adapted to perform a specific function.......
organogenesis
organogenesis, in embryology, the series of organized integrated processes that transforms an amorphous mass of......
osmoregulation
osmoregulation, in biology, maintenance by an organism of an internal balance between water and dissolved materials......
osteoblast
osteoblast, large cell responsible for the synthesis and mineralization of bone during both initial bone formation......
osteoclast
osteoclast, large multinucleated cell responsible for the dissolution and absorption of bone. Bone is a dynamic......
osteocyte
osteocyte, a cell that lies within the substance of fully formed bone. It occupies a small chamber called a lacuna,......
osteon
osteon, the chief structural unit of compact (cortical) bone, consisting of concentric bone layers called lamellae,......
ovarian cancer
ovarian cancer, a 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......
oviparity
oviparity, expulsion of undeveloped eggs rather than live young. The eggs may have been fertilized before release,......
ovulation
ovulation, release of a mature egg from the female ovary; the release enables the egg to be fertilized by the male......
ovum
ovum, in human physiology, single cell released from either of the female reproductive organs, the ovaries, which......
P blood group system
P blood group system, classification of human blood based on the presence of any of three substances known as the......
pacemaker
pacemaker, electronic cardiac-support device that produces rhythmic electrical impulses that take over the regulation......
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......
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 15-cm- (6-inch-) long......
pancreatitis
pancreatitis, inflammation of the pancreas, either acute or chronic. The disorder is most commonly caused by excessive......
Paneth’s cell
Paneth’s cell, specialized type of epithelial cell found in the mucous-membrane lining of the small intestine and......
panting
panting, a method of cooling, used by many mammals, most birds, and some reptiles, accomplished by means of the......
parasympathetic nervous system
parasympathetic nervous system, division of the nervous system that primarily modulates visceral organs such as......
parathyroid adenoma
parathyroid adenoma, disorder characterized by loss of mineral materials from the skeleton, the development of......
parathyroid gland
parathyroid gland, endocrine gland occurring in all vertebrate species from amphibia upward, usually located close......
parathyroid hormone
parathyroid hormone (PTH), substance produced and secreted by the parathyroid glands that regulates serum calcium......
parietal bone
parietal bone, cranial bone forming part of the side and top of the head. In front each parietal bone adjoins the......
parietal cell
parietal cell, in biology, one of the cells that are the source of the hydrochloric acid and most of the water......
pathology
pathology, medical specialty concerned with the determining causes of disease and the structural and functional......
pectin
pectin, any of a group of water-soluble carbohydrate substances that are found in the cell walls and intercellular......
pectoral girdle
pectoral girdle, in anatomy, the bony structure on either side of the body that connects the arm to the upper portion......
pectoralis muscle
pectoralis muscle, any of the muscles that connect the front walls of the chest with the bones of the upper arm......
pelage
pelage, hairy, woolly, or furry coat of a mammal, distinguished from the underlying bare skin. The pelage is significant......
pelvis
pelvis, in human anatomy, basin-shaped complex of bones that connects the trunk and the legs, supports and balances......
penis
penis, the copulatory organ of the male of higher vertebrates that in mammals usually also provides the channel......
periodontal membrane
periodontal membrane, fleshy tissue between tooth and tooth socket that holds the tooth in place, attaches it to......
periosteum
periosteum, dense fibrous membrane covering the surfaces of bones, consisting of an outer fibrous layer and an......
peristalsis
peristalsis, involuntary movements of the longitudinal and circular muscles, primarily in the digestive tract but......
peritoneum
peritoneum, large membrane in the abdominal cavity that connects and supports internal organs. It is composed of......
perspiration
perspiration, in most mammals, water given off by the intact skin, either as vapour by simple evaporation from......
pervasive developmental disorder
pervasive developmental disorder (PDD), term historically used in reference to any of a group of conditions characterized......
pervasive developmental disorder not otherwise specified
pervasive developmental disorder not otherwise specified (PDD-NOS), condition characterized by impairment in the......
Peyer patch
Peyer patch, any of the nodules of lymphatic cells that aggregate to form bundles or patches and occur usually......
phagocytosis
phagocytosis, process by which certain living cells called phagocytes ingest or engulf other cells or particles.......
phantom limb syndrome
phantom limb syndrome, the ability to feel sensations and even pain in a limb or limbs that no longer exist. Phantom......
pharynx
pharynx, cone-shaped passageway leading from the oral and nasal cavities in the head to the esophagus and larynx.......
phenylthiocarbamide tasting
phenylthiocarbamide tasting, a genetically controlled ability to taste phenylthiocarbamide (PTC) and a number of......
pheochromocytoma
pheochromocytoma, tumour, most often nonmalignant, that causes abnormally high blood pressure (hypertension) because......
pheromone
pheromone, any endogenous chemical secreted in minute amounts by an organism in order to elicit a particular reaction......
phospholipid
phospholipid, any member of a large class of fatlike, phosphorus-containing substances that play important structural......
photodynamism
photodynamism, conversion of certain substances in the skin of animals into other substances by the action of light.......
photophore
photophore, light-emitting organ present in fireflies and certain other bioluminescent animals. Photophores are......
photoprotein
photoprotein, in biochemistry, any of several proteins that give off light upon combination with oxygen, hydrogen......

Anatomy & Physiology Encyclopedia Articles By Title