Anatomy & Physiology, LYM-NOT
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.
Anatomy & Physiology Encyclopedia Articles By Title
lymphoblast
lymphoblast, immature white blood cell that gives rise to a type of immune cell known as a lymphocyte. The nucleus......
lymphocyte
lymphocyte, type of white blood cell (leukocyte) that is of fundamental importance in the immune system because......
lymphoid tissue
lymphoid tissue, cells and organs that make up the lymphatic system, such as white blood cells (leukocytes), bone......
macrophage
macrophage, type of white blood cell that helps eliminate foreign substances by engulfing foreign materials and......
macula lutea
macula lutea, in anatomy, the small yellowish area of the retina near the optic disk that provides central vision.......
macular degeneration
macular degeneration, group of blinding disorders that cause the gradual deterioration of the retina in the eye.......
major types of pollinators
Pollination is essential to the perpetuation of the vast majority of the world’s wild plants—and thus the perpetuation......
Malpighian tubule
Malpighian tubule, in insects, any of the excretory organs that lie in the abdominal body cavity and empty into......
maltose
maltose, organic compound composed of two glucose molecules linked together. The compound (C12H22O11) is a disaccharide......
mammary gland
mammary gland, milk-producing gland characteristic of all female mammals and present in a rudimentary and generally......
mantle
mantle, in biology, soft covering, formed from the body wall, of brachiopods and mollusks; also, the fleshy outer......
masseter
masseter, (from Greek masasthai, “to chew”), prominent muscle of the jaw. The masseter arises from the zygomatic......
mast cell
mast cell, tissue cell of the immune system of vertebrate animals. Mast cells mediate inflammatory responses such......
mastitis
mastitis, inflammation of the breast in women or of the udder in sheep, swine, and cattle. Acute mastitis in women......
maternal imagination
maternal imagination, idea that maternal thoughts during pregnancy are transmitted directly to the developing fetus,......
Mechanoreception
Mechanoreception, ability of an animal to detect and respond to certain kinds of stimuli—notably touch, sound,......
mediastinum
mediastinum, the anatomic region located between the lungs that contains all the principal tissues and organs of......
medulla oblongata
medulla oblongata, the lowest part of the brain and the lowest portion of the brainstem. The medulla oblongata......
medullary thyroid carcinoma
medullary thyroid carcinoma, tumour of the parafollicular cells (C cells) of the thyroid gland. It occurs both......
medusa
medusa, in zoology, one of two principal body types occurring in members of the invertebrate animal phylum Cnidaria.......
melanocyte
melanocyte, specialized skin cell that produces the protective skin-darkening pigment melanin. Birds and mammals......
membrane
membrane, in biology, the thin layer that forms the outer boundary of a living cell or of an internal cell compartment.......
meninges
meninges, three membranous envelopes—pia mater, arachnoid, and dura mater—that surround the brain and spinal cord.......
menopause
menopause, permanent cessation of menstruation that results from the loss of ovarian function and therefore represents......
menstrual cycle
menstrual cycle, recurring fluctuations in hormone levels that produce physical changes in the uterus and ovaries......
menstruation
menstruation, periodic discharge from the vagina of blood, secretions, and disintegrating mucous membrane that......
mesentery
mesentery, a continuous folded band of membranous tissue (peritoneum) that is attached to the wall of the abdomen......
mesoderm
mesoderm, the middle of the three germ layers, or masses of cells (lying between the ectoderm and endoderm), which......
mesomorph
mesomorph, a human somatotype (physical type) that is marked by greater than average muscular development, as determined......
Mesonephros
Mesonephros, permanent kidney of amphibians and most fish, developing posterior to and replacing the pronephros......
messenger RNA
messenger RNA (mRNA), molecule in cells that carries codes from the DNA in the nucleus to the sites of protein......
Metabolomics
Metabolomics, the study of metabolites, the chemical substances produced as a result of metabolism, which encompasses......
metacarpal
metacarpal, any of several tubular bones between the wrist (carpal) bones and each of the forelimb digits in land......
metanephros
metanephros, permanent kidney in reptiles, birds, and mammals, developing by the 10th week in human embryos from......
metatarsal
metatarsal, any of several tubular bones between the ankle (tarsal) bones and each of the hindlimb digits, in land......
microglia
microglia, type of neuronal support cell (neuroglia) occurring in the central nervous system of invertebrates and......
microRNA
microRNA (miRNA), small molecule in cells, typically about 21–25 nucleotides in length, that plays a crucial role......
microvillus
microvillus, any of numerous microscopic bristlelike protrusions that occur on the surface of a wide variety of......
midbrain
midbrain, region of the developing vertebrate brain that is composed of the tectum and tegmentum. The midbrain......
middle age
middle age, period of human adulthood that immediately precedes the onset of old age. Though the age period that......
mirror neuron
mirror neuron, type of sensory-motor cell located in the brain that is activated when an individual performs an......
mitosis
mitosis, a process of cell duplication, or reproduction, during which one cell gives rise to two genetically identical......
MNSs blood group system
MNSs blood group system, classification of human blood based on the presence of various substances known as M,......
monoclonal antibody
monoclonal antibody, antibody produced artificially through genetic engineering and related techniques. Production......
monocyte
monocyte, type of white blood cell that is a critical part of the innate immune system, which is present from birth......
mononuclear phagocyte system
mononuclear phagocyte system, class of cells that occur in widely separated parts of the human body and that have......
Monosaccharide
Monosaccharide, any of the basic compounds that serve as the building blocks of carbohydrates. Monosaccharides......
mons pubis
mons pubis, pad of fatty tissue lying in front of the pubic symphysis. The mons pubis is a rounded eminence made......
Morphogenesis
Morphogenesis, the shaping of an organism by embryological processes of differentiation of cells, tissues, and......
morula
morula, solid mass of blastomeres resulting from a number of cleavages of a zygote, or fertilized egg. Its name......
mouth
mouth, in human anatomy, orifice through which food and air enter the body. The mouth opens to the outside at the......
mouthbreeder
mouthbreeder, any fish that breeds its young in the mouth. Examples include certain catfishes, cichlids, and cardinal......
mucous membrane
mucous membrane, membrane lining body cavities and canals that lead to the outside, chiefly the respiratory, digestive,......
multiple birth
multiple birth, the delivery of more than one offspring in a single birth event. In most mammals the litter size......
multiple endocrine neoplasia
multiple endocrine neoplasia (MEN), any of a group of rare hereditary disorders in which tumours occur in multiple......
mummy
mummy, body embalmed, naturally preserved, or treated for burial with preservatives after the manner of the ancient......
muscle
muscle, contractile tissue found in animals, the function of which is to produce motion. Movement, the intricate......
- Introduction
- Types, Structure, Function
- Contraction, Movement, Structure
- Structure, Function, Types
- Arthropods, Contraction, Movement
- Skeletal, Cardiac, Smooth
- Jawed Fishes, Contraction, Movement
- Skeletal, Smooth, Cardiac
- Skeletal, Cardiac, Smooth
- Myofibrils, Contraction, Proteins
- Actin-Myosin, Regulation, Contraction
- Twitch, Tetanus, Responses
- Frequency, Contraction, Types
- Force, Velocity, Contraction
- Structure, Organization, Fibers
muscle system, human
human muscle system, the muscles of the human body that work the skeletal system, that are under voluntary control,......
myelin
myelin, white, insulating sheath on the axon of many neurons. Composed of fatty materials, protein, and water,......
myeloblast
myeloblast, immature blood cell, found in bone marrow, that gives rise to white blood cells of the granulocytic......
myelocyte
myelocyte, stage in the development of the granulocytic series of white blood cells (leukocytes) in which granules......
myofibril
myofibril, very fine contractile fibres, groups of which extend in parallel columns along the length of striated......
Myoglobin
Myoglobin, a protein found in the muscle cells of animals. It functions as an oxygen-storage unit, providing oxygen......
myopia
myopia, visual abnormality in which the resting eye focuses the image of a distant object at a point in front of......
Myosin
Myosin, any of a group of proteins that plays a central role as a molecular motor in cellular movement and force......
myxedema
myxedema, physiological reaction to lack of sufficient thyroid hormone (hypothyroidism) in the adult. It can be......
nail
nail, in the anatomy of humans and other primates, horny plate that grows on the back of each finger and toe at......
nasal concha
nasal concha, any of several thin, scroll-shaped bony elements forming the upper chambers of the nasal cavities.......
Nasal gland
Nasal gland, in marine birds and reptiles that drink saltwater, gland that extracts the salt and removes it from......
natural childbirth
natural childbirth, any of the systems of managing parturition in which the need for anesthesia, sedation, or surgery......
navel
navel, in anatomy, a small depression in the abdominal wall at the point of attachment of the umbilical cord (q.v.).......
neck
neck, in land vertebrates, the portion of the body joining the head to the shoulders and chest. Some important......
nematocyst
nematocyst, minute, elongated, or spherical capsule produced exclusively by members of the phylum Cnidaria (e.g.,......
neonatal hypothyroidism
neonatal hypothyroidism, condition characterized by the absence, lack, or dysfunction of thyroid hormone production......
Nephridium
Nephridium, unit of the excretory system in many primitive invertebrates and also in the amphioxus; it expels wastes......
nephron
nephron, functional unit of the kidney, the structure that actually produces urine in the process of removing waste......
nerve
nerve, in anatomy, a glistening white cordlike bundle of fibres, surrounded by a sheath, that connects the nervous......
Nerve net
Nerve net, primitive nerve arrangement forming the entire nervous system of many cnidarians and a part of more......
nervous system
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, human
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
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, appearing in organisms as simple......
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
nonverbal learning disorder (NVLD), a neurological condition characterized by cognitive, and occasionally 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......