The biological science concerned with the life-supporting properties, functions, and processes of living organisms or their parts.
The biological science concerned with similarities or differences in the life-supporting functions and processes of different species.
The educational process of instructing.
An acronym for Acute Physiology and Chronic Health Evaluation, a scoring system using routinely collected data and providing an accurate, objective description for a broad range of intensive care unit admissions, measuring severity of illness in critically ill patients.
Processes and properties of the CARDIOVASCULAR SYSTEM as a whole or of any of its parts.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
A branch of biology dealing with the structure of organisms.
Time period from 1901 through 2000 of the common era.
Physiological processes and properties of the RESPIRATORY SYSTEM as a whole or of any of its parts.
The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs and stimuli, hormone secretion, sleeping, and feeding.
Properties and processes of the DIGESTIVE SYSTEM as a whole or of any of its parts.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
The functions and properties of living organisms, including both the physical and chemical factors and processes, supporting life in single- or multi-cell organisms from their origin through the progression of life.
The total process by which organisms produce offspring. (Stedman, 25th ed)
Instructional use of examples or cases to teach using problem-solving skills and critical thinking.
A subspecialty of internal medicine concerned with the metabolism, physiology, and disorders of the ENDOCRINE SYSTEM.
The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.
Cellular processes, properties, and characteristics.
The period of medical education in a medical school. In the United States it follows the baccalaureate degree and precedes the granting of the M.D.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
The unfavorable effect of environmental factors (stressors) on the physiological functions of an organism. Prolonged unresolved physiological stress can affect HOMEOSTASIS of the organism, and may lead to damaging or pathological conditions.
A course of study offered by an educational institution.
Elements of limited time intervals, contributing to particular results or situations.
The processes whereby the internal environment of an organism tends to remain balanced and stable.
The chemical reactions involved in the production and utilization of various forms of energy in cells.
Use for general articles concerning medical education.
Time period from 1801 through 1900 of the common era.
Biological mechanism that controls CIRCADIAN RHYTHM. Circadian clocks exist in the simplest form in cyanobacteria and as more complex systems in fungi, plants, and animals. In humans the system includes photoresponsive RETINAL GANGLION CELLS and the SUPRACHIASMATIC NUCLEUS that acts as the central oscillator.
Theoretical models which propose methods of learning or teaching as a basis or adjunct to changes in attitude or behavior. These educational interventions are usually applied in the fields of health and patient education but are not restricted to patient care.
Instructional materials used in teaching.
Time period from 2001 through 2100 of the common era.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
Generally refers to the digestive structures stretching from the MOUTH to ANUS, but does not include the accessory glandular organs (LIVER; BILIARY TRACT; PANCREAS).
The observable response an animal makes to any situation.
Hospital units providing continuous surveillance and care to acutely ill patients.
An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.
The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.
The time period of daily exposure that an organism receives from daylight or artificial light. It is believed that photoperiodic responses may affect the control of energy balance and thermoregulation.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
The system of glands that release their secretions (hormones) directly into the circulatory system. In addition to the ENDOCRINE GLANDS, included are the CHROMAFFIN SYSTEM and the NEUROSECRETORY SYSTEMS.
Physiological processes and properties of BACTERIA.
The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.
The assessing of academic or educational achievement. It includes all aspects of testing and test construction.
Non-human animals, selected because of specific characteristics, for use in experimental research, teaching, or testing.
The relationships of groups of organisms as reflected by their genetic makeup.
The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.
The scientific discipline concerned with the physiology of the nervous system.
Relatively permanent change in behavior that is the result of past experience or practice. The concept includes the acquisition of knowledge.
A self-learning technique, usually online, involving interaction of the student with programmed instructional materials.
Societies whose membership is limited to scientists.
The physiological mechanisms that govern the rhythmic occurrence of certain biochemical, physiological, and behavioral phenomena.
The functions and activities of living organisms that support life in single- or multi-cellular organisms from their origin through the progression of life.
Physiological processes, factors, properties and characteristics pertaining to REPRODUCTION.
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
A disease or state in which death is possible or imminent.
Proteins found in any species of bacterium.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.
The balance between acids and bases in the BODY FLUIDS. The pH (HYDROGEN-ION CONCENTRATION) of the arterial BLOOD provides an index for the total body acid-base balance.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
The HEART and the BLOOD VESSELS by which BLOOD is pumped and circulated through the body.
The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.
Behavioral responses or sequences associated with eating including modes of feeding, rhythmic patterns of eating, and time intervals.
Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
Adaptation to a new environment or to a change in the old.
The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.
The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.
Time period from 1701 through 1800 of the common era.
Characteristic properties and processes of the NERVOUS SYSTEM as a whole or with reference to the peripheral or the CENTRAL NERVOUS SYSTEM.
Application of principles and practices of engineering science to biomedical research and health care.
A procedure in which total right atrial or total caval blood flow is channeled directly into the pulmonary artery or into a small right ventricle that serves only as a conduit. The principal congenital malformations for which this operation is useful are TRICUSPID ATRESIA and single ventricle with pulmonary stenosis.
An ovoid densely packed collection of small cells of the anterior hypothalamus lying close to the midline in a shallow impression of the OPTIC CHIASM.
The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.
A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.
Time period from 1601 through 1700 of the common era.
Individuals enrolled in a school of medicine or a formal educational program in medicine.
The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.
That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.
The hollow, muscular organ that maintains the circulation of the blood.
A biogenic amine that is found in animals and plants. In mammals, melatonin is produced by the PINEAL GLAND. Its secretion increases in darkness and decreases during exposure to light. Melatonin is implicated in the regulation of SLEEP, mood, and REPRODUCTION. Melatonin is also an effective antioxidant.
Facilities equipped to carry out investigative procedures.
The state of the PENIS when the erectile tissue becomes filled or swollen (tumid) with BLOOD and causes the penis to become rigid and elevated. It is a complex process involving CENTRAL NERVOUS SYSTEM; PERIPHERAL NERVOUS SYSTEMS; HORMONES; SMOOTH MUSCLES; and vascular functions.
The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)
Biological actions and events that support the functions of the RESPIRATORY SYSTEM.
Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.
Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.
The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.
Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.
Biological actions and events that support the functions of the CARDIOVASCULAR SYSTEM.
Sexual activities of animals.
Expanded structures, usually green, of vascular plants, characteristically consisting of a bladelike expansion attached to a stem, and functioning as the principal organ of photosynthesis and transpiration. (American Heritage Dictionary, 2d ed)
Educational institutions providing facilities for teaching and research and authorized to grant academic degrees.
The study of those aspects of energy and matter in terms of elementary principles and laws. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
The balance of fluid in the BODY FLUID COMPARTMENTS; total BODY WATER; BLOOD VOLUME; EXTRACELLULAR SPACE; INTRACELLULAR SPACE, maintained by processes in the body that regulate the intake and excretion of WATER and ELECTROLYTES, particularly SODIUM and POTASSIUM.
The external elements and conditions which surround, influence, and affect the life and development of an organism or population.
Basic helix-loop-helix (bHLH) domain-containing proteins that play important roles in CIRCADIAN RHYTHM regulation. They combine with CLOCK PROTEINS to form heterodimeric transcription factors that are specific for E-BOX ELEMENTS and stimulate the transcription of several E-box genes that are involved in cyclical regulation.
The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.
The chemical reactions that occur within the cells, tissues, or an organism. These processes include both the biosynthesis (ANABOLISM) and the breakdown (CATABOLISM) of organic materials utilized by the living organism.
Basic helix-loop-helix (bHLH) domain-containing proteins that contain intrinsic HISTONE ACETYLTRANSFERASE activity and play important roles in CIRCADIAN RHYTHM regulation. Clock proteins combine with Arntl proteins to form heterodimeric transcription factors that are specific for E-BOX ELEMENTS and stimulate the transcription of several E-box genes that are involved in cyclical regulation. This transcriptional activation also sets into motion a time-dependent feedback loop which in turn down-regulates the expression of clock proteins.
Ductless glands that secrete HORMONES directly into the BLOOD CIRCULATION. These hormones influence the METABOLISM and other functions of cells in the body.
A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.
Computer-based representation of physical systems and phenomena such as chemical processes.
A group of organs stretching from the MOUTH to the ANUS, serving to breakdown foods, assimilate nutrients, and eliminate waste. In humans, the digestive system includes the GASTROINTESTINAL TRACT and the accessory glands (LIVER; BILIARY TRACT; PANCREAS).
Comprehensive, methodical analysis of complex biological systems by monitoring responses to perturbations of biological processes. Large scale, computerized collection and analysis of the data are used to develop and test models of biological systems.
Preparatory education meeting the requirements for admission to medical school.
Warm-blooded vertebrate animals belonging to the class Mammalia, including all that possess hair and suckle their young.
Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.
A discipline concerned with studying biological phenomena in terms of the chemical and physical interactions of molecules.
Theoretical representations that simulate the behavior or activity of the cardiovascular system, processes, or phenomena; includes the use of mathematical equations, computers and other electronic equipment.
Complex sets of enzymatic reactions connected to each other via their product and substrate metabolites.
A functional system which includes the organisms of a natural community together with their environment. (McGraw Hill Dictionary of Scientific and Technical Terms, 4th ed)
A subtype of striated muscle, attached by TENDONS to the SKELETON. Skeletal muscles are innervated and their movement can be consciously controlled. They are also called voluntary muscles.
The protein complement of an organism coded for by its genome.
Use for general articles concerning veterinary medical education.
One of the three domains of life (the others being Eukarya and ARCHAEA), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to OXYGEN: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or PHOTOTROPHY (via light reaction); for chemotrophs by their source of chemical energy: CHEMOLITHOTROPHY (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for CARBON; NITROGEN; etc.; HETEROTROPHY (from organic sources) or AUTOTROPHY (from CARBON DIOXIDE). They can also be classified by whether or not they stain (based on the structure of their CELL WALLS) with CRYSTAL VIOLET dye: gram-negative or gram-positive.
The genetic complement of a BACTERIA as represented in its DNA.
A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.
The relationship between two different species of organisms that are interdependent; each gains benefits from the other or a relationship between different species where both of the organisms in question benefit from the presence of the other.
A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.
A nonmetallic element with atomic symbol C, atomic number 6, and atomic weight [12.0096; 12.0116]. It may occur as several different allotropes including DIAMOND; CHARCOAL; and GRAPHITE; and as SOOT from incompletely burned fuel.
Hybridization of a nucleic acid sample to a very large set of OLIGONUCLEOTIDE PROBES, which have been attached individually in columns and rows to a solid support, to determine a BASE SEQUENCE, or to detect variations in a gene sequence, GENE EXPRESSION, or for GENE MAPPING.
Travel beyond the earth's atmosphere.
Time period from 1501 through 1600 of the common era.
Divisions of the year according to some regularly recurrent phenomena usually astronomical or climatic. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.
The systematic study of the complete DNA sequences (GENOME) of organisms.
Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)
Health care provided to a critically ill patient during a medical emergency or crisis.
An element with the atomic symbol N, atomic number 7, and atomic weight [14.00643; 14.00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth's atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells.
A group of cold-blooded, aquatic vertebrates having gills, fins, a cartilaginous or bony endoskeleton, and elongated bodies covered with scales.
Those characteristics that distinguish one SEX from the other. The primary sex characteristics are the OVARIES and TESTES and their related hormones. Secondary sex characteristics are those which are masculine or feminine but not directly related to reproduction.
Advanced and highly specialized care provided to medical or surgical patients whose conditions are life-threatening and require comprehensive care and constant monitoring. It is usually administered in specially equipped units of a health care facility.
The processes of heating and cooling that an organism uses to control its temperature.
Circadian rhythm signaling proteins that influence circadian clock by interacting with other circadian regulatory proteins and transporting them into the CELL NUCLEUS.
ANIMALS whose GENOME has been altered by GENETIC ENGINEERING, or their offspring.
A vital statistic measuring or recording the rate of death from any cause in hospitalized populations.
Critical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws. (Webster, 3d ed)
The physiological processes, properties, and states characteristic of plants.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
A species of fruit fly much used in genetics because of the large size of its chromosomes.
The systematic study of the complete complement of proteins (PROTEOME) of organisms.
The usually underground portions of a plant that serve as support, store food, and through which water and mineral nutrients enter the plant. (From American Heritage Dictionary, 1982; Concise Dictionary of Biology, 1990)
Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.
Gated, ion-selective glycoproteins that traverse membranes. The stimulus for ION CHANNEL GATING can be due to a variety of stimuli such as LIGANDS, a TRANSMEMBRANE POTENTIAL DIFFERENCE, mechanical deformation or through INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.
The reproductive organ (GONADS) in female animals. In vertebrates, the ovary contains two functional parts: the OVARIAN FOLLICLE for the production of female germ cells (OOGENESIS); and the endocrine cells (GRANULOSA CELLS; THECA CELLS; and LUTEAL CELLS) for the production of ESTROGENS and PROGESTERONE.
The pattern of GENE EXPRESSION at the level of genetic transcription in a specific organism or under specific circumstances in specific cells.
Signal transduction mechanisms whereby calcium mobilization (from outside the cell or from intracellular storage pools) to the cytoplasm is triggered by external stimuli. Calcium signals are often seen to propagate as waves, oscillations, spikes, sparks, or puffs. The calcium acts as an intracellular messenger by activating calcium-responsive proteins.
A system of NEURONS that has the specialized function to produce and secrete HORMONES, and that constitutes, in whole or in part, an ENDOCRINE SYSTEM or organ.
The largest family of cell surface receptors involved in SIGNAL TRANSDUCTION. They share a common structure and signal through HETEROTRIMERIC G-PROTEINS.
The salinated water of OCEANS AND SEAS that provides habitat for marine organisms.
A medical specialty concerned with the hypersensitivity of the individual to foreign substances and protection from the resultant infection or disorder.
Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.
Individuals enrolled in a school or formal educational program.
The protection of animals in laboratories or other specific environments by promoting their health through better nutrition, housing, and care.
Cellular processes in biosynthesis (anabolism) and degradation (catabolism) of CARBOHYDRATES.
Cellular functions, mechanisms, and activities.
Established cell cultures that have the potential to propagate indefinitely.
The loss of water vapor by plants to the atmosphere. It occurs mainly from the leaves through pores (stomata) whose primary function is gas exchange. The water is replaced by a continuous column of water moving upwards from the roots within the xylem vessels. (Concise Dictionary of Biology, 1990)
The physical measurements of a body.
Transmission of the readings of instruments to a remote location by means of wires, radio waves, or other means. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Developmental abnormalities involving structures of the heart. These defects are present at birth but may be discovered later in life.
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
A light microscopic technique in which only a small spot is illuminated and observed at a time. An image is constructed through point-by-point scanning of the field in this manner. Light sources may be conventional or laser, and fluorescence or transmitted observations are possible.
The section of the alimentary canal from the STOMACH to the ANAL CANAL. It includes the LARGE INTESTINE and SMALL INTESTINE.
The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.
Specialized junctions at which a neuron communicates with a target cell. At classical synapses, a neuron's presynaptic terminal releases a chemical transmitter stored in synaptic vesicles which diffuses across a narrow synaptic cleft and activates receptors on the postsynaptic membrane of the target cell. The target may be a dendrite, cell body, or axon of another neuron, or a specialized region of a muscle or secretory cell. Neurons may also communicate via direct electrical coupling with ELECTRICAL SYNAPSES. Several other non-synaptic chemical or electric signal transmitting processes occur via extracellular mediated interactions.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (= OXYGEN CONSUMPTION) or cell respiration (= CELL RESPIRATION).
A specialized CONNECTIVE TISSUE that is the main constituent of the SKELETON. The principle cellular component of bone is comprised of OSTEOBLASTS; OSTEOCYTES; and OSTEOCLASTS, while FIBRILLAR COLLAGENS and hydroxyapatite crystals form the BONE MATRIX.
New abnormal growth of tissue. Malignant neoplasms show a greater degree of anaplasia and have the properties of invasion and metastasis, compared to benign neoplasms.
The act or fact of grasping the meaning, nature, or importance of; understanding. (American Heritage Dictionary, 4th ed) Includes understanding by a patient or research subject of information disclosed orally or in writing.
The capacity to conceive or to induce conception. It may refer to either the male or female.
Any method of artificial breathing that employs mechanical or non-mechanical means to force the air into and out of the lungs. Artificial respiration or ventilation is used in individuals who have stopped breathing or have RESPIRATORY INSUFFICIENCY to increase their intake of oxygen (O2) and excretion of carbon dioxide (CO2).
The synthesis by organisms of organic chemical compounds, especially carbohydrates, from carbon dioxide using energy obtained from light rather than from the oxidation of chemical compounds. Photosynthesis comprises two separate processes: the light reactions and the dark reactions. In higher plants; GREEN ALGAE; and CYANOBACTERIA; NADPH and ATP formed by the light reactions drive the dark reactions which result in the fixation of carbon dioxide. (from Oxford Dictionary of Biochemistry and Molecular Biology, 2001)
Total mass of all the organisms of a given type and/or in a given area. (From Concise Dictionary of Biology, 1990) It includes the yield of vegetative mass produced from any given crop.
Refers to animals in the period of time just after birth.
The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.
The properties, processes, and behavior of biological systems under the action of mechanical forces.
Studies beyond the bachelor's degree at an institution having graduate programs for the purpose of preparing for entrance into a specific field, and obtaining a higher degree.
The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.
The procedures through which a group approaches, attacks, and solves a common problem.
The measure of the level of heat of a human or animal.
Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.
Books used in the study of a subject that contain a systematic presentation of the principles and vocabulary of a subject.
Levels within a diagnostic group which are established by various measurement criteria applied to the seriousness of a patient's disorder.
The physical activity of a human or an animal as a behavioral phenomenon.
The branch of science concerned with the means and consequences of transmission and generation of the components of biological inheritance. (Stedman, 26th ed)
Ventral part of the DIENCEPHALON extending from the region of the OPTIC CHIASM to the caudal border of the MAMMILLARY BODIES and forming the inferior and lateral walls of the THIRD VENTRICLE.
Peptides released by NEURONS as intercellular messengers. Many neuropeptides are also hormones released by non-neuronal cells.