The motor nerve of the diaphragm. The phrenic nerve fibers originate in the cervical spinal column (mostly C4) and travel through the cervical plexus to the diaphragm.
A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.
A state arrived at through prolonged and strong contraction of a muscle. Studies in athletes during prolonged submaximal exercise have shown that muscle fatigue increases in almost direct proportion to the rate of muscle glycogen depletion. Muscle fatigue in short-term maximal exercise is associated with oxygen lack and an increased level of blood and muscle lactic acid, and an accompanying increase in hydrogen-ion concentration in the exercised muscle.
Recording of the changes in electric potential of muscle by means of surface or needle electrodes.
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).
Highly differentiated epithelial cells of the visceral layer of BOWMAN CAPSULE of the KIDNEY. They are composed of a cell body with major CELL SURFACE EXTENSIONS and secondary fingerlike extensions called pedicels. They enwrap the KIDNEY GLOMERULUS capillaries with their cell surface extensions forming a filtration structure. The pedicels of neighboring podocytes interdigitate with each other leaving between them filtration slits that are bridged by an extracellular structure impermeable to large macromolecules called the slit diaphragm, and provide the last barrier to protein loss in the KIDNEY.
A vague complaint of debility, fatigue, or exhaustion attributable to weakness of various muscles. The weakness can be characterized as subacute or chronic, often progressive, and is a manifestation of many muscle and neuromuscular diseases. (From Wyngaarden et al., Cecil Textbook of Medicine, 19th ed, p2251)
Mice, Inbred mdx
A strain of mice arising from a spontaneous MUTATION (mdx) in inbred C57BL mice. This mutation is X chromosome-linked and produces viable homozygous animals that lack the muscle protein DYSTROPHIN, have high serum levels of muscle ENZYMES, and possess histological lesions similar to human MUSCULAR DYSTROPHY. The histological features, linkage, and map position of mdx make these mice a worthy animal model of DUCHENNE MUSCULAR DYSTROPHY.
Contractile tissue that produces movement in animals.
Muscle Fibers, Skeletal
Large, multinucleate single cells, either cylindrical or prismatic in shape, that form the basic unit of SKELETAL MUSCLE. They consist of MYOFIBRILS enclosed within and attached to the SARCOLEMMA. They are derived from the fusion of skeletal myoblasts (MYOBLASTS, SKELETAL) into a syncytium, followed by differentiation.
Lung Volume Measurements
The specialized postsynaptic region of a muscle cell. The motor endplate is immediately across the synaptic cleft from the presynaptic axon terminal. Among its anatomical specializations are junctional folds which harbor a high density of cholinergic receptors.
Myosin Heavy Chains
The larger subunits of MYOSINS. The heavy chains have a molecular weight of about 230 kDa and each heavy chain is usually associated with a dissimilar pair of MYOSIN LIGHT CHAINS. The heavy chains possess actin-binding and ATPase activity.
Total Lung Capacity
The volume of air contained in the lungs at the end of a maximal inspiration. It is the equivalent to each of the following sums: VITAL CAPACITY plus RESIDUAL VOLUME; INSPIRATORY CAPACITY plus FUNCTIONAL RESIDUAL CAPACITY; TIDAL VOLUME plus INSPIRATORY RESERVE VOLUME plus functional residual capacity; or tidal volume plus inspiratory reserve volume plus EXPIRATORY RESERVE VOLUME plus residual volume.
Work of Breathing
RESPIRATORY MUSCLE contraction during INHALATION. The work is accomplished in three phases: LUNG COMPLIANCE work, that required to expand the LUNGS against its elastic forces; tissue resistance work, that required to overcome the viscosity of the lung and chest wall structures; and AIRWAY RESISTANCE work, that required to overcome airway resistance during the movement of air into the lungs. Work of breathing does not refer to expiration, which is entirely a passive process caused by elastic recoil of the lung and chest cage. (Guyton, Textbook of Medical Physiology, 8th ed, p406)
Paired but separate cavity within the THORACIC CAVITY. It consists of the space between the parietal and visceral PLEURA and normally contains a capillary layer of serous fluid that lubricates the pleural surfaces.
Derangement in size and number of muscle fibers occurring with aging, reduction in blood supply, or following immobilization, prolonged weightlessness, malnutrition, and particularly in denervation.
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).
Functional Residual Capacity
The volume of air remaining in the LUNGS at the end of a normal, quiet expiration. It is the sum of the RESIDUAL VOLUME and the EXPIRATORY RESERVE VOLUME. Common abbreviation is FRC.
A cluster of convoluted capillaries beginning at each nephric tubule in the kidney and held together by connective tissue.
Compounds that contain the decamethylenebis(trimethyl)ammonium radical. These compounds frequently act as neuromuscular depolarizing agents.
The upper part of the trunk between the NECK and the ABDOMEN. It contains the chief organs of the circulatory and respiratory systems. (From Stedman, 25th ed)
Glomerular Filtration Barrier
A specialized barrier in the kidney, consisting of the fenestrated CAPILLARY ENDOTHELIUM; GLOMERULAR BASEMENT MEMBRANE; and glomerular epithelium (PODOCYTES). The barrier prevents the filtration of PLASMA PROTEINS.
A clinical manifestation of abnormal increase in the amount of carbon dioxide in arterial blood.
Muscular Dystrophy, Duchenne
An X-linked recessive muscle disease caused by an inability to synthesize DYSTROPHIN, which is involved with maintaining the integrity of the sarcolemma. Muscle fibers undergo a process that features degeneration and regeneration. Clinical manifestations include proximal weakness in the first few years of life, pseudohypertrophy, cardiomyopathy (see MYOCARDIAL DISEASES), and an increased incidence of impaired mentation. Becker muscular dystrophy is a closely related condition featuring a later onset of disease (usually adolescence) and a slowly progressive course. (Adams et al., Principles of Neurology, 6th ed, p1415)
Respiratory Physiological Phenomena
The posture of an individual lying face up.
A muscle protein localized in surface membranes which is the product of the Duchenne/Becker muscular dystrophy gene. Individuals with Duchenne muscular dystrophy usually lack dystrophin completely while those with Becker muscular dystrophy have dystrophin of an altered size. It shares features with other cytoskeletal proteins such as SPECTRIN and alpha-actinin but the precise function of dystrophin is not clear. One possible role might be to preserve the integrity and alignment of the plasma membrane to the myofibrils during muscle contraction and relaxation. MW 400 kDa.
The long cylindrical contractile organelles of STRIATED MUSCLE cells composed of ACTIN FILAMENTS; MYOSIN filaments; and other proteins organized in arrays of repeating units called SARCOMERES .
1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt
Tumors or cancer located in muscle tissue or specific muscles. They are differentiated from NEOPLASMS, MUSCLE TISSUE which are neoplasms composed of skeletal, cardiac, or smooth muscle tissue, such as MYOSARCOMA or LEIOMYOMA.
The posture of an individual lying face down.
Neuromuscular Depolarizing Agents
A potent inhibitor of the high affinity uptake system for CHOLINE. It has less effect on the low affinity uptake system. Since choline is one of the components of ACETYLCHOLINE, treatment with hemicholinium can deplete acetylcholine from cholinergic terminals. Hemicholinium 3 is commonly used as a research tool in animal and in vitro experiments.
Neuromuscular Nondepolarizing Agents
Drugs that interrupt transmission at the skeletal neuromuscular junction without causing depolarization of the motor end plate. They prevent acetylcholine from triggering muscle contraction and are used as muscle relaxants during electroshock treatments, in convulsive states, and as anesthesia adjuvants.
Enlargement of air spaces distal to the TERMINAL BRONCHIOLES where gas-exchange normally takes place. This is usually due to destruction of the alveolar wall. Pulmonary emphysema can be classified by the location and distribution of the lesions.
Techniques for effecting the transition of the respiratory-failure patient from mechanical ventilation to spontaneous ventilation, while meeting the criteria that tidal volume be above a given threshold (greater than 5 ml/kg), respiratory frequency be below a given count (less than 30 breaths/min), and oxygen partial pressure be above a given threshold (PaO2 greater than 50mm Hg). Weaning studies focus on finding methods to monitor and predict the outcome of mechanical ventilator weaning as well as finding ventilatory support techniques which will facilitate successful weaning. Present methods include intermittent mandatory ventilation, intermittent positive pressure ventilation, and mandatory minute volume ventilation.
Maximal Voluntary Ventilation
That portion of the body that lies between the THORAX and the PELVIS.
Advanced Practice Nursing
Interactive Ventilatory Support
Failure to adequately provide oxygen to cells of the body and to remove excess carbon dioxide from them. (Stedman, 25th ed)
Hernia, Diaphragmatic, Traumatic
The type of DIAPHRAGMATIC HERNIA caused by TRAUMA or injury, usually to the ABDOMEN.
Muscle Fibers, Slow-Twitch
Neurotoxic proteins from the venom of the banded or Formosan krait (Bungarus multicinctus, an elapid snake). alpha-Bungarotoxin blocks nicotinic acetylcholine receptors and has been used to isolate and study them; beta- and gamma-bungarotoxins act presynaptically causing acetylcholine release and depletion. Both alpha and beta forms have been characterized, the alpha being similar to the large, long or Type II neurotoxins from other elapid venoms.
A respiratory stimulant that enhances respiration by acting as an agonist of peripheral chemoreceptors located on the carotid bodies. The drug increases arterial oxygen tension while decreasing arterial carbon dioxide tension in patients with chronic obstructive pulmonary disease. It may also prove useful in the treatment of nocturnal oxygen desaturation without impairing the quality of sleep.
Vestibular Nucleus, Lateral
A giant elastic protein of molecular mass ranging from 2,993 kDa (cardiac), 3,300 kDa (psoas), to 3,700 kDa (soleus) having a kinase domain. The amino- terminal is involved in a Z line binding, and the carboxy-terminal region is bound to the myosin filament with an overlap between the counter-connectin filaments at the M line.
The muscles of the PHARYNX are voluntary muscles arranged in two layers. The external circular layer consists of three constrictors (superior, middle, and inferior). The internal longitudinal layer consists of the palatopharyngeus, the salpingopharyngeus, and the stylopharyngeus. During swallowing, the outer layer constricts the pharyngeal wall and the inner layer elevates pharynx and LARYNX.
A quaternary skeletal muscle relaxant usually used in the form of its bromide, chloride, or iodide. It is a depolarizing relaxant, acting in about 30 seconds and with a duration of effect averaging three to five minutes. Succinylcholine is used in surgical, anesthetic, and other procedures in which a brief period of muscle relaxation is called for.
Zonula Occludens-1 Protein
An autosomally-encoded 376-kDa cytoskeletal protein that is similar in structure and function to DYSTROPHIN. It is a ubiquitously-expressed protein that plays a role in anchoring the CYTOSKELETON to the PLASMA MEMBRANE.
A historical and cultural entity dispersed across a wide geographical area under the influence of Greek civilization, culture, and science. The Greek Empire extended from the Greek mainland and the Aegean islands from the 16th century B.C., to the Indus Valley in the 4th century under Alexander the Great, and to southern Italy and Sicily. Greek medicine began with Homeric and Aesculapian medicine and continued unbroken to Hippocrates (480-355 B.C.). The classic period of Greek medicine was 460-136 B.C. and the Graeco-Roman period, 156 B.C.-576 A.D. (From A. Castiglioni, A History of Medicine, 2d ed; from F. H. Garrison, An Introduction to the History of Medicine, 4th ed)
Direct contact of a cell with a neighboring cell. Most such junctions are too small to be resolved by light microscopy, but they can be visualized by conventional or freeze-fracture electron microscopy, both of which show that the interacting CELL MEMBRANE and often the underlying CYTOPLASM and the intervening EXTRACELLULAR SPACE are highly specialized in these regions. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p792)
The appearance of carbonyl groups (such as aldehyde or ketone groups) in PROTEINS as the result of several oxidative modification reactions. It is a standard marker for OXIDATIVE STRESS. Carbonylated proteins tend to be more hydrophobic and resistant to proteolysis.
A general term most often used to describe severe or complete loss of muscle strength due to motor system disease from the level of the cerebral cortex to the muscle fiber. This term may also occasionally refer to a loss of sensory function. (From Adams et al., Principles of Neurology, 6th ed, p45)
A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.
A muscular organ in the mouth that is covered with pink tissue called mucosa, tiny bumps called papillae, and thousands of taste buds. The tongue is anchored to the mouth and is vital for chewing, swallowing, and for speech.
A diverse superfamily of proteins that function as translocating proteins. They share the common characteristics of being able to bind ACTINS and hydrolyze MgATP. Myosins generally consist of heavy chains which are involved in locomotion, and light chains which are involved in regulation. Within the structure of myosin heavy chain are three domains: the head, the neck and the tail. The head region of the heavy chain contains the actin binding domain and MgATPase domain which provides energy for locomotion. The neck region is involved in binding the light-chains. The tail region provides the anchoring point that maintains the position of the heavy chain. The superfamily of myosins is organized into structural classes based upon the type and arrangement of the subunits they contain.
Pulmonary Disease, Chronic Obstructive
A disease of chronic diffuse irreversible airflow obstruction. Subcategories of COPD include CHRONIC BRONCHITIS and PULMONARY EMPHYSEMA.
Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.
Disease Models, Animal
Lung Diseases, Obstructive
Brachial Plexus Neuritis
A syndrome associated with inflammation of the BRACHIAL PLEXUS. Clinical features include severe pain in the shoulder region which may be accompanied by MUSCLE WEAKNESS and loss of sensation in the upper extremity. This condition may be associated with VIRUS DISEASES; IMMUNIZATION; SURGERY; heroin use (see HEROIN DEPENDENCE); and other conditions. The term brachial neuralgia generally refers to pain associated with brachial plexus injury. (From Adams et al., Principles of Neurology, 6th ed, pp1355-6)
A tubular organ of VOICE production. It is located in the anterior neck, superior to the TRACHEA and inferior to the tongue and HYOID BONE.
Neuromuscular Junction Diseases
Conditions characterized by impaired transmission of impulses at the NEUROMUSCULAR JUNCTION. This may result from disorders that affect receptor function, pre- or postsynaptic membrane function, or ACETYLCHOLINESTERASE activity. The majority of diseases in this category are associated with autoimmune, toxic, or inherited conditions.
The force per unit area that the air exerts on any surface in contact with it. Primarily used for articles pertaining to air pressure within a closed environment.
Esophageal Sphincter, Lower
The physiologic or functional barrier to GASTROESOPHAGEAL REFLUX at the esophagogastric junction. Sphincteric muscles remain tonically contracted during the resting state and form the high-pressure zone separating the lumen of the ESOPHAGUS from that of the STOMACH. (Haubrich et al, Bockus Gastroenterology, 5th ed., pp399, 415)
A long flat muscle that extends along the whole length of both sides of the abdomen. It flexes the vertebral column, particularly the lumbar portion; it also tenses the anterior abdominal wall and assists in compressing the abdominal contents. It is frequently the site of hematomas. In reconstructive surgery it is often used for the creation of myocutaneous flaps. (From Gray's Anatomy, 30th American ed, p491)
Mechanical devices used to produce or assist pulmonary ventilation.
Severe or complete loss of motor function in all four limbs which may result from BRAIN DISEASES; SPINAL CORD DISEASES; PERIPHERAL NERVOUS SYSTEM DISEASES; NEUROMUSCULAR DISEASES; or rarely MUSCULAR DISEASES. The locked-in syndrome is characterized by quadriplegia in combination with cranial muscle paralysis. Consciousness is spared and the only retained voluntary motor activity may be limited eye movements. This condition is usually caused by a lesion in the upper BRAIN STEM which injures the descending cortico-spinal and cortico-bulbar tracts.
Respiratory Function Tests
Cell surface proteins that bind acetylcholine with high affinity and trigger intracellular changes influencing the behavior of cells. Cholinergic receptors are divided into two major classes, muscarinic and nicotinic, based originally on their affinity for nicotine and muscarine. Each group is further subdivided based on pharmacology, location, mode of action, and/or molecular biology.
Muscle Fibers, Fast-Twitch
SKP Cullin F-Box Protein Ligases
The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)
Vaginal Creams, Foams, and Jellies
Medicated dosage forms for topical application in the vagina. A cream is a semisolid emulsion containing suspended or dissolved medication; a foam is a dispersion of a gas in a medicated liquid resulting in a light, frothy mass; a jelly is a colloidal semisolid mass of a water soluble medicated material, usually translucent.
Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.
A genus of the order Sirenia comprising what are commonly called manatees. The distinguishing characteristics include a tail that is not notched, a short nasal cavity, the absence of nasal bones, and enamel-covered teeth. Members of this genus are found in marine bays and/or sluggish rivers, usually in turbid water. (From Scott, Concise Encyclopedia Biology, 1996)
The lower portion of the BRAIN STEM. It is inferior to the PONS and anterior to the CEREBELLUM. Medulla oblongata serves as a relay station between the brain and the spinal cord, and contains centers for regulating respiratory, vasomotor, cardiac, and reflex activities.
Surgically placed electric conductors through which ELECTRIC STIMULATION is delivered to or electrical activity is recorded from a specific point inside the body.
Drugs that inhibit cholinesterases. The neurotransmitter ACETYLCHOLINE is rapidly hydrolyzed, and thereby inactivated, by cholinesterases. When cholinesterases are inhibited, the action of endogenously released acetylcholine at cholinergic synapses is potentiated. Cholinesterase inhibitors are widely used clinically for their potentiation of cholinergic inputs to the gastrointestinal tract and urinary bladder, the eye, and skeletal muscles; they are also used for their effects on the heart and the central nervous system.
A condition characterized by severe PROTEINURIA, greater than 3.5 g/day in an average adult. The substantial loss of protein in the urine results in complications such as HYPOPROTEINEMIA; generalized EDEMA; HYPERTENSION; and HYPERLIPIDEMIAS. Diseases associated with nephrotic syndrome generally cause chronic kidney dysfunction.
Tomography, X-Ray Computed
The act, process, or result of passing from one place or position to another. It differs from LOCOMOTION in that locomotion is restricted to the passing of the whole body from one place to another, while movement encompasses both locomotion but also a change of the position of the whole body or any of its parts. Movement may be used with reference to humans, vertebrate and invertebrate animals, and microorganisms. Differentiate also from MOTOR ACTIVITY, movement associated with behavior.
PUROMYCIN derivative that lacks the methoxyphenylalanyl group on the amine of the sugar ring. It is an antibiotic with antineoplastic properties and can cause nephrosis.
A glucocorticoid given, as the free alcohol or in esterified form, orally, intramuscularly, by local injection, by inhalation, or applied topically in the management of various disorders in which corticosteroids are indicated. (From Martindale, The Extra Pharmacopoeia, 30th ed, p739)
Physiologically, the opposition to flow of air caused by the forces of friction. As a part of pulmonary function testing, it is the ratio of driving pressure to the rate of air flow.
Plethysmography, Whole Body
Measurement of the volume of gas in the lungs, including that which is trapped in poorly communicating air spaces. It is of particular use in chronic obstructive pulmonary disease and emphysema. (Segen, Dictionary of Modern Medicine, 1992)
Rats, Inbred Strains
A local anesthetic of the ester type that has a slow onset and a short duration of action. It is mainly used for infiltration anesthesia, peripheral nerve block, and spinal block. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1016).
Receptor, Fibroblast Growth Factor, Type 5
Systemic inflammatory response syndrome with a proven or suspected infectious etiology. When sepsis is associated with organ dysfunction distant from the site of infection, it is called severe sepsis. When sepsis is accompanied by HYPOTENSION despite adequate fluid infusion, it is called SEPTIC SHOCK.
An enzyme that catalyzes the hydrolysis of ACETYLCHOLINE to CHOLINE and acetate. In the CNS, this enzyme plays a role in the function of peripheral neuromuscular junctions. EC 188.8.131.52.
A heterogeneous group of inherited MYOPATHIES, characterized by wasting and weakness of the SKELETAL MUSCLE. They are categorized by the sites of MUSCLE WEAKNESS; AGE OF ONSET; and INHERITANCE PATTERNS.
Descriptive anatomy based on three-dimensional imaging (IMAGING, THREE-DIMENSIONAL) of the body, organs, and structures using a series of computer multiplane sections, displayed by transverse, coronal, and sagittal analyses. It is essential to accurate interpretation by the radiologist of such techniques as ultrasonic diagnosis, MAGNETIC RESONANCE IMAGING, and computed tomography (TOMOGRAPHY, X-RAY COMPUTED). (From Lane & Sharfaei, Modern Sectional Anatomy, 1992, Preface)
The interruption or removal of any part of the vagus (10th cranial) nerve. Vagotomy may be performed for research or for therapeutic purposes.
Blood Gas Analysis
Measurement of oxygen and carbon dioxide in the blood.
A transient absence of spontaneous respiration.
The neck muscles consist of the platysma, splenius cervicis, sternocleidomastoid(eus), longus colli, the anterior, medius, and posterior scalenes, digastric(us), stylohyoid(eus), mylohyoid(eus), geniohyoid(eus), sternohyoid(eus), omohyoid(eus), sternothyroid(eus), and thyrohyoid(eus).
Evoked Potentials, Motor
The area covering the terminal portion of ESOPHAGUS and the beginning of STOMACH at the cardiac orifice.
The pectoralis major and pectoralis minor muscles that make up the upper and fore part of the chest in front of the AXILLA.
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.
Neuromuscular Blocking Agents
Drugs that interrupt transmission of nerve impulses at the skeletal neuromuscular junction. They can be of two types, competitive, stabilizing blockers (NEUROMUSCULAR NONDEPOLARIZING AGENTS) or noncompetitive, depolarizing agents (NEUROMUSCULAR DEPOLARIZING AGENTS). Both prevent acetylcholine from triggering the muscle contraction and they are used as anesthesia adjuvants, as relaxants during electroshock, in convulsive states, etc.
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 research and development of ELECTRICAL EQUIPMENT AND SUPPLIES for such medical applications as diagnosis, therapy, research, anesthesia control, cardiac control, and surgery. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)