The heart (Latin cor) is a hollow, muscular organ that pumps blood through the blood vessels by repeated, rhythmic contractions. The term cardiac means "related to the heart", from the Greek kardia (καρδια) for "heart". Heart - The human heart. Heart - Early development. The human embryonic heart (EHR) begins beating at approximately 21 days after conception, or five weeks after the last normal menstrual period (LMP), which is the date normally used to ...

Including:

• Heart - The human heart
• Heart - Early development
• Heart - Structure
• Heart - The cardiac cycle
• Heart - Regulation of the cardiac cycle
• Heart - Other physiological functions
• Heart - Diseases and treatments
• Heart - First aid
• Heart - The hearts of other animals
• Heart - Heartbeat
• Heart - Food use
• Heart - As an icon

Read more here: » Heart: Encyclopedia - Heart

See also:

Heart, Heart - The human heart, Heart - Structure, Heart - The cardiac cycle, Heart - Regulation of the cardiac cycle, Heart - Other physiological functions, Heart - Diseases and treatments, Heart - First aid, Heart - The hearts of other animals, Heart - Heartbeat, Heart - Food use, Heart - As an icon

Read more here: » Heart: Encyclopedia II - Heart - First aid

The study of diseases of the heart is known as cardiology. Important diseases of the heart include: Coronary heart disease is the lack of oxygen supply to the heart muscle; it can cause severe pain and discomfort known as Angina. A heart attack occurs when heart muscle cells die because blood circulation to a part of the heart is interrupted. Congestive heart failure is the gradual loss of pumping power of the heart. Endocarditis and myocarditis are inflammations of the heart. Cardiac arrhythmia is an irregularity in the heartbeat. It is sometimes treated by implanting an artificial pa ...

See also:

Heart, Heart - The human heart, Heart - Structure, Heart - The cardiac cycle, Heart - Regulation of the cardiac cycle, Heart - Other physiological functions, Heart - Diseases and treatments, Heart - First aid, Heart - The hearts of other animals, Heart - Heartbeat, Heart - Food use, Heart - As an icon

Read more here: » Heart: Encyclopedia II - Heart - Diseases and treatments

Cardiac cycle is the term used to describe the sequence of events that occur as a heart works to pump blood through the body. Every single 'beat' of the heart involves three major stages: atrial systole, ventricular systole and complete cardiac diastole. The term systole is synonymous with contraction of a muscle. Electrical systole is the electrical activity that stimulates the myocardium of the chambers of the heart to make them contract. This is soon followed by Mechanical systole, which is the mechanical contraction of the heart. The term dia ...

Including:

• Cardiac cycle - Atrial systole
• Cardiac cycle - Detection of atrial systole
• Cardiac cycle - Ventricular systole
• Cardiac cycle - Detection of ventricular systole
• Cardiac cycle - Complete cardiac diastole
• Cardiac cycle - Regulation of the cardiac cycle
• Cardiac cycle - Physiological mechanism of systole

Read more here: » Cardiac cycle: Encyclopedia - Cardiac cycle

Cardiac output is the volume of blood being pumped by the heart in a minute. It is equal to the heart rate multiplied by the stroke volume. So if there are 70 beats per minute, and 70 ml blood is ejected with each beat of the heart, the cardiac output is 4900 ml/minute. This value is typical for an average adult at rest, although cardiac output may reach up to 30 liters/minute during extreme exercise. When cardiac output increases in a healthy but untrained individual, most of the increase can be attributed to increase i ...

Including:

• Cardiac output - Measuring Cardiac Output
• Cardiac output - The Fick principle
• Cardiac output - Dilution methods
• Cardiac output - Doppler method
• Cardiac output - Impedance plethysmography
• Cardiac output - Equations

Read more here: » Cardiac output: Encyclopedia - Cardiac output

Blood pressure is the pressure exerted by the blood on the walls of the blood vessels. Unless indicated otherwise, blood pressure is understood to mean arterial blood pressure, i.e., the pressure in the large arteries, such as the brachial artery (in the arm). The pressure of the blood in other vessels is lower than the arterial pressure. The peak pressure in the arteries during the cardiac cycle is the systolic pressure, and the lowest pressure (at the resting phase of the cardiac cycle) is the diastolic pressure ...

Including:

• Blood pressure - Measurement
• Blood pressure - Physiology
• Blood pressure - Pathophysiology
• Blood pressure - Effects of high blood pressure
• Blood pressure - Effects of low blood pressure
• Blood pressure - Factors influencing blood pressure
• Blood pressure - Other causes of low blood pressure
• Blood pressure - Venous pressure
• Blood pressure - Related topics

Read more here: » Blood pressure: Encyclopedia - Blood pressure

Arteries are muscular vessels that carry blood away from the heart to the tissues and organs of the body (The vessels which return blood to the heart are veins). The circulatory system is extremely important in sustaining life. Its proper functioning is responsible for the delivery of oxygen and nutrients to all cells, as well as the removal of carbon dioxide, waste products, maintenance of optimum pH, and the mobility of the elements, proteins and cells, of the immune system. In First World countries the two leading causes of ...

Including:

• Artery - Description
• Artery - Anatomy
• Artery - Types of arteries:
• Artery - Pulmonary arteries
• Artery - Systemic arteries
• Artery - The Aorta
• Artery - Arterioles
• Artery - Arterioles and blood pressure
• Artery - Capillaries
• Artery - Blood pressure
• Artery - See Also

Read more here: » Artery: Encyclopedia - Artery

Muscle is a contractile form of tissue. It is one of the four major tissue types, the other three being epithelium, connective tissue and nervous tissue. Muscle contraction is used to move parts of the body, as well as to move substances within the body. Muscle - Types. There are three general types of muscle: Cardiac muscle is a specialized kind of muscle found only within the heart. It cannot get tired and is "involuntary". Skeletal muscle or "voluntary muscle" is anchored by tendons ...

Including:

• Muscle - Types
• Muscle - Anatomy
• Muscle - Physiology
• Muscle - Nervous control
• Muscle - Efferent leg
• Muscle - Afferent leg
• Muscle - Role in health and disease
• Muscle - Exercise
• Muscle - Disease
• Muscle - The strongest human muscle
• Muscle - Efficiency
• Muscle - Muscle evolution

Read more here: » Muscle: Encyclopedia - Muscle

The word exercise can mean the following: An activity that is done with a specific motive to improve some component of physical fitness. A setting in action or practicing. Any activity designed to develop or hone a skill or ability. Physical exercise Exercise - Physical exercise. Physical exercise is the performance of some activity in order to develop or maintain physical fitness and overall health. Frequent and regular physical exercise is an important ...

Including:

• Exercise - Physical exercise
• Exercise - Exercise benefits
• Exercise - Common myths
• Exercise - Spot reduction
• Exercise - Only overweight people need a physical before beginning an exercise program.
• Exercise - Muscle tissue will turn into fat once a person stops exercising.
• Exercise - Abdominal exercises will remove fat in my midsection.
• Exercise - It takes hundreds of crunches to get ab muscles in shape.
• Exercise - You have to train your abs everyday if you want a six pack.
• Exercise - Men and women should train their abs differently.
• Exercise - If I stop training my abs they’ll turn to fat.
• Exercise - Too much exercise
• Exercise - List of activities used as physical exercises
• Exercise - List of classes of physical exercise
• Exercise - Breathing

Read more here: » Exercise: Encyclopedia - Exercise

Caffeine, or theine, is a xanthine alkaloid found in the leaves and beans of the coffee tree, in tea, yerba mate, guarana berries, and in small quantities in cocoa, the kola nut and the Yaupon holly. In plants, caffeine acts as a natural pesticide that paralyzes and kills many insects feeding upon them. Caffeine is a central nervous system (CNS) stimulant, having the effect of warding off drowsiness and restoring alertness. Caffeine-containing beverages, such as coffee and tea, enjoy great popularity, making caffeine the ...

Including:

• Caffeine - Sources of caffeine
• Caffeine - Caffeine equivalents
• Caffeine - History of caffeine use
• Caffeine - Effects of caffeine
• Caffeine - Caffeine metabolism
• Caffeine - Mechanism of Action
• Caffeine - Side effects of caffeine
• Caffeine - Withdrawal
• Caffeine - The dangers of caffeine pills
• Caffeine - Extraction of pure caffeine

Read more here: » Caffeine: Encyclopedia - Caffeine

Anabolic steroids are a class of natural and synthetic steroid hormones that promote cell growth and division, resulting in growth of muscle tissue and sometimes bone size and strength. Steroids act in different ways on the body to promote muscle growth, and every steroid has androgenic and anabolic properties. It is because of this, they are properly referred to in medical texts as AAS (anabolic/androgenic steroids).Testosterone is the best known natural anabolic steroid, as well as the best known natural androgen. ...

Including:

• Anabolic steroid - Effects
• Anabolic steroid - Medical uses
• Anabolic steroid - Use and abuse in athletics and bodybuilding
• Anabolic steroid - Minimizing the side-effects
• Anabolic steroid - History
• Anabolic steroid - List of Anabolic Compounds Commonly used as Ergogenic Aids

Read more here: » Anabolic steroid: Encyclopedia - Anabolic steroid

An action potential is a wave of electrical discharge that travels along the membrane of a cell. Action potentials are used by the body to communicate fast internal messages between its tissues making them an essential feature of animal life at the microscopic level. They can be created by many types of body cells, but are used most extensively by the nervous system to send messages between nerve cells and from nerve ...

Including:

• Action potential - Overview
• Action potential - Underlying mechanism
• Action potential - Resting membrane potential
• Action potential - Action potential phases
• Action potential - Threshold and initiation
• Action potential - Circuit model
• Action potential - Propagation
• Action potential - Speed of propagation
• Action potential - Saltatory conduction
• Action potential - Refractory period
• Action potential - Why an action potential?

Read more here: » Action potential: Encyclopedia - Action potential

The lung is the essential organ of respiration in air-breathing vertebrates. Its principal function is to transport oxygen from the atmosphere into the bloodstream, and excrete carbon dioxide from the bloodstream into the atmosphere. This it accomplishes with its mosaic of specialized cells that form millions of tiny, exceptionally thin-walled air sacs where gas exchange takes place. Lungs also have nonrespiratory functions. Medical terms related to the lung often begin with pulmo-, from the Latin pulmonarius ("of the lungs"), cogn ...

Including:

• Lung - The respiratory function of the lung
• Lung - Nonrespiratory functions of the lung
• Lung - Mammalian lungs
• Lung - Anatomy
• Lung - Avian lungs
• Lung - Reptilian lungs
• Lung - Amphibian lungs
• Lung - Arachnid lungs
• Lung - Crustacean lungs
• Lung - Origins

Read more here: » Lung: Encyclopedia - Lung

In Hinduism and its spiritual systems of yoga and in some related eastern cultures, as well as in some segments of the New Age movement -- and to some degree the distinctly different New Thought movement -- a chakra is thought to be an energy node in the human body. The word comes from the Sanskrit cakra चक्र meaning "wheel, circle", and sometimes also referring to the "wheel of life". The pronunciation of this word can be approximated ...

Including:

• Chakra - Introduction
• Chakra - The Seven Basic Chakras
• Chakra - Origins and Development
• Chakra - Chakras and the endocrine system
• Chakra - Various models
• Chakra - The Tantric Chakras
• Chakra - Hesychastic centres of prayer
• Chakra - Scientific basis
• Chakra - References in Fiction
• Chakra - Reference Material and Books

Read more here: » Chakra: Encyclopedia - Chakra

Asthma is a disease of the human respiratory system in which the airways narrow, often in response to a “trigger” such as exposure to an allergen, cold air, exercise, or emotional stress. This narrowing causes symptoms such as wheezing, shortness of breath, chest tightness, and coughing, which are the hallmarks of asthma. Between episodes, most patients feel fine. The disorder is a chronic inflammatory condition in which the airways develop increased responsiveness to various stimuli, characterized by bronchial hyper-respon ...

Including:

• Asthma - History
• Asthma - Signs and symptoms
• Asthma - Diagnosis
• Asthma - Differential diagnosis
• Asthma - Pathophysiology
• Asthma - Bronchoconstriction
• Asthma - Bronchial inflammation
• Asthma - The immune response
• Asthma - Pathogenesis
• Asthma - Treatment
• Asthma - Relief medication
• Asthma - Prevention medication
• Asthma - Long-acting β2-agonists
• Asthma - Emergency treatment
• Asthma - Alternative medicine
• Asthma - Prognosis
• Asthma - Epidemiology
• Asthma - US Socioeconomic Factors
• Asthma - Asthma and athletics

Read more here: » Asthma: Encyclopedia - Asthma

Acute respiratory distress syndrome (ARDS), also known as respiratory distress syndrome (RDS) or adult respiratory distress syndrome (in contrast with IRDS) is a serious reaction to various forms of injuries to the lung. This is the most important disorder resulting in increased permeability pulmonary edema. ARDS is a severe lung disease caused by a variety of direct and indirect insults. It is characterized by inflammation of the lung parenchyma leading to impaired gas exchange with concommitant sys ...

Including:

• Acute respiratory distress syndrome - Definition
• Acute respiratory distress syndrome - Historical background
• Acute respiratory distress syndrome - Consensus after 1967 and 1994
• Acute respiratory distress syndrome - Patient presentation and diagnosis
• Acute respiratory distress syndrome - Pathophysiology
• Acute respiratory distress syndrome - Inflammation
• Acute respiratory distress syndrome - Mechanical stress
• Acute respiratory distress syndrome - Progression
• Acute respiratory distress syndrome - Treatment
• Acute respiratory distress syndrome - General
• Acute respiratory distress syndrome - Mechanical ventilation
• Acute respiratory distress syndrome - Positive end-expiratory pressure
• Acute respiratory distress syndrome - Prone position
• Acute respiratory distress syndrome - Fluid management
• Acute respiratory distress syndrome - Corticosteroids
• Acute respiratory distress syndrome - Nitric oxide
• Acute respiratory distress syndrome - Surfactant therapy
• Acute respiratory distress syndrome - Complications
• Acute respiratory distress syndrome - Epidemiology

Read more here: » Acute respiratory distress syndrome: Encyclopedia - Acute respiratory distress syndrome

Traumatic brain injury (TBI), traumatic injuries to the brain, also called acquired brain injury, intracranial injury, or simply head injury, occurs when a sudden trauma causes damage to the brain. Parts of the brain that can be damaged include the cerebral hemispheres, cerebellum, and brain stem (see brain damage). Symptoms of a TBI can be mild, moderate, or severe, depending on the extent of the damage to the brain. Outcome can be anything from complete recovery to permanent disability or death. Traumatic brain injury ...

Including:

• Traumatic brain injury - Epidemiology
• Traumatic brain injury - Signs and Symptoms of TBI
• Traumatic brain injury - Causes of and Risk Factors for TBI
• Traumatic brain injury - Types of TBI
• Traumatic brain injury - Effects on consciousness
• Traumatic brain injury - Complications
• Traumatic brain injury - General Trauma
• Traumatic brain injury - Disabilities Resulting From TBI
• Traumatic brain injury - Other Long-Term Problems Associated With TBI
• Traumatic brain injury - Treatment
• Traumatic brain injury - Rehabilitation
• Traumatic brain injury - Prevention
• Traumatic brain injury - Famous persons with TBI

Read more here: » Traumatic brain injury: Encyclopedia - Traumatic brain injury

See also: 1998 in music, 1999 in British music, other events of 1999, 2000 in music, 1990s in music and the list of 'years in music' 1999 in music - Events. January 7 After eight years of marriage, Rod Stewart and supermodel wife Rachel Hunter announce their separation. Paul McCartney attends the premiere of his step-daughter Heather's first housewares collection in Georgia. January 11 - During the American Music Awards, Billy Joel is awarded the Special Award of ...

Including:

• 1999 in music - Events
• 1999 in music - Albums released
• 1999 in music - Top hits
• 1999 in music - Top 10 selling albums of the year
• 1999 in music - Classical music
• 1999 in music - Opera
• 1999 in music - Musical theater
• 1999 in music - Births
• 1999 in music - Deaths
• 1999 in music - Awards
• 1999 in music - Grammy Awards
• 1999 in music - Country Music Association Awards
• 1999 in music - Eurovision Song Contest
• 1999 in music - Mercury Music Prize
• 1999 in music - Charts
• 1999 in music - KROQ
• 1999 in music - Triple J Hottest 100

Read more here: » 1999 in music: Encyclopedia - 1999 in music

Chronic fatigue syndrome (CFS), also known as myalgic encephalomyelitis (ME), post-viral fatigue syndrome (PVFS) and various other names, is a syndrome of unknown and possibly multiple etiology, affecting the central nervous system (CNS), immune, and many other systems and organs. Most definitions other than the 1991 UK "Oxford", require a number of features, the most common being severe mental and physical depletion, which according to the 1994 Fukuda definition is "unrelieved by rest", and is usually made worse by even trivial exertion (controver ...

Including:

• Chronic fatigue syndrome - History
• Chronic fatigue syndrome - Nomenclature
• Chronic fatigue syndrome - Symptoms
• Chronic fatigue syndrome - Course
• Chronic fatigue syndrome - Onset
• Chronic fatigue syndrome - Activity levels
• Chronic fatigue syndrome - Post-exertion symptom exacerbation
• Chronic fatigue syndrome - Duration
• Chronic fatigue syndrome - Diagnosis
• Chronic fatigue syndrome - CDC 1994 criteria aka Fukuda
• Chronic fatigue syndrome - Other systems
• Chronic fatigue syndrome - Controversies
• Chronic fatigue syndrome - Epidemiology
• Chronic fatigue syndrome - Disease associations
• Chronic fatigue syndrome - Co-morbidity
• Chronic fatigue syndrome - Proposed etiologies and corresponding treatments
• Chronic fatigue syndrome - Allergies
• Chronic fatigue syndrome - Autonomic nervous system disruption
• Chronic fatigue syndrome - Damage to ascending reticular activating system
• Chronic fatigue syndrome - Depression
• Chronic fatigue syndrome - Hormonal dysfunction
• Chronic fatigue syndrome - Immune dysfunction
• Chronic fatigue syndrome - Infectious agents
• Chronic fatigue syndrome - Inner-ear disorders
• Chronic fatigue syndrome - Metabolic disorders
• Chronic fatigue syndrome - Nutritional deficiency or imbalance
• Chronic fatigue syndrome - Psychosomatic causes
• Chronic fatigue syndrome - Spinal problems
• Chronic fatigue syndrome - Toxic agents
• Chronic fatigue syndrome - Other treatments
• Chronic fatigue syndrome - Social issues
• Chronic fatigue syndrome - Notable sufferers

Read more here: » Chronic fatigue syndrome: Encyclopedia - Chronic fatigue syndrome

Cardiac muscle is myogenic, which means that it is self-exciting. This is in contrast with skeletal muscle, which requires either conscious or reflex nervous stimuli. The heart's rhythmic contractions occur spontaneously, although the frequency or heart rate can be changed by nervous or hormonal influences such as exercise or the perception of danger. For example, the phrenic nerve accelerates heart rate and the vagus nerve decelerates heart rate. The rhythmic sequence of contractions is coordinated by the sinoatrial and ...

See also:

Cardiac cycle, Cardiac cycle - Atrial systole, Cardiac cycle - Detection of atrial systole, Cardiac cycle - Ventricular systole, Cardiac cycle - Detection of ventricular systole, Cardiac cycle - Complete cardiac diastole, Cardiac cycle - Regulation of the cardiac cycle, Cardiac cycle - Physiological mechanism of systole

Read more here: » Cardiac cycle: Encyclopedia II - Cardiac cycle - Regulation of the cardiac cycle