Heart - As an icon

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

Heart - Structure. In the human body, the heart is normally situated slightly to the left of the middle of the thorax, underneath the sternum (breastbone). It is enclosed by a sac known as the pericardium and is surrounded by the lungs. In normal adults, its mass is 250-350 g, but extremely diseased hearts can be up to 1000 g in mass. It consists of four chambers, the two upper atria (singular: atrium< ...

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 - 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 date pregnancy. The human heart begins beating at a rate near the mother’s, about 75-80 beats per minute (bpm). It then accelerates linearly for the first month of beating, peaking at 165-185 bpm during the early 7th week, (early 9th week after the LMP). This acceleration is approximately 3.3 bpm per day, or about 10 bpm every three days, an in ...

See also:

Heart, 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 II - Heart - The human heart

The heart of fish have only two chambers: one atrium and one ventricle. In fish, the system has only one circuit. The blood pumps through the gills and on to the the body tissues without returning to the heart. Amphibians and reptiles have a three-chambered heart: two atria and one ventricle. Blood from both the body and the lungs is pumped into the single ventricle, where unoxygenated and oxyge ...

See also:

Heart, 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 II - Heart - The hearts of other animals

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

See cardiac arrest for emergencies involving the heart If a person is encountered in cardiac arrest (no heartbeat), cardiopulmonary resuscitation (CPR) should be started, and help called. If an automated external defibrillator is available, this device may automatically administer defibrillation if this is indicated. ...

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

Heart - Heartbeat. Smaller animals have faster heartbeats. This is evident within a species as well, as the young beat their hearts faster than the adults. The Gray Whale's heart beats 9 times per minute, Harbour Seal 10 when diving, 140 when on land, elephant 25, human 70, sparrow 500, shrew 600, and hummingbird 1,200 when hovering. The earthworm has a series of multiple primitive hearts. Heart - Food use. The hearts of cattle, sheep, pigs and certain fowl are consumed ...

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 - The hearts of other animals