-
Heart
The heart is a muscular organ in most animals, which pumps blood through the blood vessels of the circulatory system. Blood provides the body with oxygen and nutrients, as well as assisting in the removal of metabolic wastes. In humans, the heart is located between the lungs, in the middle compartment of the chest.In humans, other mammals, and birds, the heart is divided into four chambers: upper left and right atria and lower left and right ventricles. Commonly the right atrium and ventricle are referred together as the right heart and their left counterparts as the left heart. Fish, in contrast, have two chambers, an atrium and a ventricle, while reptiles have three chambers. In a healthy heart blood flows one way through the heart due to heart valves, which prevent backflow. The heart is enclosed in a protective sac, the pericardium, which also contains a small amount of fluid. The wall of the heart is made up of three layers: epicardium, myocardium, and endocardium.The heart pumps blood with a rhythm determined by a group of pacemaking cells in the sinoatrial node. These generate a current that causes contraction of the heart, traveling through the atrioventricular node and along the conduction system of the heart. The heart receives blood low in oxygen from the systemic circulation, which enters the right atrium from the superior and inferior venae cavae and passes to the right ventricle. From here it is pumped into the pulmonary circulation, through the lungs where it receives oxygen and gives off carbon dioxide. Oxygenated blood then returns to the left atrium, passes through the left ventricle and is pumped out through the aorta to the systemic circulation−where the oxygen is used and metabolized to carbon dioxide. The heart beats at a resting rate close to 72 beats per minute. Exercise temporarily increases the rate, but lowers resting heart rate in the long term, and is good for heart health.Cardiovascular diseases (CVD) are the most common cause of death globally as of 2008, accounting for 30% of deaths. Of these more than three quarters are a result of coronary artery disease and stroke. Risk factors include: smoking, being overweight, little exercise, high cholesterol, high blood pressure, and poorly controlled diabetes, among others. Cardiovascular diseases frequently do not have symptoms or may cause chest pain or shortness of breath. Diagnosis of heart disease is often done by the taking of a medical history, listening to the heart-sounds with a stethoscope, ECG, and ultrasound. Specialists who focus on diseases of the heart are called cardiologists, although many specialties of medicine may be involved in treatment.
-
Hart (noun)
A male deer, especially the male of the red deer after his fifth year.
-
Hart (noun)
A red deer or one of related species.
-
Hart (noun)
obsolete spelling of heart
-
Heart (noun)
A muscular organ that pumps blood through the body, traditionally thought to be the seat of emotion.
-
Heart (noun)
Emotions, kindness, moral effort, or spirit in general.
“The team lost, but they showed a lot of heart.”
-
Heart (noun)
The seat of the affections or sensibilities, collectively or separately, as love, hate, joy, grief, courage, etc.; rarely, the seat of the understanding or will; usually in a good sense; personality.
“a good, tender, loving, bad, hard, or selfish heart”
-
Heart (noun)
Courage; courageous purpose; spirit.
-
Heart (noun)
Vigorous and efficient activity; power of fertile production; condition of the soil, whether good or bad.
-
Heart (noun)
A term of affectionate or kindly and familiar address.
“Listen, dear heart, we must go now.”
-
Heart (noun)
Personality, disposition.
“a cold heart”
-
Heart (noun)
A wight or being.
-
Heart (noun)
A conventional shape or symbol used to represent the heart, love, or emotion: ♥ or sometimes
-
Heart (noun)
A playing card of the suit hearts featuring one or more heart-shaped symbols.
-
Heart (noun)
The twenty-fourth Lenormand card.
-
Heart (noun)
The centre, essence, or core.
“The wood at the heart of a tree is the oldest.”
“Buddhists believe that suffering is right at the heart of all life.”
-
Heart (verb)
To be fond of. Often bracketed or abbreviated with a heart symbol.
-
Heart (verb)
To give heart to; to hearten; to encourage; to be devoted.
-
Heart (verb)
To fill an interior with rubble, as a wall or a breakwater.
-
Heart (verb)
To form a dense cluster of leaves, a heart, especially of lettuce or cabbage.
-
Hart (noun)
an adult male deer, especially a red deer over five years old.
-
Heart (noun)
a hollow muscular organ that pumps the blood through the circulatory system by rhythmic contraction and dilation. In vertebrates there may be up to four chambers (as in humans), with two atria and two ventricles.
-
Heart (noun)
the region of the chest above the heart
“holding hand on heart for the Pledge of Allegiance”
-
Heart (noun)
the heart regarded as the centre of a person’s thoughts and emotions, especially love or compassion
“he has no heart”
“he poured out his heart to me”
“hardening his heart, he ignored her entreaties”
-
Heart (noun)
one’s mood or feeling
“they had a change of heart”
“they found him well and in good heart”
-
Heart (noun)
courage or enthusiasm
“they may lose heart as the work mounts up”
“Mary took heart from the encouragement handed out”
-
Heart (noun)
the central or innermost part of something
“right in the heart of the city”
-
Heart (noun)
the vital part or essence
“the heart of the matter”
-
Heart (noun)
the close compact head of a cabbage or lettuce.
-
Heart (noun)
a conventional representation of a heart with two equal curves meeting at a point at the bottom and a cusp at the top.
-
Heart (noun)
one of the four suits in a conventional pack of playing cards, denoted by a red heart-shaped figure.
-
Heart (noun)
a card of the suit of hearts.
-
Heart (noun)
a card game similar to whist, in which players attempt to avoid taking tricks containing a card of the suit of hearts.
-
Heart (noun)
the condition of agricultural land as regards fertility
“a well-maintained farm in good heart”
-
Heart (verb)
like very much; love
“I totally heart this song”