The heart is a myogenic muscular organ found in all animals with a circulatory system (including all vertebrates ), which pumps blood throughout the blood vessels by repeated, rhythmic contractions. The term cardiac (as in cardiology ) means related to the heart and comes from the Greek καρδιά, kardia , for heart . The vertebrate heart is principally composed of cardiac muscle and connective tissue . Cardiac muscle is an involuntary striated muscle tissue found only in this organ and responsible for the ability of the heart to pump blood. The average human heart , beating at 72 beats per minute, will beat approximately 2.5 billion times during an average 66 year lifespan. It weighs approximately 250 to 300g in females and 300 to 350g in males. In invertebrates that possess a circulatory system, the heart is typically a tube or small sac and pumps fluid that contains water and nutrients such as proteins , fats , and sugars . In insects , the heart is often called the dorsal tube and insect blood is almost always not oxygenated since they usually respirate (breathe) directly from their body surfaces (internal and external) to air. However, the hearts of some other arthropods (including spiders and crustaceans such as crabs and shrimp ) and some other animals pump hemolymph , which contains the copper -based protein hemocyanin as an oxygen transporter similar to the iron -based hemoglobin in red blood cells found in vertebrates .
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Online Doctor Chat (42) - Heart
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User : dear doc,the ecg report of my father 68 years old shows bifascicular block..is it serious and how can it be treated?
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User : is this condition...
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User : Hi Doc,I'm 36 year old year male operating out of xxx
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User : On 26th Sept,2010, my father has passed away due to a massive cardiac arrest.Post that we are...
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are yu back
User : yes i am
User :
but i am unable to see my earlier transcripts
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is she having any symptoms
User :
anyway, you can go ahead
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like breathlessness
User :
she is not having any...
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how can i help you
User : my fiance is 22 years old he was born with pulmonary atresia with VSD he's healty but woke up this morning with brown bruise like spots on his hands. Could this mean something is...
User : iam a 15 yr old boy , who has been getting severe pain in my chest , crushing stabbing pains near my heart , and also getting electricity feeling down my left arm very worried please help me ,
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Since when are you...
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Public Forum (234) - Heart
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hi..i start diabetic type 1 when i was 19yrs old now I m 40 and mother of three..so about last year i was told that i have osteoarthristis...then three month later i was told that i have fibromyalgia ....then last week i got heart muscular . waiting for letter about heart specailist. at the moment i still got vibration my foot , my leg.and my...
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Hi I have been taking Loette for 10 months. The previous last strip I started taking after 14 days lapsed (when it should be 7 days after the last pill ). After the 11th day, spotting started, on the 15th & 16th spotting, 20th spotting, 22nd spotting (no more taking loette), 23rd day, menstruation started for the rest 16 days (now). NOt very...
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If heart beat is 18 per min for an 55 year old man what will happen how to increase the heart beat of 55 year old man
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What does it mean when your heart is racing really fast that you have to go to the hospital? My granpa has a heart condotion for years but i just found out he has been in and out of the hospital for the past couple of days becasue his heart is racing really fast and hes hooked to all these machines. I Just wondering what is means? I dont want to...
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Will Clarithromyc 500 mg treat a UTI ?
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I recently got diagnosed with one and waiting for my echocardiogram results to come in. I want to know how people can get them, and what can make the murmur worse? I m really worried. I forgot a couple questions, Why is my doctor making me take penicillin/amoxcillin before I go to the dentist? How can my body develop infection just because I...
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yesterday my heart started to feel sharp pains , i thought it would pass but it has gotton worst and every body movement i take puts pressure on my heart im in pain. when i move my shoulders it hurts im scared. my heart feels heavy it beats so hard sometime i can feel it like itz goin to exsplode. please help me . juanita thanks
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ok im 17 and 86 pounds i faint a lot and i always feel light headed! I odnt kno what 2 do i eeat alot but im still skinny!
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what is a heart mumor?
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Where is your heart actually located?
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