Tuesday, November 8, 2016

ch. 11 | the cardiovascular system

overview of the cardiovascular system:

parts of the heart:
atrium: collect blood from circulation
ventricle: pump that delivers blood to the circulation
valves: keep the blood flowing the right direction through the heart
atrioventricular valves: tricuspid (right side) & bicuspid/mitral (left side)
semilunar valves: pulmonic (right side) & aortic (left side)
arteries: blood vessels that carry blood away from the heart
veins: blood vessels that convey blood from tissues back to the heart

  • arteries= red except at the heart
  • veins= blue except at the heart
layers of heart:

blood flow through heart:
  • sinoatrial (SA) node: starts a contraction impulse in the right atrium
  • resting heart rate: 70-75 beats per minute
  • tachycardia: heart rate that exceeds the normal resting rate
  • bradycardia: abnormally slow heart action
  • arrhythmia: an irregular heart rhythm
  • myocardial infarction: heart attack
  • atherosclerosis: inflammatory disease condition, fatty materials build up in the walls of blood vessels
  • systole: contraction phase of cardiac cycle 
  • diastole: relaxation phase of cardiac cycle
  • cardiac cycle lasts about 0.8 seconds
systemic blood vessels:
arteries --> arterioles --> capillaries --> venules --> veins
  • aorta is the largest artery of the body
structure of arteries & veins:
  • edema: accumulation of interstitial fluid; tissue swelling 
  • skeletal muscle pump: contractions of skeletal muscles squeeze veins & move blood along
  • respiratory pump: pressure changes in thoracic & abdominal cavities during breathing squeeze the abdominal veins & move blood through them
major veins:
coronary sinus: main vein of heart
superior vena cava: drains head/neck/chest/upper limbs
inferior vena cava: largest vein in body, drains abdomen/pelvis/lower limbs
great saphenous veins: longest veins in body 

  • pulmonary circulation:
-pulmonary trunk comes from right ventricle carrying deoxygenated blood
-pulmonary arteries are the only arteries that carry deoxygenated blood
-pulmonary veins are the only veins carry oxygenated blood (from lungs to left atrium)
  • heptic portal circulation: 
-liver receives blood from heptic portal vein which is an exception to the rule that venous blood returns directly to the heart 
-allows liver to process absorbed substances 

blood pressure: force exerted by blood against walls of blood vessels due to contraction of heart & influenced by elasticity of vessel walls; measured in "mm Hg"
-normal blood pressure: 
-hypertension: chronic high blood pressure

major arteries:

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