The Heart Flashcards
How many miles of blood vessel do you have in your body?
60,000
Artery
- transports blood away from the heart to arterioles
- has thick muscular walls because it is under high pressure
- elastic tissue
- diameter changes from blood flow create pulse
Arteriole
- transports blood away from artery to capillary
- thin walled
Vein
- returns blood to the heart
- has thin walls because it undergoes little or no pressure
- larger diameter than arteries
- have valves to assist in return of blood (assisted by skeletal muscles)
Venule
- carries blood from capillaries to veins and are thin walled
Capillary
- one cell thick
- site of exchange between blood and the bodies cells (ex: O2, CO2, wastes, nutrients)
Three pathways of blood flow
- cardiac
- systemic
- pulmonary
Sinoatrial node
acts as a pacemaker and sets the rhythm of the heart in beats per minute.
Cardiac output
= heart rate x stroke volume
= 70 beats/min x 70mL/beat
= 4900mL/min
Aorta
- largest artery in body
- carries oxygenated blood to the systemic pathway
Right atrium
- collects deoxygenated blood from the body via the vena cava veins
Left atrium
- collects oxygenated blood from the pulmonary vein
Right ventricle
- collects blood from the right atrium and pumps it into the pulmonary artery to the lungs
Left ventricle
- collects blood from the L atrium and pumps it into the aorta
- generates blood pressure
Superior vena cava
- vein which returns the blood from the anterior portion of the body to the right atrium
Inferior vena cava
- vein which returns blood from the posterior portion of the body to the R atrium
Pulmonary artery
- carries deoxygenated blood to the lungs from the heart
Pulmonary vein
- carries oxygenated blood from the lungs to the heart
Bicuspid (mitral/AV) valve
- controls flow of blood from the left atrium to the left ventricle and prevents back flow
Tricuspid (AV) valve
- controls flow of blood from right atrium to right ventricle and prevents back flow
Semilunar valves
- found where blood leaves the ventricles and prevents back flow.
Septum
- separates right and left ventricles.
What causes the “lub dub” sound in the heart
the “lub” is caused by the atrioventricular valves closing, and the “dub” is created by the semilunar valves to the pulmonary artery and aorta closing.
What blood vessel do you measure blood pressure from?
the artery
Sphygmomanometer
the blood pressure cuff
How is blood pressure measured and expressed?
- measured in mm of mercury
- expressed as a fraction (Ex: 120/80) where the numerator is the systolic pressure, and the denominator is the diastolic pressure
Systolic pressure
the maximum pressure generated when the ventricles contract and the atria relax and fill with blood. This phase is called systole
Diastolic pressure
the lowest pressure generated when the atria are contracting and the ventricles are relaxing and filling with blood. This phase is called diastole.
Atherosclerosis
a tear causes deposits of plaques of fatty material on the inner blood vessel walls resulting in a heart attack or stroke
Aneurism
enlargement of artery caused by weakness in arterial walls.
