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  • Systemic circulation
    The heart pumps oxygenated blood to the whole body. The aorta leaves the heart and divides into many smaller arteries that then form capillaries
    In the capillary beds in the different tissues oxygen is given up to the tissues and CO2 returns from the tissues to the blood.
    In the capillary beds nutrients are exchanged from the blood to the tissues. Cells can also send out hormones and chemical signals to the rest of the body through the blood.
    The blood leaves the capillaries via the venules which then join to form veins. The cava veins return to the heart.
  • Pulmonary circulation:
    The blood that returns to the heart via the veins is pumped out to the pulmonary artery which carries oxygen poor blood to the lungs. The pulmonary artery forms capillaries around the alveoli in the lungs and oxygen from the air enters the blood. CO2 from the blood goes out into the air in the lungs and is exhaled.
    From the capillary beds in the alveoli, the oxygenated blood returns to the heart via the pulmonary vein.
    From there oxygenated blood is pumped out to the body via the aorta.
  • THE CARDIAC CYCLE
    • Valves open and close as the heart goes through the
    cardiac cycle
    • Ventricles relaxed and filling (diastole)
    • Ventricles contracted and pumping (systole)
    • “Lub-dub” sounds heard with stethoscope
    • Lub – AV valves closing
    • Dub – closing of semilunar valves
  • • Heart contains “self-excitable” autorhythmic fibers
    • Most important is the sinoatrial (SA) node
    • Located in wall of right atrium
    • Acts as pacemaker
    • Autonomic nervous system can modulate rate
  • CARDIOVASCULAR DISEASES
    • Leading cause of death in the United States
    • Atherosclerosis
    • Accumulation of fatty material within arteries
    • Impedes blood flow
    • Arteriosclerosis
    • Arterial hardening due to calcium deposition
  • BLOOD FLOW AND BLOOD PRESSURE
    • Blood Pressure measured as systole/diastole
    • Systole – ventricle contraction
    • Diastole – ventricle relaxation
    • Increases with blood volume
    • Blood volume is regulated by four hormones:
    • Antidiuretic hormone (ADH)
    • Aldosterone – encourages kidney to excrete potassium
    and retain sodium
    • Atrial natriuretic hormone – increases sodium excretion
    and decreases blood pressure
    • Nitric oxide (NO) – vasodilator
  • Retaining sodium causes more water to be retained and blood pressure increases
    That is why people that have high blood pressure should NOT eat salt
  • Systemic circulation
    The heart pumps oxygenated blood to the whole body. The aorta leaves the heart and divides into many smaller arteries that then form capillaries
    In the capillary beds in the different tissues oxygen is given up to the tissues and CO2 returns from the tissues to the blood.
    In the capillary beds nutrients are exchanged from the blood to the tissues. Cells can also send out hormones and chemical signals to the rest of the body through the blood.
    The blood leaves the capillaries via the venules which then join to form veins. The cava veins return to the heart.
  • Pulmonary circulation:
    The blood that returns to the heart via the veins is pumped out to the pulmonary artery which carries oxygen poor blood to the lungs. The pulmonary artery forms capillaries around the alveoli in the lungs and oxygen from the air enters the blood. CO2 from the blood goes out into the air in the lungs and is exhaled.
    From the capillary beds in the alveoli, the oxygenated blood returns to the heart via the pulmonary vein.
    From there oxygenated blood is pumped out to the body via the aorta.
  • THE CARDIAC CYCLE
    • Valves open and close as the heart goes through the
    cardiac cycle
    • Ventricles relaxed and filling (diastole)
    • Ventricles contracted and pumping (systole)
    • “Lub-dub” sounds heard with stethoscope
    • Lub – AV valves closing
    • Dub – closing of semilunar valves
  • • Heart contains “self-excitable” autorhythmic fibers
    • Most important is the sinoatrial (SA) node
    • Located in wall of right atrium
    • Acts as pacemaker
    • Autonomic nervous system can modulate rate
  • CARDIOVASCULAR DISEASES
    • Leading cause of death in the United States
    • Atherosclerosis
    • Accumulation of fatty material within arteries
    • Impedes blood flow
    • Arteriosclerosis
    • Arterial hardening due to calcium deposition
  • BLOOD FLOW AND BLOOD PRESSURE
    • Blood Pressure measured as systole/diastole
    • Systole – ventricle contraction
    • Diastole – ventricle relaxation
    • Increases with blood volume
    • Blood volume is regulated by four hormones:
    • Antidiuretic hormone (ADH)
    • Aldosterone – encourages kidney to excrete potassium
    and retain sodium
    • Atrial natriuretic hormone – increases sodium excretion
    and decreases blood pressure
    • Nitric oxide (NO) – vasodilator
  • Retaining sodium causes more water to be retained and blood pressure increases
    That is why people that have high blood pressure should NOT eat salt