Cardiovascular System 1

• Three types of Cardiovascular Blood Vessels:

  Arteries, Capillaries, Veins
• Carry blood away from the heart

  Arteries
• Where nutrient and gas exchange occur

  Capillaries
• Carry blood toward the heart

  Veins
• Largest artery

  Aorta
• The middle layer of an artery wall consist of what type of muscle?

  Smooth Muscle
• This can constrict or dilate, changing blood pressure

  Arterioles
• Drain blood from capillaries then join to form veins

  venules
• Prevent backward flow of blood when closed

  Valves
• cone-shaped muscular organ located between lungs behind sternum

  heart
• outer membranous sac with lubricating fluid

  pericardium
• four chambers of the heart:

  left atrium, right atrium, left ventricle, right ventricle
• between atria and ventricles

  atrioventricular valves
• valve on the right

  tricuspid valve
• valve on the left

  bicuspid valve
• blood follows this sequence through the heart

  superior and inferior vena cava, right atrium, tricuspid valve, pulmonary semilunar valve, pulmonary trunk and arteries, lungs, pulmonary veins leaving lungs, left atrium, bicuspid valve, left ventricle, aortic semilunar valve, aorta, body
• Each heartbeat is called a

  cardiac cycle
• contraction of heart chambers

  systole
• relaxation of heart chambers

  diastole
• heart sounds medically:

  lub-dup
• Initiates heartbeatcausing atria to contract

  sinoatrial node or pacemaker
• initiates contraction of ventricles

  atrioventricular node
• slows down heart rate


  parasympathetic
• increases heart rate

  sympathetic
• hormones from adrenal medulla, stimulates faster heart rate

  epinephrine and nonepinephrine
• recording of the electrical changes that occur in the myocardium during a cardiac cycle.

  electrocardiogram
• Circuit that circulates blood through lungs

  pulmonary circuit
• circuit that circulates blood to the rest of the body

  systematic circuit
• high when the heart expels the blood.

  systolic pressure
• occurs when the heart ventricles are relaxing.

  diastolic pressure