Circulation

• What is the main purpose of the circulatory system?

  To provide oxygen and nutrients to cells and remove waste products
• What are the main components of the circulatory system?

  • Heart
  • Blood vessels
• How many chambers does the heart have?

  Four chambers
• What are the two sides of the heart responsible for?

  The left side pumps oxygenated blood, and the right side pumps deoxygenated blood
• What color are arteries and veins typically represented by?

  Arteries are red, and veins are blue
• What is the function of capillaries?

  To enable the exchange of water, nutrients, and essential chemicals between blood and tissues
• What provides oxygen for the fetus in utero?

  The mother's placenta
• What are the three fetal shunts present in utero?

  Patent ductus arteriosus (PDA), foramen ovale, and ductus venosus
• How is heart rate controlled?

  By an electrical stimulus from specialized cells in the heart
• What does depolarization in heart cells cause?

  Contraction of the heart
• What does the P wave represent in an ECG?

  Atrial depolarization and contraction
• What does the QRS complex represent in an ECG?

  Ventricular depolarization and contraction
• What does the T wave represent in an ECG?

  Relaxation of the ventricles and repolarization
• What is the normal rhythm of the heart called?

  Sinus rhythm
• What controls heart rate in children and adults?

  The sinoatrial (SA) node and the autonomic nervous system
• What is the normal heart rate for a newborn?

  110 – 160 bpm
• What is the normal heart rate for a 3-year-old?

  95 – 140 bpm
• What is the normal heart rate for a 12-year-old?

  60 – 100 bpm
• What are the main pulses in the body?

  • Radial
  • Brachial
  • Carotid
  • Femoral
  • Dorsalis pedis (pedal)
  • Popliteal
  • Posterior tibial
• How should heart rate be recorded in older children and adults?

  By feeling for a pulse and counting over a full minute
• How should heart rate be recorded for babies and younger children?

  By listening with a stethoscope over the apex of the heart
• What is cardiac output?

  The amount of blood ejected by the heart in 1 minute
• What is the formula for cardiac output?

  Cardiac output = stroke volume x heart rate
• What is stroke volume?

  The amount of blood ejected from the heart on each contraction
• What is blood pressure?

  The pressure of circulating blood on the walls of blood vessels
• How is blood pressure expressed?

  As systolic pressure/diastolic pressure
• What is the normal blood pressure for a 1-month-old?

  80/35
• What is the normal blood pressure for a 6-year-old?

  100/55
• What is the normal blood pressure for a 15-year-old or over?

  120/60
• What is the role of baroreceptors in blood pressure regulation?

  • Located in the arch of the aorta and carotid sinus
  • Send signals to the medulla oblongata when BP increases
  • Cause heart rate to decrease and vasodilation
  • Stimulated when BP drops, causing increased heart rate and vasoconstriction
• What is the function of antidiuretic hormone (ADH) in blood pressure regulation?

  It reduces diuresis and increases circulating volume and BP
• How does the hypothalamus affect blood pressure?

  It responds to emotion and stimulates the sympathetic system
• What is the renin-angiotensinogen system?

  • A group of related hormones
  • Acts together to affect blood pressure
  • Works with the kidneys for long-term BP regulation
• What is capillary refill time used to assess?

  Perfusion
• How is capillary refill time measured?

  By pressing on a finger bed or chest for 5 seconds and counting the time to return to original color
• What is the normal capillary refill time?

  Less than 2 seconds
• What does prolonged capillary refill time indicate?

  Reduced blood flow (perfusion) to that area
• How does dehydration affect skin temperature?

  It can make the skin feel cooler due to reduced blood flow to the arms and legs
• What should be assessed regarding skin temperature during circulatory assessment?

  Skin should feel warm to touch and similar peripherally and centrally
• What should be done if there are concerns about a patient's skin temperature?

  Check with the family if this is normal and ensure the environment remains warm