Cardiovascular

• How many chambers does the human heart have?

  4 chambers: 2 atria and 2 ventricles
• What does the tricuspid valve separate?

  It separates the right atrium (RA) and the right ventricle (RV)
• What does the bicuspid valve separate?

  It separates the left atrium (LA) and the left ventricle (LV)
• Name the two types of semilunar valves and their function.

  • Aortic valve: regulates blood flow from the left ventricle to the aorta
  • Pulmonary valve: regulates blood flow from the right ventricle to the pulmonary artery
• What is the function of the pulmonary artery?

  The pulmonary artery carries blood away from the heart to the lungs
• What is the function of the pulmonary vein?

  The pulmonary vein carries blood to the heart from the lungs
• Where does the aorta carry blood?

  The aorta carries oxygenated blood to the body
• What are the main components of blood?

  Erythrocytes (red blood cells), platelets, leucocytes (white blood cells), and plasma
• What is the primary function of red blood cells (RBCs)?

  RBCs carry oxygen $(O_2)$
• Describe the path of blood flow through the heart.

  1. Right atrium
  2. Tricuspid valve
  3. Right ventricle
  4. Pulmonary artery
  5. Lungs
  6. Pulmonary vein
  7. Left atrium
  8. Bicuspid valve
  9. Left ventricle

  10. Aorta

  11. Body circulation
• What percentage of blood is actively circulating and what percentage is in reservoirs?

  1% is actively circulating and 99% is in reservoirs
• How much blood enters the left ventricle (LV) at a time?

  $1000ml$
• How many contractions occur after $1000ml$ blood enters the LV?


  2 contractions occur
• Where is all the blood pumped at once from the heart?

  All blood is pumped into the aorta and the body
• How does heart muscle facilitate blood flow?

  Heart muscle contracts to pump blood
• Name the three types of heart valves.

  • Atria valves: regulate blood flow into the atria
  • Atrio-ventricular valves: regulate blood flow between the atria and ventricles
  • Semilunar valves: regulate blood flow from the ventricles to the aorta and pulmonary artery
• What is the Bundle of His?

  The Bundle of His is a part of the cardiac conduction system that transmits electrical impulses from the AV node to the ventricles
• List the components of the vasculature.

  • Head
  • Neck
  • Pharynx
  • Larynx
  • Trachea
  • Bronchi
  • Bronchioles
  • Alveoli
• What is tidal volume?

  Tidal volume is the normal volume of air inhaled and exhaled during a single breath
• How does tidal volume change during exercise?

  Tidal volume becomes deeper and faster in exercise
• What does inspiratory reserve volume (IRV) represent?

  IRV is the additional volume of air that can be inhaled after a normal tidal inhalation
• How does IRV change during exercise?

  IRV decreases in exercise as tidal volume increases
• What does expiratory reserve volume (ERV) represent?

  ERV is the additional volume of air that can be exhaled after a normal tidal exhalation
• What is vital capacity?

  Vital capacity is the maximum volume of air that can be breathed in and out
• Does vital capacity change during exercise?

  No, vital capacity does not change during exercise
• What is residual volume?

  Residual volume is the air left in the lungs after a maximum exhalation
• What are the two primary control mechanisms for breathing?

  Hormonal and neuronal controls
• How quickly is the message from chemoreceptors relayed to breathing muscles?

  The message is relayed quickly
• What do chemoreceptors detect in the control of breathing?

  They detect changes in O2 and CO2 concentrations
• Via which nerve does the medulla send messages to breathing muscles?

  The medulla sends messages via T nerve to breathing muscles
• Describe the neural reaction to exercise and the subsequent blood flow control mechanisms.

  • Exercise starts
  • Signals sent to brain via sensory neurones
  • Medulla processes information
  • Action potential sent to motor neurones
  • Action potential passes through neuromuscular junction
  • Acetylcholine released from neuron
  • Impulse reaches muscle fibre
  • Sarcoplasmic reticulum releases calcium
  • T tubules fire
  • Blood flow increases due to elevated $O_2$ levels in blood
  • Demand for $O_2$ in working tissue increases
  • Arterioles vasodilate, allowing blood flow to muscles
  • $O_2$ diffuses from haemoglobin to myofibrils
  • $CO_2$ diffuses into blood back to heart
  • Venous return via vena cava
• List the parts of the heart.

  • Pericardium: outer wall that surrounds the heart
  • Myocardium: heart muscle responsible for pumping blood
  • Coronary artery: artery inside the heart that supplies food and nutrients
  • Chambers: four chambers including left and right atria, and left and right ventricles
• How rapidly does blood flow in arteries?

  Blood flows rapidly in arteries
• What are the two main mechanisms for controlling blood flow?

  Vasodilation and vasoconstriction through smooth muscle
• How does blood flow speed compare in capillaries versus arteries?

  Blood flow gets slower in capillaries compared to arteries
• What are the two types of blood pressure?

  Systolic and diastolic blood pressure
• What does pulse rate measure?

  Pulse rate measures the number of heart beats per minute (bpm)
• What is the primary role of platelets in blood?

  Platelets carry proteins that help in blood clotting
• What is the normal platelet count in an adult?

  $150,000-400,000$ platelets per microliter
• Where are platelets produced?

  Platelets are produced in the bone marrow