Heart Study Questions –KEY

  1. Why does a diagram of the heart appear to have mixed up left and right sides?

It’s from the patient perspective; a mirror image.

  1. Label the structures on the heart diagram below and trace the path of blood flow through the heart.

  1. Label each of the following structures as being part of the right or left side of the heart?
  2. Vena Cavas- Right
  3. Left Ventricle- Left
  4. Right Atrium- Right
  5. Pulmonary Vein– Left (because brining oxygenated blood into the left atrium)
  6. Pulmonary Artery– Right (because taking deoxygenated blood from the right ventricle)
  7. Right Ventricle- Right
  8. Left Atrium- Left
  9. Mitral Valve- Left
  10. Pulmonary Valve- Right
  11. Aortic Valve- Left
  12. Tricuspid Valve-Right
  13. Aorta– Left

(The right side of the heart deals with deoxygenated blood (carrying CO2 instead) and the left side of the heart deals with oxygenated blood.

  1. How are the superior and inferior vena cavas similar? How are they different?

The both bring deoxygenated blood from the body back to the heart, emptying into the right atrium. The superior vena cava brings blood from the neck, head and brain back to the heart whereas the inferior vena cava brings blood from the trunk of the body and limbs back to the heart.

  1. What is the function of a valve? What four types of valves have we talked about and where are they located? Name and describe the AV and SV valves we have discussed in class.

To ensure blood always flows in the correct direction, preventing backflow.

  • Atrioventricular Valves (AV) - these valves are located between the atrium and the ventricle and prevents backward blood flow (ie, prevents blood from the ventricle from flowing back into the atrium)
  • Tricuspid - right side AV; between right atrium and right ventricle
  • Mitral Valve (Bicuspid) - left side AV; between left atrium and left ventricle
  • Semilunar Valves (SV) – these valves are located between ventricles and arteries to regulate blood flow and prevent backward blood flow (ie. Prevents blood from the arties from flowing back into the ventricles.)
  • Aortic Valve – controls proper blood flow and direction from the left ventricle to the aorta
  • Pulmonary Valve – controls proper blood flow and direction from the right ventricle to the pulmonary artery
  1. What is the apex of the heart?

The tip of the heart. It points left.

  1. What is the scientific name for the SA node and what is the function of the SA node?

Sinoatrial Node. It’s the pacemaker of the heart. It produces electrical current to regulate the heartbeat.

  1. What are the functions of the chordae tendinae and papillary muscles?

The chordae tendinae are strings that attach the papillary muscles to the valves. The contracting and relaxing of the papillary muscles control the opening and closing of the valves.

  1. Describe the main differences between arteries and veins.

Blood Vessel Types
Arteries / Veins
  • Carries oxygenated blood AWAY from the heart
  • Exception: Blood flowing through the pulmonary artery is deoxygenated.
  • Thick, elastic muscle layer that can handle high pressure as blood pulses through it
  • Red vessels
  • Aorta  Artery  Arteriole  Capillary
/
  • Carries deoxygenated blood TO the heart
  • Exception: Blood flowing through the pulmonary vein is oxygenated.
  • Thin, elastic muscle layer
  • Blue vessels (although the blood is NOT blue)
  • Vein Venule Capillary

  1. What are capillaries? What is the function of capillaries?

Capillaries are very tiny cells with membranes only one cell thick that gas exchange can easily occur across. This is important because oxygen and carbon dioxide are exchanged by diffusing across the capillary cell membrane to enter or exit the bloodstream.

  1. What is the difference between systemic and pulmonary circulation?

Systemic circulation is the blood flow between the body and the heart. It involves the travel of oxygenated blood from the heart to the body cells and then the travel of deoxygenated blood from the body back to the heart.

Pulmonary circulation is the blood flow between the heart and the lungs. Its purpose is to re-oxygenate the red blood cells. It involves deoxygenated blood flowing from the heart to the lungs where CO2 is given off and O2 is picked up and the flow of that blood back to the heart from the lungs.

  1. When does blood go from being oxygenated to deoxygenated?

At the body cell level because O2 is released into the cells and CO2 is picked up.

  1. When does blood go from being deoxygenated to oxygenated?

In the lungs where the capillaries are touching the alveoli. The blood gives off CO2 to be exhaled and picks up the O2that has been inhaled.

  1. What are alveoli?

The smallest unit in the lungs. Their membranes are only one cell thick so gas exchange between capillaries and alveoli is fast and efficient.

  1. Describe how the respiratory system and circulatory system work together to ensure the body gets the oxygen it needs.

The respiratory system is responsible for inhaling the oxygen and exhaling the carbon dioxide. The circulatory system is responsible for delivering the inhaled oxygen to the body cells and brining the carbon dioxide waste from the body cells back to the lungs to be exhaled. The circulatory system literally meets the respiratory system in the lungs where capillaries wrap around the alveoli. Both capillaries and alveoli have membranes that are one cell thick so that gas exchange is fast and efficient.

  1. What is the ductus arteriosus and why does a baby in utero need this duct, but not need it once he/she has been born?
  2. A growing fetus has a vessel, the ductus arteriosus, in the heart that connects the pulmonary artery with the aorta and conducts blood directly from the right ventricle to the aorta. Why do you think this vessel closes soon after birth?

The ductus arteriosus closes off after birth so that blood can flow properly through the heart. While in utero, a baby’s ductus arteriosus connects the pulmonary artery to the aorta so that blood is shunted from the developing lungs of the fetus. This way the baby can get oxygen form its mother through the placenta. After birth, the baby breathes in his/her own oxygen.

  1. Which chamber of the heart contracts the most forcefully? Why?

The left ventricle. It is surrounded by the thickest, strongest muscle so that it can contract with great force to power the circuit and pump the blood throughout the entire body.