Figure 5 shows the human heart - AQA - GCSE Biology Combined Science - Question 5 - 2021 - Paper 1

The blood vessel that transports blood at the highest pressure is the aorta (Option C). The aorta receives blood pumped directly from the left ventricle, which generates the highest blood pressure in the circulatory system.

The correct order for blood flowing through the heart to the lungs is: right atrium → right ventricle → pulmonary artery. This process carries deoxygenated blood from the heart to the lungs for oxygenation.

The use of statins and stents both aim to reduce the risk of heart attacks but do so through different mechanisms.

Statins:

• Advantages:

  • They are easy to take and not invasive.
  • They lower cholesterol levels and slow down the buildup of fatty materials in arteries.
  • They maintain blood flow to heart muscle cells and are relatively low cost.

• Disadvantages:

  • They can have side effects, such as muscle pain.
  • Their effects might take time to manifest, requiring ongoing commitment from the patient.

Stents:

• Advantages:

  • Stents hold arteries open to ensure blood flow is maintained.
  • They increase blood flow to heart muscle cells immediately.
  • The recovery from surgery is generally quick.

• Disadvantages:

  • There is a higher risk of infection and complications from the surgery itself.
  • Potential for thrombosis or blood clots afterwards.

In conclusion, while statins are more about preventive treatment, stents provide immediate physical support to arteries. The choice of treatment may depend on the individual patient's condition and risks.

Heart attack survivors often experience reduced strength in their heart muscle, which can impair their ability to pump blood effectively. Consequently, this results in less oxygen being circulated to the body, especially during physical activity.

As a result, survivors may find that their bodies require more effort to perform the same activities they used to manage easily, leading to a quicker onset of breathlessness. Additionally, the heart may have adapted to less efficient aerobic respiration, potentially relying more on anaerobic pathways, which can also contribute to feelings of breathlessness.

Stem cells are used to make the patches because they are undifferentiated cells, which means they have the potential to develop into different types of specialized cells. In this case, they can differentiate into heart muscle cells, which are needed to repair damaged heart tissue after a heart attack. The use of stem cells ensures that the patches can effectively replace the cells that have died, thus restoring the function of the affected heart areas.

1. No risk of rejection: Using stem cells from the person’s own cells reduces the likelihood of the immune system rejecting the cells, which can occur with foreign, embryonic stem cells.
2. Informed consent: The use of a patient’s own cells avoids ethical concerns associated with embryonic stem cells, as the patient can provide consent and there is no risk of destroying an embryo.