8.3. The heart
A subsection of Biology, 9700, through 8. Transport in mammals
Listing 10 of 173 questions
shows how blood pressure changes in the human systemic circulation. blood pressure / kPa maximum blood pressure minimum blood pressure Distance from left ventricle Aorta Large arteries Small arteries Arterioles Venules Capillaries Small veins Large veins Vena cavae Describe the changes in blood pressure shown in . Explain how the structure of veins is related to their function in returning blood to the heart. Angiotensin is a polypeptide produced in the body to raise blood pressure. Angiotensin converting enzyme (ACE) catalyses the final step in angiotensin production. shows this step. 10 amino acid polypeptide: Asp-Arg-Val-Tyr-Ile-His-Pro-Phe-His-Leu Asp-Arg-Val-Tyr-Ile-His-Pro-Phe ACE His-Leu angiotensin: Describe the step shown in . People with high blood pressure can be treated with a drug which lowers the concentration of angiotensin in the blood. This drug is a competitive inhibitor of ACE. Explain how this drug acts as a competitive inhibitor.
9700_s15_qp_23
THEORY
2015
Paper 2, Variant 3
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shows four types of cell that can be seen in a prepared slide of blood taken from a mammal. Identify the four types of cell shown in . Write the name of the cell type on the answer line provided by each cell in . During systole and diastole of the cardiac cycle, changes in blood pressure occur in the four chambers of the heart. shows changes in the blood pressure in the left side of the heart and the aorta during one cardiac cycle. blood pressure / kPa time / s –2 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 With reference to the blood pressure changes shown in : • state the maximum blood pressure reached in the left ventricle kPa • state the time at which the bicuspid (left atrioventricular) valve closes. s Chronic obstructive pulmonary disease (COPD) can cause a condition known as pulmonary hypertension. This involves an increase in systolic blood pressure in the right ventricle and in the pulmonary arteries. is a summary of some of the events that can result from COPD. COPD chronic alveolar hypoxia blood vessels leading to gas exchange areas decrease in lumen diameter (pulmonary vasoconstriction) pulmonary hypertension loss of alveolar capillaries Chronic alveolar hypoxia describes a condition where the partial pressure of oxygen in the gas exchange regions of the lungs is always lower than normal. Explain how COPD leads to chronic alveolar hypoxia. Explain how the loss of alveolar capillaries affects the functioning of the lungs in a person with COPD.
9700_s21_qp_23
THEORY
2021
Paper 2, Variant 3
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Questions Discovered
173