Integrated Control Of CVS

The cardiac output is calculated by multiplying the heart rate by the stroke volume. In this case, the heart rate has increased from 70 to 150 beats per minute, while the stroke volume has decreased from 80 to 40 ml per beat. Therefore, the cardiac output would be 150 beats per minute multiplied by 40 ml per beat, which equals 6.0 L/min.

Based on the given information, the patient has a heavily calcified coronary artery with a calculated diameter of half the normal size. This suggests that the patient may have coronary artery disease (CAD), which can lead to decreased blood flow to the heart. This can result in symptoms such as chest pain, shortness of breath, and lightheadedness. The pressure-volume loop generated for this patient shows that the end-systolic volume (ESV) is 60ml and the end-diastolic volume (EDV) is 110ml. Cardiac output is calculated by subtracting the ESV from the EDV and multiplying by the heart rate. Therefore, the cardiac output in this case would be (110-60) * 90 = 4.5 L/min.

When a healthy individual changes from a supine to a standing position, the baroreceptors in the body detect the decrease in blood pressure caused by gravity pulling blood downwards. This leads to a decrease in baroreceptor firing, which in turn reduces the activation of the NTS (nucleus tractus solitarius) in the brainstem. As a result, there is a decrease in parasympathetic activity and an increase in sympathetic activity, leading to an increase in heart rate.

When the baroreceptor reflex is activated during the act of changing body position from supine to standing, there is a decrease in baroreceptor firing and a decrease in activation of NTS. This leads to a decrease in heart rate.

As the workload increases during the graded exercise test, it is expected that the stroke volume and systolic pressure will increase. This is because the heart needs to pump more blood to meet the increased demand for oxygen and nutrients by the muscles. However, the diastolic pressure is expected to remain unchanged as the blood vessels dilate to accommodate the increased blood flow. Additionally, the heart rate is expected to increase in order to pump more blood. Therefore, the correct answer is "increase increase no change increase".

Based on the information provided, the patient's blood pressure is 150/90 mmHg. To calculate the mean arterial pressure (MAP), we use the formula MAP = diastolic pressure + 1/3 (systolic pressure - diastolic pressure). In this case, the diastolic pressure is 90 mmHg and the systolic pressure is 150 mmHg. Plugging these values into the formula, we get MAP = 90 + 1/3 (150 - 90) = 90 + 1/3 (60) = 90 + 20 = 110 mmHg. Therefore, the patient's mean arterial pressure is closest to 110 mmHg.

The pressure-volume loop generated for the patient indicates that the flow through the heavily calcified coronary artery is reduced 16-fold. This means that the flow is significantly decreased compared to normal. The calcification in the artery has caused a significant obstruction, leading to reduced blood flow and the patient's symptoms of light headedness, syncope, chest pain, and shortness of breath.

During exercise, when blood flow to exercising skeletal muscles increases, there is a decrease in renal vascular resistance (RVR) to allow for more blood flow to the muscles. This is because the body prioritizes delivering oxygen and nutrients to the working muscles. On the other hand, resistance to blood flow to exercising skeletal muscles (SkVR) decreases because of the increased blood flow. The total peripheral resistance (TPR) decreases as well because of the decreased resistance in the exercising muscles. Overall, the changes in RVR, SkVR, and TPR are expected to be an increase in RVR and a decrease in both SkVR and TPR.

During Phase IV of the Valsalva maneuver, venous return and cardiac output are increased. The Valsalva maneuver is a breathing technique that involves forceful exhalation against a closed airway. In Phase IV, which occurs after the release of the Valsalva maneuver, there is a sudden decrease in intrathoracic pressure. This causes a rapid increase in venous return, leading to an increase in preload and subsequently an increase in cardiac output. This is due to the release of intrathoracic pressure, allowing blood to flow more easily back to the heart.

The pressure-volume loop shows a decrease in the end-diastolic volume (EDV) and end-systolic volume (ESV), indicating a decrease in the amount of blood filling the ventricles during diastole and being ejected during systole. This decrease in volume suggests a decrease in preload and stroke volume, which could be caused by a decrease in capillary fluid pressure. A decrease in capillary fluid pressure would result in reduced filling of the ventricles, leading to decreased EDV and ESV. Therefore, the correct answer is that capillary fluid pressure is decreased.

The patient's expression of anxiety about his father's illness is considered an associated symptom because it is related to the patient's presenting complaints. It is not a sign of a panic attack or acute anxiety, as those would typically involve more intense and immediate symptoms. It is also not a baseline health statement or unrelated to the presenting complaints, as it directly relates to the patient's concern about his father's illness.

The correct answer suggests that when arterial pressure decreases by 25 mm Hg, there will be an increase in skeletal muscle vascular resistance (SkVR), an increase in plasma vasopressin [AVP]Pl, an increase in plasma angiotensin II [Ang II]Pl, an increase in plasma norepinephrine [NE]Pl, and a decrease in cardiac parasympathetic nerve activity (cardiac PANS). This is likely because the baroreceptor reflex is activated in response to the decrease in arterial pressure, leading to vasoconstriction and increased release of vasoconstrictive hormones to increase blood pressure. The decrease in cardiac parasympathetic nerve activity may be due to the compensatory increase in sympathetic activity.

The effect of the patient's father's illness would be reported in all of the mentioned sections - HPI, mental status examination, psychiatric review of systems, and family history. The patient's symptoms of chest pain, sweating, and palpitations are likely related to anxiety or stress caused by his father's diagnosis of severe hypertension. These symptoms and their association with the father's illness would be discussed in the HPI. The patient's mental status examination would assess his emotional state and any signs of anxiety or distress. The psychiatric review of systems would further explore any psychological or emotional symptoms related to the father's illness. Lastly, the family history section would document the father's diagnosis and its potential impact on the patient's health.

After a hemorrhage, the patient's total peripheral resistance (TPR) is likely to decrease. This is because hemorrhage leads to a decrease in blood volume, which results in a decrease in the amount of blood circulating in the blood vessels. With less blood volume, the blood vessels do not need to constrict as much to maintain adequate blood pressure, leading to a decrease in TPR.