At what point does blood lactate begin to accumulate and rise exponentially? 30% 40% 50% 60%

How does shear stress induce the release of nitric oxide in endothelial cells?

Caffeine lowers the heart rate by increasing rates of depolarization at the SA node   True False   Nicotine raises the heart rate because it stimulates the activity of the sympathetic neurons in medulla oblongata   True False   The Frank-Starling Law of the Heart states that the force of heart contraction is directly proportional to the initial length of the muscle fiber, within optimal limits of length   True False If the sarcomeres stretched beyond the optimal length, the force of contraction would go down, but that can potentially happen only during open heart surgery when the heart is not constrained by the pericardium, lungs, ribs and diaphragm.   True False It is the Na+ channel-driven spontaneous depolarization that is affected by sympathetic and parasympathetic inputs to speed up or slow down the firing rate of the SA node and other conductive cells.   True False

Describe in detail the renin-angiotensinogen pathway

JH, a 53 year-old female, had not been feeling well lately and suddenly started to feel acutely worse. She started to have shortness of breath, and was experiencing an irregular heartbeat, chest pain, muscle weakness, and feelings of severe nausea. She called 911 and was taken to the hospital where blood samples were drawn. The following table summarizes the results of her bloodwork (Table 1) Table 1: JH ion concentrations at intake (blood). lon Plasma concentration - measured (mM) Plasma concentration - normal (mM) K+ 8 5 Na+ 142 142 Cl- 105 105 Ca2+ 2.5 2.5 JH was diagnosed with hyperkalemia and ordered IV fluids. The IV fluids she was given contained calcium gluconate and insulin. Her potassium levels were monitored over a 24-hour period and were as summarized in Table 2. Table 2. JH potassium concentrations post-IV fluids (blood). Time (hours) Measured plasma K+ (in mM) 0 8.0 3 7.1 6 6.4 9 5.9 12 5.6 15 5.3 18 5.1 21 5.0 24 5.0 2. Using Table…