Explanation: SA node pacemaker activity relies on the hyperpolarization-activated funny current (If) – mixed Na+/K+ inward current, plus decreasing outward K+ current.
Explanation: Hyperglycemia exceeds renal glucose reabsorption threshold → glucose in tubules → osmotic retention of water → increased urine output.
A) Increased ADH secretion B) Decreased glomerular filtration rate C) Osmotic diuresis from glucosuria D) Inhibition of sodium reabsorption in the loop of Henle ganong physiology mcq pdf
Explanation: Hypotension reduces baroreceptor firing → increased sympathetic outflow to heart (β1 receptors) → increased HR. Vagal tone decreases, not increases.
A) Increased PaCO2, increased pH B) Decreased PaCO2, increased pH C) Decreased PaCO2, decreased pH D) Increased PaCO2, decreased pH Explanation: SA node pacemaker activity relies on the
A) Increased parasympathetic (vagal) efferent activity to SA node B) Decreased sympathetic efferent activity to the heart C) Increased sympathetic efferent activity to the heart D) Increased atrial natriuretic peptide (ANP) secretion
A) Rapid influx of Na+ through fast voltage-gated channels B) Inward “funny current” (If) carried mainly by Na+ and K+ efflux decrease C) Exclusive T-type Ca2+ channel activation D) Na+/Ca2+ exchanger operating in reverse mode Vagal tone decreases, not increases
A) Decreased renin release B) Increased angiotensin II formation C) Decreased aldosterone secretion D) Increased ANP release