In: Anatomy and Physiology
Linda ate some immature potatoes. Despite being cooked
thoroughly, the glycoalkaloid content caused her to
develop severe abdominal pain and cramps, vomiting, and diarrhea.
After about ten to twelve episodes of watery
diarrhea, she became so pale and weak that her husband took her to
the clinic. She was diagnosed with severe
dehydration resulting in hypovolemic shock.
The body has several response mechanisms that are utilized
to try to maintain blood pressure and blood
flow in response to hypovolemic shock. Which of the following would
occur ?
Sympathetic stimulation of the heart is increased.
Renin release is inhibited.
Chemoreceptors are depressed.
Parasympathetic stimulation is increased.
Answer should be sympathetic stimulation of the heart is increased.
It is an immediate compensatory mechanisms in cases of hypovolemic shock.
Shock is a condition in which both extracellular or intracellular fluid loss occur due to which tissue perfusion is decreased.
In shock there is cool clammy skin, pale skin , rapid breathing, tachycardia, etc.
As there is blood loss, there is decreased blood volume and hence decreased blood pressure which is sensed by baroreceptors which inturn stimulate sympathetic system to increase heart rate, force of contraction and velocity of conduction which ultimately increase the cardiac output.
Also with blood loss ,there is changes in arterial blood gases which is detected by chemoreceptors which stimulates sympathetic system.
The long compensatory mechanisms include - Renin angiotensinogen system, and hormonal control.
Renin release is increased which converts angiotensinogen into angiotensin which increases sodium and water retention thus increasing blood volume, vasoconstriction which increases blood pressure and also increase aldosterone release which acts on distal tubule of kidney to increase sodium and water reabsorption.
Chemoreceptors are activated by changes in arterial blood gases ( acidosis) which also activates sympathetic system.