Diving or falling into very cold water will reflexively: A. Make you take a deep
ID: 3482224 • Letter: D
Question
Diving or falling into very cold water will reflexively:
A. Make you take a deep breath
B. Slow HR and stop respiration
C. Increase HR and heat production
D. Cause your knee to jerk
The connection neurons for the baroreceptor reflexes are in the:
A. Cartotid sinuses
B. Aortic arch
C. Medulla oblongata
D. Right atrium
A physically fit person would most likely have a higher _____ than a couch potato:
A. SV
B. HR
Atrial and ventricular diastole overlap during?
A. P - R interval
B. R - T interval
C. T - P interval
D. None of the above
Explanation / Answer
Question 1
Answer is B
The diving or falling into very cold water present intense slowing of the heart rate due to parasympathetic activity and peripheral vasoconstriction of sympathetic activty of the extremities. Breath is holded or stopped during the dive, arterial Po2 and pH fall and Pco2 rises, and the chemoreceptor reflex increases the diving response. The arterioles of the brain and heart are not constricted so cardiac output is supplied to these organs. The brain and heart use the stored oxygen in the blood.
Question 2
Answer is C that is medulla oblongata
Afferent neurons from the baroreceptors from carotid sinuses travel with gloss pharyngeal nerve, and the afferent neurons from aortic baroreceptors move acroos the vagus nerve. Both the baroreceptor afferents terminate in the Medulla Oblongata.
Question 3
Answer is A that is stroke Volume(SV)
That indicates a greater volume of oxygen is supplied to the body per heartbeat. The physically fit persons have a lower resting heart rate.
In couch potato muscles require given amount of energy, even at rest also, the heart rate does not change. But in physically fit persons has increased the volume of oxygen that can be delivered to the muscles per heartbeat, the heart needs to beat less. Therefore the heart rate is lowered.