Please explain 1, 2, and 5. Thank you! 1) Which of the following are responsible
ID: 10103 • Letter: P
Question
Please explain 1, 2, and 5. Thank you!1) Which of the following are responsible for the prolonged rise in heart rate during prolonged exercise?
a) sympathetic neural stimulation
b) circulating e catecholamines
c) increased core temperature
d) a and b
e) b and c
2) Resting bradycardia, resulting from exercise training, is due to _
a. Decreased sympathetic activity
b. Increased sympathetic activity
c. Decreased parasympathetic activity
d. Increased parasympathetic activity
3) Which of these “determines” systolic blood pressure?
a. Total peripheral resistance
b. Elasticity of the arteries
c. Stroke volume
d. a and b
e. b and c
4) which of the following mechanical events does the P wave of the electrocardiogram proceed?
a. Ventricular systole
b. Atrial diastole
c. Atrial systole
d. Ventricular diastole
5) The relationship between the force of contraction of the heart and end diastolic volume within normal limits can best be described as:
a. Directly related
b. Equal
c. Inversely related
d. hyperbole
Explanation / Answer
1) C I believe the answer is just "C" since sympathetic neural stimulation allows for circulating catecholamines. Thus, since A B and C is not an option, it can only be C increased core temperature. As temperature increases, heart rate increases to meet metabolic demands i.e. regulatory homeostasis. 2) D This question requires insight into the autonomic nervous system. The sympathetic nervous system is, for the most part, involved in engaging the body to mobilize. Conversely, the parasympathetic nervous system is involved in relaxing the body. 3) C must be true according to the following equation which involves systolic blood pressure. SV = EDV - ESV Stroke volume = End Diastolic Volume - End Systolic Volume B is also true. Elasticity of the arteries would affect pressure as it is a measure of force exerted by the blood on the arterial walls. 4) C Electrical systole of the atria begins with the onset of the P wave on the ECG. The wave of bipolarization (or depolarization) that stimulates both atria to contract at the same time is due to sinoatrial node which is located on the upper wall of the right atrium. 5) A An increase in contractility tends to increase stroke volume and thus a secondary increase in preload. SV = EDV - ESV ; where SV = Stroke Volume EDV = End Diastolic Volume ESV = End Systolic Volume Thus, they're directly related Sources: Campbell's 8th Edition, Wiki, My Brain