Which statement is (are) not correct about the time that you’re exercising? a. S

Question

Which statement is (are) not correct about the time that you’re exercising?

a. Sympathetic division increases heart rate by stimulating the activity of only SA node  

b. Sympathetic division increases the contractility of ventricles

c. Cardiac muscles receive norepinephrine molecules released from the cardiac accelerator nerves  

d. Beta-1 adrenergic receptors in the sarcolemma of cardiac muscle fibers are involved in stimulation of these muscles by the sympathetic division  

e. Sympathetic nerves release epinephrine molecules in the neuromuscular junction with cardiac muscle cells

f. Both b and d

g. Both c and e

a. Sympathetic division increases heart rate by stimulating the activity of only SA node  

Explanation / Answer

Answer is option E as we know that sympathetic supply to heart via sympathetic nerves which released Norepinephrine at beta 1 receptor and the circulating blood level of the epinephrine is responsible for the sympathetic action on the heart.

So all other option are correct, but in option e says that sympathetic nerve released epinephrine which is wrong because with prolonged stimulation of sympathetic system it stimulates adrnal medulla gland to secret epinephrine after methylation of norepinephrine.

While at beta their is sympathetic nerve they released nor epinephrine.

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.