Which of the following has the fastest rate of spontaneous depolarization?
A) the SA node
B) the AV node
C) Purkinje fibers
D) AV bundle branches
Answer: A) the SA node
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Mary noticed a large, brown spot on her skin. She has been playing tennis in the sun for several years without sun protection
She reported the discovery to a friend, who told her to apply the ABCD rule to determine whether or not she had malignant melanoma. Her friend told her that if her answer was "no" to the questions that were asked by the ABCD rule, she had nothing to worry about. What is the ABCD rule and should she ignore the spot if her answers are negative? What will be an ideal response
Answer the following statements true (T) or false (F)
1. Aldosterone stimulates the reabsorption of sodium while enhancing potassium secretion. 2. Pressure diuresis decreases blood volume and blood pressure. 3. Aldosterone is secreted in response to low extracellular potassium. 4. To remain properly hydrated, water intake must equal water output. 5. The main way the kidney regulates potassium ions is to excrete them.
Erection and ejaculation can be initiated by
A. impulses from the cerebellum. B. increased levels of LH and FSH. C. contraction of smooth muscle. D. increased blood levels of testosterone. E. manual stimulation of the penis.
All of the following muscles flex the forearm except the
a. brachialis. b. biceps brachii. c. brachioradialis. d. anconeus.