Ejaculation of semen from the penis is caused by:
A. a parasympathetic reflex that contracts the seminal vesicles, epididymis, and vas deferens.
B. a somatic reflex that initiates sperm production and motility, and contracts skeletal muscle surrounding the vas deferens.
C. voluntary relaxation of the internal urethral sphincter, and sympathetic stimulation of smooth muscle contraction in the walls of the ureters and the urethra.
D. sympathetic nerve firing, which initiates smooth muscle contraction in the epididymis, vas deferens, ejaculatory ducts, prostate, and seminal vesicles.
E. parasympathetic stimulation of smooth muscle in the ureters, urinary bladder, and urethra.
D
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Thin myofilaments are called ________
A) Myosin B) Myofibril C) Actin D) Z bars
What molecules form the thick filaments within muscle?
a. microfilaments b. myosin c. actin d. myoblasts e. troponin
The vesicles containing hydrolytic enzymes are called ________.
A. ribosomes B. lysosomes C. nucleus D. centrioles E. mitochondria
Information about pain and temperature is conveyed to the brain by way of the
A. fasciculus gracilis. B. posterior funiculus-medial lemniscal pathway. C. anterolateral pathway. D. tectospinal tract. E. spinocerebellar pathway.