PSB4731 Quiz 2Elaine HullL&B 4: Men’s Bodies and Male Reproductive Behavior Review1. What is circumcision?- The surgical removal of the foreskin or prepuce.2. What are the corpora cavernosa? - The main erectile parts that consists of the Ischiocavernosus and Bulbospongiosus muscles that assist with erection and ejaculation by forming a hydraulic system.o Retard blood flow out of the penis or clitoris.o Help hold the penis erect or tense the vagina.o Kegel exercises help strengthen them.3. What is the corpus spongiosum?- One of the three erectile structures that extends from the shaft of the penis to the glans. - The covering is more elastic than the corpora cavernosa so it becomes less hard when erect in order to not cut off the flow of semen through the urethra. 4. What are the seminiferous tubules? What is their function?- The site of spermatogenesis that dominates the structure of the testes in which it contains both Sertoli and Leydig cells that creates and nourish sperm before leaving and entering theepididymis.5. What is the epididymis?- Storage site for sperm where they mature before leaving and entering the vas deferens.- C-shaped structure behind each testes.6. What are the functions of the Sertoli cells? The Leydig cells?- Sertoli cells: secrete peptide hormones and control sperm development by attaching to spermatocytes that nourish sperm as they undergo 1st and 2nd meiotic divisions and removemuch of their cytoplasm (similar to granule cells in females).- Leydig cells: stimulated luteinizing hormone (LH) from the pituitary gland increases cholesterol desmolase activity (Cholest.) by converting cholesterol to progesterone (P) leading to the synthesis and secretion of testosterone (T) (similar to thecal cells in females).7. What is the location and function of the prostate gland?- Contains 30% volume of semen.- Zinc ions trigger coagulation.- Contracts in aid of seminal emission.- Surrounds the urethra 8. What is the main contribution of the seminal vesicle?- Contains 70% volume of semen.- Contracts in aid of seminal emission.PSB4731 Quiz 2Elaine Hull9. What keeps the penis flaccid when a male is not sexually aroused? (Sympathetic or parasympathetic nervous system? What does it do?)- Sympathetic Nervous System is active in normal state through norepinephrine.- Veins open and Arterioles are constricted.- Trabecular smooth muscle is contracted with low pressure.10. How is an erection produced? - Parasympathetic Nervous System in active through Nitric Oxide (NO).- Veins are occluded and Arterioles are relaxed.- Trabecular smooth muscle is relaxed with high pressure.11. What is the role of nitric oxide (NO)? - Nitric Oxide (NO) from parasympathetic nerves vasolidates arterioles and relaxes smooth muscle in corpora cavernosa in which so much blood flows in that it presses against the venous outflow and traps blood there.12. How do Viagra, Cialis, & Levitra work?- Prolong the effects of NO by inhibiting the enzyme that breaks down cGMP, which is NO’s second messenger, so that if there’s continuing sexual stimulation then erection will continue.- However, if erection continues too long then damage can occur since the oxygen in the trapped blood will be used up and tissue can die.13. How is ejaculation produced? - Before ejaculation there is increased Sympathetic Nervous System activity through norepinephrine with increased breathing, heart rate, and contraction of the Ischiocavernosus and Bulbospongiosus muscles in which the cremaster and dartos muscles then draw the testes upward.- Seminal emission occurs just before ejaculation caused by contractions of prostate, seminalvesicles, and vas deferens in which it then loads semen into the posterior urethra where the bladder neck closes.- Altogether caused by contractions of pelvic floor, urethral muscles, and both the Ischiocavernosus and Bulbospongiosus muscles. - 2 brain areas organized in the spinal cord can elicit ejaculation: the Medial Preoptic Area (MPOA) and the Paraventricular Nucleus (PVN). 14. Why do the testicles hang down outside of the abdomen?- Separate hanging down scrotum regulates the temperature needed for sperm production by keeping the testes at a temperature of 4-7 Celsius degrees lower than normal body temperature.- If the scrotum is too hot it sweats, or if it’s too cold then the dartos muscle pulls the testicles closer to the body.- Undescended testicles stuck in the abdomen causes too hot temperatures that can lead to decreased fertility and can promote testicular cancer.15. What are spermatogonia, and where are they located?PSB4731 Quiz 2Elaine Hull- Spermatocytes attach to Sertoli cells by tight junctions to nourish and control maturation ofsperm in the Seminiferous Tubules of the Testes. 16. Where do the first and second meiotic divisions occur in sperm production?- Sertoli cells17. What happens in the epididymis? - Sperm leave Seminiferous Tubules and enter the Epididymis for one week to work their way through it in which they continue to fully mature by becoming more concentrated and capable of moving before moving into the vas deferens. 18. What are 3 major components of semen? How much do sperm contribute? - Prostate Gland (30% of volume): Citric acid and Enzymes.- Seminal Vesicle (70% of volume): Fructose and Fibrinogen.- Testes (1% of volume): Sperm19. What is the vomeronasal organ? What does it do?- Connects to the accessory olfactory bulb to pick up undetected scents of pheromones that are part of the chemosensory system, which is critical in the mating behavior of rodents. 20. What is the main integrative area for control of male sexual behavior? What transmitter is released there before and during mating? - The Medial Preoptic Area (MPOA) is the main integrative area for control of male sexualbehavior in which dopamine is released both before and during mating. 21. What are three brain areas where dopamine is released during mating? What is the role of each?- Nigrostriatal tract: initiation of movement.o Substantia Nigra (midbrain)—Dorsal Striatum - Mesolimbic tract: general motivation.o VTA (midbrain)—Nucleus Accumbens- MPOA: male sexual behavior.o Anterior end of Hypothalamus22. How good is the correlation between testosterone levels and sexual ability in humans? What factors may be more important than testosterone levels for explaining individual differences in males' sex drive?- Correlation between sex drive and testosterone levels is not very high due to individual