Male Repro

Question 1

How do males undergo defeminization during puberty?

Answer 1

Alpha fetal protein binds estrogen and prevents exposure to estradiol as testosterone enters brain instead to form estrogen

Question 2

Physiologic definition of puberty

Answer 2

Specific hypothalamic nuclei release GnRH to cause gonadotropin release and cause spermatogenesis and ovulation (dependent mostly on threshold body weight)

Question 3

Which species have fibroelastic, sigmoid flexure?

Answer 3

Bull (rapid erection/ejaculation) and boar (slow erection/ejaculation and cork-screw glans penis)

Question 4

Which species have four accessory sex glands?

Answer 4

Stallion and bull

Question 5

What species have penile spines and what is their purpose?

Answer 5

Tom has cone-shaped glans penis with keratinized papillae for stimulation of vaginal mucosa because Queen is an induced ovulator

Question 6

How is testosterone synthesized?

Answer 6

Leydig cells have receptors for LH and produce testosterone
Sertoli cells have receptors for FSH (estradiol) to stimulate spermatogenesis and also produce inhibin to suppress FSH (AP)

Question 7

Where does spermatogenesis take place?

Answer 7

seminiferous tubules

Question 8

What is the differentiation phase?

Answer 8

spermiogenesis: spermatid to spermatozoa (continually released into the lumen)

Question 9

Duration of spermatogenesis in bull

Answer 9

61d

55d in stallion, 47d in ram, and 39d in boar