this lecture covered the anatomy and embryology of the male and female reproductive systems, first introduced in histology last semester. first it went through basic anatomical features of the female reproductive system. at the end of the vagina is the cervix, which is the opening to the uterus (the areas beside the cervix are called "fornices"). the uterus has four sections, the cervix, isthmus, body, and fundus. the uterine tubes branch off of the uterus and are divided into section as well: isthmus, ampula (where fertilization takes place), infundibulum, ending in the fimbria which open up into the peritoneal cavity. the uterus itself can be tilted forward, called anteversion, and additionally bent forward, called anteflexion. it is held in place by the round ligament, the uterosacral ligament, and the transverse sacral ligament. the ovaries are held in place by suspensory and ovarian ligaments.
the male reproductive anatomy basically follows spermatogenesis as it begins in the testes and ends at the penis. spermatogenesis occurs in the seminiferous tubules of the testis, aided by sertoli cells and leydig cells (which secrete testosterone). the spermatogonia in the walls of the tubules develop into spermatocytes, into spermatids, into spermatozoans, which are then released from the tubules. they travel into the rete testis, and into the ductus epididymus, which is a 4-5m long highly coiled tube where spermatozoans mature. from there they travel up the ductus deferens, which goes through the inguinal canal and behind the bladder, encountering the first of the ducts which combine with sperm to create seminal fluid.
the first of these is the seminal vesicles, which secrete a whitish viscous fluid containing fructose (recall the polyol pathway from biochemistry, and how sperm cells use fructose instead of glucose for metabolism). next is the ejaculatory ducts, which meet the urethra at the urethric crest of the prostate. next is the prostatic ducts in the prostate. finally, the bulbourethral gland is embedded in the external urethral sphincter and lubricates the penile urethra as well as neutralizing acidity from the urine.
some homologies of external genitalia between males and females are discussed: the penis and clitoris are both formed from the "genital tubercle". the "labiascrotal swelling" forms the scrotum in males and the labia majora in females. the urethral folds forms the urethra in males and the labia minora in females.
next we discuss the embryology of the reproductive systems. male/female differentiation begins around 4 weeks during development. before this point, germ cells in both sexes migrate from the yolk sac to the sex cords, forming the precursor to the gonads. in males, the mesonephric ducts (wolffian) develop while the paramesonephric (mullerian) ultimately degrade. the mesonephric ducts form the efferent ductules, ductus deferens, seminiferous tubules, and ejaculatory ducts.
in females, the follicles (recall the anatomy from the histology lecture) are formed by sex cords which form cortical cords, which form follicles. inside the follicles are oogonia, which began forming and dividing from the germ cells that migrated from the yolk sac. as mentioned above, the mesonephric duct eventually disappears and the paramesonephric duct develops into the female reproductive anatomy: the top of the ducts form the uterine tubes, ending in the infundibulum, and the bottom of the ducts form the uterus and vagina. the sinovaginal bulb is formed by the fusion of the urogenital sinus and the paramesonephric ducts, and the opening to the vagina forms by the hollowing out of the sinovaginal bulb.
some pathologies in development: hypospadias is the opening of the urethra in the ventral side of the penis instead of at the glans. chryptorchism is incomplete descent of the testis due to abnormal androgen production. congenital inguinal hernia is when the intestines come through the inguinal canal into the scrotal area. hydrocele is the acculumulation of fluid in the tunica vaginalis, which covers the testis.
questions
anatomy...
1. greater and lesser pelvis separated by...
2. what is the pelvic diaphragm made of?
3. what are the four parts of the uterus?
4. what are anteversion and anteflexion?
5. what is the connective tissue that holds the uterus?
6. what are the sections of the uterine tube?
7. what is the ovary held in place by?
8. what is the broad ligament formed from?
9. what are the fornices?
10. what is the tunica albuginea?
11. leydig cells secrete...
12. sertoli cells support...
13. describe spermatogenesis. (not on test)
14. describe the pathway of the sperm out from the seminiferous tubules to the ductus deferens.
15. describe the epididymus.
16. ductus deferens transports sperm cells through...
17. what do the seminal vescicles do?
18. where do the ejaculatory ducts open into the urethra?
19. prostate gland secrete into urethra via...
20. where is the bulbourethral gland? what does it do (2)?
21. what forms the seminal fluid?
22. what are the layers to the prostate?
23. what are the zones of the prostate?
24. what zones does hypertrophy of the prostate affect?
25. what zones does prostate cancer affect?
26. what does the prostate gland secrete? (4)
26b. what is an indicator for prostate cancer?
27. where is the superficial inguinal ring?
28. where is the deep inguinal ring?
29. conjoint tendon is the lowest part of...
30a. describe the path of the spermatic cord.
30b. what is the equivalent of the spermatic cord in the female and where does it pass through?
31. what is the pampiniform plexus?
32. what is the cremaster muscle?
33. what is an inguinal hernia?
34. what is the difference between a direct and indirect inguinal hernia?
what is the analogous erectile tissue on the female:
35. penis
36. corpus cavernosum
37. corpus spongiosum
38. bulb of penis and glans penis
39. what is it that imparts turgidity during an erection?
40. describe the corpus spongiosum.
41. describe the general purpose of the ischiocavernous muscle in males and females.
42. describe the general purpose of the bulbospongiosus muscle in males and females.
43. describe the general purpose of the transverse perinei muscle in males and females.
44. what gland on females is analogous to the bulbourethral gland in males?
45. what gland on females is analogous to the prostate gland in males?
46. describe the blood supply for erectile tissue.
47. describe the nervous system's role in producing an erection.
48. what is detumescence and how does it occur?
embryology...
49. urogenital ridge is formed from...
50. germ cells arise from... and migrate to...
51. in male genital development, seminiferous tubules are formed from...
52. mesonephric duct becomes...
53. some mesonephric ducts become...
54. in female genital development, follicles are formed from...
55. describe oogonia development.
56. paramesonephric duct is formed by which hormones?
57. what does the cranial end of the paramesonephric duct grow into?
58. what does the caudal end grow into?
59. where does the sinovaginal bulb form?
60. what does the vagina form from?
61. what is uterine duplication caused by?
62. what are the characteristics of female pseudohermaphrotidism?
63. what does the genital tubercle develop into in males and females?
64. what does the urethral fold develop into in males and females?
65. what does the labioscrota develop into in males and females?
66. what is hypospadias?
67. testes descend through...
68. piece of peritoneum is retained as...
69. what is chryptorchism?
70. what is a congenital inguinal hernia?
71. what is a hydrocele?
answers
1. pelvic brim
2. levator ani+coccygeus, pudendal nerve, muscle suspended across lesser pelvis
3. body, isthmus, cervix, fundus
4. anteversion is the tilting of the uterus forward onto the bladder. anteflexion is the further bending of the uterus forward. (retroversion and retroflexion are the opposite)
5. round, transverse cervical, and uterosacral ligaments.
6. isthmus, ampula, infundibulum, ovary.
7. suspensory ligaments, ovarian ligaments
8. the parietal layer of the peritoneum that covers the reproductive organs.
9. the spaces in the vagina around the cervix.
10. the inner covering of the testis
11. testosterone
12. spermatogenesis
13. spermatogonia->spermatocytes->spermatids->mature sperm cells
14. leave the seminiferous tubule via the rete testis, which then dumps into the efferent ductules, which then converges into the epididymus, then to the ductus deferens.
15. a highly coiled tube that is 4-6 meters long, the site for sperm maturation.
16. inguinal canal
17. secretes viscous whitish-yellow fluid containing fructose
18. urethral crest of prostate.
19. prostatic ducts
20. embedded in the external urethral sphincter, lubricates penile urethra and neutralizes acid from urine. the last contributor to seminal fluid.
21. bulbourethral, seminal vescicle, prostate secretions.
22. main, submucosal, mucosal.
23. peripheral, central, transitional, periurethral. (from largest to most focused)
24. central and transitional.
25. peripheral zone.
26. prostatic acid phosphatase (PAP), fibrinolysin, citric acid, and prostate-specific antigen.
26b. increased PAP and PSA levels.
27. in the external oblique
28. in the transversalis fascia
29. transverus and internal oblique muscles
30a. through the inguinal canal and into scrotum
30b. the round ligament of the uterus, passes through inguinal canal to labia majora.
31. the venae comitantes that maintain thermoregulation in the spermatic cord.
32. the muscle innervated by genitofemoral nerve that raises the testes for thermoregulation.
33. protrusion of intestine through abdominal wall
34. direct is via a weakened conjoint tendon, indirect is through the inguinal canal.
35. clitoris
36. corpus cavernosum
37. labia minora
38. bulb of vestibule and glans clitoris
39. the tunica albuginea
40. separated by the vagina in females but surrounds the urethra in males. has less CT, therefore less turgidity.
41. overlies corpus cavernosus
42. overlies bulb of penis/vestibule
43. tauten perineal membrane
44. greater vestibular
45. urethral and paraurethral
46. internal iliac artery to internal pudendal artery to deep artery of the penis/clitoris
47. during erection, parasympathetic nerves (S2,3,4) dilate helicine arteries and allow blood to flow into erectile tissue
48. sympathetic nervous activity constricts helicine arteries and reroutes blood into venous plexus and deep dorsal vein.
49. intermediate mesoderm
50. yolk sac and gonad
51. sex cords
52. ductus deferens, seminal vesicles, ejaculatory duct.
53. efferent ductules
54. sex cords which form cortical cords, which form follicles.
55. oogonia form from germ cells, and undergo mitosis during fetal development. after birth no more oogonia are formed.
56. maternal or placental estrogens.
57. uterine tubes, ending in infundibulum that opens up into peritoneum.
58. uterus and vagina
59. where the paramesonephric ducts fuse with the urogenital sinus
60. the fusion of the bulbs, which begin to hollow out.
61. improper fusion or development of paramesonephric ducts.
62. masculinization of female external genitalia: partial fusion of labia majora, clitoral hypertrophy, and persistent urogenital sinus.
63. penis and clitoris
64. penile urethra and labia minora
65. scrotum and labia majora.
66. urethral openings on the ventral surface of the penis rather than at the glans.
67. inguinal canal, along gubernaculum.
68. tunica vaginalis
69. abnormal androgen production produces undescended testes.
70. patency of inguinal canal which allows intestines to enter scrotum
71. excess fluid in the tunica vaginalis.
No comments:
Post a Comment