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Zoology
COMPARATIVE ANATOMY: UROGENITAL ORGANS OF RABBIT AND FROG
By BS MediaTwitter Profile | Updated: Wednesday, 12 December 2018 12:03 UTC
RABBIT | FROG |
1. Sexual dimorphism is well marked due to presence of penis and scrotal sacs containing tests only in male. | 1. Not distinct. However, in male frog, base of first inner finger forms a thick nuptial pad during breeding season to clasp female in amplexus. Vocal sacs present in males. |
2. Include 2 testes,2 epididymes, 2vasa deferentia, urethra, penis and some accessory glands. | 2. Include two testes, several vasa efferentia, bidders canal two urinogenital ductsand cloaca. |
3. Small, oval, white bodies. Remain inside abdominal cavity in young. But descend from abdomen in to scrotal sacs during breeding season in adult. | 3. Ovoid or rod-like, light yellow, attached to anteroventral surface of kidneys by mesorchium. |
4. Rectal gland present. | 4. Rectal gland absent. |
5. Each testes attached by anterior end to dorsal abdominal wall by a spermatic cord and by posterior end to wall of scrotal sac by gubernaculum. | 5. Absent. |
6. Epididymis well developed and has 3 distinct parts, caput, cauda and corpus epididymes attached to the anterior, posterior and inner sides, respectively, of testis. | 6. Vas deferens does not form an epididymis. |
7. Two vasa deferentia, arising from cauda epididymis of their side, open into neck of urinary bladder or urethra. | 7. Each vas dererens unites with ureter of its side forming a urinogenital duct, opening separately into roof of cloaca. |
8. Small, slightly bifurcated blind sac, called uterus masculinus or seminal vesicle opens dorsally and independently into urethra. | 8. In some species of frog, terminal part of urinogenital duct enlarges forming a temporary seminal vesicle. |
9. It includes small erectile cylindrical penis in front of anus of male. It serves to transmit sperms into vagina of female during copulaiton. | 9. Copulatory apparatus absent. Fertilization external, inwater, where ova and spermatozoa are shed during amplexus. |
10. Male has one pair of prostate, Cowper's, perenial and rectal glands. Their secretions either attract the female or contribute to semen. | 10. Do not occur. |
RABBIT | FROG |
11. Include paired ovaries, oviducts, uteri and singlevestibule, vagina, clitoris and some accessory glands. | 11. Include a pair of ovaries, a pair of oviducts and a cloaca. |
12. Two ovaries are small, oval, white bodies attached symmetrically and dorsally behind kidneys by mesovarium. | 12. Ovaries are a pair of large irregular multilobed, oval, blackish bodies attached near kidneys to dorsal abdominal wall by mesovarium. |
13. Two oviducts are large, coiled tubes meeting behindinto vagina, andcalled fallopian tubes. Anterior end of each opens near ovary by a smalloviducal funnel with fimbriated ostium. | 13. Oviducts are very long and much coiled glandulartubes opening behind into cloaca. Their anterior ends form separate oviducal funnels with separate openings or ostia, at the bases of lungs. |
14. No shell glands present in oviducts. | 14. Shell glands are absent. |
16. Fallopian tubes are followed by much wider, longer convoluted, vascular and muscular uteri where embryos develop. | 15. Before entering cloaca, each oviduct expands into a thin-walled ovisac, erroneously called uteruswhich is absent. |
16. Both uteri meet into a common long, wide and median vagina. It opens with urethra into common urino-genital sinus or vestibule. | 16. Vagina absent. So called uteri or ovisacs open directly into cloaca. Vestibule absent. |
17. Vestibule opens to outside ventral to anus, through a longitudinal slit like aperture called VULVA. | 17. No vulva present. Cloaca opens directly to exterior through a small circular cloacal aperture. |
18. Special female sex glands include Cowper's, perineal and rectal glands. | 18. No glands. |
19. Mammaryglands secrete milk and open on 4 to 5 pairs of ventral teats or nipples in female rabbit. | 19. Absent. |
End of the article