....ANATOMY OF THE DOG— 14 



MALE SEXUAL Ot^OASIS 



FEMALE 

 SEXVAL 

 OflOANS 



LEFT, MALE SEXUAL ORGANS, 1. Blad- 

 der. 2. The rectum portion of the colon or large 

 intestine leading on to the external opening or 

 anus at 3. 4. Scrotum or bag containing the 

 testicles (5). 



6. Penis. 7. Sheath or covering of penis. 

 8a and 8b. Vas deferens — tubes from the 

 prostate gland to each testicle (and carrying 

 semen into the urethra). 



9. Urethra duct, carrying urine from bladder 

 to external exit {penis, male; vagina, female). 

 In male, urethra is also a genital duct for 

 semen. Do not confuse urethra with ureters, 

 of which there are two, one leading from each 

 kidney to the bladder. 10. Prostate gland. 



RIGHT, FEMALE SEXUAL ORGANS— 

 1. and 1. Ovarian bursa or sacs. 2. Ovaries 

 (one on each side). 3. Horns or Fallopian tubes 

 (one on each side) of uterus (womb). 



4. Main body of uterus or womb. 5. Bladder. 

 6. Os uteri (mouth of womb), from which pup- 

 pies emerge. 



7. Vagina (external opening). 8. External 

 urethral orifice (where urine emerges). 9. Fossa 

 clitoridis. 10. Feti (puppies) in the womb. 



11. Region of kidneys. 12. Rectal opening 

 (above vaginal opening). 13. Vulva attached to 

 pelvic bone. 



IX. REPRODUCTIVE SYSTEM 



The reproductive system in the male consists 

 of two testicles, the excretory duct or vas 

 deferens, and the penis, which contains the 

 urethra. 



The two testicles in the male are inclosed in 

 a sac the scrotum. Each testicle hangs in the 

 bag or scrotum by a spermatic cord which 

 consists of the vas deferens, an artery and a 

 vein. 



Cryptorchid 



Testicles in the fetus or unborn male are 

 not located in the hag but in the abdomen ; 

 later (about the age of 3 months), they de- 

 scend thru the inguinal canal, an opening thru 

 the abdominal wall, into the bag. In rare 

 instances one or both may fail to descend ; in 

 this instance the animal is known as a cryptor- 

 chid. A testicle remaining in the abdomen 

 atrophies by the age of eight months and is 

 ineffective. 



An animal with one descended testicle, how- 

 ever, can be fully effective sexually. An op- 

 eration can drop a testicle altho on account of 

 the mesh of blood vessels, nerves and tissue, 

 it often is not successful. Injection of atrui- 

 tin may hasten the dropping. 



The vas deferens is a small tube which car- 

 ries the semen or male reproductive fluid from 

 the testicle into the urethra, the canal thru 

 which the semen is carried outside the body. 

 Cause of Tie 



The penis is the male organ of copulation. 

 It consists of tissues that become erect upon 

 an inflow of blood, which, due to depression 

 of the veins, cannot leave promptly. The con- 

 tinued swelling within the vagina of the fe- 

 male holds the penis there until the semen is 

 poured into the vagina. It also, being extreme 

 in the dog, causes the tie or inability of the 

 male to withdraw the penis promptly. 



The bone inside the penis is known as the 

 OS penis. 



