The Reproductive System

Canine Testis (104X)1. Seminiferous tubules (showing spermatogenesis) 2. Interstitial tissue (with Leydig cells, which produce androgens

Positions of the Scrotum:A. Perineal (tomcat)B. Intermediate (dog)C. Inguinal (bull)

1. Testicular artery

2. Deferent duct (ductus deferens)

3. Testis

4. Pelvic symphysis

Equine Testis1. Head of epididymis 2. body of epididymis 3. Pampiniform plexus

Equine testis1. Testis 2. Epididymis 4. Deferent duct (ductus deferens) 5. Pampiniform plexus

Longitudinal section of testis and epididymis

1. Tunica albuginea

2. Mediastinum

3. Seminiferous tubules

4. Straight tubules

5. Rete testis

7. Deferent duct (ductus deferens)

8. Head of epididymis

9. Body of epididymis

10. Tail of epididymis

Canine testicle (corrosion cast)Testicular artery (red); Pampiniform plexus (blue) Deferent duct (yellow)

Scrotum of a bullCremaster muscle contracted

Stress or cold temperature

Bladder and Urethra (Equine), opened

6. Opening of ejaculatory duct

7. Openings of prostatic ducts

8. Openings of bulbourethral ducts

9. Vesicular gland

10 Prostate

11. Bulbourethral gland

Accessory Reproductive Glands

A. Stallion

B. Bull

C. Boar

D. Dog

4. Ampullary Gland

5 Vesicular Gland

6. Body of prostate

7. Bulbourethral gland

Male Urogenital Apparatus (dog)2. Deferent duct 3. Urethra 5. Os penis 6’ bulb of penis

7. bulbis glandis (glans) 8. Prepuce 9. Prostate

Quiescent and erect penis (canine)

Urogenital organs of the tomcat5. Testicle 6. Penis 7. Bulbourethral gland

8. Prostate 9. Deferent duct

Feline Penis1. Prostate 3 Urethra 4. Bulbourethral gland

2. 7. Testis 8. Prepuce 9. Glans (with spines)

Feline Glans Penis (Scanning Electron Micrograph)

Feline Penis (caudal view)1. Tail (raised) 7. Penis 8. Retractor penis muscle 9. bulbourethral gland

Tomcat spraying (urine)

Feline Mating Posture

Equine Penis (out of sheath)

Bovine Penis

Bovine Penis and Surrounding structures

Reproductive organs of the Rooster1. Testis; 2. Kidney; 3. Deferent duct; 4. Cloaca

Female Reproductive Tract4. Ovary; 5 Fallopian Tube; 6 Uterus; 7. Cervix; 8. Vagina 12. Vulva

The bovine ovary1. Ovarian Follicle (egg ready to be ovulated)

The ovary of a bitch (quiescent)

Canine ovary with multiple folliclesCanines reproduce in litters, so multiple follicles mature at one time.

Ovary of the sowDo sows have singles or litters?

Diagram of stages of ovarian activity1. Ovarian medulla; 5. Primordial follicle; 6. Primary follicle; 7. Secondary follicle; 8. early tertiary follicle; 9. mature follicle; 10. Oocyte; 11. Ruptured follicle; 13. Corpus luteum

Cow Reproductive tract

1. Ovary; 2. Infundibulum;

3. Uterine tube (Fallopian tube);

4. Horn of uterus;

6. Body of uterus; 8. Cervix;

10. Vagina;

12. External urethral opening;

14. Clitoris; 15. Vulva

The Reproductive Tract of the Bitch

Vagina has been opened.

1. Ovaries

2. Uterine horns

3. Uterine body

4 Vagina

The reproductive tract of the mare

1. Right ovary

2. Uterine (Fallopian) tube

3. Horn of uterus

4. Body of uterus

5. Cervix

6. Vagina

Reproductive Tract of the Cow

Vagina has been opened

Note differing shapes of the uteri.

The Reproductive Tract

of the Sow

1. Left ovary

4. Uterine (Fallopian) Tube

5. Uterine Horn

(6. Broad Ligament)

7. Parallel segments of the uterine horns

8. Body of Uterus

9. Cervix

10. External uterine orifice

13. Vagina

16. Vestibule

Reproductive Tract of the Hen

1. Ovary with follicles in different stages of development

2. Oviduct

3. Uterus

4. Colon

5. Cloaca

Ventral view of reproductive organs in the hen

1. Ovary with follicles in different stages of development; 2. Oviduct; 3. Uterus; 4. Colon; 5. Cloaca

Variation in Uterine Shape by SpeciesA. Uterus duplex (rabbit); B. Uterus bicornis (small body—sow and cow); C. Uterus bicornis (large—mare); D. Uterus Simplex (woman).

The Estrus Cycle

Canine Estrous Cycle Graphs

contributed by Bruce E Eilts on 12-July-01modified by Eric Huey

Proestrus, estrus (during which ovulation occurs), diestrus, metestrus (quiet phase between cycles)

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Some Specific Reproductive Parameters (Table 5-1, page 206)

Species Puberty Cycle Estrus Duration Ovulation Pregnancy

Dog 6-9 mo >90d 9 days 3 days after 62 days

Cat 6-9 mo varies 7-10 days 24 hrs after 63-65

Horse 20 mo 19-22d 5-6 days 1-2 d before end 330d/11mo

Cattle 6-18 mo 18-24d 18 hours 10-12 hrs bef end 280d/9 mo

Sheep 6-12 mo 16-18d 24-36 hours 30-36 hrs after 150d/5mo

Goat 4-8 mo 21d 24-36 hours 30-36 hrs after 150d/5mo

Pig 5-10 mo 19-21d 48-72 hours 35-45 hrs after 114d (!4 mo)

Pregnancy

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Formation of Extraembryonic

Membranes

1. Embryo

2. Chorion

4. Yolk sac

5. Allantois

6. Amnion

7. Chorioallantois

Zonary Placenta (carnivores)The zonary placenta has the closest and most interaction between the fetal membranes and the endometrium.

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Equine PlacentationThe equine placenta is not very complex. The villi do not penetrate deeply into the endometrium.

Equine PlacentationEndometrial cups (mare) during early pregnancy. These cups are responsible for the production of pregnant mare's serum gonadotropin (PMSG).

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Porcine PlacentationLike the horse, this a relatively simple placenta

Ruminant Placentation (bovine)Ruminants have a cotyledonary placenta with many placentomes

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Partial separation of the maternal and fetal placentomeThis placentome is partially separated, showing the interdigitation of the maternal and fetal parts

Equine fetus1. Yolk sac; 2. Chorionic girdle; 3. Allantochorion

Discoidal placenta of a rat.

The outside of the cow placenta showing cotyledons

Separating the fetal membranes from the placenta

Peeling the placental cotyledon away from the fetal membrane. Note how interlaced the capillaries are; this is where nutrient exchange can take place.

Parturition

ParturitionNote Stage 1 (restlessness, rolling), Stage 2 (active contractions, expulsion of the fetus) and Stage 3 (expulsion of fetal membranes, not shown)

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Newborn foal with damDevelopmental status shortly after birth. A, Neonatal foal with mother (the mare has yet to discharge the fetal membranes [after birth]).

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Neonatal Guinea PigsDevelopmental status shortly after birth. B, Newborn guinea pigs, which are born in a more developed state.

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Neonatal Kittens with QueenDevelopmental status shortly after birth in altricial species. A, Newborn kittens.

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Tree-Day-Old Mouse PupsDevelopmental status shortly after birth in altricial species. B, Three-day-old mouse pups.

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Skeletal Ossification (canine)Progress of skeletal ossification in puppy. C, 1, 14, and 28 days after birth, respectively.

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LactationProvides colostrum and nutrition

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Mammary Gland DistributionDistribution of mammary glands in certain mammals. The dots indicate the number of orifices on the teat. A, Sow. B, Bitch. C, Cat. D, Woman. E, Cow. F, Ewe and she-goat. G, Mare.

Holstein UdderHolstein cow with well-developed udder. 1, Mammary vein.

The Bovine UdderTransverse section of the abdominal floor and cranial quarters of the bovine udder. 1, External abdominal oblique; 2, internal abdominal oblique; 3, rectus abdominis; 4, peritoneum; 5, linea alba; 6, lymph vessel; 7, external pudendal vein; 8, external pudendal (mammary) artery; 9, medial laminae of suspensory apparatus; 10, lactiferous sinus; 11, papillary duct; 12, lateral laminae of suspensory apparatus.

Mammary TissueSection of (A) nonlactating and (B) lactating mammary glands; a compound tubuloalveolar gland (70×). 1, Alveolus; 2, interlobular septum.