FRS

Introduction to the Female Reproductive System

• The female reproductive tract's main functions are fertilization, implantation, maintenance of the fetus, and delivery of offspring.
• The system is comprised of several organs: ovary, fallopian tubes, uterus, cervix, and vagina.

Ovary

• Produces eggs from germinal follicles in response to pituitary hormones.
• It is an endocrine organ, producing estrogen from Graafian follicles and progesterone from the corpus luteum.

Fallopian Tube (Oviduct)

• Site of fertilization.
• Transports the fertilized egg to the uterine horn for implantation.

Uterus

• Site of fetal implantation.
• Provides a suitable environment for fetal development through progesterone, and nutrient delivery via the placentome.
• Uterine wall produces prostaglandin to lyse the corpus luteum and re-start follicular development.

Cervix

• Facilitates sperm entry during oestrus (cervix open).
• Isolates the uterus from the outside world during pregnancy (cervix closed).
• Contains normal flora.

Vagina

• Site of sperm deposition during breeding.
• Not sterile; contains normal flora.

Hormonal Functions

• Hypothalamus/pituitary gland regulates ovarian function.
• Hormones such as Follicle-stimulating hormone (FSH), Luteinising hormone (LH), and Estrogen, play crucial roles in reproductive processes.
• Failures in hormonal function can lead to problems like inactive ovary, cystic ovary, failure of ovulation, and infertility.

Ovarian Cysts

• Cysts larger than 1 cm in diameter are common in livestock, causing infertility (85% of culled infertile cows have ovarian cysts).
• Three major types of ovarian cysts: Cystic Graafian follicle, Luteinized cyst, Cystic corpus luteum.

Cystic Graafian Follicle

• The most common type of ovarian cyst.
• More prevalent in high-producing cows due to failure of the Graafian follicle to rupture and release eggs.
• May cause anestrus and reduced fertility.
• Mature follicles aren't exposed to ovulating hormone, causing enlarged follicles (≥ 2 cm in diameter).
• Cyst walls are thicker than mature follicles, with oedema in the vulva, cervix,and uterus, and lack of the ovum within.
• Leads to nymphomania, irregular oestrus, and infertility.

Luteinized Cysts

• Develops due to delayed or insufficient luteinizing hormone during oestrus.
• Usually single cysts with luteinization and ovulation.
• The cyst cavity appears spherical lined by fibrous tissue.

Cystic Corpus Luteum

• Develops after ovulation but with a cyst cavity in the developing corpus luteum.
• Cysts are not larger than 5 mm.
• Detectible 4-8 days after ovulation.
• Generally does not significantly impair reproductive performance, though misdiagnosis is possible.

Ovarian Neoplasia

• Uncommon in veterinary medicine.
• Often discovered incidentally during ovariohysterectomy.

Fallopian Tube

• A small, ciliated tubal structure where fertilization occurs. Allows for smooth movement of sperm and egg.
• Failure can cause repeat breeding in fertile animals.

Salpingitis

• Inflammation of the fallopian tube (oviduct).
• Usually occurs with other reproductive tract inflammations
• Typically bilateral and often not visually apparent.
• Inflammation may be serous, catarrhal, or fibrinous.

Hydrosalpinx

• Fallopian tube distention due to fluid accumulation.
• Often caused by inflammatory reactions from surrounding tissues and blockages in the lumen.
• Inflammatory reaction may result from traumatic manipulation of the ovary.

Pyosalpinx

• Fallopian tube distention caused by pus accumulation.
• A consequence of acute inflammation and ascending infection( from uterus).
• Blocked lumen accumulating pus.
• Acute inflammation typically involves neutrophils, lymphocytes, and some plasma cells.

Uterus

• Normal, non-pregnant uterus under estrogen influence and highly resistant to infections like brucellosis, campylobacteriosis.
• Under progesterone influence (pregnant uterus), it's more susceptible to non-specific bacteria. - Critical times for uterine infections are post-coital and post-parturient.

Endometritis

• Inflammation of the endometrium.
• Commonly caused by less pathogenic organisms (Trichomonas foetus, Campylobacter fetus, pyogenic cocci, and coliforms).
• Mild inflammation with leukocyte infiltration, occasional lymphocytes.
• Desquamation of superficial epithelium.
• Can lead to infertility or abortion.

Puerperal Endometritis

• Severe grade of endometritis, occurring via post-parturient infection.
• Characterized by a markedly enlarged and flabby uterus, containing chocolate-coloured or greyish-yellow lochia mixed with cellular debris.
• Histological examination showing haemorrhages, congested mucosa, leukocyte infiltration, abnormal endometrial glands, and bacterial colonies.

Chronic Endometritis

• Prolonged inflammation in endometrium.
• Fibrosis, leukocytosis, thickened endometrium and atrophied glands.
• Mucosal lining can either be intact or denuded with focal hyperplasia, squamous metaplasia, or scar tissues.

Metritis

• Inflammation of all uterine layers (usually with discharge).
• Affected uterine wall appears thickened, congested with blood vessels and oedema.
• Serosal surface shows petechial or paint-brush hemorrhages, and exudate may be foetid and yellowish or red-black in colour.
• Histological features reveal purulent inflammation of mucosa, haemorrhage, necrosis, neutrophil infiltration of subserosa, and similar inflammatory lesions in myometrial vessels.

Sequela to Endometritis and Metritis

• Many cases of mild endometritis resolve but severe cases can result in chronic endometritis, uterine abscessation, parametritis, salpingitis, and pyometra.
• This might lead to infertility.

Pyometra

• Pus accumulation in the uterine lumen.
• Often a consequence of complicated uterine infection by pyogenic bacteria.
• Retention of corpus luteum beyond its normal cyclic span is a key factor.

Pathogenesis of Pyometra

• Prolonged progesterone presence leads to a lack of prostaglandin and subsequent endometrial infection, ultimately resulting in uterine destruction.

Uterine Torsion

• Uterine twisting (mainly in cows after pregnancy, pyometra, or hydrometra).
• Minor torsion (<90°) often resolves naturally.
• Severe torsion (>180°) can cause local circulatory issues, leading to congestion, oedema, placental problems, foetal death, necrotic uterine wall, and uterine rupture.
• Correction is typically performed using surgical methods (like Schaffer's)

Uterine Prolapse

• Uterus protruding out of the vagina.
• Often observed in cows after complicated births, retained placenta, extended dystocia, or high estrogen levels after parturition.
• Affected uterus shows congestion, oedema, hemorrhage, necrosis, and potential for gangrene.

Uterine Rupture

• Uterine rupture (often following obstetrical procedures).
• Usually occurs in the uterine fundus near the pelvic brim.
• Can involve only the mucosal layer or the entire uterine wall.
• Mucosal ruptures are less severe but complete ruptures have significant risk of haemorrhages, peritonitis, and shock leading to death.

Cystic Endometrial Hyperplasia

• A condition causing cystic endometrial growths.
• Often seen in dogs and cats, occasionally in mares and cows.
• Develops due to excessive/long-lasting estrogen stimulation.
• Results in prominent presence of cysts in the uterine tissues.
• Associated with infertility.

In Utero Foetal Death

• Conditions where a foetus dies within the uterus.
• Abortion: Expulsion of a non-full-term dead fetus.
• Usually caused by infections (e.g., brucellosis, listeriosis), physiological issues (e.g., malnutrition), toxins, or physical trauma.
• Stillbirth: Expulsion of a full-term dead foetus.
• Often related to malnutrition or mild infections late in pregnancy with insufficient placentome development.

Foetal Mummification

• Dead foetus within the uterus, that's dried up and shrunken.
• Caused by resorption of fluids and foetal membranes wrapping around the foetus.
• Results in brown, black leathery appearance with no odour or exudates.
• More commonly seen in uniparous animals but possibly in multiparous ones during parturition, along with normal siblings.

Foetal Maceration

• Dead oedematous foetus within the uterus.
• Caused by specific infections affecting the early embryo stage,
• Results from non-specific infections and lack of sufficient placentome development.
• Frequently seen in cases of campylobacteriosis or trichomoniasis.
• The foetus appears oedematous, foul-smelling, and potentially with gas accumulation.

Mammary Gland (Mastitis)

• Inflammation of the mammary glands.
• Most commonly seen in dairy cows.
• Various bacterial or fungal species can cause this, and two important causes in cows are Streptococcus agalactiae, and Corynebacterium pyogenes.

Mastitis Outcomes

• Clinical Mastitis: acute, peracute, or subacute.
• Subclinical Mastitis: no visible signs of inflammation.
• Mastitis outcomes depend on the organism's virulence, route of infection, and connective tissue reactions.
• Outcomes may include:
  • tissue reactions causing the ductal system to become oedematous and have rapid fibroplasia,
  • occlusion of intralobular ducts, and
  • involution of secretory epithelium in response to stroma.

Mastitis Types

• Acute Catarrhal Mastitis: mild organisms causing inflammation in individual quarters, typically with short duration and limited systemic response.
• Acute Haemorrhagic Mastitis: virulent organisms causing necrotizing inflammation, severe swelling, and possible fatality, often associated with serosanguinous or fibrinous secretions.
• Suppurative Mastitis: multiple abscesses with yellow-green pus (primarily caused by Corynebacterium pyogenes or Pseudomonas aeruginosa).
• Subclinical Mastitis: non-specific bacterial infections resulting in elevated leukocytes in milk but no obvious gross abnormalities.
• Mammary gland neoplasms are also mentioned for consideration, but further details are needed.

Test your knowledge about the human reproductive system in this comprehensive quiz. Questions cover various topics, including the functions of the Fallopian tubes, the role of hormones, and conditions affecting the female reproductive organs. Perfect for students and anyone interested in human anatomy and reproductive health.