1 – Female Reproduction Flashcards
What is obstetrics?
- Study of vet med involving pregnancy, birth, and post-partum period
What is gynecology?
- Study of vet med involving female reproductive system and breast/mammary gland
What is andrology?
- Study of vet med involving the male reproductive system which often overlaps with the urinary system
Genitalia
- Internal and external organs concerned with reproduction
o Only external=vulva
*What is the function of the female reproductive system?
- Produce viable ova
- Promote fertilization of ova
- Carry conceptus or conceptuses to term
- Delivery (expel) fetus or fetuses through birth canal
What are the 3 sequential stages of sexual development?
- Chromosomal sex
- Gonadal sex
- Phenotypic sex
What are some of the genes that drive sexual development?
- SRY: ‘maleness’ on Y chromosomes
- DAX1 gene on X chromosomes
Before sexual differentiation the embryo has a bipotential gonad and 2 sets of ducts
- Mesonephric (Wolffian) ducts
a. Disappears in embryo w/o a SRY gene
b. Testosterone promotes development - Paramesonephric (Mullerian) ducts
a. Form female tubular genitalia in embryo w/o SRY gene
b. Mullerian inhibition from testes=regression
DAX1 gene present on X chromosome
- Responsible for production of a nuclear receptor that plays a role in normal development of ovaries and testes (hormone producing tissues)
- Expression during development=development of ovaries
- Down regulation=development of testes
How can developmental disorders of sexual development (DSD) be categorized?
- Abnormal or atypical
o Chromosomal sex
o Gonadal sex
o Phenotypic sex - Individuals with DSD=INTERSEX
What 2 categories can DSD involving chromosomal abnormalities be divided into?
- Abnormal structure of sex chromosome
- Abnormal or atypical number of sex chromosomes
*often associated with abnormal sexual phenotype and infertility
Examples of DSD involving abnormalities with chromosomal sex in HUMANS
- Turner’s syndrome: only one X chromosome
- Klinefelter’s syndrome: XXY
What is the most common example of abnormality in chromosomal sex in animals
- Freemartins
o Most often in cattle
o Results from 2 or more sets of cells that have different chromosomes (b/c from different animals) present in the same animal
What must there be for freemartinism to occur?
- Placental vascular ANASTOMOSES between twin fetuses of DIFFERENT sexes
o Allows for mixing of hematopoietic cells early in gestation
o Partial expression of genes on male fetus Y chromosome within female fetus impedes development of ovaries (and external genitalia)
What happens to the female as a result of freemartinism?
- Abnormally developed internal genital
- Hypoplastic, vagina, vestibule and vulva
- *male is minimally affected
DSD involving abnormalities in gonadal sex
- XX: present in genetically female individuals, but so called ambiguous phenotypes
- *have some form of GONADAL DYSGENESIS
o Rudimentary gonads
1 testis and 1 ovary
1 gonad with mixed tissues (OVOTESTIS) - *called INTERSEX
DSD involving abnormalities in phenotypic sex
- Have normal numbers of sex chromosomes and only one type of gonadal tissue
- *but genitalia has developed in way that causes MALE-FEMALE AMBIGUITY
- Ex. XY genetically male individual with female phenotype
Example of XY DSD genetically male individual with female phenotype
- Abnormalities develop due to INAPPROPRIATE GONADAL DEVELOPMENT that results in a female phenotype
- *can also be classified by presence or absence of SRY gene
What are some developmental abnormalities of the ovaries?
- Aplasia
- Hypoplasia
- Duplication
- Ovarian and paraovarian cysts
Aplasia of ovary
- One or both or entire reproductive tract
o If both=fail to form reproductive tract and remains INFANTILE
Hypoplasia of ovary
- Mostly in cows
- Usually bilateral (may not be symmetric) but can be unilateral
o If both=INFANTILE
What are some known causes of ovarian hypoplasia?
- Females with abnormal number of X chromosomes (ex. DSD X_ or XXX)
Duplication of ovary
- RARE
- May represent true duplication of developing ovary or splitting of an ovary
- *may cause OVARIAN REMNANT SYNDROME
What is ovarian remnant syndrome?
- Incompletely spayed cats and dogs go through estrus
Ovarian (in) and parovarian (around) cysts
- Common
- Several origins
- No clinical importance or might be associated with abnormal estrous cycles or infertility
What is oophoritis?
- Inflammation of ovary
- Rare and of little clinical importance
Ovarian neoplasia occurrence
- Rarely occurs
What may ovarian neoplasia’s arise from?
- Germ cells (produce gametes)
- Sex cord cells (form granulosa and thecal cells)
- Stromal cells
- Epithelial cells
What are the 2 examples of germ cell ovarian neoplasia?
- Dysgerminomas
- Teratomas
Dysgerminomas
- Usually malignant, rarely metastasize
- Analogous to seminomas in males
Teratomas
- Benign
- Contain cells or tissue of at least 2 of 3 embryonic germ layers (ectoderm, mesoderm, endoderm)
- Skin and adnexa are often present
What is the most common (although rare) ovarian tumor in domestic animals?
- Sex cord-stromal cell tumors
o When sex cords and stromal cells combine to form a tumor
Sex cord-stromal cell tumors
- Have potential to produce and secrete hormones (estrogen, progesterone, testosterone, inhibin)
- Can be associated with a variety of ABNORMAL REPRODUCTIVE BEHAVIOURS (ex. persistent anestrus, irregular estrus)
What are the terms used to describe the microscopic appearance of sex cord-stromal cell tumors?
- Granulosa cell tumors
- Granulosa-theca cell tumors
- Thecomas
- Luteomas
Where can epithelial tumors of the ovary arise from?
- Surface epithelium
- Rete ovarii (forms from primary sex cords in females)
- *form adenomas or carcinomas
- *papillary and cystic
What are the abnormalities seen with uterine tubes?
- Obstruction
- Ex. Segmental aplasia
- Ex. salpingitis
- *can result in distension of uterine tube with clear fluid=HYDROSALPINX
Salpingitis
- Results in obstruction due to formation of ADHESIONS AND FIBROSIS
- Can also lead to pyosalpinx
Salpingitis is rare, but when it does occur, what is associated with?
- Bacterial endometritis, metritis or pyometra
What are some developmental abnormalities of the uterus and cervix?
- Uterus: variety described, none common
- *Cervix: double external cervical os=infrequent but regular encounter in CATTLE
o 2 cervical canals within the same cervix or a bifurcated cervical canal
o Can cause problems with PARTURITION
What are the 2 ways that organisms that cause inflammation in the uterus can enter? (most often)
- Via the vulva (ASCENDING INFECTION)
- Via blood (HEMATOGENOUSLY)
Generally, when do ascending infections of the uterus occur?
- When cervix is OPEN
o Estrus
o Breeding
o Parturition
Generally, when do hematogenous infections of the uterus occur?
- Pregnancy (cervix is CLOSED)
When are infections of the uterus more easily cleared?
- During estrus
Why are infections of the uterus more easily cleared DURING estrus?
- Better drainage through open cervix
- Increased number of neutrophils
- Increased neutrophil activity
How does estrogen and progesterone influence the migration of neutrophils to the uterus and phagocytosis by neutrophils?
- Estrogen=increased
- Testosterone=decreased
When is the uterus most susceptible to infection?
- Diestrus
- Pregnancy
In bitch and queen, what are most cases of pyometra a result of?
- Bacterial infection secondary to endometrial hyperplasia
Pyometra
- Sequel to endometritis or metritis in which there is accumulation of PUS IN UTERINE LUMEN due to closed or mostly closed cervix
What are the non-inflammatory lesions of the uterus and cervix?
- Torsion
- Prolapse
- Subinvolution of placental sites
- Endometrial hyperplasia
- Hydrometra and mucometra
When does torsion of uterus most commonly occur?
- When enlarged by
o Pregnancy
o Pyometra
o Mucometra
What is the sequela of uterine torsion?
- Circulatory compromise
- Death of any fetuses present
- Edema
- Congestion
- Necrosis of affected portions of uterus
o Susceptible to rupture
Uterine prolapse
- Protrusion of uterine body and 1 or both horns through the cervix
- Can occur following parturition in all species especially if complicated
o Dystocia
o Assisted delivery
o Retained placenta - *MORE common in ungulate farm animals (ex. cow, ewe, sow)
Subinvolution of placental sites
- ONLY IN DOGS
- *persistence of trophoblasts in uterus beyond normal 12 weeks following parturition (FAILURE OF NORMAL INVOLUTION)
- UNKNOWN cause
Trophoblasts function/role
- Attach embryo to uterus
- Help nourish blastocyst
- Form outer layers of placenta
What does subinvolution of placental sites present as clinically?
- Bloody vaginal discharge for longer than normal (ex. several weeks to months following parturition)
- *WHELPING
What does subinvolution of placental sites look like GROSSLY?
- Presence of ANNULAR BANDS of thickening and roughening of uterine mucosa
o These correspond to some or all placental sites
o TWICE AS THICK as normal for the given stage of involution
Subinvolution of placental sites microscopically
- Trophoblasts in deep aspects of myometrium associated with
o Necrosis
o Hemorrhage
o Occasionally: Perforation of uterus and peritonitis
Endometrial hyperplasia: what does it occur in and what is the cause?
- Occurs in all domestic mammals, except DOGS
- Due to prolonged hyperestrogenism
What can prolonged hyperestrogenism be due to causing endometrial hyperplasia?
- Endogenous
o Cystic follicles or granulosa cell tumors - Exogenous
o Estrogen-like chemicals in plants or mycotoxins
What does estrogen induce in animals and what is progesterone’s role? When do the changes reverse?
- Increase in endometrial gland length
- Progesterone: endometrial glands undergo further hyperplasia and hypertrophy=become convoluted
- Changes REVERSE when progesterone levels decline
What occurs in DOGS if there is a source of irritation or inflammation within the uterus (Ex. bacteria)?
- Uterus undergoes hyperplasia like in PREGNANCY
- *cystic endometrial hyperplasia
What is cystic endometrial hyperplasia?
- IN DOGS
- Exaggerated or inappropriate response resulting in formation of:
o CYSTS WITHIN HYPERPLASTIC GLANDS
o Accumulation of fluid within both glands and uterine lumen=great media for bacterial growth and inflammation=endometritis and pyometra - Unknown why it happens in some and not others
What are the 2 reasons hydrometra and mucometra occur?
- Obstruction of normal outflow
- Increased secretory activity of endometrial glands while cervis is closed
Neoplasia of uterus and cervix: examples
- Not common
- Carcinoma in cows at slaughter
- Leiomyoma (fibroids) of bitch
- Lymphoma (lymphosarcoma) in cows with enzootic bovine leukosis
Carcinoma in cows at slaughter
- In endometrium of older cows
- Associated with marked desmoplastic or scirrhous reaction
- Metastasis to regional lymph nodes and lungs is common
- Transcoelmic implantation may occur
Leiomyoma of bitch
- Uterus, cervix and vagina
- *fibroids=grow and become hard
- Vary in size
o Confined within wall OR form pedunculated masses that are susceptible to trauma and hemorrhage
What are leiomyomas often present concurrently with? What is though to stimulate the tumors development?
- Endometrial hyperplasia
- Follicular cysts
- Mammary neoplasms
- *estrogens
Lymphoma (lymphosarcoma) in cow
- Part of enzoonotic bovine leukosis/lymphoma
- *affects heart, abomasum, lymph nodes, uterus
What causes enzootic bovine leukosis/lymphoma?
- Bovine leukemia virus (oncovirus in retrovirus family)
What age category does enzootic bovine leukosis/lymphoma occur?
- Mature animals (4-8 years old)
What age category does sporadic bovine leukosis tend to occur in?
- Animals under 3 years
- Cause of the different forms (calf, thymic, cutaneous) is NOT KNOWN
What are the 2 important diseases in rabbits?
- P. multocida: SNUFFLES
- Uterine adenocarcinomas
