Female Reproductive Tract Overview

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Questions and Answers

What is the primary role of the female reproductive system?

Produce testosterone

Support muscular development

Make gametes and support pregnancy (correct)

Facilitate sperm production

Which part of the broad ligament supports the ovaries?

Round ligament

Mesosalpinx

Mesometrium

Mesovarium (correct)

What hormone is primarily produced by the corpus luteum?

Progestin (correct)

Testosterone

Estrogen

Follicle-stimulating hormone

Where are the ovaries located in the female body?

Dorsal abdomen near the kidneys Signup and view all the answers

During which stage of the ovarian cycle does the ovum get released from the follicle?

Ovulation Signup and view all the answers

What distinguishes the ovarian cycle from sperm production in males?

Ova are produced in a cycle, not continuously Signup and view all the answers

What happens to unripened follicles during the ovarian cycle?

They undergo degeneration Signup and view all the answers

What is the broad ligament's cranial attachment point?

Body wall near the last rib Signup and view all the answers

Which structure is responsible for hormone production during the early stages of breeding/pregnancy?

Corpus luteum Signup and view all the answers

What are animals born with in relation to their ovarian function?

A set number of oocytes Signup and view all the answers

What hormone is primarily responsible for triggering ovulation in the estrous cycle?

Luteinizing Hormone (LH) Signup and view all the answers

Which phase of the estrous cycle involves the development of the corpus luteum?

Metestrus Signup and view all the answers

In which type of estrous cycle do animals experience multiple cycles throughout the year if not bred?

Polyestrous Signup and view all the answers

During which phase does the highest production of progesterone occur?

Diestrus Signup and view all the answers

What significant physical change occurs during proestrus?

Cornification of the vaginal epithelia Signup and view all the answers

What describes the anestrus stage in the estrous cycle?

Period of temporary ovarian inactivity Signup and view all the answers

Which animal typically has two estrous cycles per year?

Cats Signup and view all the answers

What occurs if an embryo implants during the diestrus phase?

The corpus luteum continues to produce hormones Signup and view all the answers

What is the main role of Follicle Stimulating Hormone (FSH) during the estrous cycle?

Stimulating the maturation of ova Signup and view all the answers

What is a common condition that may occur as a result of prolonged diestrus in bitches?

Pseudocyesis Signup and view all the answers

What is the role of follicle stimulating hormone (FSH) in follicular development?

Acts on follicular cells to promote development Signup and view all the answers

What characterizes a mature follicle (Graafian follicle)?

It has a well-defined antrum and peak estrogen production Signup and view all the answers

What triggers ovulation in the follicular development process?

A rise in luteinizing hormone (LH) Signup and view all the answers

Which of the following statements about the corpus luteum is true?

It arises from the ruptured follicle post-ovulation Signup and view all the answers

What is the main function of the oviduct?

To catch the ovum and facilitate fertilization Signup and view all the answers

During which stage does a primordial follicle become a growing follicle?

When the zona pellucida forms Signup and view all the answers

What is follicular atresia?

The degeneration of partially developed follicles Signup and view all the answers

What components are involved in the external portion of the female reproductive system?

Clitoris, vestibule, labia Signup and view all the answers

What is the main hormone produced by the corpus luteum?

Progesterone Signup and view all the answers

What structure is formed from the ruptured follicle after ovulation?

Corpus hemorrhagicum Signup and view all the answers

Which type of species typically produces multiple ova during breeding?

Multiparous species like dogs and cats Signup and view all the answers

What is NOT a function of the uterus?

Facilitates milk production Signup and view all the answers

What structure primarily protects the uterus and fetus from infections?

Cervix Signup and view all the answers

What is the role of fimbriae in the reproductive system?

To help catch the ovum released during ovulation Signup and view all the answers

What is the primary function of the placenta?

Nutrient exchange and waste removal for the fetus Signup and view all the answers

What distinguishes the hemochorial placenta from other types?

There is direct contact between chorionic epithelium and maternal blood Signup and view all the answers

Which structure is responsible for preventing luteolysis during implantation?

Trophoblast Signup and view all the answers

How do the umbilical arteries function in relation to fetal circulation?

They transport unoxygenated, waste-filled blood to the placenta Signup and view all the answers

What is the role of the allantois in placental anatomy?

It helps in waste management and urine collection Signup and view all the answers

Which of the following statements is true regarding the connection between the umbilical cord and the placenta?

The umbilical cord contains both arteries and veins that assist in blood circulation Signup and view all the answers

What occurs during implantation of the blastocyst into the uterine endometrium?

The chorion begins to attach to the uterine lining Signup and view all the answers

What is a characteristic of epitheliochorial placentation?

Endometrial epithelium and chorion epithelium remain intact Signup and view all the answers

What is the initial step in the mating process among domestic animals?

Mounting and standing position Signup and view all the answers

Which factor does NOT facilitate sperm transport to the oviducts?

Seminal vesicles secretion Signup and view all the answers

What is the process of sperm becoming fertile while in the female reproductive tract called?

Capacitation Signup and view all the answers

Which block prevents polyspermy after fertilization?

Cortical reaction Signup and view all the answers

What does the term 'morula' refer to during embryo development?

A 16-celled embryo Signup and view all the answers

Which part of the blastocyst develops into the fetal placenta?

Trophoblast Signup and view all the answers

What significant change occurs during the blastocyst formation?

Fluid accumulation within the morula Signup and view all the answers

Which reaction involves the release of enzymes and allows sperm to penetrate the zona pellucida?

Acrosome reaction Signup and view all the answers

During what phase does the fusion of male and female pronuclei occur?

Syngamy Signup and view all the answers

What is NOT a change observed in female behavior during the estrus phase?

Aggression towards males Signup and view all the answers

What type of placental attachment is characterized by numerous small attachment sites?

Cotyledonary Signup and view all the answers

Which species is associated with diffuse placental attachment?

Pigs Signup and view all the answers

What hormone increases oxytocin sensitivity in the myometrium during parturition?

Estrogen Signup and view all the answers

What is the role of colostrum produced in the first few days after birth?

Supplies antibodies to the newborn Signup and view all the answers

Which type of placental attachment is rarely retained after birth?

Zonary Signup and view all the answers

What structure in ruminants forms the placentome by combining with the maternal tissue?

Caruncle Signup and view all the answers

What hormonal changes trigger the initiation of labor?

Prostaglandin F2alpha and ACTH Signup and view all the answers

What is a characteristic of the mammary glands in cattle?

Four separate quarters Signup and view all the answers

During which trimester does the final development of alveoli in the mammary glands occur?

3rd trimester Signup and view all the answers

Which condition may arise from incomplete placental detachment in ruminants?

Metritis Signup and view all the answers

Which hormone is primarily responsible for the ejection of milk during lactation?

Oxytocin Signup and view all the answers

What happens to lactation if suckling and mammary gland emptying does not occur?

Mammary gland involution Signup and view all the answers

What is the essential function of the alveoli in the mammary gland?

Production of milk Signup and view all the answers

What is the main component that prevents leakage from the teat in mammary glands?

Sphincter muscle Signup and view all the answers

Study Notes

The Female Reproductive Tract

The female reproductive tract is supported by the broad ligament which is a sheet of peritoneum
The broad ligament has three parts:
- Mesovarium: supports the ovaries
- Mesosalpinx: supports the oviduct
- Mesometrium: supports the uterus
The suspensory ligament is attached to the body wall near the last rib
The round ligament is a cord of fibrous tissue and smooth muscle that is part of the broad ligament
The round ligament is cut during ovariohysterectomy (OVH)

Ovaries

The ovaries produce gametes (oogenesis)
The ovaries produce hormones:
- Estrogens: produced by follicles, cause behavioral changes and prepare the female for breeding
- Progestins: produced by the corpus luteum, prepare the uterus for implantation and maintain pregnancy
All female animals are born with a set number of oocytes

The Ovarian Cycle

The ovarian cycle is a series of events involved in the development and release of an ovum
The ovarian cycle is controlled by the anterior pituitary gland which produces follicle stimulating hormone (FSH) and luteinizing hormone (LH)
FSH stimulates follicle development, and LH triggers ovulation
The number of eggs produced depends on the species:
- Uniparous species (horse, human, cow) produce one ova
- Multiparous species (cats, dogs, sows) produce multiple ova

Follicular Development

Follicular development begins with primordial follicles, which consist of an oocyte and a thin layer of flat follicular cells
FSH acts on the follicular cells to stimulate their growth
Follicular development stages:
- Primordial follicle: oocyte with a thin layer of flat follicular cells
- Growing follicle: an activated primordial follicle with a zona pellucida layer surrounding the oocyte
- Mature follicle (Graafian follicle): follicle at its maximal size with an antrum filled with fluid.
- Peak estrogen production occurs in the mature follicle
Follicular atresia: the degeneration of follicles that have not been ovulated

Ovulation

The release of an ovum from the follicle is triggered by rising LH levels
The ruptured follicle forms the corpus hemorrhagicum (CH)
Granulosa cells lining the CH multiply under the influence of LH hormone and form the corpus luteum (CL)
The CL produces progestins (progesterone)

Oviducts

Site of fertilization
The infundibulum of the oviduct catches the ovum after ovulation
The oviduct delivers the ovum to the uterus
Oviduct lining contains cilia and smooth muscle fibers

Uterus

Site of pregnancy
Pushes the fetus out during birth
Forms the placenta
Y-shaped in most domestic animals
The uterus has three layers:
- Endometrium: the inner layer, simple columnar epithelium
- Myometrium: the thickest layer, smooth muscle
- Perimetrium: the outermost layer, covered in visceral peritoneum

Cervix

Smooth muscle sphincter
Located between the body of the uterus and the vagina
Protects the uterus and fetus from infection from outside world
Remains closed except during estrus and parturition

Vagina

Tube that receives the penis during breeding
Birth canal during parturition
Lined with mucous glands

Vulva

External portion of the female reproductive system
Consists of:
- Vestibule: entrance to the vagina, where the urethra opens
- Clitoris: located on the floor of the vestibule, equivalent to the male penis
- Labia: lips that form the external boundary of the vulva

Estrus Cycle

Period during which the female is receptive to the male
Period from the beginning of one heat to the beginning of the next
Controlled by FSH and LH
FSH stimulates follicular development and estrogen production
LH triggers ovulation and formation of the corpus luteum
Stages of the estrous cycle:
- Proestrus: period of follicular development
- Estrus: heat period, peak estrogen levels with physical and behavioral changes signifying receptive to breeding
- Metestrus: period after ovulation, the CL develops and produces progesterone, uterus lining grows
- Diestrus: active luteal phase, progesterone is produced, CL either continues (pregnancy) or degenerates (no pregnancy)
- Anestrus: temporary ovarian inactivity, animals are not capable of breeding

Clinical Relevance: Pyometra

Infection of the uterus

Breeding

Estrogen drives the physical and behavioral changes of estrus
Male animals are attracted to visual, olfactory, and behavioral cues from females in estrus
Females show signs of estrus such as increased activity/restlessness, vocalization, mounting, lordosis, and tail flagging
Copulation/mating occurs during estrus
Intromission is the insertion of the penis into the vagina

Fertilization

Sperm travels rapidly to the oviduct by estrogen-stimulated myometrial contractions, prostaglandins in semen, oxytocin release, and cilia in the oviduct
Spermatozoa are not initially fertile, they undergo capacitation and acrosome reaction in the female reproductive tract to become fertile
Fertilization occurs when sperm penetrates the zona pellucida and binds to the oocyte plasma membrane
The oocyte undergoes a cortical reaction to prevent polyspermy, creating a “zona block” and “vitelline block”

Pregnancy

Zygote is a fertilized ovum
Syngamy is the fusion of the male and female pronuclei, forming a diploid chromosome number.
Cleavage divisions are rapid mitotic divisions that occur after the formation of the zygote
Blastocyst forms from a morula and is composed of the inner cell mass (ICM) and trophoblast
Implantation is when the blastocyst embeds itself in the uterine endometrium
Maternal recognition of pregnancy prevents luteolysis and varies between species

Placenta

Placenta functions in nutrient and waste exchange, as well as hormonal production for pregnancy maintenance and parturition
Chorion of the fetus attaches to the endometrium of the dam
Umbilical cord connects the fetus to the placenta
Fetal and maternal blood do not mix
Placental attachment can be diffuse, cotyledonary, zonary, or discoid

Parturition

Parturition is triggered by hormonal changes
Relaxin from the placenta relaxes pelvic ligaments
Fetal stress releases ACTH and cortisol
Placenta releases PGF2⍺ causing progesterone to drop and estrogen to rise
Oxytocin sensitivity of the myometrium increases, leading to myometrial contractions

Lactation

Mammary glands are present in both males and females
Hormones initiate and maintain function
Prolactin is the primary hormone of milk production
Oxytocin is the hormone of milk ejection
Colostrum is produced in the first 2-3 days after birth and offers important nutrients and antibodies to the newborn
Milk "let down" occurs when the nipple is stimulated, sending nerve impulses to the brain
Oxytocin causes contraction of myoepithelial cells, squeezing milk into larger ducts and sinuses

Udder of the Cow

Cows have four mammary glands (quarters), which are separate
The udder can weigh up to 100 lb at milking time
Median and lateral suspensory ligaments support the udder

Alveoli and Duct System

Alveoli are where milk is produced and are arranged like clusters of grapes
Ducts converge into larger ducts
Teat serves as a passage for milk release
Streak canal is protected by elastic fibers and a sphincter muscle to prevent leakage

Mammary Gland Development

Initial development occurs during puberty
Prolactin, growth hormone, estrogen, and progesterone are necessary for duct and alveoli development
Final development occurs in the third trimester of pregnancy with the help of prolactin, ACTH, and placental lactogen

Maintenance of Lactation

Milk production continues as long as suckling and emptying occur
Nerve impulses from teat stimulation provide positive feedback
Mammary gland involution is the gradual decrease and stop of lactation, due to decreased stimulation or prolonged pressure buildup

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Description

This quiz covers the anatomy and function of the female reproductive tract, including ligaments, ovaries, and the ovarian cycle. Learn about the supportive structures like the broad ligament and the hormones produced during oogenesis. Test your knowledge on the processes sustaining female reproductive health.