Anatomy and Physiology of the Female Reproductive Tract

Question 1

What are the two openings at either end of the endocervical canal called?

Answer 1

The internal OS (between the endocervical canal and the endometrial cavity) and the external OS (between the cervix and the vagina).

Question 2

What is the region called where the endocervical columnar epithelium joins the ectocervical squamous epithelium?

Answer 2

The Squamous-columnar junction.

Question 3

What is the Squamo-columnar junction?

Answer 3

The region where the endocervical columnar epithelium joins the ectocervical squamous epithelium.

Question 4

In a prepubescent girl where is the squamo-columnar junction found?

Answer 4

The SCJ is present exactly at the external OS.

Question 5

Describe the process that takes place to the squamo-columnar junction (SCJ) in adulthood.

Answer 5

In an adult the endocervical epithelium defends and gets exposed to the acidic environment of the vagina&raquo_space;> once in the vagina the glandular epithelium cannot survive and has to adapt to cope with the environment&raquo_space;> endocervical epithelium changes via metaplasia into metastatic squamous epithelium&raquo_space;> you end up with endocervical glands covered by metaplastic squamous epithelium called the Transformation Zone

Question 6

What cells make up the Transformation Zone?

Answer 6

Endocervical glands covered by metaplastic squamous epithelium.

Question 7

What is metaplasia?

Answer 7

The replacement of one cell type with another that is not usually found in a given location.

Question 8

In the case of the cervical SCJ what factors can cause metaplasia?

Answer 8

Exposure to acidic environment of the vagina, mechanical trauma such as labour and infection.

Question 9

How might you identify a metaplastic cell?

Answer 9

It will usually display some features of its predecessor.

Question 10

What are the 3 steps towards metaplasia at the SCJ?

Answer 10

1) . Basal Cell Hyperplasia
2) . Acquiring squamous characteristics
3) . Settling of the new epithelium mimicking the adjacent original squamous epithelium but retaining underlying glands.

Question 11

Describe basal cells.

Answer 11

Basal cells are small cuboidal cells that rest on the basement membrane. They have the ability to give rise to further basal cells and to other cell types found within the epithelium.

Question 12

What features might the term ‘acquiring squamous characteristics’ describe?

Answer 12

Intracytoplasmic keratinisation and the formation of intercellular bridges (localised, not extensive).

Question 13

What is the site of origin of pre-neoplastic cervical lesions?

Answer 13

The SCJ.

Question 14

Describe the importance of the transformation zone.

Answer 14

The transformation zone is the result of a defensive process to enable the cervical tissue to cope with physiological changes.

It is the site of cytological sampling for screening purposes.

It contains the SCJ which is the site of origin of pre-neoplastic lesions.

Excision of the transformation zone is standard treatment of cervical pre-neoplastic lesions.

Question 15

What happens to the SCJ post menopause?

Answer 15

Post menopausal atrophy occurs whereby the SCJ pulls back into the endocervical canal after the menopause (even higher than at the prepubescent stage).

Question 16

The uterine is made up of the uterine _______ and the uterine ________.

Answer 16

The uterus is made up of the uterine cervix and the uterine corpus.

Question 17

Describe an ovarian follicle.

Answer 17

The ovarian follicle is the basic unit of the ovary. It is composed of roughly spherical aggregations of granulosa cells surrounding a single ovum. Theca cells surround the granulosa cells.

Granulosa cells produce oestrogen.

Theca cells produce testosterone.

Question 18

List the functions of oestrogen.

Answer 18

1) . Promotes development of secondary sex characteristics in females.
2) . Increases growth hormone and accelerates height growth.
3) . Reduces bone resorption and therefore decreases the risk of osteoporosis in menopause do women.
4) . Increases antithrombin iii, plasminogen and platelet levels. This means that there is an increased risk of DVT with the use of oral contraceptives.
5) . Promotes fat deposition and can lead to unsightly body fat.
6) . Increases HDL and triglyceride levels and decreases LDL levels. This leads to a decreased risk of cardiac disease.
7) . Precipitates salt and water retention causing premenstrual tension.
8) . Promotes endometrial proliferation. If this gets out of control can lead to endometrial hyperplasia and cancer (danger if high oestrogen levels are not opposed by progesterone).

Question 19

List the functions of progesterone.

Answer 19

1) . Prepares the uterus for the implantation of the fertilised ovum.
2) . Edits the maternal immune response to allow for the acceptance of pregnancy.
3) . Inhibits lactation during pregnancy and soon after delivery the fall in progesterone level is one of the stimuli for milk production.
4) . Protects the endometrium from the proliferative action of the oestrogen which unopposed could cause cancer.

Question 20

Where is FSH secreted?

Answer 20

FSH is secreted by the anterior pituitary.

Question 21

What does Follicular Stimulating Hormone (FSH) do? What effect does it have on the follicle?

Answer 21

FSH regulates the development, growth, pubertal maturation, and reproductive processes of the body.

FSH stimulates the proliferation and growth of the follicle.

Question 22

Where is Leutenising Hormone (LH) produced?

Answer 22

The anterior pituitary.

Question 23

What induces ovulation?

Answer 23

The LH surge.

Question 24

Where is Gonadotropin Releasing Hormone (GNRH) secreted?

Answer 24

GNRH is secreted by the hypothalamus.

Question 25

What is the function of GNRH?

Answer 25

GNRH stimulates the secretion of FSH and LH from the pituitary gland.

Question 26

What effect does LH have on the follicle?

Answer 26

LH acts in the follicle causing leutenisation and production of progesterone.

Question 27

What effect does oestrogen have on the anterior pituitary?

Answer 27

Oestrogen causes negative feedback to stop FSH production at the anterior pituitary.

Question 28

What effect does progesterone have in the anterior pituitary?

Answer 28

Progesterone causes negative feedback to stop LH production at the anterior pituitary.

Question 29

What effect does progesterone have on the ovaries?

Answer 29

Progesterone stimulates the endometrium to go into a secretory phase. After the secretory phase all hormone levels drop and if there is no pregnancy it ends up in shedding and menstruation.

Question 30

What are the three phases of the menstrual cycle? Describe the hormone levels associated with each phase.

Answer 30

1) . Proliferative phase - levels of FSH, LH and oestrogen increase towards mid cycle. Especially the LH surge which causes ovulation. At the end of the proliferative stage progesterone levels begin to rise.
2) . Secretory phase - LH, FSH levels drop. Progesterone levels are higher than oestrogen.
3) . Menstrual phase - low levels of FSH, LH, oestrogen and progesterone.

Question 31

What is the first developmental indication of the urinary system in a human?

Answer 31

The first indication of the urinary system in the human being is the development of the mesonephros not at 21 days of gestation.

Question 32

At what point of development does the mesonephro become the metanephro?

Answer 32

The development of the metanephron starts at approximately 42 days.

Question 33

What duct system develops into the male reproductive system under the correct conditions?

Answer 33

The mesonephric / wolffian duct.

Question 34

The Müllerian system develops into what?

Answer 34

The female reproductive system.

Question 35

What hormone is primarily responsible for the formation of the male reproductive system rather than the female reproductive system?

Answer 35

Müllerian inhibiting hormone will lead to the establishment of the mesonephric duct to form the male reproductive system and the disintegration of the Müllerian system. With no Müllerian inhibiting hormone the opposite happens.

Question 36

Look at the development of the female reproductive system.

Answer 36

See diagrams.

Question 37

What is the patch of Douglas and where is it located?

Answer 37

The patch of Douglas is located between the posterior aspect of the cervix and the rectum.

It is a common site for the accumulation of the precipitating cells from the peritoneum.

Washing from this pouch are taken in staging procedures for gynaecological cancer as it represents pooling of cells from the peritoneal cavity.

Question 38

What is the basic structure and function of the uterus?

Answer 38

The uterus is 95% smooth muscle (myometrium) which is lined by a thin layer of endometrium.

During pregnancy the myometrium undergoes hypertrophy leading to enlarged uterine size.

After menopause the uterine size regresses.

Question 39

Describe the structure and function of the endometrium.

Answer 39

The endometrium is composed of two layers called the stratum basalis and the stratum functionalis. The stratum functionalis is the top layer which is nearest the lumen.

The endometrium is equipped to receive the fertilised ovum and for foetal development.

Question 40

What is the central canal of the cervix called?

Answer 40

The endocervical canal.

Question 41

Describe the vagina.

Answer 41

The vagina is a fibromuscular canal approximately 10cm long. The vagina joins the cervix from one end forming an arch on either side called the formix. The vagina opens externally, joining the vulva. The vagina is located between the rectum and the urinary bladder.

Question 42

Describe the structure and function of the Fallopian tubes.

Answer 42

The Fallopian tubes are two tubes; one on either horn of the uterus ending in a funnel shaped infundibulum surrounded by finger-like extensions (fimbrae).

The fimbrae embrace the ovary to facilitate the transport of the ovum from the ovary to the uterus through the rhythmic beating of cilia present on the epithelial lining and the peristaltic action if the tubular muscular wall.

The journey from the ovary to the uterus takes about 7 days. Fertilisation usually occurs within the first 48 hours of this journey.

Question 43

What are located at the fimbral end of each Fallopian tube?

Answer 43

The ovaries.

Question 44

How are the ovaries are suspended in place in the pelvis?

Answer 44

By ligaments attached to the pelvic wall.

Question 45

What is the vulva?

Answer 45

The vulva surrounds the vaginal orifice and contains the external female genitalia including the mons pubis, the clitoris, the labia majora and the labia minora.

Question 46

What is the mons pubis?

Answer 46

The mons pubis is a pad of fatty tissue over the anterior part of the pubic bone. It becomes covered with hair during puberty. It functions to protect underlying structures.

Question 47

What is the clitoris?

Answer 47

The clitoris is an erectile hooded organ at the upper joining of the labia that contains a high concentration of nerve endings.

Question 48

Describe the labia majora.

Answer 48

The labia majora are two spongy folds on either side of the vaginal opening that cover and protect the genital structures. They extend from the mons pubis to the perineum and contain the Bartholin’s gland that secretes yellowish mucus.

Question 49

What is the function of the broad ligament?

Answer 49

The broad ligament is a peritoneal sheet attached to the pelvic wall and contains the Fallopian tubes and ovaries, the arterial supply and round ligament.

Question 50

What is the function of the round ligament?

Answer 50

To maintain the anteflexion if the uterus.

Question 51

Describe the labia minora.

Answer 51

The labia minora are two erectile folds between the labia majora that extend from the clitoris on both sides of the urethral and vaginal openings.

Question 52

What is the function of the perineum?

Answer 52

The perineum contains a network of muscles located between and surrounding the vagina and the anus that support the pelvic cavity and help keeping organs in place. This is the site of episiotomy.