Session 3

Question 1

Label the following ligaments of the female reproductive tract on the diagram:

Uterosacral ligament

Pubocervical ligament

Transverse/cardinal ligament

Answer 1

Question 2

On the diagram, label the following superficial structures of the pelvic floor:

Ischiocavernosus

Bulbospongiosus

Perineal body

Superficial transverse perineal muscle

Answer 2

Question 3

On the diagram label the following deep muscles of the female pelvic floor:

Puborectalis

Pubococcygeus

Iliococcygeus

Coccygeus

Answer 3

Question 4

What are the functions of the pelvic floor?

Answer 4

Support
A main function of the pelvic floor is support of the pelvic organs; namely the vagina, uterus, ovaries, bladder and rectum.
There are three levels of support:

1. Suspension This maintains an ‘anti-gravity’ position by providing strong vertical support, mainly from the cardinal ligaments & the uterosacral ligaments.
2. Attachment This is support that comes from attachments on the pelvic organs. For example, the vagina is supported by its attachment to endopelvic fascia, levator ani muscles and the perineal body.
3. Fusion This is support that arises from fusion of different tissues, for example the urogenital diaphragm and the perineal body.

Continence
A key function of the pelvic floor is to facilitate micturition and defecation, and maintain urinary and faecal continence.

Intra-abdominal pressure
The pelvic floor maintains a high intra-abdominal pressure during sneezing, laughing, coughing, or other bodily functions that would increase the pressure in the abdomen.

Childbirth
The pelvic floor also contributes to the birth canal and facilitates childbirth.

Sexual Function

Breathing

Question 5

What are the deep muscles of the pelvic floor?

Answer 5

The pelvic floor is made up predominantly by the levator ani muscles. These deep muscles are a U-shaped set of muscles that act like a sling, to encircle the urethra, vagina and rectum, and provide support for these organs.

There are three muscles that contribute to the levator ani, all named after their respective attachments;  Pubococcygeus  Puborectalis  Iliococcygeus

The midpoint of these attachments is the perineal body.

Question 6

What are the superficial muscles of the pelvic floor?

Answer 6

There are also three superficial muscles, found in men and women: 

Bulbospongiosus 

Ischiocavernosus 

Superficial transverse perineal

Question 7

What is an episiotomy, and what muscles are involved? What are the risks?

Answer 7

Surgical incision of the perineum and the posterior vaginal wall to quickly enlarge the opening for the baby to pass through.

The bulbospongiosus and transverse perineal muscles can undergo iatrogenic damage during medio-lateral episiotomy in childbirth. This is done to avoid damage to the perineal body, because of its integral role in providing pelvic floor support as a site of attachment. An episiotomy can be done if the baby is large, there is a difficult delivery or using instruments such as forceps during a delivery. It can cause complications such as infection, haemorrhage, dyspareunia and damage to the anal sphincter. However it is done to prevent further perineal damage (e.g. 2nd or 3rd degree tears)

Question 8

What is the perineal body?

Answer 8

This is the central point between the vagina and the rectum, and its main function is to act as a site of attachment for pelvic floor muscles and other structures that provide support for the pelvic floor.

Question 9

What is the urogenital diaphragm?

Answer 9

This is a sheet of dense fibrous tissue that spans the anterior half of the pelvic floor. It also attaches medially to the urethra, vagina and perineal body. Arises from the ischiopubic ramus. Supports the pelvic floor.

Question 10

What is the nerve supply to the pelvic floor?

Answer 10

The nerve supply is via the pudendal nerve. Therefore damage to this nerve can cause problems with pelvic floor support.

Question 11

What is pelvic organ prolapse? How can it be categorised? What are the complications?

Answer 11

Loss of support for the uterus, bladder or colon can result in a prolapse of any of these organs into the vagina. It has big implications on quality of life due to its disturbance to anorectal, urinary and sexual function. It can also cause an altered sense of body image, leading to depressive symptoms. It can also be a source of pain or infection.

Pelvic organ prolapse can be classified by the compartment that the prolapse has occurred in, and the organ that has prolapsed.

Anterior compartment

This relates to the bladder and/or urethra:

o Cystoceole = bladder

oUrethrocoele = urethra

o Cystourethrocoele = both

Middle compartment

This relates to the uterus prolapsing into the vagina. It can have various degrees based on how far it has prolapsed.

Posterior compartment

This typically relates to bowel or surrounding structures:

o Rectocoele = rectum

o Enterocoele = loops of bowel involved entering the rectouterine pouch (Pouch of Douglas)

Question 12

What is a vault prolapse?

Answer 12

‘Vault’ prolapse can occur after hysterectomy; as the supportive ligaments have to be cut when removing the uterus. This can therefore mean that the apex of the vagina (‘vault’) can prolapse.

Question 13

What are the risk factors for pelvic organ prolapse?

Answer 13

. The biggest risk factors for pelvic organ prolapse are age, parity (number of children) and mode of delivery (particularly vaginal delivery). Others to consider are oestrogen deficiency e.g. post- / peri-menopausal, and chronic increased abdominal pressure e.g from obesity. There is also a contribution from having connective tissue or neurological disorders.

Question 14

How does pelvic organ prolapse present?

Answer 14

The typical symptoms that a patient will present with are feeling a lump down below, or something ‘coming down’. They may also experience symptoms relating to where the prolapse is occurring, e.g. constipation. These may be obvious on examination, particularly if severe, but some require more thorough examination.

Question 15

How is pelvic floor prolapse managed?

Answer 15

This should be centred on how much the prolapse is interfering with the patient’s quality of life, the severity of the prolapse, as well as factors such as how fit they are for any surgical intervention. Discussion also needs to be done to educate patients that prolapses can recur, in order to manage their expectations.

1. Non-surgical options Use of pessaries e.g. ring pessaries as additional support
2. Surgical options There are many, depending on the type of prolapse. It might involve removal of the uterus (hyseterectomy), or using ‘mesh’ support in a vault prolapse.

Question 16

How can pelvic floor dysfunction contribute to urinary incontinence?

Answer 16

Dysfunction of the pelvic floor typically results in stress incontinence. This is when increased abdominal pressure causes ‘leaks’ of urine, as the support to the urethral sphincter (via the pelvic floor) is inadequate.

Question 17

What are the risk factors for stress incontinence?

Answer 17

R isk factors for developing stress incontinence are the same as those for developing pelvic organ prolapse, particularly age and oestrogen deficiency.

Question 18

What is the management for stress incontinence?

Answer 18

First line management is pelvic floor muscle training. Surgical intervention can be used to create ‘slings’ to support the urethral sphincter

Question 19

How does stress incontinence present?

Answer 19

Typical symptoms of stress incontinence are passing urine on coughing, laughing, or other activities that increase abdominal pressure. There may not be much to see on examination, other than obvious injury to the pelvic floor. Urodynamic studies can be used to investigate further.

Question 20

Other than stress incontinence and pelvic organ prolapse what other conditions are important to remember when looking at pelvic floor dysfunction?

Answer 20

Vulval problems

This can be where patients experience pain with no obvious finding on examination. It is often related to tension of the levator ani muscles.

Female Genital Mutilation

This is a cultural practice of damaging the female external genitalia

Posterior Compartment Pelvic Floor Dysfunction

This includes a range of conditions affecting the posterior part of the pelvic floor, such as constipation/incomplete evacuation and anal incontinence due to anal sphincter injury. The anal sphincter is attached to levator ani muscles, therefore any damage can lead to loss of voluntary control of defecation

Question 21

What is female genital mutilation, what are the consequences, is it legal and what are the different types?

Answer 21

This is a cultural practice of damaging the female external genitalia. It can have significant consequences such as severe pain, potential sepsis or haemorrhage. The potential long term complications include psychological effects, sexual dysfunction and difficulty conceiving, as well as chronic pain and menstrual disorders.

FGM is illegal in the UK. It needs to be reported and is a safeguarding issue if the girl is <18 years old.

Question 22

Describe how the pelvic floor provides support through suspension

Answer 22

The cardinal ligaments - holding the cervix and upper vagina in place

The uterosacral ligaments - holding the back of the cervix and upper vagina laterally

The round ligament - maintain the anteverted position of the uterus

Question 23

What two forces push down on the pelvic floor?

Answer 23

Gravity and intra-abdominal pressure

Question 24

Describe how the pelvic floor provides support through attachment

Answer 24

Arcus tendinosus fascia pelvis (ATFP) - also known as the white line

Endopelvic fascia - stretches like a hammock from the white line laterally, to the vaginal all medially. Urethra lies anerior and above it and, thus gets compressed against it during increased intra-abdominal pressure so it is important in maintaining urinary continence.

Question 25

Describe how the pelvic floor provides support through fusion

Answer 25

Involves the urogenital diphragm and the perineal body

The lower half of the vagina is supported by fusion of the endopelvic fascia to the perineal body posteriorly, the levator ani laterally and the urethra anteriorly

Question 26

Which set of muscles in the pelvic floor are most commonly affected by trauma?

Answer 26

Perineal muscles (superficial pelvic floor muscles)

Often involved in accidental, sexual and obstetric trauma

Question 27

What are the perineal muscles of particular note and why?

Answer 27

Transverse perineal muscles (superficial and deep)

Bulbospongiosus - encircles the vagina,

Stretch or trauma to the vagina will also affect these muscles

Question 28

Why would damage to the perineal body affect the anal sphincter region?

Answer 28

The perinial body is attached to the external anal sphincter and helps to support the anus so damage to it would comprimise the anus.

Question 29

Describe the bloody supply and drainage, lymphatic drainage and nerve supply to the pelvic floor

Answer 29

Blood Supply -

The internal and external pudendal arteries and corresponding veins

Lymphatic drainage -

Via inguinal lymph nodes

Nerve supply -

Branches of the pudendal nerve, which derives its fibres from the ventral branches of the second, third and fourth sacral nerve

Question 30

What is OASIS, prevention management etc

Answer 30

Obststric Anal Sphincter InjurieS

Perineal tears involving the anal sphincter complex

Types - 3rd and 4th degree tears

Can result in significant morbidity

Prevention - Episiotomy and encouraging mother not to push when the baby is crowning

Question 31

What is Vestibulodynia

Answer 31

Painful Vulva

Question 32

Define vaginismus

Answer 32

Pain on vaginal penetration, due to involuntary muscle spasm

Question 33

What is anal/faecal incontinece?

Answer 33

Involuntary loss of flatulus, liquid or solid stools that is a social or hygienic problem

Question 34

What is a gamete?

Answer 34

Gametes are the cells responsible for reproduction; i.e. sperm in males and ova in females. These are haploid cells derived as a product of meiosis, containing half the normal amount of DNA (23 chromosomes), and they fuse together to form a diploid zygote.

Question 35

How does genetic variation in gametes occur?

Answer 35

Genetic variation can happen to ensure each gamete is genetically unique. This can happen in a number of ways, including: 

Crossing over of homologous chromosomes (recombination) (exchange of regions of DNA between 2 homologous chromosomes)

Independent assortment (random orientation of each bivalent along the metapahse plate with respect to other bivalents) 

Random segregation (random distribution of alleles among the four gametes)

Question 36

Which gamete determines the sex of the baby?

Answer 36

The ovum will always contain an X chromosome, therefore the sex will be determined by the sperm depending on whether it carries an X or Y chromosome

Question 37

Describe the differences between oogenesis and spermatogenesis

Answer 37

Females produce approximate 400 ova in a lifetime. Males, however, produce a huge number of sperm (around 200 million every day). These ova are present from birth and stimulated at puberty, effectively giving a female 400 chances to reproduce whereas sperm are essentially ‘disposable’ cells, The production of ova is not continuous, it is intermittent whereas spermatogenesis is continuous.

Question 38

Describe spermatogenesis

Answer 38

This occurs in the seminiferous tubules of the testes. Initially, spermatogonia (germ cells) reside in the basal compartment. These divide by mitosis to give two primary spermatocytes; the Ad spermatagonium (resting:reserve stock) and the Ap spermatagonium (active: maintain stock and from puberty onwards produce type B spermatagonia which give rise to primary spermatocytes). Ap replaces the spermatogonia and Ad undergoes meiosis I to produce two secondary spermatocytes. These secondary spermatocytes undergo meiosis II to produce 2 spermatids each (i.e. 4 spermatids in total). Each of those spermatids will differentiate into spermatazoa via spermiogenesis.

Question 39

How do Ad and Ap spermatagonia look different under the microscope?

Answer 39

Ap look pale

Ad look dark

Question 40

Why do spermatids need to be at different levels of maturation? What is the spermatogenic cycle? What is the spermatogenic wave?

Answer 40

As there is a relatively limited time when women are actually fertile during their cycle, there needs to be a store of matured sperm that are ‘ready to go’ when that time arises. If all the sperm are in the same stage of the cycle, then men would in a sense need to wait until full maturation had occurred rather than being fertile all the time. Therefore, spermatids are at different levels of maturation at different sections of the seminiferous tubules.
The spermatogenic cycle rdefined as the length of time taken for reappearance of the same stage within a given segment of tubule ( Roughly 16 days in humans.)
The spermatogenic wave refers to the distance between groups of spermatids at the same level of maturation.
The different stages mve as waves in corkscrew like spirals towards the inner part of the lumen.

Question 41

What is spermiogenesis

Answer 41

The process by which spermatids become spermatozoa (mature sperm) is called spermiogenesis. Spermatids released into lumen of the seminiferous tubule (spermiation). They remodel as they pass down the seminiferous tubule , through rete testis and ductuli efferntes and into the epididymis to finally form spermatazoa. This maturation process allows the non-motile spermatids to become motile, and this process is complete once they have reached the epididymis.

Question 42

How are spermatids transported down the lumen of the seminiferous tubule?

Answer 42

Non-motile so transport via sertoli cell secretions assisted by peristaltic contrcations until they reach the epididymis

Question 43

Describe the structure of sperm

Answer 43

The head contains the nucleus, i.e. the haploid genetic information that will fuse with the oocyte. Importantly, the acrosome layer will allow this to happen when contact with the ovum is made.

The tail provides motility for the sperm, with mitochondria producing ATP that provide energy to drive the flagella tail allowing motility of the sperm. Tail moves by dynein filaments

Question 44

What is sperm capactitation?

Answer 44

This occurs in the female reproductive tract, and is the final process by which spermatozoa are now considered ‘fertile’ by removing the top layer of glycoproteins and cholesterol from the outer membrane. Involves activation of sperm signalling pathways (atypical soluble adenylyl cyclase and PKA involved). This allows sperm to bind to the zona pellucida of oocyte and initiate acrosome reaction. Human sperm for in vitro fertilisation must first be incubated in capacitation media. This mimics the conditions of the female reproductive tract.

Question 45

Describe oogenesis

Answer 45

This process describes the maturation of oocytes in the ovary. Before birth, germ cells originate from the yolk sac, colonise the gonadal coretx (ovary) and differentiate into oogonia . They rapidly divide via mitosis. By the end of the 3rd month oogonia arranged in clusters surrounded by flat epithelial cells. majority continue to divide by mitosis but some then enter meiosis and stop at prophase of meiosis I.

These are known as primary ooctyes. The max number of germ cells reached by mid gestation is roughly 7 million. Cell death then begins and many oogonia and primary oocytes degenerate in a process called atresia. By the 7th month of gestation the majority of the oogonia have dejenerated. The primary oocytes will remain at this level until puberty. All surviving (roughly 2 million) primary oocytes have now entered meiosis I and are individually surrounded by flat epithelial cells called follicular cells, and are now termed primordial follicles. They are still in the prophase I stage of meiosis.

After birth, the number of these cells deteriorates further through more atresia so roughly 40,000 remain by puberty.. From puberty, approximately 15-20 oocytes will start to mature each month in stages.

Question 46

What are the different stages of oocyte maturation? (in chronological order)

Answer 46

Preantral phase

Antral phase

Pre-ovulatory phase

Question 47

Describe the Pre-antral phase of oocyte maturation

Answer 47

As primordial follicles begin to grow, the surrounding follicular cells change from flat to cuboidal and proliferate to form a startified epithelium of granulosa cells, which secrete a layer of glycoprotein called the zona pellucida. This is now called a primary follicle

Question 48

Describe the antral phase of oocyte maturation

Answer 48

Antral phase
As development of the primary follicle continues, fluid filled spaces start to appear between the granulosa cells. These coalesceto form a collective space called the antrum, and the follicle is now called a secondary follicle. The outer fibrous layer develops into the theca interna (inner scretory layer) and theca externa (outer fibrous layer).

Several follicles begin to develop with each ovarian cycle. Usually only one reaches maturity (rest become atretic (degenerate))

Question 49

Describe the pre-ovulatory phase of oocyte maturation

Answer 49

The LH surge induces this stage of development, and the follicle now completes meiosis I, producing 2 haploid cells. However, the majority of the cytoplasm will go to only one of these daughter cells, the other receiving very little (becomes the ‘polar body’). Each daughter cell now has 23 chromosomes and 46 chromatids. Although many follicles start to develop, one is chosen to mature fully, known as the Graafian follicle.

This will enter meiosis II but arrests in metaphase ~3 hours before ovulation. It will not complete meiosis II until fertilisation occurs. If fertilisation does not occur, the
oocyte will degrade approximately 24 hours later.

If fertilisation does occur, a second polar body is produced and discarded, because all energy is focused on a single ovum at the end of this process (unlike in the male were 4 spermatids are produced)

Question 50

How does the Graafan follicle break away from the ovary

Answer 50

The LH surge increases collagenase activity. prostoglandins increase response to LH and casue local muscular contractions in ovarian wall causing the oocyte to extrude and break free from the ovary

Question 51

What happens to the graafan follicle after ovulation?

Answer 51

Following ovulation, the remaining granulosa and theca interna cells become vascularised. They develop a yellowish pigment and change into lutein cells forming the corpus luteum, which secretes oestrogen and progesterone. These stimulate uterine mucosa to enter secretory stage in preparation for embryo implantation. The lifespan of the corpus luteum remains constant, i.e. if no fertilisation occurs, this will degenerate after 14 days. When it degenerates it forms the corpus albicans, which is a mass of scar tissue.

Question 52

Describe oocyte transport

Answer 52

Shortly before ovulation, fimbrae sweep over the surface of the ovary. The uterine tube begins to contract rhythmically. At ovulation, the oocyte is released when the follicle ruptures and is ‘caught’ by sweeping movements of the fimbrae and motion of cilia on the epithelial lining at the distal end of the fallopian tube. Oocyte then propelled by peristaltic muscular contractions of the tube and by cilia in the mucosa.If fertilize, oocyte reaches uterine lumen in roughly 3-4 days.

Question 53

What is the function of the rete testes?

Answer 53

Concentrate the sperm

Question 54

On a microscopic level where does spermatogenesis occur? How does this relate to the blood testis barrierand its functions?

Answer 54

Spaces between adjacent sertoli cells.

This area can be divided into a basal compartment and an adluminal compartment which can be created due to that we have tigh junctions btwewn cells which form the blood testis barrier which is important as the celular enviroment for mainatnence of the germ cell line (making the spermatagonium) is different to the environment required for the development of the sperm into the emerging spermatids.

Blood testis barrier allows these two environments to exist next to each other.

Blood testis barrier also prevents immune response mounted against the sperm

Question 55

What do leydig cells do?

Answer 55

Produce testosterone

Question 56

Describe the path sperm take when leaving the body from start to finish

Answer 56

Question 57

Describe the composition of the ejaculate

Answer 57

Question 58

What is zinc important for in the ejaculate

Answer 58

Zinc is released from the prostate gland. It controls the motility of sperm so as the concentration of zinc decreases as the sperm enter the female reproductive system the sperm become more motile.

Question 59

What is the point of atresia of the oocytes?

Answer 59

To ensure only the best remain.

Question 60

Describe the differences in the fate of the corpus luteum depending on fertilisation.

Answer 60