3 Flashcards
What are the functions of the pelvic floor?
- support the pelvic organs (mainly vagina, uterus, ovaries, bladder and rectum)
- maintain intra-abdominal pressure during coughing, vomiting, sneezing and laughing
- facilitate defecation and micturition
- maintain urinary and faecal continence
- facilitate childbirth
- breathing
- sexual function
What are the three mechanisms that help the pelvic floor to support? Define them
- Suspension: maintains an “anti-gravity” position by providing strong vertical support, mainly from the cardinal ligaments and Uterosacral ligaments
- Attachment: structures piercing the pelvic floor muscles are attached to it, for example the vagina is supported by its attachment to endopelvic fascia, levator ani muscle and the perineal body
- Fusion: support that arises from fusion of different tissues, for example the urogenital diaphragm and the perineal body, implies link, connection, inseparable
- Ex: lower half of vagina is supported by fusion of vaginal endopelvic fascia to the perineal body posteriorly, levator ani laterally and urethra anteriorly
Describe the cardinal ligament
- holds the cervix and upper vagina in place
- a transverse ligament that works against gravity
Describe the Uterosacral ligaments
-holding the back of the cervix and upper vagina laterally
Describe the round ligament
- maintains the antiverted position of the uterus
- more of a position support
Describe the two fascia that help with attachment
- Argus tendinitis fascia pelvis (AFTP): aka the “white line”
- Endopelvic fascia: stretches like a hammock from the white line laterally, to the vaginal wall medially
- urethra lies anterior and above it and, thus, gets compressed against it during increased intra-abd pressure
- IMPORTANT IN MAINTAING URINARY CONTINENCE (forces urethra to close)
What are the layers of the pelvic floor, from top to bottom?
- Levator ani muscles
- urogenital diaphragm/perineal membrane
- perineal body (fusion of all the muscles)
- perineal muscles
- posterior compartment
Describe the deep muscles of the pelvic floor
-U-shaped set of muscles that act like a sling to encircle the urethra, vagina and rectum, and provide support for these organs
-stretches backwards and inwards from either side of the pelvis to meet in the middle line
-originates from back of the pubic bone, the white line over obturator internus, and medial aspect of ischial spine
-some of the fibres are inserted as they encircle the urethra, some are inserted as they encircle the vagina, where they take part in forming the perineal body
-some fibres are inserted as they encircle the rectum and rest are inserted in the lower part of the coccyx and anococcygeal raphe
THREE MUSCLES: puborectalis (around rectum), pubococcygeus, iliococcygeus
What are the 3 superficial muscles and what is their purpose?
- most commonly involved in perineal trauma-accident, sexual, obstetric
- Bulbospongiosus, ischiocavernosus, superficial transverse perineal
Describe a medio-lateral episiotomy
- done to avoid damage to the perineal body, b/c of its integral role in providing pelvic floor support as a site of attachment
- can be done if baby is large or difficult deliver
- can cause complications such as infection, haemorrhage, dyspareunia and damage to anal sphincter
- done to prevent perineal damage
- bulbospongiosus and transverse perineal muscles undergo iatrogenic damage
Describe the perineal body
- central point between the vagina and the rectum
- main function is to act as a site of attachment for pelvic floor muscles and other structures that provide support for the pelvic floor
- attached posteriorly to external anal sphincter and the coccyx
- support of the perineal structures rely on it
Describe the urogenital diaphragm
- Triangular sheet of dense fibrous tissue that spans the anterior half of the pelvic floor
- also attaches to the urethra, vagina and perineal body
- arises from the inferior ischiopubic Ramus
- supports the pelvic floor
What is the blood supply, innervation, venous and lymphatic drainage of the pelvic floor?
- blood supply: internal and external pudendal artery and drains through CORRESPONDING veins
- lymphatic drainage: 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
Describe pelvic floor dysfunction
-wide range of symptoms and conditions that can arise as a result of problems to do with pelvic floor Different types: -Pelvic organ prolapse -Incontinence: urinary (stress) -Posterior compartment pelvic floor dysfunction -Obstetric trauma including episiotomy -FGM -Vaginismus -Vulval pain syndromes
What is pelvic organ prolapse?
- loss of support for the uterus, bladder or colon which results of a prolapse of any of these organs into the vagina
- not life-threatening but has a significant impact on quality of life, perception of body image and can cause depressive symptoms
- associated with significant function disturbances including: anorectal, urinary, and sexual
What are the POPs in the anterior compartment?
- usually relates to bladder and/or urethra
- cystoceole: bladder
- urethrocoele: urethra
- cystourethrocoele: both
What POP can occur in the middle compartment?
- uterine prolapse
- procidentia: when ENTIRE uterus prolapses
- after a hysterectomy: apex may still prolapse which is called POST_HYSTERECTOMY VAULT PROLAPSE
What POP can occur in the posterior compartment?
- rectum may prolapse into the posterior part of the vagina-rectocele
- loops of bowel may prolapse into the rectovaginal space (pouch of Douglas): enterocele
What are the causes and risk factors of POP?
- age
- parity
- mode of delivery (i.e. vaginal delivery)
- oestrogen deficiency
- chromic increased abd pressure, obesity
- connective tissue or neurological disorders (ex. Muscular dystrophy, Marfans)
What type of history and examination would you take for pt’s with POP?
- pt. Will feel a lump down below, or something “coming down”, dragging
- may also experience constipation if rectal prolapse
How would you manage a pt with POP?
Need to consider these factors:
-nature of symptoms and degree of bother
-nature and extent of prolapse
-completion of family and future pregnancy plans
-sexual activity
-fitness for surgery and anaesthesia
-woman’s goals
-work, physical activity and domestic circumstances
Non surgical option: pessaries (holds the pelvis and its organs up between the two bones) including ring, shelf, and gel horn pessaries
Surgical option:
-more definitive treatment
-risk of recurrence and potential complications
-can be performed vaginally, abdominal, laparoscopically
-included anterior/posterior repair, vaginal hysterectomy etc.
Describe Obstetric Anal Sphincter Injuries (OASIS)
- perineal tears involving the anal sphincter complex
- types: 3rd and 4th degree tears
- can result in significant morbidity
- demonstrates the functions of the pelvic floor: continence and support
What is an episiotomy?
When a cut is surgically made through pelvic floor which will accommodate space for the baby during birth
What is vaginismus?
- when pelvic muscles are so taut they keep everything close
- lots of pain when even inserting a tampon
How can you prevent OASIS?
- think about episiotomy (risk groups and correct angle) i.e. restrictive use
- for every 6 degrees the episiotomy is made away from the midline, there is a 50% reduction in third degree tear
- perineal protection at crowning can be protective
- encouraging the mother NOT to push when the head is crowning
Describe urinary incontinence
- increased abd pressure causing “leaks” of urine as the support to the urethral sphincter is inadequate
- stress incontinence
- other types: urge incontinece due to problems with the bladder not the pelvic floor
What are risk factors of urinary incontinence?
- same as POP
- particularly age and oestrogen deficiency
How would you examine a pt. With urinary incontinece?
- passing urine on coughing, laughing or other activities that increase abd pressure
- obvious injury to pelvic floor
- urodynamic studies can be used to investigate further
How would you manage a pt. With urinary incontinence?
- pelvic muscle floor training
- surgical intervention can be used to create “slings” to support the urethral sphincter
Describe vulval problems
- where pt’s experience pain with on obvious finding on examination
- often related to tension of levator ani muscles
- vestibulodynia: painful vulva
- vaginismus: pain on vaginal penetration due to involuntary muscle spasm
- assessment and management reflects understanding of the pelvic floor
What is Female Genital Mutilation (FGM)?
- all procedures involving partial or total removal of external female genitalia or other injury the to the female genital organs, whether for cultural or other non-therapeutic reasons
- reasons: religious practice, culture (purification), social acceptance, family honour
- significant consequences such as severe pain, potential sepsis or haemorrhage
- potential long term complications include psychological effects, sexual dysfunction, difficulty conceiving, chronic pain, and menstrual disorders, PTSD
- it is illegal in the UK
- no offence if cutting is connected to labour and delivery
What are the different types of FGM?
Type 1: partial or total removal of the clitoris and/or prepuce (clitoridectomy)
Type 2: partial or total removal of the clitoris and labia minors, with or without excision of the labia majora (excision)
Type 3: Narrowing of the vaginal orifice with creation of a covering seal by cutting and appositioning of the labia minors and/or labia majora, with or without excision fo the clitoris (infibulation)
Type 4: all other harmful procedures to the female genitalia for non-medical purposes, ex. Pricking, piercing, incising, scraping and cauterizing
Describe posterior compartment pelvic floor dysfunction
Presents as: -vaginal or rectal bulge/lump -constipation -incomplete evacuation -dyssynergic defecation (anismus) -anal incontinence Causes: -structural (ex. Rectocele, rectal prolapse) -drugs (ex. Opiates, iron supplements) -dehydration -immobility -pregnancy -post-op pain
Describe anal/faecal incontinence
- involuntary loss of flatus, liquid or solid stools that is a social or hygienic problem
- causes both physical and psychological distress: lead to significant impairment of quality of life
- commonest cause of faecal incontinence in women: obstetric anal sphincter injury
What is a gamete?
- cells that are responsible for reproduction
- proliferate by imitosis
- reshuffle genetically and reduce to haploid by meiosis
- cytodifferentiate into mature gametes
- timing and scale varies between sexes
What is spermatogenesis?
- for males
- make about 200 million/day
- continuous production
- essentially “disposable” cells
- occurs in seminiferous tubules of testes
- initially Spermatogonia resides in basal compartment
- these divide by mitosis to give two primary spermatocytes
- one replaces the spermatogonia and one undergoes meiosis 1 to produce two secondary spermatocytes
- secondary spermatocytes undergo meiosis 2 to produce 2 spermatids each
- available for up to 70 years
What factors contribute to genetic variation?
- crossing over: exchange of regions of DNA between 2 homologous chromosomes
- independent assortment: random orientation of each bivalve the along the metaphase plate with respect to other bivalents
- random segregation: random distribution of alleles among the four gametes
Describe the basal and adluminal compartment
- basal: where is sperm is initially
- Sertoli cell barrier splits the two compartments and they contain tight junctions for sperm to pass
- adluminal: where sperm matures
Define ad spermatogonium and AP spermatogonium
- ad spermatogonium: “resting” reserve stock
- AP spermatogonium: “active”: maintain stock and from puberty onwards produce type B spermatogonia which give rise to primary spermatocytes
Describe the spermatogonia cycle and wave
- sperm are in different stages of the cycle so that there is always a mature batch ready
- cycle: refers to the length of time it takes for spermatids at the same stage in the cycle to “show up” again when looking at a specific point along the seminiferous tubules
- wave: refers to the distance between groups of spermatids at the same level of maturation
- each stage follows in an orderly sequence along the length of the tubule
- waves move in corkscrew like spirals towards the inner part of the lumen
Describe spermiogenesis
- process by which spermatids become spermatozoa
- spermatids release into lumen of seminiferous tubules (spermiation)
- sperm remodel as they pass down the tubule, through the rete testis and ductili efferentes and into the epididymis to finally form spermatozoa
- non-motile (transport via Sertoli cell secretions assisted by peristaltic contraction) until they reach epididymis
Describe the structure of sperm
- head contains nucleus (genetic info)
- tail provides motility for sperm
- mitochondria producing ATP that provide energy to drive the flagella tail allowing motility of sperm
How is the sperm delivered?
- through semen (makes up 2ml of ejaculate)
- seminal vesicle secretionS (about 70%): amino acids, citrate, fructose, prostaglandins (fructose used instead of sucrose to prevent direct competition)
- secretions of prostate (about 25%): proteolysis enzymes, zinc
- sperm (via vas deferens) (2-5%): about 200-500 million per ejaculate
- bulbourethral gland secretions (Cowper gland): mucoproteins help lubricate and neutralize acidic urine in distal urethra (<1%)
Which Fallopian tube has better successful fertilization?
Right side
Describe sperm capacitiation
- when glycoproteins coat and cholesterol on head of sperm is released when in the vagina
- after removal, sperm is fertile and ready to fertilize ovum
- allows sperm to bind to zona pellucida of oocyte and initiate acrosome reaction
- important when thinking about IVF
Describe oogenesis
- maturation of oocytes in ovary
- before birth female has developed her entire stock of potential gametes (oogonia)
- rapidly divide via mitosis and then enter meiosis 1 and stop at prophase
- primary oocytes are surrounded by flat epithelia cells (follicular cells) and are termed as primordial follicles
- cell death (atresia) of oogonia occurs
- about 40 000 oocytes remain by puberty
- from puberty onwards about 15-20 oocytes start to mature each month passing through 3 stages (preantral, antral, and preovulatory)
What is the preantral stage?
- follicular cells of primordial follicle proliferate to form granulosa cells, which secrete the zona pellucida
- surrounding follicular cells change from flat to cuboidal and proliferate to produce stratified epithelium of granulosa cells
- now known as primary follicle
What is the antral stage?
- as development of primary follicle continues, fluid filled spaces appear between the granulosa cells
- these coalesce to form the collective space known as the antrum
- follicle is now called a secondary follicle
- granulosa cells surrounding oocyte are called Cumulus oophorus
- outer fibrous layer develops into theca interna and theca externa
- theca interna receives LH and FSH to produce androstenedione
- androstenedione is taken up by granulosa cells to produce oestrogen
What is the pre-ovulatory stage?
- surge in LH induces preovulatory growth phase
- meiosis 1 is now complete resulting in 2 unequally sized haploid cells
- fully mature one is known as the Graafian follicle
- Graafian follicle enters meiosis 2 just before ovulation but wont complete meiosis 2 until fertilization occurs
- if no fertilization then cell degenerates about 24 hours later
What happens right after ovulation?
- following ovulation, remaining granulosa and theca interna cells become vascularised, forming the corpus luteum which secretes estrogen and progesterone
- stimulates uterine mucosa to enter secretory stage in preparation for embryo implantation
- if no fertilization then corpus luteum degenerates after 14 days
- when corpus luteum degenerates it forms the corpus alibicans, which is a mass of scar tissue
Describe ovulation
- FSH and LH stimulate rapid growth of follicle several days before ovulation occurs
- mature follicle now about 2.5cm in diameter and called Graafian follicle
- LH surges collagenase activity
- prostaglandins increase in response to LH and cause local muscular contractions in ovarian wall
- oocyte extruded and breaks free from ovary
Describe oocyte transport
- shortly before ovulation, Fimbriae sweep over surface of ovary
- uterine tube begins to contract rhythmically
- oocyte carried into tube by sweeping movements of fimbriae and by motion of cilia on epithelial lining
- oocyte then propelled by peristaltic muscular contraction of the tube and by cilia in the mucosa
- if fertilized, oocyte reaches uterine lumen in about 3-4 days
- implanted embryo releases HCG which maintains corpus luteum until the placenta takes Over production of progesterone
What hormones affect the ovarian cycle?
- under influence of hypothalamic GnRH, anterior pituitary releases FSH, and LH
- follicles stimulated to grow by FSH and to mature by FSH and LH
- ovulation occurs on LH surge
- LH also promotes development of the corpus luteum
Compare spermatogenessis and oogenesis
- sperm: 200 million sperm per day
- ovary: usually 1 ovum per 28 day menstrual cycle (400 in lifetime)
- sperm: 4 spermatids of equal size, no polar body
- ovary: one ovum with unequal division, 3 polar bodies
- sperm: starts at puberty
- ovary: starts in fetus
- sperm: continues throughout adult life
- ovary: ends at menopause
- sperm: motile gametes
- ovary: non-motile gametes
- sperm: all stages complete in testes
- ovary: last stage of meiosis 2 occurs in oviduct
