Reproductive system Flashcards
What is the histology of the seminal vesicles?
Slightly coiled tubule, lined by secretory columnar epithelium
Surrounded by 2 layers of smooth muscle and a fibroelastic layer
What is the prostate gland made up of?
Made up of 3 concentric rings of glands that are surrounded by smooth muscle and a fibrous capsule. Smooth muscle contracts in ejaculation to squeeze prostatic secretions into the urethra Inner periurethral (mucosal) glands - directly surround the urethra so secrete directly into it Outer periurethral (submucosal) glands - Secrete into urethra via short ducts Peripheral zone glands - Secrete into urethra via long glands. Is incomplete anteriorly.
When does structural development of the reproductive tract occur?
In the embryonic stage of gestation
Where do the gonads derive from?
Intermediate mesoderm - part of urogenital ridge
Where do extragonadal germ cells originate?
In the yolk sac
What develops if there’s a Y chromosome?
Y chromosome contains SRY gene so gonad develops into testis, ducts into male internal genitalia and male external genitalia form?
What develops if conceptus is XX?
Gonad develops into ovaries, duct system into tubes and uterus and female external genitalia develop
What do wolffian ducts develop into?
In the presence of testosterone, they’re joined by seminiferous tubules and form the epididymis, vas deferens and seminal vesicles
What hormones promote formation of male genitalia rather than female?
Testosterone cause persistence of wolffian ducts and is secreted from interstitial cells. Testosterone also causes fusion of genital folds. Sertoli cells secrete mullerian inhibitory hormone to cause regression of mullerian ducts
What reproductive hormones are produced by the hypothalamus?
Gonadotrophin releasing hormone
Prolactin releasing hormone
Prolactin inhibiting hormone
What reproductive hormone is released from the posterior pituitary gland?
Oxytocin
What reproductive hormones are released from the anterior pituitary gland?
FSH, LH, prolactin
What reproductive hormones are released from the gonads?
Both produce inhibin.
Testes also produce testosterone and mullerian inhibitory hormone
Ovaries produce oestrogen and progesterone
Which hormones, released by the anterior pituitary gland are glycoprotein hormones?
LH, FSH, TSH
Which hormones, released by the anterior pituitary gland are polypeptide hormones?
ACTH, MSH, Growth hormone, prolactin
Which hormones exert negative feedback in the HPG axis?
Testosterone, Inhibin, moderate oestrogen, progesterone
What hormone exerts positive feedback in the HPG axis?
High levels of oestrogen, in the absence of progesterone
What is the action of inhibin and where is it released from?
Inhibits FSH release. Released from granulosa cells in the ovary and sertoli cells in the testis.
How do gonadotrophs affect the testes?
LH acts on leydig cells to promote testosterone secretion. Testosterone then acts on sertoli cells to promote spermatogenesis . LH is enhanced by inhibin and prolactin. Testosterone also negatively feeds back on LH and GnRH
FSH maintains sertoli cells and makes them responsive to testosterone. Sertoli cells produce inhibin which inhibits FSH and promotes LH
What effects do FSH and LH have on the ovary in the antral phase?
LH binds to receptors on theca internal cells which stimulate production of androgens by the theca cells.
FSH binds to granulosa cells which stimulate enzymes production, causing conversion of androgens into oestrogen.
What effects do FSH and LH have on the ovary in the pre-ovulatory phase?
Follicle has grown so oestrogen levels are now high.
LH receptors develop on granulosa cells. High oestrogen levels cause positive feedback so there’s a LH surge. This increases production of collagenase so follicle breaks down and ovulation occurs
What effects do FSH and LH have on the ovary in the luteal phase?
LH stimulates oestrogen and progesterone production by the corpus luteum. There’s now negative feedback so LH, FSH and GnRH levels fall
What are the regulatory effects of testosterone?
Maintains internal genitalia
Anabolic actions
Behavioural effects causing aggression and sexual activity
What effects does oestrogen have on the body?
Thin, alkaline cervical mucus Fallopian tube function Thickening of endometrium Growth and motility of myometrium Skin, hair and metabolism changes Vaginal changes Changes in calcium metabolism
What effects does progesterone have on the body?
Thick, acid cervical mucus Mild anabolic effects Changes to mammary tissue Increased thickening of endometrium Growth and reduced motility of myometrium Increased body temperature Electrolyte changes
What are the main stages of the menstrual cycle?
Follicular phase which comprises of the menstrual phase and the proliferative phase
Luteal phase or secretory phase
What changes occur to the endometrium in the follicular phase?
During the menstrual portion, the necrotic endometrium is shed.
Then, as oestrogen levels begin to rise again after a rest, basal cells of endometrium begin to proliferate and glands are formed but don’t yet secrete.
What happens to the endometrium in the luteal phase?
Progesterone released after ovulation causes further proliferation of the endometrium and myometrium but motility of myometrium is reduced. Glands start to secrete a glycogen rich ‘milk’ ready for implantation.
As oestrogen and progesterone decrease, spiral arteries supplying endometrium become ischaemic and so endometrium starts to shed.
How do oestrogen and progesterone differ in the way that they inhibit GnRH?
Progesterone reduces the frequency of GnRH pulses while oestrogen reduces the amount that’s released per pulse.
Why might a breast feeding woman not be able to fall pregnant?
May have high levels of prolactin. Prolactin disturbs release of GnRH so can affect ovulation and other aspects of fertility.
What are the layers of the capsule that surround the testis?
Tunica vasculosa
Tunica albuginea (thick)
Tunica vaginalis
Where are leydig cells found?
In islands in between seminiferous tubules of the testes (interstitial cells)
What are the different layers of germ cells in the seminiferous tubules?
Deepest are spermatogonia then spermatocytes then spermatids. Scattered throughout are sertoli cells.
What is seen histologically at the junction between the seminiferous tubules and the tubuli recti?
A plug of sertoli cells
What epithelium is found in the tubuli recti?
Simple cuboidal
What epithelium is found in the rete testis?
Simple cuboidal
What epithelium is found in the ductus efferentes?
Mixture of simple cuboidal for absorption and simple columnar ciliated for transport
What is the histology of the epididymis tubule?
Lined by pseudostratified columnar epithelium with stereocilia on it’s apical membrane. It’s outermost wall contains smooth muscle.
What is the histology of the vas deferens?
Folded lumen, lined by pseudostratified columnar epithelium. Also has three muscular layers; a central circular layer and two longitudinal layers either side
What epithelium is found in the seminal vesicles?
Pseudostratified columnar that secretes a fluid rich in fructose, prostaglandins and proteins
What are the different layers of glands found in the prostate?
All tubuloalveolar glands. From inner- to outermost, they are mucosal, submucosal and main glands
What is the histology of the prostate?
Epithelium of glandular element is heterogenous. Surrounded by a fibromuscular capsule that divides the gland into lobules.
Glands sit in a fibromuscular stroma.
What does the prostate gland secrete?
Acid phosphatase and prostate specific antigen.
What are prostatic concretions?
aka corpora amylacea - lamellated bodies found in the glandular elemnt of the prostate. They contain nucleic acids, proteins, cholesterol and calcium phosphate.
What is contained in the cortex of an immature, prepubertal ovary?
Primordial follicles
What affect does FSH have on the pubertal ovary?
Stimulates follicle development. Granulosa cells become cuboidal instead of sqaumous and multiple layers form.
What changes occur in the pubertal ovary up until antrium formation?
Zona pellucida forms and ovarian stromal cells develop into theca folliculi.
Fluid filled spaces develop between granulosa cells. These grow and coalesce to form an antrum and granulosa cells are pushed to the periphery. Eventually, the oocyte is pushed to one side of the follicle, surrounded by a corona radiata of granulosa cells and sits on a plug of granulosa cells called the cumulus oophorus.
Also in this stage, theca cells differentiate into theca externa and interna
What happens to the follicle in order for ovulation to occur?
The cumulus oophorus breaks down and the oocyte and its corona radiate float free in the follicular fluid until tissue surrounding the follicle thins and breaks down, releasing the oocyte into the fallopian tube
What effect does LH have on the follicle after ovulation?
Turns granulosa cells into granulosa lutein cells and theca interna cells into theca lutein cells.
Stimulates production of oestrogen and progesterone
What happens to the corpus luteum if fertilisation doesn’t occur?
Becomes fibrosed and hyalinised and forms a corpus albicans which normally regresses and is resorbed. Erythrocytes and normally phagocytosed but if this is incomplete then it forms a pigmented remnant - coprus nigricans
What are the histological differences between the ampulla and the isthmus?
Ampulla has two smooth muscle layers (longitudinal and circular) and isthmus has 3
Ampulla has mostly ciliated cells and isthmus has higher proportion of peg cells
Mucosa is more folded in ampulla than in isthmus
What epithelia is found in the uterus?
Simple columnar
What are the different layers of the uterus?
Outer myometrium made up of 4 smooth muscle layers.
Inner endometrium - stratum basalis and stratum functionalis.
Stratum functionalis divides into compact and spongy layers
What is the blood supply to the endometrium?
Via uterine arteries which branch to give arcuate arteries.
Arcuate arteries branch to give spiral arteries which supply the functional layer and straight arteries which supply the basal layer
How do the endometrial glands change over the uterine cycle?
In proliferative phase, they are straight and start to increase in length. Then, in secretory phase, they grow more than the surrounding lamina propria so they become coiled
What happens to stroma cells in the secretory phase?
Develop into decidual cells. These can give rise to placenta and secrete prolactin if implantation occurs
What causes necrosis of endometrium?
It’s thought, in absence of fertilisation, prostaglandins are released and these cause spasm of spiral arteries, cutting off nutrients to the functional layer of the endometrium. This causes necrosis of the endometrium
What are the main portions of the cervix?
Extends from internal Os to external Os with cervical canal in between
What epithelia is found in the cervix?
Cervical canal is lined by simple columnar but this changes to stratified squamous non keratinised roughly at start of external os (this point moves mores inwards throughout life)
How is the vagina lubricated?
By mucus secreted by cervical glands and vestibular glands
What is the purpose of glycogen storage by vaginal epithelial cells?
It’s metabolism forms acid pH and is used by lactobacilli
What’s the age range for start of puberty in males and females?
Males 9-14
Females 8-13
What is the sequence of events of puberty in females?
Growth begins Thelarche Adrenarche Growth spurt Menarche Adult pubic hair Adult breasts
What are the different stages of thelarche?
1 - pre-pubertal 2 - breast buds form 3 - juvenile smooth contour 4 - areola and papilla extend above breast 5 - adult contour
What are the different stages of adrenarche?
1 - juvenile - no hair
2 - sparse, straight, long, pigmented hair grows mainly along labia/ base of penis
3 - hair is dark, coarser and curlier
4 - hair fulls out towards adult distribution
5 - adult distribution. Extends to medial thigh in males
When does the first ovulation in puberty occur?
Roughly 10 months after menarche
What are the main stages seen in male puberty?
Genital development Adrenarche Spermatogenesis begins Growth spurt Adult genitalia Adult pubic hair
What are the phases of genital development in male puberty?
1 - pre-adolescent
2 - Increase in penis length
3 - further increase in length and diameter
4 - development of glans penis and darkening of scrotal skin
5 - adult genitalia
What drives the growth of pubic and axillary hair?
Androgens - testosterone in males or androgens from adrenal glands in females
What hormones drive the pubertal growth spurt?
Growth hormones and steroids.
In females, oestrogen causes earlier fusion of epiphyses
What are the main known causes of precocious puberty?
Neurological due to early stimulation of maturation eg due to meningitis or pineal gland tumous
Uncontrolled secretion of gonadotrophins or steroids ie in a hormone secreting tumour
What’s the pre-menopausal stage?
Changes in menstrual cycle due to reduced oestrogen secretion. Decrease in length of follicular phase?
What is the classification of the menopause?
6-12 months after last menstruation. No more follicles to be developed and massive decrease in oestrogen and progesterone.
What are the common effects of the menopause?
Hot flushes Collagen loss Bone breakdown Painful joints loss of vaginal rugae and mucus - pain on intercourse Regression of endometrium and myometrium
What are the advantages of HRT?
Relief of menopause symptoms
Increased well being
Can limit osteoporosis
What are the disadvantages of HRT?
Increased risk of DVT, cardiovascular disease and breast cancer
What is menorrhagia?
Excessively long periods (over 7 days)
What is oligomenorrhoea?
Interval between periods > 35 days
What are the main classes of causes of amenorrhoea?
Outflow tract
Gonadal
Pituitary/ hypothalamic
What are the main outflow tract causes of amenorrhoea?
Primary - imperforate hymen, vaginal atresia, cryptomenorrhoea, mullerian agenesis
Secondary - Intrauterine adhesions ie in asherman’s syndrome
What are the main gonadal causes of amenorrhoea?
Primary - Gonadal dysgenesis Androgen insensitivity syndrome LH/FSH receptor abnormalities Congenital adrenal hyperplasia Secondary - Pregnancy, anovulation, menopause, premature menopause, polycystic ovarian syndrome, drug induced
What are the main hypothalamic/ pituitary causes of amenorrhoea?
Primary - Kallmann syndrome which is disrupted hypothalamus/pituitary interaction
Secondary - sheehan’s syndrome, Exercise amenorrhoea, stress amenorrhoea, eating disorders and weight loss
Hyperprolactinaemia, haemochromatosis
Hypo/hyperthyroidism
How should secondary amenorrhoea be evaluated?
Menstrual history, contraception use, any surgery, pregnancy possibility/past, weight change, medication, any chronic disease/stress
Take family history on menopause age, thyroid disfunction, cancer and diabetes
Do physical exam for BMI, hair distribution, thyroid, abdominal masses/tenderness, visual fields
How should amenorrhoea be managed?
Take thorough history and make sure possiblity of pregnancy is eliminated.
blood work if indicated by hirsuitism, CNS problems, presence of chronic disease, possible ovarian axis problem
What is dysfunctional uterine bleeding?
Excessively heavy, prolonged or frequent bleeding of uterine origin, not due to pregnancy, pelvic of systemic disease
What is the embryological origin of the scrotum?
Genital folds
What indicates the bilateral formation of the scrotum?
The scrotal raphe, continuous with the penile raphe on the ventral surface of the penis
What is the blood supply of the scrotum?
Anterior and posterior scrotal arteries
Where does lymph from the scrotum go to?
Superficial inguinal nodes
When is the visceral tunica vaginalis not covering the testis?
Where the testis attaches to the epididymis and the spermatic cord
What is the venous drainage of the testes?
Right testicular vein drains directly into the abdominal aorta.
Left testicular vein drains into the left renal vein adn then into the abdominal aorta
What are the divisions of the epididymis?
Head formed by convergence of ductus efferentes.
Body consisting of single, convoluted tubule
Tail at area of transition between epididymis and vas deferens
What are the contents of the spermatic cord?
Vas deferens Artery to vas deferens Cremasteric artery Testicular artery Pampiniform plexus of testicular vein Genital branch of genitofemoral nerve Lymphatics Processus vaginalis
What is the passage of spermatic cord and its contents from the abdomen?
Exits abdomen through the deep inguinal ring, lateral to the inferior epigastric vessels. Then exits superficial inguinal ring and enters scrotum at posterior of testis.
What are the coverings of the spermatic cord, deep to superficial?
Internal spermatic fascia formed by transversalis fasica
Cremasteric fascia and muscle formed by transversalis and internal oblique
External spermatic fascia formed by external oblique aponeurosis
What is the pampiniform plexus?
Network of small veins that wrap around the testicular artery, acting as a heat exchanger to cool down the blood that supplies the testes
What are the main important anatomical relationships of the prostate gland?
Base - neck of bladder Apex - urethral sphincter and deep perineal muscles Muscular anterior - urethral sphincter Posterior - ampulla of rectum Inferolateral - levator ani
What are the different segments of erectile tissue in the penis?
Pair of corpora cavernosa on dorsum
Single corpus spongiosum on ventral surface
What is the blood supply to the penis?
Arterial. Aorta to common iliac to internal iliac to anterior branch of internal iliac to internal pudendal artery
also, cavernous arteries
Venous. Cavernous spaces to venous plexus to deep dorsal vein to prostatic venous plexus to internal iliac vein to common iliac vein to inferior vena cava
What is a hydrocoele?
Build up of serous fluid in the tunica vaginalis
What is a haematocoele?
Build up of blood in the tunica vaginalis
What is a varicocoele?
Varicosity of the pampiniform plexus
On which side of the body are varicocoeles most common?
On the left
What is a spermatocoele?
Retention cyst in epididymis containing spermatogonia
What’s the difference between oligozoospermia and azoospermia?
Oligozoospermia is abnormally low levels of spermatozoa in semen. Azoospermia is the absence of spermatozoa in semen
What is a cryptochid testis?
One that is undescended. Sertoli and leydig cells still secrete male sex hormones but germ cells are absent so spermatogenesis is impaired.
What is orchitis and when does it most commonly occur?
Inflammation of the testis. Can occur after mumps in puberty
What is testicular torsion?
A twisting of the spermatic cord, putting testis at risk of necrosis
By what methods do prostatic malignancies metastasise?
Through lymphatics to internal iliac and sacral nodes.
Through venous system and internal vertebral plexus to vertebrae and brain.
What are the features of a gynecoid pelvis?
Round pelvic inlet Straight side walls Well curved sacral promontory Not too prominent ischial spines Sub-pubic arch around 80 degrees
What makes up the pelvic inlet?
Sacral promontory Margins of ala Arcuate line Pecten pubis Pubic crest
What bony landmarks are included in the linea terminalis?
Arcuate line, pecten pubis and pubic crest
What makes up the pelvic outlet?
Inferior border of body of pubis Inferior ramus of pubis Ramus of ischium Ishcial tuberosity Sacrotuberous ligaments
What makes up the true pelvis?
The pelvic inlet and outlet
What measurements are taken to asses the pelvic inlet size?
Anatomic conjugate from sacral prmontory to superior border of pubic symphysis
Obstetric conjugate from promontory to midpoint of pubic symphysis
Diagonal conjugate from promontory to inferior border of PS
How is the mid-pelvis assessed before childbirth?
Check for straight side walls
Measure the bispinous diameter
How is the pelvic outlet assessed?
Measure infrapubic angle and the distance between ischial tuberosities
What is a unilaminar primary follicle?
When oocyte is surrounded by layer of simple cuboidal cells
What is a multilaminar primary follicle?
When the oocyte is surrounded by layer of stratified cuboidal epithelia
What does the theca folliculi secrete?
Steroid hormones. Theca cells differentiate from ovarian stromal cells
What does the theca folliculi differentiate into?
Theca interna which secretes oestrogen and the theca externa which is vascular connective tissue.
What changes occur in the follicle when fluid filled spaces start to form between granulosa cells?
Space pushes granulosa cells to the edge and eventually forms one large antrum. Oocyte is surrounded by few layers of granulosa cells, this is called the corona radiata. Eventually the oocyte is only attached to the edge by a small plug of granulosa cells and this peg is the sumulus oophorus.
What happens to the cumulus oophorus just prior to ovulation?
Breaks down so that the oocyte is floating free in the antrum.
What happens to the follicle after ovulation?
Granulosa cells convert into granulosa lutein cells and the theca interna cells convert into theca lutein cells. The follicle is now a corpus luteum. This will breakdown after 2 weeks if fertilisation hasn’t occurred.
What is a corpus nigricans?
Remnant of the corpus luteum of phagocytosis of its erythrocytes isn’t complete
What types of epithelia line the fallopian tubes?
Combination of simple columnar and mucus secreting peg cells. Nearer to the ampulla it’s mostly simple columnar and nearer the isthmus it’s mostly peg cells.
How many smooth muscle layers are found in the fallopian tubes?
At the ampulla end, 2 layers and at the isthmus end, 3 layers
What epithelia lines the endometrium?
Simple columnar
How can the endometrium be divided?
Stratum functionalis which can divide into deep spongy and outer compact
Stratum basalis
What is the blood supply to the endometrium?
From paired uterine arteries which branch into arcuate arteries. Arcuate arteries branch into coiled arteries for stratum functionalis and straight arteries in stratum basalis
What hormone drives the proliferative phase of the endometrium?
Oestrogen
What happens during the proliferative phase of the endometrium?
There’s a regeneration of the stratum funtionalis, from the cells lining the glands in the stratum basalis. There’s an increase in the length of the endometrial glands and a proliferation of the stromal cells that surround the endometrial glands
What drives the secretory phase of the endometrium?
Increasing progesterone levels
What happens during the secretory phase of the endometrium?
Endometrial glands grow more than the lamina propria and so the glands become coiled. The stroma surrounding the glands become oedematous and stromal cells convert into decidual cells
In the event of fertilisation cells, what’s the purpose of decidual cells?
Secrete prolactin and go on to form the placenta
What drives the menstrual phase of the endometrium?
Falling progesterone levels in the absence of ferilisation
What happens in the menstrual phase of the endometrium?
There’s a spasm of the coiled arteries. There’s therefore lack of blood flow to the stratum functionalis so it becomes necrotic and sheds. This spasm is thought to be due to locally released prostaglandins
Where is the cervix?
Connects the uterine cavity with the vagina and it extends from the internal to the external Os. Inbetween these points is the cervical canal.
What epithelium lines the cervix?
Mostly simple columnar but just before the external os, it changes to non-keratinised stratified squamous. This point of change gradually moves internally with increasing age
What is the vagina?
A fibromuscular tube that connects the cervix to the exterior. Has a muscular layer that contains both skeletal and smooth muscle.
What epithelia lines the vagina?
Non-keratinised stratified squamous.
What is the role of glycogen in the vagina?
It accumulates in vaginal epithelia under the influence of oestrogen. It is metabolised by lactobacilli and this provides the acid pH of the vagina
What lubricates the vagina?
Vagina has no glands so is lubricated by mucus from cervical glands but also by vestibular glands.
What leads to breast enlargement in puberty?
Rising oestrogen levels cause accumulation of adipose tissue and lactiferous ducts.
What epithelia lines lactiferous ducts of the breast?
First simple cuboidal then simple columnar then stratified squamous at the point of the lactiferous sinuses.
What changes occur in the breast in the menstrual cycle?
The oestrogen peak stimulates duct proliferation leading to breast enlargement. There may also be oedema and tenderness.
What changes occur in the breast during pregnancy?
Breasts are maximally developed. It’s thought that oestrogen causes duct proliferation and progesterone causes development of secretory tissue. Duct lumens become full of secretory product so secretory cells can appear vacuolated due to fat content of milk
From where do the gonads derive?
Intermediate mesoderm as part of the urogenital ridge
What happens to the gonad to convert it from indifferent to sex specific?
Shortly after embryonic growth begins, primordial extragonadal germ cells are allocated which arise in the yolk sac and migrate along the dorsal mesentery into the gonads. Then, depending on the sex chromosomes present, reproductive system development continues
How does the SRY gene drive male development?
It’s located on the Y sex chromosome and drives the development of the gonads into the testes and the development of the external and internal genitalia
What does the gonad develop into with XX sex chromosomes?
Ovary
What does the male duct system comprise of?
Epididymis, vas deferens and urethra
What does the female external genitalia consist of?
Vagina, vestibule, labia minor and majora, and the clitoris
What are some male secondary sexual characteristics?
Relatively large body size Smell Body hair distribution Male pattern baldness Coarser hair and skin Body shape Fat distribution
What are some female secondary sexual characteristics?
Relatively small body size Subcutaneous fat distribution Smoother hair and skin Breast development Central nervous effects
How does testosterone affect the mesonephric and paramesonephric ducts?
Helps maintain them
What’s another word for the mesonephric ducts?
Wolffian ducts
What’s another name for the paramesonephric ducts?
Mullerian ducts
What do the mesonephric ducts go on to form, in the presence of testosterone?
They’re joined by the seminiferous tubules at the rete testis. The remainder forms the vas deferens, epididymis and seminal vesicles
Where is mullerian inhibitory hormone secreted?
By sertoli cells lining the seminiferous tubules
What effects does mullerian inhibitory hormone have?
Causes regression of the paramesonephric ducts
What happens to the paramesonephric ducts in the absence of mullerian inhibitory hormone?
Start as invaginations of the urogenital ridge epithelium. Then, with embryonic folding, fuse to form the uterus, fallopian tubes, vagina and cervix.
How are the vagina and cervix formed?
Sinovaginal bulb forms above the urogenital sinus this grows to form the vagina. Vagina is separated partly from the outside by the hymen
How do the testes descend?
Start off in the upper lumbar area and as the body grows, they’re brought more caudally. They’re tethered to the labioscrotal folds by the gubernaculum.
A musculofascial layer evaginates into the scrotum, bringing the peritoneum to form the processus vaginalis.
Testes then migrate over the pubic bone until they reach the scrotum and are surrounded by the processus vaginalis. They pass through the inguinal canal.
How is the spermatic cord formed?
From fascial layers, the obliterated stem of processus vaginalis, vas deferens and the testicular vessels and nerves
What is the remnant of the gubernaculum?
Scrotal ligament in males
Round ligament of uterus in females
What are the different types of hypospadias?
First degree - orifice opens onto glans penis
Second degree - urethral orifice opens on to shaft
Third degree - orifice opens onto perineum
What is a bicornuate uterus and what are some consequences?
When fusion of mullerian ducts is improper or incomplete so that the cephalic portion of the uterus is bifurcated. Causes problematic pregnancies with recurrent pregnancy loss, pre term births, breech births and deformity.
What’s the advantage of the testes being suspended outside of the body by the spermatic cord?
Keeps them slightly cooler than the rest of the body. This means that if the body temperature rises the sperm production won’t be affected
What are the components of the capsule surrounding the testis?
From innrer to outermost Thick tunica albuginea which also extends into fibrous septa which divide the testes into lobules containing seminiferous tubules. Tunica vasculosa Tunica vaginalis Scrotum
What are the two types of cells that line the seminiferous tubules?
Sertoli cells which secrete mullerian inhibitory hormone but also support developing sperm and secrete testicular fluid into the tubules
Spermatogonia which undergo meiosis to give rise to spermatozoa
What is spermatogenesis?
The process through which diploid spermatogonia stem cells undergo meiosis to become haploid spermatozoa.
What divisions do spermatogonia undergo in spermatogenesis?
Mitosis - primary spermatocytes
Meiosis - Secondary spermatocytes
Meiosis - Spermatids
When are cytoplasmic bridges of spermatocytes broken?
When the leave the seminiferous tubules
Where does spermatogenesis take place?
Divisions take place between sertoli cells. After this, Spermatids are remodelled within the sertoli cells and then pass into the rete testis, ductus efferentes and epididymis, maturing the whole time until they become spermatozoa
What’s a spermatogenic cycle?
New cycles of spermatogenesis that start every 16 days
What’s a spermatogenic wave?
New spermatogenic cycles starting at new points all along the seminiferous tubules so that sperm is constantly being produced
What are the 3 parts of the epididymis?
Head - Superior section and point of entry for ductus efferentes
Body - middles section
Tail - Inferior section, continuous with the vas deferens
What separates the epididymis from the testis?
Tunica vasculosa and tunica albuginea
What is the purpose of the vas deferens?
Transports sperm from the epididymis to the ejaculatory duct during the emission phase of ejaculation. Has 3 smooth muscle layers to aid with ejaculation
What do the seminal vesicles secrete?
Fructose rich, alkaline fluid forming 70% of ejaculated semen
What does the prostate gland secrete?
Seminal fluid rich in bicarbonate buffers, citric acid and fibrinolytic enzyme
What’s the importance of the bicarbonate buffers in prostate secretions?
Helps to neutralise the acidity of the vagina.
What’s the purpose of the fibrinolytic enzyme in prostate secretions?
Liquefies semen
What does the secretory activity of the prostate depend on?
Testosterone levels
What’s the purpose of the bulbourethral glands?
Secrete sugar rich mucus into the membranous urethra to lubricate the urethra. It also contributes to pre-ejaculatory emissions
Where is the infundibulum in relation to the ovary?
Lies lateral to it
What are the three components of the ovary?
Surface - covered in germinal simple cuboidal epithelium that’s continuous with the peritoneum.
Cortex - Made up of stroma tissue that supports follicles. Made up of spindle cells, ground substance and collagen cells. Has superficial cortex, or tunica albuginea that’s more fibrous than the deep cortex
Medulla - Made of supporting stroma with a rich network of vessels and nerves
What peritoneal ligaments does the ovary attach to?
Suspensory ligament that attaches mesovarium to the pelvic wall
Round ligament that connects the ovary to the fundus of the uterus
What is oogenesis?
The process by which oogonia undergo meiosis to form primary oocytes
How do granulosa cells influence oogenesis?
Stimulate oogonia entry into oogenesis and then pause process at meiosis by secreting Oocyte Maturation Inhibitor. Oocytes are kept at this stage until puberty
What are the 3 main phases of follicle development before ovulation?
Pre antral follicle - Zona pellucida forms between oocyte and granulosa cells. Receptors develop on granulosa cells for oestrogen and FSH and on thecal cells for LH
Antral follicle - fluid filled antrum forms. Thecal cells bind LH and are then stimulated to synthesise androgens which are then converted to oestrogen by the granulosa cells. Oestrogen and FSH stimulate the development of LH receptors on granulosa cells.
Pre-ovulatory follicle - Primary oocyte’s stimulated by LH surge to undergo meiosis and form and secondary oocyte and the first polar body. Granulosa cells start to produce progesterone and then the follicle ruptures and ovulation occurs
What hormones does the corpus luteum secrete?
Oestrogen and progesterone
What reproductive hormones are released by the hypothalamus?
Gonadotrophin releasing hormone (GnRH)
Prolactin releasing hormone
Prolactin inhibiting hormone
What reproductive hormones are released by the posterior pituitary gland?
Oxytocin
What reproductive hormones are released by the testes?
Testosterone
Inhibin
Mullerian inhibiting hormone
What reproductive hormones are released by the anterior pituitary gland?
Follicle stimulating hormone
Luteinising hormone
Prolactin
What reproductive hormones are released by the ovaries?
Oestrogen
Progesterone
Inhibin
What reproductive hormones are released by the placenta?
Human chorionic gonadotrophin
Human placental lactogen
Progesterone
Oestrogen
What cell type secretes prolactin in the anterior pituitary gland and what does prolactin do?
Lactotrophs. Stimulates oestrogen and progesterone and milk production
What affects release of GnRH from the hypothalamus?
Environmental factors Weight Oestrogen Progesterone Testosterone
In what kind of pattern is the release of GnRH?
Pulsatile, roughly once an hour
What hormones exert negative feedback on GnRH secretion by the hypothalamus?
Testosterone
Moderate oestrogen (reduces amount released)
Progesterone (reduces frequency)
What hormones exert positive feedback on GnRH secretion by the hypothalamus?
High oestrogen, in the absence of progesterone
What hormones exert negative feedback on LH release by the anterior pituitary?
Testosterone
Moderate oestrogen
Progesterone
What hormones exert negative feedback on FSH release by the anterior pituitary?
Testosterone
Moderate oestrogen
Progesterone
Inhibin
What cells secrete inhibin?
Sertoli cells in seminiferous tubules
Granulosa cells
What hormones exert positive feedback on LH production in the male?
Inhibin
Prolactin
What action does LH have in the male?
Acts on leydig cells to stimulate them to produce testosterone
What action does FSH have in the male?
Acts on Sertoli cells which support spermatogenesis and also release inhibin
At which follicular stages is negative feedback exerted on GnRH release from the hypothalamus?
Antral. Oestrogen levels are moderate as follicle is in primitive stages so is small. The larger the follicle, the more oestrogen is produced.
Luteal - corpus luteum produces oestrogen and progesterone, as stimulated by LH. Progesterone blocks the positive feedback of the high oestrogen levels.
At what follicular stage is positive feedback exerted on the hypothalamus?
Pre ovulatory. Follicle is growing so oestrogen levels are rising. There is no progesterone so oestrogen exerts positive feedback. LH and FSH rise although FSH less due to negative feedback from inhibin.
What is meant by a determinative effect?
Means it is only partly, or not at all reversible
What is meant by a regulatory effect?
One that is highly reversible and requires constant (hormonal) stimulation for maintenance
What are some determinative effects of testosterone?
Facial and body hair Increased size and mass of muscle, bone and vocal cords. Increased stature Deepening of voice Growth of penis
What are some regulatory effects of testosterone?
Maintenance of internal genitalia
Anabolic actions
Behavioural effects
What are the main effects of oestrogen?
Thin, alkaline cervical mucus Fallopian tube function Endometrial thickening Myometrial thickening and motility Skin, hair and metabolic changes Vaginal changes Increased calcium resorption
What are the main effects of progesterone?
Thick, acid cervical mucus
Catabolic changes
Endometrial thickening into secretory form
Myometrial thickening but reduced motility
Mammary tissue changes
Increased body temperature
Electrolyte changes
In the menstrual cycle, what can the follicular phase be further subdivided into?
Menstrual phase days 0-4
Proliferative phase days 5-14
What’s the main purpose of the follicular phase of the menstrual cycle?
Follicle development
Uterine preparation
What occurs to LH and FSH levels in the follicular phase of the menstrual cycle?
Oestrogen and progesterone are both low so FSH and LH can increase.
FSH causes maturation of several antral follicles.
Development of theca interna and LH stimulates cells to release oestrogen so oestrogen levels rise.
Oestrogen peak exerts positive feedback, especially on LH.
LH levels rise and stimulate ovulation.
Rising oestrogen levels also can proliferation of endometrial basal cells and glandular formation and formation of thin, alkaline cervical mucus.
What can the luteal phase of the menstrual cycle be further subdivided into?
Secretory phase days 25-22
Late secretory phase days 23-28
What are the main purposes of the luteal phase of the menstrual cycle?
Ovulation
provide brief period of fertility
Develop corpus luteum
Waiting phase
What happens in the ovary during the luteal phase of the menstrual cycle?
LH acts on granulosa cells to reorganise to form corpus luteum.
Luteal cells secrete oestrogen and progesterone.
Waiting phase for hCG secretion in the event of a pregnancy
If there’s no pregnancy, LH and FSH levels fall too much to be able to maintain corpus luteum so it degnerates into corpus albicans.
When corpus luteum degenerates, no longer progesterone and oestrogen secretion so LH and FSH can rise again
What happens to the endometrium during the luteal phase of the menstrual cycle?
After ovulation, progesterone stimulates the differentiation of the endometrium so there’s storage of nutrients, glands prepare for secretion and the endometrium thickens further.
Glands then start to secrete a glycogen rich milk in preparation for implantation
As progesterone and oestrogen levels fall, spiral arteries of functional layer necrose and blood leaks from these vessels and the whole of the functional layer is shed.
What would be the effect of hyperprolactinaemia be on fertility?
Would suppress fertility as prolactin disturbs the pulsatile release of GnRH
In what order do puberty events occur in females
Thelarche (breast buds) Adrenarche (pubic hair) Growth spurt Menarche (periods) Adult breasts Adult pubic hair
What are the stages of thelarche?
Breast bud development
Juvenile smooth contour
Areola and papilla project above the breast
Adult breasts
What are the stages of adrenarche in females?
Sparse pigmented, long straight hair forms, mostly along labia
Hair becomes darker, more coarse and thicker
Hair fills out towards adult distribution
What hormone drives the closure of epiphyseal plates in females?
Oestrogen
When do menstrual cycles become ovulatory?
Roughly 10 months after menarche onset
What are the stages of puberty in males?
Spermatogenesis begins Genital development Adrenarche Growth spurt Adult genitalia Adult pubic hair Adult height
What are the main stages of genital development in males?
1-preadolescent Lengthening of penis Increase in length and circumference Development of glans penis and darkening of scrotal skin Adult genitalia
How is adrenarche in males different to in females?
Same except initial hair growth is around base of penis, rather than labia
What drives the onset of puberty?
Driven by brain and increase in GnRH causing increased secretion of LH and FSH. May occur due to decreased sensitivity to negative feedback of steroids or may be because of maturation of central mechanisms
What hormones drive adrenarche?
Androgens. Testosterone in males and androgens from adrenal glands in females
What hormone drives breast development?
Oestrogen
What hormones drive the growth spurt in puberty?
Growth hormone and sex steroids. Oestrogen causes earlier closure of epiphyseal plates.
What hormone drives male genital development?
Testosterone
What drives the initiation of menarche?
Thought to be related to weight. Needs roughly 47kg or equivalent proportion of eventual weight.
What is precocious puberty?
Signs of puberty at less than 8 years old
What may cause precocious puberty?
Neurological causes because of early stimulation of central mechanisms. May occur due to things like meningitis or melatonin secreting pineal tumours
Uncontrolled gonadotrophin/steroid hormone secretion due to hormone secreting tumours
Over what ages does thelarche normally occur?
Onset between 8-13
finishing at around 16
Over what ages does adrenarche normally occur in females?
Onset between 9 and 16. Normally ending around 16
Over what ages does growth spurt normally occur in females?
From around 10-15
Over what ages does menarche normally occur?
11-15. Average around 12.5
Over what ages does genital development occur in males?
Onset around 10-14
Over what ages does adrenarche occur in males?
Onset around 10-14
Last stage around 16
Over what age does spermatogenesis and testicular volume develop?
Starts between 9-13. Final stage around 12-16
Over what ages does growth spurt normally occur in males?
Around 12-17
When does menopause normally occur?
Between ages of 40-55 with average being 52. Lasts around 2-8 years
What happens in the pre-menopausal stage?
Changes to the menstrual cycle. Follicular phase decreases in length so ovulation occurs earlier or not at all. There’s falling oestrogen so LH and FSH start to rise.
What happens during the menopause?
Cessation of menstrual cycles. There are no new follicles to develop so there’s a dramatic fall in oestrogen. This means that LH increases and FSH dramatically increases.
What are the effects of the menopause?
Vascular changes leading to hot flushes Collagen loss leading to reduced skin and bladder tone. Regression of endometrium and shrinkage of myometrium Thinning of cervix Loss of vaginal rugae Involution of breast tissue Decreased bone mass Decreased libido
At what rate is bone mass lost in the menopause?
Roughly 2.5% per year
What does hormone replacement therapy involve?
Replacing oestrogens to treat menopausal symptoms and prevent long term effects. Can also use progesterone to prevent endometrial hyperplasia and carcinoma
What are some advantages of hormone replacement therapy?
Easy to administer
Relieves menopausal symptoms
Increases well being
Can limit osteoporosis
What are some disadvantages of hormone replacement therapy?
Not firstline treatment for osteoporosis
Can increase risk of breast cancer
Increase risk of DVT due to increased coagulability of blood.
Increased risk of cardiovascular disease
What is amenorrhoea?
The lack of periods
What are the different types of amenorrhoea and how are they defined?
Primary - either lack of periods with presence of secondary sexual characteristics at 16 years or lack of periods and lack of secondary sexual characteristics at 14 years
Secondary - Ceasing of menstruation. If a history of regular cycles then no periods for more than 3 months. If a history of irregular cycles then no periods for more than 9 months
What is menorrhagia?
Excessively heavy periods lasting for more than 7 days
What is dysmenorrhoea?
Painful periods
What is oligomenorrhoea?
Periods that occur at intervals of more than 35 days
What is premenstrual sysndrome?
Recurrent symptoms that occur in the last half of the menstrual cycle
What are the 3 main origins of amenorrhoea?
Outflow tract
Gonadal/end organ
Pituitary and hypothalamic/ central regulatory disorders
What hormone changes are there in outflow tract causes of amenorrhoea?
Should be none. HPG axis is still functional
What are some outflow tract causes of primary amenorrhoea?
Mullerian agenesis
Imperforate hymen
Vaginal atresia
Cryptomenorrhoea
What is cryptomenorrhoea?
Experience of cyclic menstrual pain but with apparent amenorrhoea
What’s an outflow tract cause of secondary amenorrhoea?
Intrauterine adhesions or scarring, ie asherman’s syndrome
What is asherman’s syndrome?
Fibrosis of the endometrium. Often due to surgical trauma
What hormonal changes are seen in end organ causes of amenorrhoea?
Ovaries are unresponsive to pituitary stimulation so there’s low oestrogen that may need treatment, and high fsh.
May need chromosomal testing if hypergonadotrophic in young individuals
What are some gonadal/end organ disorders that cause primary amenorrhoea?
Gonadal dysgenesis, ie in turner’s
Androgen insensitivity syndrome
LH/FSH receptor abnormalities
Congenital adrenal hyperplasia
What are some gonadal/end organ disorders that cause secondary amenorrhoea?
Polycystic ovarian syndrome Pregnancy Anovulation Menopause Premature menopause Drug induced
What hormone changes are seen in central regulatory disorders that cause amenorrhoea?
Insufficient FSH so ovaries aren’t stimulated to produce enough oestrogen for menses to occur.
What’s a central regulatory cause of primary amenorrhoea?
Kallmann syndrome which is a disrupted interaction between the hypothalamus and pituitary gland that only affects LH and FSH
What are some central regulatory causes of secondary amenorrhoea?
Exercise amenorrhoea Stress amenorrhoea Eating disorders Weight loss Sheehan syndrome Hyperprolactinaemia Haemochromatosis Hyper-/Hypoparathyroidism
How should secondary amenorrhoea be evaluated?
Menstrual history Contraception use Surgical history Pregnancy Weight changes Medication Chronic disease Stress levels Diet Family history of menopause age, thyroid dysfunction, diabetes, cancer Physcial exam looking at BMI, hair distribution, thyroid, visual field, breast discharge, abdominal masses/tenderness
Why should visual field be assessed when assessing secondary amenorrhoea?
As visual field changes are one of the first symptoms of a pituitary tumour
How should amenorrhoea be managed?
Take good history
Rule out pregnancy
Do blood tests for:
TSH, prolactin, LH and FSH if it’s an ovarian axis problem
LFTs in chronic disease
Testosterone, androgens and progesterone in presence of hirsuitism
MRI is CNS problem is indicated
When is a menstrual cycle indicated to be anovulatory?
If there’s oligomenorrhoea or amenorrhoea, with or without menorrhagia
What is dysfunctional uterine bleeding?
Excessively heavy, prolonged or frequent bleeding of uterine origin that’s not due to pregnancy, pelvic or systemic disease. Tends to be a diagnosis of exclusion and is anovulatory
When does dysfunctional uterine bleeding tend to occur?
At extremes of reproductive life and in women with polycystic ovarian syndrome
Why does dysfunctional uterine bleeding occur?
Due to a disturbance in the HPG axis so there’s a change in menstrual cycle length. There’s no withdrawal of progesterone from the endometrium so the endometrium builds up and there’s then erratic bleeding as the endometrium breaks down.
How is dysfunctional uterine bleeding managed?
Do coagulation workup
Measure TSH and HCG levels
Consider smear test
Can give oestrogen therapy
Why does menorrhagia most often occur?
Secondary to a distortion of the uterine cavity whereby the uterus is unable to contract the venous sinuses of the zona basalis. This causes heavy bleeding that may be prolonged.
What are some general categories of causes of menorrhagia?
Organic
Endocrine
Iatrogenic
Haemostatic
How should menorrhagia be managed?
Full history
FBC
Physical exam for anaemia, obesity. androgen excess, thyroid, liver, spleen, pelvic/uterine causes, cervix, adnexal
Treat with COCP or NSAIDs and long acting progestogens
What is true precocious puberty?
Onset of puberty due to premature secretion of gonadotrophins. Before age 6/7 depending on ethnicity in girls and before 9 in boys
What may be causing primary amenorrhoea if LH and FSH levels are normal?
Tissues aren’t responding to steroids.
Outflow tract problem
Androgen insensitivity syndrome
What is androgen insensitivity syndrome?
Occurs in XY males who are insensitive to tesosterone. Develop some secondary sexual characterisitics of female so normally present with amenorrhoea. There’s female external genitalia but not internal genitalia due to presence of MIH
What may be causing primary amenorrhoea if LH and FSH levels are low?
Pituitary/hypothalamic problem.
May be anorexia nervosa/nutrition
How is puberty stage assessed?
Checking height, weight, body hair, genitalia and bone age
What is delayed puberty?
Lack of sexual maturation by 15 years
What is the most common cause of delayed puberty?
Constitutional delay. Benign representation of normal variation. Will eventually undergo normal puberty. Mostly familial
May be due to serious systemic disease
How can bone age be assessed?
Taking hand-wrist films and comparing them with standards for the subject’s chronological age
What is the average rate of growth spurt in males?
10cm per year
How can cause of delayed puberty in males be distinguished
If bone age is less than chronological age, is constitutional delay.
If FSH is low, pituitary/hypothalamus problem
If testosterone is low - hypogonadism
What is precocious pseudopuberty?
The apparent onset of puberty with virilisation but no sperm production. Due to androgen secretion from adrenals or testes
What can cause precocious pseudopuberty?
Andrenal hyperfunction ie due to congenital adrenal hyperplasia
Adrenocortical tumour
How can the causes of precocious pseudopuberty be differentiated between?
Imaging to detect tumour
Enzyme testing for enzyme that’s elevated in congenital adrenal hyperplasia
What are some effects of oestrogen depletion in the menopause?
Hot flushes disturbed sleep Breast atrophy Mood changes Vaginal/urethral atrophy Osteoporosis Changing cholesterol/lipid profile
What are fibroids?
Benign, hormone dependent tumours of smooth muscle in the myometrium
How may fibroids be diagnosed?
Mostly asymptomatic
May present with menorrhagia
Can be palpable if very large by bimanual examination as an irregularly shaped uterus
Mass can be visualised on ultrasound but can’t differentiate between that and ovarian tumours
What constitutes as excessive menstrual blood loss?
More than 80 ml. Enough to cause anaemia
How can menorrhagia extent be assessed?
Pad/tampon count
Haematocrit/haemoglobin count
How can fibroids be treated?
Depends on patient’s age, symptoms and desire for fertility. If she’s close to menopause, should regress in absence of steroid hormones
Can treat with a GnRH agonist
Remove by endoscopic resection
Do abdominal myomectomoy/hysterectomy
Evaluate the removal of ovaries alongside uterus?
Avoid future ovarian pathology but ovarian type tumours can arise from the peritoneum de novo
WIll also cause sudden menopause onset
What is the scrotum?
A fibromuscular extension of the perineum that holds the testes, epididymis and first part of spermatic cord.
