Abnormalities of Gonads Flashcards
CAH
Congenital adrenal hyperplasia
DSD
Disorder sexual differentiation
PPV
Patent processus vaginalis
CAIS
Complete androgen insensitivity
What is meant by sex of rearing?
Decision about what sex the child is going to be raised as.
What does virilized mean?
Virilization or masculinization is the biological development of sex differences, changes that make a male body different from a female body. Most of the changes of virilization are produced by androgens.
What is meant by brain sex?
The amount of androgen a fetus is exposed to inutero.
What does the SRY gene do?
The SRY gene provides instructions for making a protein called the sex-determining region Y protein.
At what point in embryological development do the gonads begin developing?
6 weeks
Where do the testes and ovary develop from?
Gonadal ridge
The wolfian duct differentiates into what?
Epididymis and vas deferens
What hormone stimulates the wolfian duct to differentiate into the epididymis and vas deferens?
Testosterone
Anti-mullerian hormone is produced by what cells?
Sertoli cells
At what point does testicular descent occur?
Week 23
Patent processus vaginalis allows communication between where?
A patent processus vaginalis (PPV) allows a communication between the peritoneum and scrotum.
How does patent processus vaginalis present?
Hydrocele or indirect inguinal hernia.
What is hydrocele?
Fluid in the tunica vaginalis of the testes due to a failure in closure of the processus vaginalis.
What is an inguinal hernia?
A wide open patent processus vaginalis allowing herniation of the abdominal contents into along the canal into the scrotum.
What is the treatment for an irreducible inguinal hernia?
Risk of surgery so is a surgical emergency.
What is the treatment for a reducible inguinal hernia?
They do not resolve spontaneously and so must be repaired by inguinal ligation of the sac.
What problems can occur with the descent of the testes?
Undescended testis, so they do not end up in the scrotum.
How are undescended testes classified?
Palpable / Impalpable
Gonadal agenesis?
Make no gonads
Hypospadias
Urethral meatus is in the wrong place (not on the head of the penis).
What is the main cause of disorders of sexual differentiation?
Congenital adrenal hyperplasia
What can under virilisation be caused by?
Lack of testosterone - testicular failure / leydig cell hypoplasia.
Failure to convert to DHT - 5alpha-reductase
Failure to respond to androgens - androgen receptor deficit.
What is congenital adrenal hyperplasia?
A condition in which there are enlarged adrenal glands present from birth.
What causes the cell proliferation and tissue growth in CAH?
Caused by a deficiency in an enzyme involved with steroid production. (Adrenal corticosteroid production pathway).
Zona glomerulosa synthesises which hormone?
Aldosterone
Pregnenolone is a precursor to what?
All of the hormones produced by the adrenal cortex.
Progesterone
What does aldosterone do?
Signals the kidney to reabsorb more Na+ into the blood and excrete more potassium.
Causes more water to move into the blood increasing blood volume and pressure.
Zona fasciulata synthesises what hormone?
Cortisol
Zona reticularis synthesis what hormones?
Androgens e.g testosterone
What hormones is most importantly affected in CAH?
Low cortisol levels as a result of enzyme deficiency in conversion pathways leads to excessive ACTH production.
The excessive ACTH production causes the hyperplasia of the adrenal glands.
What is the most common enzyme deficiency of CAH?
21 hydroxylase deficiency.
A deficiency in 17alpha-hydroxylase leads to what?
CAH
Low androgen production causing poorly developed genitals and secondary sex characteristics.
21 and 11beta hydroxylase deficiency leads to what symptoms in the androgen pathway?
Increased production in the androgen pathway causing masculisation, ambiguous genitalia and early onset of puberty in females.
17a hydroxylase deficiency causes what symptoms in the androgen pathway?
Decreased production in the androgen pathway.
Males - leads to ambiguous genitalia and undescended testes.
Females - lack of secondary sex characteristics.
21 hydroxylase deficiency leads to what symptoms in the aldosterone pathway.
Decreased production in the aldosterone pathway causing, salt wasting, dehydration and hypotension.
How do 21 11beta and 17alpha hydroxylase affect the cortisol pathway?
Decreased production in the cortisol pathway which could lead to hypoglycaemia.
How is congenital adrenal hyperplasia diagnosed?
Based on symptoms
Blood and urine tests to identify enzyme deficiencies in the adrenocorticosteroid synthesis pathway.
How is congenital adrenal hyperplasia treated?
Life long steroid replacement (aldosterone, testosterone, estrogen and cortisol).
Feminising genital reconstruction.
Life long psychological support and counselling.
Imperforate hymen
An imperforate hymen is a congenital disorder where a hymen without an opening completely obstructs the vagina. It is caused by a failure of the hymen to perforate during fetal development.
How and when is imperforate hymen diagnosed?
It is most often diagnosed in adolescent girls when menstrual blood accumulates in the vagina and sometimes also in the uterus causing cyclical pain.
Transverse vaginal septum
A transverse vaginal septum is a horizontal “wall” of tissue that has formed during embryologic development and essentially creates a blockage of the vagina.
Longitudinal vaginal septum
A longitudinal vaginal septum (LVS) is sometimes called a double vagina because it creates two vaginal cavities separated by a vertical wall of tissue.
What problems may be seen with longitudinal vaginal septum?
Dyspareunia / difficulty with tampons / problems in labour
Obstructed uterine horns
Uterine horn is where the uterus and fallopian tubes meet, obstruction can cause pain.
Cervical agenesis
The cervix does not form
What problems are seen in cervical agenesis?
Primary amenorrhoes
Abdominal pain
Haematometra
Hematometra
Hematometra is a medical condition involving collection or retention of blood in the uterus.
Mayer-Rokitansky-Kuster-Hauser
This condition causes the vagina and uterus to be underdeveloped or absent, although external genitalia are normal.
What issues occur with Mayer-Rokitansky-Kuster-Hauser?
Primary amenorrhoea
Primary amenorrhoea
Primary amenorrhea is the failure of menses to occur by age 16 years, in the presence of normal growth and secondary sexual characteristics.
Menorrhagia refers to
Heavy menstrual bleeding
What can heavy menstrual bleeding lead to?
Anaemia
How is amenorrhoea different to primary amenorrhoea?
Amenorrhoea is the absence of menstruation.
Primary amenorrhoea is when menstruation has not started by 16 years.
Secondary amenorrhoea
When previously normal menstruation ceases for 3 or more months.
Dysmenorrhoea (painful menstruation) is associated with what?
High prostaglandin levels in the endometrium causing contractions and uterine ischaemia.
What is the genetic inheritance of CAH?
Autosomal recessive
How does CAH present regarding genitalia?
Ambiguous genitalia at birth.
Enlarged clitoris and amenorrhoea and puberty.
Androgen insensitivity syndrome
Androgen insensitivity syndrome (AIS) occurs when a male has cell receptor insensitivity to androgens, which are converted peripherally to oestrogens. The individual appears to be female; the diagnosis is only discovered when ‘she’ presents with amenorrhoea.
Between what weeks is there bipotential in the embryo?
0-6weeks
What is meant by bipotential?
The gonadal ridge is bipotential and can develop into an ovary or a testis.
The gonadal ridge is derived from where?
Mesonephros
Testes determining factor promotes development of the testes. What gene produces TDF?
Sex-determining gene Y
The mesonephric duct develops into what in the male?
Ductus deferens epididymus
Anti-mullerian hormone is secreted by what cells?
Sertoli cells
Cryptochidism
A condition in which one or both of the testes fail to descend from the abdomen into the scrotum.
What problems does cryptochidism cause?
Undescended testes pose a problem because when they are located in the abdomen the higher temperature there is not compatible with spermatogenesis.
What causes hypospadias?
Failure of the fusion of the urethral folds.
The seminal vesicles bud off where?
Mesonephric duct
When and how do the external genitalia begin to form?
The external genitalia begin as cloacal folds in week 5.
How do the labia majora and scrotum form?
On each side of the cloacal folds genital swellings form giving rise to the labia majora or scrotum.
What does the genital tubercle form?
The genital tubercle elongates to form the penis in the male or the clitoris in the female.
