Male Infertility Flashcards
(72 cards)
What do fetal testes secrete?
Testosterone and Mullerian inhibiting factors
What are the two primitive genital tracts?
Wolffian and Mullerian ducts
In males, which duct degenerates, Wolffian or Mullerian?
Mullerian
The wolffian becomes the repro tract
What occurs if no male testicular hormones are present?
Fetus will develop female internal genital tract
In females, which duct degenerates, Wolffian or Mullerian?
Wolffian
The Mullerian becomes the repro tract
What is Androgen Insensitivity syndrome? (Testicular feminisation)
Congenital insensitivity to androgens
X-linked karyotype (46XY)
Testes develop but don’t descend
What happens in Androgen Insensitivity syndrome?
Androgen induction of wolffian inhibition does not occur, Mullerian inhibition does occur
born phenotypically external geneitalia female, absence of a uterus and ovaries with short vagina
When does Androgen Insensitivity syndrome commonly present?
At puberty with primary amenorrhoea, lack of pubic hair
How do the testes descend?
In utero, testes develop in abdominal cavity of foetus and drop into scrotal sac before birth (androgen dependant)
Why is it important that the testes descend?
Lower temperature outside the body to facilitate spermatogenesis
How do the testes raise and lower according to external temperature?
Nervous reflexes trigger dartos muscle contraction in scrotal sac
What is Cryptorchidism?
Undescended testes
What are the clinical implications of Cryptorchidism?
Reduced sperm count, if unilateral usually infertile
What procedure helps to reduce risk of testicular germ cell cancer?
Orchidopexy (done before age 14 years
If testes are undescended as an adult, what procedure should be considered and why?
Orchidectomy because cancer risk is X6
Where does spermatogenesis occur?
Seminiferous tubules
Where is testosterone produced?
Leydig cells
What part of the sperm contains enzymes for penetrating the ovum?
The acrosome
Why does the sperm have many mitochondria?
To power the tail
What is a spermatozoon?
A sperm cell
What is present in the tail?
Microtubules
What are the 6 roles of Sertoli cells?
Forms a blood-testes barrier Provides nutrients Phagocytosis Secrete seminiferous tubule fluid Secrete androgen binding globulin Secrete inhibin and activin hormones
What can a lack of testosterone lead to?
Osteoporosis
Why is a blood-sperm barrier important?
Protects sperm from antibody attack
Provides suitable fluid composition which allows later stages of sperm development
