Male infertility Flashcards
What determines gender?
Socially constructed roles and behaviours that a society typically associated with males and females
Genotype and phenotype are determined by
Sex
What is the phenotype of androgen insensitivity syndrome
- female external genitalia
- lack of pubic hair
What is the common presentation of androgen insensitivity syndrome
Present with amenorrhoea
Androgen sensitivity is an _-______ ______ disorder
Androgen sensitivity is an x-linked recessive disorder
What is the karyotype of androgen insensitivity disorder?
46 XY
Describe the pathogenesis of androgen insensitivity disorder?
Testis develop but don’t descend, no androgen and so induction of wolffian duct does not occur. Absent uterus and ovaries with short vagina and female external genitalia
What is the function of the testis?
- Spermatogenesis (seminiferous tubules)
- Production of testosterone (leydig cells)
Testicular artery is a branch of what artery?
The aorta
The left testicular vein joins the _____ _____ ____ and right testicular vein drains into _________ ____ ____
The left testicular vein joins the left renal vein and right testicular vein drains into inferior vena cava
Where is the lymphatic drainage of the testis?
Into the abdomen
Why is it important that the testes descend?
Lower temperature outside the body for spermatogenesis
______/______ muscle contraction in scrotal sac _____/______ testes according to external ______
dartos/cremaster muscle contraction in scrotal sac lowers/raises testes according to external temperature
The dartos muscle is ______ ______
The dartos muscle is smooth muscle
The cremaster muscle is _____ _______ and a continuation of the _______ _______
The cremaster muscle is skeletal muscle and a continuation of the internal oblique
What is contained in the spermatic cord?
Arteries, veins, nerves, lymphatics, vas deferens
What covers the testis
Tunica vaginalis- peritoneal remnant and then tunica albuingea (firm fibrous covering)
What is cryptorchidism?
Individual has reached adolescence/adulthood and testes have not descended
When do testes normally descend?
Between 6-9 months of age
When should orchidopexy be performed?
By 12 months because of strong association with infertility (azoospermia) and by 12 years to minimise risk of testicular germ cell cancer
What should be done if undescended testis are discovered as an adult?
Consider orchidectomy as risk of cancer is 6x baseline
What is corpus cavernosum?
Two columns of tissue running along the sides of the penis- blood fills to cause an erection
What is corpus spongiosum?
A column of sponge like tissue running along the front of the penis ending at the glans penis; it fills with blood during an erection keeping the urethra open
Spermatozoa contain ______ genetic material
Spermatozoa contain haploid genetic material
What are the roles of Sertoli cells?
- form blood-testes barrier
- provide nutrients
- phagocytosis
- secrete seminiferous tubule fluid
- secrete androgen binding globulin
- secrete inhibin and activin hormones
What is the function of the blood-testes barrier?
- Protects the sperm from antibody attack
- Provides a suitable fluid composition which allows later stages of development of sperm- v different from blood.
What is the role of phagocytosis by Sertoli cells?
Remove surplus cytoplasm from packaging process & destroys defective cells
What is the role of seminiferous tubule fluid?
Carries cells to epididymis
What is the role of androgen binding globulin?
Binds testosterone so concentration remains high in lumen
Essential for sperm production
What is the role of inhibin and activin hormones?
regulates FSH secretion and controls spermatogenesis
GnRH is a ____peptide released from the ________ in ______ every ___ hours (beginning at age ____ years)
GnRH is a decapeptide released from the hypothalamus in bursts every 2-3 hours (beginning at age 8-12 years)
GnRH stimulates the anterior pituitary to produce __ and ____ and is under _______ ______ ____ from testosterone
GnRH stimulates the anterior pituitary to produce LH and FSH and is under negative feedback control from testosterone
Gonadotrophins are _______ secreted by the anterior pituitary
Gonadotrophins are glycoproteins secreted by the anterior pituitary
What is the role of LH in men?
Acts on leydig cells- regulates testosterone secretion