Male reproduction Flashcards
Identify the major male reproductive organs
Testes, epididymus, ductus deferens, prostate, seminal vesicles, BUGs, penis
List the major actions of androgens during fetal development of the male reproductive tract
release of MIS causing the degeneration of Mullerian ducts; contribute to development of secondary sex characteristics and masculinization of urogenital tract and external genitalia
Describe the role of MIS in male reproductive tract development
degeneration of Mullerian ducts
Describe the function of germ cells and Sertoli cells
Sertoli cells: regulate maturation and provide a source of nutrition; regulate germ cell development germ cells: spermatogonia to spermatozoa
Describe the function of LH and FSH in the testis
LH- acts on Leydig cells, stimulates secretion of testosterone FSH- acts on Sertoli cells, acts indirectly on spermatogenesis
Describe with diagrams the regulatory system that controls the secretion of testosterone by Leydig cells
Describe with diagrams the feedback system that controls the secretion of testerone
Describe whether the major effects of testosterone on spermatogenesis are mediated directly or indirectly
LH-> Leydig cells -> testosterone -> spermatogenesis FSH-> Sertoli cells (direct) -> promote spermatogenesis Androgens (testosterone) acts INDIRECTLY on spermatogenesis because germ cells do not have androgen receptors
List the major clinically important male reproductive diseases/problems
Cryptorchidism Infertility Benign prostatic hyperplasia Testicular tumors
Wolffian duct
develops in males, forms the epididymus, vas deferens, seminal vesicles and ejaculatory ducts
urogenital sinus
Males: becomes the prostate Females: becomes the caudal part of the vagina
Mullerian duct
Developed in females, becomes ovaries, uterine horns, vagina (cranial 1/3), uterus, oviducts
Mullerian inhibiting substance (MIS)
important in degeneration of the Mullerian ducts during fetal development in males, secreted by Sertoli cells
testes
produces sperm and secretes hormones
epididymis
major function is maturation of sperm; also involved in storage and transport
seminal vesicles
provide about 60% of semen volume, secrete alkaline, viscous fluid containing fructose, prostaglandins, and clotting proteins (different from blood)
prostate
present in all species, provides about 25% of semen volume, secretes milky, slightly acidic fluid containing citric acid, several proteolytic enzymes, acid phosphatase
bulbourethral glands
BUGs; secrete alkaline fluid that protects passing sperm by neutralizing acids from urine in urethra, mucus lubricates end of penis and lining of urethra (not present in all species)
penis
organ used in urination and copulation
spermatogenesis
Drives it: Leydig cells and the androgens they produce Dependent on androgens (act indirectly) Takes a variable period of time, cells go through meiosis
benign prostatic hyperplasia
seen in dogs and humans; benign hyperplasia, enlargement of the prostate gland clinical symptom (dogs)- incontinence treatment- castration
cryptorchidism
bilateral or unilateral undescended testicle; can be at any point along the descent tract; testicle continues to produce testosterone and makes animal more prone to testicular cancer if untreated; 0.8-15% in dogs; can be medically or surgically treated
infertility
sterile; sperm are not viable and cannot produce viable offspring; frequently idiopathic
testicular tumors
types: Sertoli cell tumors, Seminomas, Interstitial cell tumors; all can be malignant; have seen increased incidence of testicular tumors in veterinary medicine
What is testicular feminization?
Androgen insensitivity syndrome; XY, no development of secondary sex characteristics but MIS still secreted which leads to degeneration of Mullerian ducts
