Module 11 Flashcards
What are the components of the male external genitalia?
Glans penis, prepuce (foreskin), body of penis, corpus spongiosum, testis, corpus cavernosum
Fill in the following table
Label the following diagram
Label the following diagram
Label the following diagram
Label the following diagram
Label the following diagram
What are the components of the male duct system?
Epididymis, prostatic urethra, vas deferens, ejaculatory duct, spongy urethra, membranous urethra
What are the accessory glands of the male reproductive system?
prostate, bulbourethral gland, seminal vesicle
What is the tunica albuginea and describe its location.
It is a white fibrous connective tissue coat on the surface of the testis
The tunica albuginea extends into the testis to form walls or septa, creating a number of small cavities called lobules. What structures, responsible for the production of sperm are found within each lobule?
Seminiferous tubules
Name the endocrine cells which are also located in these lobules and what hormone do they secrete?
Interstitial cells (leydig)- testosterone
Is testosterone amino acid, protein or steroid based?
Steroid
What is its mode of action?
Attach to carrier protein in blood, diffuses through cell membrane to directly influence DNA
Name the sequence of structures the spermatozoa pass through from seminiferous tubules to vas deferens
1) Seminiferous tubules 2) Straight tubules (rectus) 3) Rete tesits 4) Efferent ductules 5) Head of epididymis 6) body of epididymis 7) talk of epididymis 8) vas deferens
What type of epithelium lines the inside of the epididymis?
Pseudostratified columnar with elongated microvilli, known as stereocilia
What are stereocilia located here?
To increase the surface area of epithelium in order to absorb fluid, not movement
What is the function of the epididymis?
Also storage of sperm, phagocytosis of degenerating sperm, final maturation of sperm
How are sperm moved through the epididymis?
Muscular contractions of its smooth muscle wall
The vas deferens is a tube that transports sperm from the epididymis to the ejaculatory duct, located posterior to the bladder. The vas deferens travels inside the spermatic cord on its way to the pelvic cavity. What other structures are found in the spermatic cord?
Testicular artery, nerves, lymphatics and pampiniform plexus
Describe the path of the ductus deferens from testis to bladder
Runs up through the spermatic cord, enters the pelvic cavity via the inguinal canal, travels over and behind the urinary bladder towards the prostate gland from the posterior aspect
The end of the ductus deferens enlarges to form the ampulla. Which accessory gland has a duct that unites with the ampulla to form the ejaculatory duct?
Seminal vesicle
The ejaculatory duct runs through which gland, to open into the urethra?
prostate
Examine the histological image of the ductus (vas) deferens. How do you think sperm are able to travel through the length of the tube during an ejaculation, considering they are still not motile?
Peristaltic contractions of the smooth muscle layers.
Describe the appearance of erectile tissue of the penis
Vascular sinusoids that fill with blood
Which column of erectile tissue contains the urethra?
Corpus spongiosum
The proximal end of the corpus spongiosum expands slightly to form the bulb of the penis, which accessory gland is found near the bulb?
Bulbourethral gland
The corpus spongiosum expands at the distal end of the penis to form which structure?
The glans penis
What is the name for the loose fold of skin that normally covers the part named in Q5?
Prepuce/foreskin
Which branch of the autonomic nervous system stimulates erection?
Parasympathetic
Which branch of the autonomic nervous system stimulates emission?
Sympathetic
What is the name of the thickened layer of white fibrous tissue surrounding the corpora cavernosa (hint: hasthe same name as the white fibrous tissue surrounding the testis)? What might its role be?
Tunica albuginea , allows compression of veins during erection
Accessory glands contribute ~95% of the volume of seminal fluid. What makes up the last 5%?
sperm from the testes
What is the purpose of the semen clotting just after ejaculation?
To keep the deposited semen in place in the vagina
What is the average volume of a normal ejaculation?
2-5ml
What is the overall pH of semen?
Alkaline (7.2-8.0)
Why is it necessary for the male and female gametes to have a haploid configuration?
To allow the fertilised oocyte to have a diploid configuration (2n)
How do the layers of the seminiferous epithelium relate to the location of the developing sperm cells? Where are the most mature cells located?
Spermatogonia – in contact with basement membrane, Spermatocytes are in an intermediate position, spermatids are in contact with the lumen, sperm cells are free within the lumen
) Why do the spermatogonia divide into separate ‘A’ and ‘B’ daughter cells?
‘A’ replenishes the stem cell pool, ‘B’ will become a primary spermatocyte
What is the role of the Sertoli cells during spermatogenesis?
Secretion of growth factors and nutrients for the developing sperm. Secretes ABP (see Q7)
What is the role of Androgen Binding Protein, what cell produces it?
Sertoli cells produce ABP to increase levels of testosterone near seminiferous tubules
What is the difference between spermatogenesis and spermiogenesis?
Spermatogenesis is the process by which spermatozoa (mature sperm cell) develop from a stock cell called a spermatogonium Spermiogenesis is the last phase in the spermatogenesis process where a spermatid is modified to become a spermatozoa (mature sperm cell). This process does not involve any cell divisions but just the altering of the spermatid. The cell develops a head, midpiece and tail, acrosome
Indicate the function of each component of a sperm
Head – contains chromosomes Mid-piece – contains the mitochondria Tail – propel the sperm forward Acrosome – contains enzymes to help penetrate ovum Nucleus – contains genetic material Mitochondria – produce ATP required for movement
What is the approximate length of sperm (head to tail)?
50µm
Which hypothalamic hormone stimulates FSH and LH secretion from the anterior pituitary?
Gonadotropin Releasing Hormone (GnRH)
What is the effect of LH secretion in the male?
Stimulates testosterone secretion by interstital (Leydig) cells of testes
Name some of the effects of testosterone.
Development of sex organs and secondary sexual characteristics
What is the effect of FSH secretion in the male?
Binds to sustentacular (Sertoli) cells of seminiferous tubules, causes the production of ABP
Why are LH and FSH referred to as ‘gonadotropins’?
They bind onto cells in the gonads (testes) stimulating their function (tropic hormones)
Where on the diagram above would androgen-binding protein (ABP) be found?
Sertoli cells
) Describe the effect of testosterone on the hypothalamus and anterior pituitary.
Inhibition of GnRH and reduction in FSH and LH
Where is inhibin produced and what is its role?
Sustentacular cells and inhibits FSH secretion
