Lecture 21 - Male Reproductive Flashcards
How long is the epididymis?
4cm long = length of epididymis
Where is the epididymis located?
Epididymis
Location = in scrotum, btwn the seminiferous tubules and the vas deferens
Which border of the testes does the epididymis occupy?
The posterior border
Describe the structure and their functions of the - Epididymis
Head:
- contains and receives sperm from the seminiferous tubules
- forms a cap around the upper pole of the testes
Body:
- lies on the posterior boarder of the testes and contains the highly coiled duct of epididymis
Tail:
- near the inferior boarder of the testes
- no coiling
- reverses its direction and ascends into the ductus deferens
- stores sperm
- continuous with the vas deferens
Where are sperm stored
Tail of epididymis = stores sperm
Describe the histology of the Epididymis
Epididymis - Histology
- lined with pseudostratified columnar epithelium with stereocilia (microvilli)
- regulates the composition of tubular fluid
- walls contain smooth muscle and peristaltic contractions move sperm thru the duct
What are the functions of the epididymis (3)
Epididymis
1) Monitor and adjust fluid composition form seminiferous tubules
2) Recycle damaged sperm
3) Storage and functional maturation of sperm
How long are the ductus deferens?
45 cm long = length of ductus deferens
Where does the ductus deferens start and end?
Start: epididymis
End: ejaculatory duct
What forms the ejaculatory duct
The ductus deferens joins the seminal vesicles to form the ejaculatory duct
What part of the ductus deferens joins the ejaculatory ductqq
the ampulla of the ductus deferens joins the seminal vesicles to form the ejaculatory duct
Where does the ejaculatory duct empty into the urethera?
In the prostate the ejaculatory duct empties into the urethra
What is the composition of the ductus deferens epithelium?
Vas deferens = pseudostratified columnar epithelium with sterocilia
How many layer of muscle does the vas deferens have
3 - in and out long, mid circle
What is the function of the vas deferens?
Vas deferens = conveys sperm during sexual arousal from the epididymis towards the urethra by peristaltic contractions
- can store sperm, but will eventually reabsorb if not used
What forms the ejaculatory duct
The union of the seminal vesicle and the ampulla of the ductus deferens fomes the ejaculatory duct
Urethra length =
Urethra length = 15-20cm
Urethra purpose (male)
Urethra = passageway for semen and urine
Describe the pathway of the urethra (male)
Thru: prostate -> deep muscles of the peritoneum -> penis
What are the 3 subdivisions of the urethra? (male)
- prostatic urethra
- membranous urethra
- spongy urethra
Where does the urethra end (male)
The urethra ends at the external urethral orfice
Seminal vesicles - Location
Seminal vesicles = located on posterior surface of the bladder in front of the rectum
Of the male accessory glands, which is the ‘ large coiled tubular glands’?
The seminal vesicles are large coiled tubular glands
What is the epithelium of the seminal vesicles - what does it depend on?
The seminal vesicles are:
pseudostratified or cuboidal
- depends on the levels of testosterone
What so the seminal vesicles secrete?
Seminal vesicles secrete:
- alkaline viscous fluid = seminal fluid
- contains fructose, ascorbic acid, coagulating enzymes, clotting proteins, and prostaglandin
What % of semen comes from the seminal vesicles?
60% - seminal vesicles
How many prostate glands?
1
What % of semen is produced by the prostate gland?
Prostate gland produces 30% of semen
What does the prostate gland secrete?
The prostate gland secretes “prostatic fluid”
- alkaline secretion 7.28 pH
- milky
- seminal plasma = antibiotic
- citrate = makes sperm active
What is the prostate composed of?
The prostate is composed of 30-50 tubular glands embedded in smooth muscle
What is the epithelium of the prostate gland composed of?
pseudostratified columnar epithelium
What do the bulbourethral glands secrete
Bulbourethral glands secrete:
- thick, clear, alkaline mucous that drains into the penile urethra
- secretion is released before ejaculation to neutralize traces of acidic urine in the urethra and to lubricate the urethra and penis
What is the epithelium of the bulbourethral glands?
simple columnar epithelium = bulbourethral glands
What are the functions of the accessory glands (3)?
1) Seminal glands secrete an alkaline, viscous fluid that helps neutralize female genetailia tract after ejaculation
2) The prostate secretes a milky, slightly acidic fluid that contains enzymes that break down clotting proteins from the seminal glands
3) Bulbourethral glands secrete alkaline fluid that neutralizes the acidic environment of the urethra and mucous that lubricates the lining of the urethra and the penis for sex
What is the composition of semen?
2-5 ml – 20-100 million sperm
- 60% seminal vesicles
- 30% prostate
- 5% sustentacular cells
- < 5% bulbourethral cells
Why does semen coagulate within 5 minutes of ejaculation?
- coagulates within 5 minutes due to the presence of clotting proteins from seminal vesicles
What functions to liquidify semen
fibrinolysin functions to liquidfy semes
What are the 3 parts of the p
-Root
- Body
- Glans
Describe the different portions of the penis
Root:
- fixed portion that attaches the penis to the ischium
Body:
- tubular moveable portion
- consists of errectile tissue
Glan:
- extended distal end
- surrounds the urethral meatus
Describe the Corpus Cavernosa
Corpus cavernosa:
- 2 erectile cylinders on the dorsal surface of the penis
- majority of the penis
- the crura of the penis is the proximal portions of the corpora cavernosa and its attached to the bony pelvis via the ischiocaveronsus muscle
What forms the majority of the penile mass?
The corpus cavernosa forms the majority of the penile mass
Describe the Corpus Spongeosum
- surrounds the urethra
- distal end expands to form the glans
- proximal end is enlarged and called the bulb of the penis
- the bulb is covered by the bulbospongiosum muscle which secures it to the urigenital diaphragm
What muscle is associated with the corpus spongiosum, where does it attach
Corpus spongiosum
- bulbosponsiosum muscle
- attaches to the urigenital diaphragm
In the flaccid state are the bv constricted or relaxed>
Flaccid state
- bv contricted
- smooth muscle tense reducing blood flow
What stimulation stims erection
parasympathetic stimulation =
What is the blood supply of the penis
Penis - Blood
- deep and dorsal arteries of the penis
- deep dorsal vein
