Lecture 2- The male reproductive system

Question 1

overview of the male reproductive glands

Answer 1

The testes–>spermatic cord –>prostate gland –> urethra

Question 2

• Testes is connected to the rest of the reproducitive tract by the

Answer 2

vas deferens (ductus deferens)

Question 3

where does the urethra pass to allow semen to be expelled from the penis

Answer 3

• Urethra passes through the pelvic floor and into the erectile tissue of the penis before the semen is expelled from the penis

Question 4

microsturcture of the testes ; what is the functional unit of the testes

Answer 4

seminferious tubules (epithelium of the tubules)

• looks like noodles

Question 5

what occurs in the seminiferous tubules

Answer 5

spermatogenesis

Question 6

• Compartment of seminiferous tubules are separated by a

Answer 6

capsule (tunica albuginea)

Question 7

where do seminiferious tubules drain into

Answer 7

efferent ductulus (through the rete testes) into the epididymis (fluid reabsorbed and sperm concentrated)

Question 8

• Epididymis goes on and form the

Answer 8

vas deferens

Question 9

• The testes are then also covered by a

Answer 9

serous layer- tunica vaginalis (part of the peritoneum)

Question 10

Clinical correlate for the Tunica vaginalis-

Answer 10

Hydrocoele

• A cavity which can fill with fluid –> hydrocoele
• Many causes

Question 11

hydrocele

Answer 11

A hydrocele (HI-droe-seel) is a type of swelling in the scrotum that occurs when fluid collects in the thin sheath surrounding a testicle. Hydrocele is common in newborns and usually disappears without treatment by age 1. Older boys and adult men can develop a hydrocele due to inflammation or injury within the scrotum.

Question 12

cells of the testes

Answer 12

sertoli and leydig cells

Question 13

Think of the tests like

Answer 13

spaghetti (seminiferous tubules) bolognaise (interstitial fluid).

Question 14

Wall of the seminiferous tubules are made up of

Answer 14

Sertoli cells – which support the developing sperm and help them mature- pruning away the cytoplasm

• Sperm comes from the germinal epithelium where the stem cells are found that form the sperm

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Question 15

Interstitial tissue in the testes

• Contains a cell called the

Answer 15

Leydig cell

Question 16

leydig cells

Answer 16

Leydig cells, also known as interstitial cells of Leydig, are found adjacent to the seminiferous tubules in the testicle. They produce testosterone in the presence of luteinizing hormone (LH).

• lots of smooth ER (lipid metabolism)–> testosterone is based around choelsterol which eneds lipid metabolism

Question 18

blood supply of the testes

Answer 18

• Testes develop in the abdomen and then descend down stretching the neurovascular supply

left and right teste have slighty different blood supply

Question 19

• Right testicle blood supply

Answer 19

from the right testicular artery and vein (origin = level of renal vesicles

Question 20

-Left testicles- left testicular vein going into the left renal vein

Answer 20

o Left testes sits lower than the right ( this may be because there is slightly more resistance to the venous drainage on the right than the left)

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Question 21

• While the Testicular vein descends it forms a

Answer 21

plexus - pampiniform plexus around the artery

o Heat exchanged between the vein and artery to keep the testes cool for spermatogenesis

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Question 22

lymphatic drainage of the testes

Answer 22

Different lymphatic drainage of the testis and scrotal skin (important when feeling for lymphadenopathy):

Question 23

testis lymphatics

Answer 23

• Testis- drain lymph into the para-aortic lymph nodes

Question 24

scrotal skin lymphatics

Answer 24

• Scrotal skin- drain to the inguinal lymph nodes

Question 25

**Can testicles get twisted?**

Answer 25

**Yes!**

Question 26

which reflex is used to diagnose testicular tortion

Answer 26

cremastetic reflex

Question 27

The cremasteric reflex

Answer 27

is performed as part of an evaluation of acute scrotal pain to assess for evidence of testicular torsion. The **absence** of the reflex is considered to be diagnostic for testicular torsion

Question 28

testicular tortion is a

Answer 28

surgical emergency

Question 29

outline testicular tortion

Answer 29

* If the reflexion of the visceral and parietal levels extends up the testis like in Bell-clapper deformity, then it can twist and lead to torsion * First you get venous drain occlusion * This causes increase capillary pressure * Compresses the arteries – cuts off blood supply to testes- ischaemia --\> necrosis

Question 30

why can infertility occur with testicular tortion

Answer 30

Could become infertile- due to the testis having **immune privilege** (if it becomes necroses the immune system will see the antigens in the necrosed teste and the immune system will start to recognise the other teste (doesn’t happen in everyone)

Question 31

**Can testicles swap sides?**

Answer 31

**NO** **due to scrotal septum**

Question 32

**Descent of the testes**

Answer 32

Has to get from inside the abdomen to the scrotum – abdomen has a muscular well. 1. The gubernaculum is a band that connect the bottom of the scrotum to the bottom of the testis 2. Gubernaculum only shortens slightly, but guides the testis down as the rest of the body grows 3. The testis do not penetrate the abdominal wall, it **invaginates** the abdominal wall 4. These abdominal muscles become the walls of the spermatic cord, invested in fascia

Question 33

**The spermatic cord has**

Answer 33

* Three fascial layers * **External** * **Cremasteric** * **Internal**

Question 34

external spermatic fascia is

Answer 34

fibrous and derived fromt he external oblique

Question 35

cremasteric spermatic fascia derived from

Answer 35

internal oblique--\>muscle fibres- cremaster muscle

Question 36

* Cremaster muscle regulates

Answer 36

* the height of where the testis sits * When cold the cremaster muscle contracts and pulls the testes up * When hot- relaxed- maximum surface area for heat exchange

Question 37

* **Internal** fascia derived from

Answer 37

(fibrous)(transversalis fascia)

Question 38

* Contents of spermatic cord (rule of 3x blood vessels and 3x nerves X3 other)

Answer 38

Blood vessels * Testicular artery/ vein (pampiniform plexus * Cremasteric artery (cremaster muscle)/ vein to cremaster * Artery to the vas/ vein to the vas **Nerves** * Nerve to the cremaster * Genital branch of the genitofemoral nerve from the lumbar plexus * Sympathetic (cause ejaculation of sperm) going to the Vas (sit close to the blood vessels to the vas) * Ilioinguinal nerve (sits outside the spermatic cord Other * Lympathics- to the para-aortic lymph nodes * The Vas * Obliterated processes vaginalis

Question 39

**The vas deferens (ductus deferens, Vas) has some important pelvic relations** *

Answer 39

* Important relationship between the Vas and the ureter * In the male- the ureter passes beneath the Vas (water under the bridge) * In the female- the ureter passes beneath the uterine artery

Question 40

the vas takes contirbution from the

Answer 40

sSeminal vesicles to form the ejaculatory ducts (x2) which pass through the prostate gland to the enter the urethra.

Question 41

* The prostate gland has three important openings

Answer 41

* Urethra hole * 2x ejaculatory ducts which enter round the back

Question 42

* If the prostate enlarges then there will be

Answer 42

* compression of the urethra * lower urinary tract obstruction

Question 43

................. zone of the prostate directly surrounding urethra is most likely to enlarge

Answer 43

transitional zone

Question 44

* Cancers of the prostate tend to be in the ................... zone and may not effect urinary flow

Answer 44

peripheral zone

Question 45

**Contributions different glands make to the volume of the ejaculate**

Answer 45

* Testes only contribute 10% of volume * **Majority of volume from the seminal vesicle** (65%) * Prostate gland (25%) (prostate massage can cause ejaculation) * Bulbourethral (Cowpers) gland – 1%

Question 46

**The male urethra and catheterisation**

Answer 46

* The male urethra has bends in it- makes passing a catheter hard (easier in females) * Have to try and straighten the bend * Straighten the penis * Gentle tension to the penis will straighten the second bend (if you don’t straighten the penis you can create false entry- make holes in the prostate

Question 47

function of the penis

Answer 47

* Expulsion of urine via urethra * Deposition of sperm in female genital tract * Removal of competitors sperm * Attraction of mates

Question 48

structure of the penis: composed of how many blocks of erectile tissue

Answer 48

3 blocks of erectiel tissue - X2 ETs eyes are the coprus cavernosum - ETs mouth is the urethra within the corpus spongiosum

Question 50

how is an erection achieved

Answer 50

* Vasodilation (esp corpus cavernosum) in penile arterioles and compression of veins results in erection

Question 51

vasodilatio n is intitated by

Answer 51

parasympathetic stimulation

Question 52

actual ejaculation is

Answer 52

sympathetic

Question 53

* Erection is terminated by

Answer 53

vasoconstriction (sympathetic)

Question 54

penis is anchored to the

Answer 54

pubic symphysis * Corpora cavernosa is anchored to the pelvis

Question 55

**The penis is homologous to the**

Answer 55

**clitoris**

Question 56

The tunica albuginea of the penis

Answer 56

* White membrane that surrounds the corpus cavernosum and spongiosum * Provides the shape of the penis in an erect penis * Collagen fibres run in both transverse and longitudinal planes- provides support (would be like a slinky if it was just in transverse plan)

Question 57

**Clinical correlation- disruption to the tunica albuginea of the penis**

Answer 57

If the tunica albuginea ruptures blood from the corpus cavernosum can spill out and cause dense fibrous scar tissue- cause a bend to occur (surgical emergency)

Question 58

**Blood supply to the penis** *

Answer 58

* Comes from the **internal iliac artery**- becomes the internal pudendal artery which supplies the arteries to the penis * Perineal arterial * Dorsal arteries * Cavernous artery * Bulbourethral artery circumflex artery