Male reproductive organs Flashcards
1
Q
Where do the primordial germ cells come from?
A
The wall of the yolk sac (ectodermal)
2
Q
What structure attaches to the inferior part of the testes and pulls it inferiorly?
A
Gubernaculum
3
Q
What can lead to an indirect inguinal hernia or a hydrocele?
A
If the proximal part of the tunic vaginalis stays open
4
Q
Why does the scrotom allow for in the testes?
A
Keeps temperature lower than body core which makes it ideal for spermatogenesis
5
Q
Describe the skin of the testes?
A
- Rugose
- Has no fat
- Contains the dartos muscle
Smooth muscle
Supplied by sympathetic fibres in the genital branches of the genitofemoral nerves - Has midline raphe and divided by septum
6
Q
What are the layers of the scrotum from superficial to deep?
A
- Skin
- Subcutaneous tissue (supf fascia): dartos muscle and fascia
- External spermatic fascia: from fasacia of external oblique muscle
- Cremasteric muscle and fascia: fibres and fascia of internal oblique muscl
- Internal spermatic fascia: from transversalis fascia
- Tunica vaginalis (visceral and parietal layers): from peritoneum
7
Q
How can the scrotum be divided neurologically?
A
- Anterior 1/3
- Posterior 2/3
8
Q
What is the blood supply to the scrotum?
A
- Anteriorly: external pudensal branches of the femoral artery
- Posteriorly: Branches of the internal pudendal branch of the internal iliac
9
Q
What is the venous drainage to the scrotum?
A
Mirrors arterial supply
- Anteriorly: External pudendal veins to the great (long) saphenous vein
- Posteriorly: Internal pudendal veins to the internal iliac vein
10
Q
What is the nerve supply to the scrotum?
A
- Anterior 1/3: L1 with ilioinguinal and genitofemoral nerves
- Posterior 2/3: S2-3 via scrotal branches of the perineal branches of the pudendal nerve
- This is significant if operating under regional anaesthesia
11
Q
What is the lymphatic drainage of the scrotum?
A
Superficial inguinal nodes
12
Q
What is hydrocele?
A
Fluid accumulation within parietal and visceral layers of tunica vaginalis
13
Q
What are the testes suspended by?
A
Spermatic chord (tethered by gubernaculum)
14
Q
What do the Leydig cells secrete?
A
Testosterone
15
Q
What do the Sertoli cells secrete?
A
Inhibin
16
Q
What are the coats/tunics which line the testis?
A
- Tunica vaginalis
- Tunica albuginea
- Tunica vasculosa with branches of testicular vessels
17
Q
Describe the tunica vaginalis?
A
- Visceral and parietal layers
- A potential space for movement of testis
- Hydrocele
18
Q
Describe the tunica albuginea
A
- Tough and fibrous
- Maintains internal pressure to help sperm transport
- Forms mediastinum and septae, turns into lobes
19
Q
Where does spermatogenesis take place in the testes and where does the sperm travel?
A
Seminiferous tubules (sperm then passes to the rete testis in the mediastinum and then via the efferent ductules to the epididymis)
20
Q
What is the blood supply to the testis?
A
- Testicular artery from aorta at L2 (plus anastomosis with cremasteric artery and artery to ductus deferens)
21
Q
What is the venous drainage of the testis?
A
TEsticular vein starting as a pampiniform venous plexus (converge as left testicular vein draining into left renal vein and right testicular vein draining into the IVF)
22
Q
WHat is the lymph drainage of the testis?
A
Para-aortic (lumbar) nodes
23
Q
What is the nerve supply to the testis?
A
Sympathetic lesser splanchnic nerve, T10-11, with referred pain being peri-umbilical
24
Q
What is cryptochidism?
A
Undescended testes
25
When is cryptorchidism usually treated?
6 months old
26
How is cryptorchidism treated medically?
- Human chorionic gonadotropin (hCG)
- Gonadotropin-releasing hormone
- If these do not work surgery (orchiopexy)
27
Can cryptorchidism recurr?
Re-ascent can occur in up to 25%
28
What are the risks of cryptorchidism?
Testicular cancer and infertility
29
WHat is rectractile testis?
- Descended testis which moves back and forth between scrotum and groin
- Cremaster muscle overactive
30
Are recractile testis a concern?
For most boys, the problem goes away sometime before or during puberty
31
How long is the epididymis?
Approx 6m long (highly coiles tube)
32
What does the epididymis contain?
Head, body and tail
33
What does the epididymis continue as?
Ductus deferens
34
What does the epididymis do?
- Contractions of the smooth muscle on the wall of the epididymis expel mature spermatozoa into the ductus deferens
- Maturation and acquisition of motility of the spermatozoa
35
Describe the ductus/vas deferens
Thick-walled, cord-like tube around 45cm long
36
Describe the course of the ductus/vas deferens?
- Lies posterior to the testis and medial to the epididymis
- Leaves the scrotum and passes through the abdominal wall within the spermatic cord and the inguinal canal
- Emerges into the abdomen lateral to the inferior epigastric artey and lies on the lateral wall of the pelvis
- Lies medial to the pelvic vessels before passing antero-medially to the ureter (anterior to the rectum)
- Joins with duct of the seminal gland to form the ejaculatory duct
37
What are the 3 arteries in the spermatic cord?
- Testicular artery and pampiniform venous plexus
- Artery to ductus deferens
- Cremasteric artery and vein
38
What are the 3 tubes in the spermatic cord?
- Ductus deferens
- Lymphatic vessels from testes
- Vestige (obliterated tube) of processus vaginalis
39
What are the 2 nerves of the spermatic cord?
- Genital branch of genitofemoral (L1/2)
| - Sympathetics (efferents and afferents to testes)
40
What artery does the artery of ductus deferens arise from?
Inferior vesical artery
41
What artery does the cremasteric artery arise from?
- Inferior epigastric
42
What is the cremasteric reflex (L1)?
Ipsilateral testiculat retraction on stroking superior medial thigh
43
What do varcose pampiniform veins feel like?
Bag of worms
44
Which side is more likely to have a varcose pampiniform venous plexus?
Left due to almost right angle at which the left testicular vein drains into the left renal vein
45
What are the symptoms of varcose pampiniform veins?
- Dull, aching or throbbing pain in testicle, may lead to infertility
46
What is a vasectomy?
Bilateral bisection of ductus deferens
47
Where is the majority of sperm produced?
Seminal glands (vesicles)
48
Where do the smeinal glands sit?
Just above prostate gland between the bladder and rectum
49
What do the seminal glands produce?
Secrete seminal fluid to nourish sperm
50
What do the seminal glands produce?
Alkaline fluid which contains fructose and choline (forensic), nourishes sperm
51
What 2 ducts unite to form the ejaculatory duct?
Dilated ampullary end of the ductus deferens unites with the duct from the seminal gland to form the ejaculatory duct that passes through the prostate gland to enter the urethra
52
Where does the prostate lie?
- Inferior to the neck of the bladder
- Posterior to the pubic symphysis
- Anterior to the rectum
- Superior to the urogenital diaphragm
- Prostatic urethra descends through anterior prostated
53
What is the prostate?
A fibromuscular glandular organ that surrounds the urethra
54
What does the prostate secrete?
- Prostaglandins
- Acid phosphatase
- Proteolytic enzymes
- Prostate-specific antigen (PSA) into bloodstream
55
Where do the prostatic ducts open?
20 - 30 of them open chiefly into the prostatic sinuses that lie on either side of the seminal colliculus (verumonatanum) on the posterior wall of the prostatic urethra
56
Where does the prostatic utricle open?
- The centre of the seminal colliculus
| - On each side of the prostatic utricle is the opening of the ejaculatory ducts
57
What are the 5 lobes of the prostate?
No histological boundaries
- Median (middle) lobe: between urethra and ejaculatory ducts (BPH)
- Posterior lobe: behind urethra, inferior to ejaculatory ducts
- Anterior lobe: anterior to urethra (has no glandular tissue)
- Left and right lobes: on both sides of the urethra
58
What are the MacNeal's zones of the prostate?
- Transitional zone, around urethra, anterior to ejaculatory ducts
- Central zone, posterior to transitional zone, contains ejaculatory ducts
- Peripheral zone, around transitional and central zone
- Anterior zone
59
What prostate zone does a benign prostatic hypertrophy usually develop from?
Transitional zone
60
What prostatic zone is where cancers usually develop?
Peripheral zone
61
What are the 3 diseases of the prostate?
- Inflammation
- Benign prostatic hypertrophy
- Cancer
62
What can bulbo-urethral glands also be known as?
Cowper's glands
63
Where are the bulbo-urethral glands found?
- Deep perineal pouch, postero-lateral to the membranous urethra
- Surrounded by transervse fibres of external urethral sphincter muscle
64
What do the bulbo-urethral glands secrete and where?
- Drains into spongy urethra
| - Secretes mucus before ejaculation and neutralize the pH of the urethra and lubricates urethra
65
What fascia surrounds the penis?
Superficial (dartos) fascia (indistinct merging of Camper's and Scarpa's) surrounds whole penis
66
What is phimosis?
Prepuce that is too tight to retract
67
What forms smegma?
Secretions of sebaceous glands in the foreskin
68
What is the foreskin?
Fold of skin continuous with the glans and therefore also with the mucous membrane of the urethra
69
What is the tip of the penis called?
The glans
70
What does the body of the penis contain?
Spongy urethra and 3 long cylindrical bodies
71
Describe the corpora cavernosa (cavernous bodies)
- Divided by a septum that is complete proximally, but pectiniform distally
- Each surrounded by thick tunica albuginea
- Filled with blood during erection
72
Describe the corpus spongiosum (spongy body)
- Transmits the urethra
| - Forms the glans as a cap over the cavernous bodies
73
What are the cavernous and spongy bodies surrounded by?
Deep (Buck's) fascia
74
What are the cavernous and spongy bodies surrounded by?
Deep (Buck's) fascia
75
What muscle surrounds the roots of the penis?
Ischiocavernosus muscle (attaches to ischium)
76
What muscle surrounds the bulb of the penis?
Bulbospongiosus
77
What are the functions of the bulbospongiosus?
- Compresses the urethra during ejaculation
| - Compresses the urethra to expel urine
78
What muscles support the penis and contribute towards an erection?
- Bulbospongiosus
| - Ischiocavernosus
79
What are the supportive ligaments of the penis?
- Fundiform ligament
| - Suspensory ligament
80
What are the 4 parts of the urethra?
- Preprostatic
- Prostatic
- Membranous
- Spongy
81
What does the preprostatic urethra prevent?
Retrograde ejaculation
82
Where is the preprostatic urethra found?
In bladder neck
83
Where do the ejaculatory ducts open?
In the prostatic urethra
84
Where is the membranous urethra found?
In deep perineal pouch
85
What is the membranous urethra surrounded by?
External urethral sphincter (voluntary)
86
What are the 2 parts of the spongy urethra?
- Bulbar urethra (in bulb of penis)
| - Penile urethra (spongy body)
87
Describe the structure of the membranous part of the urethra and the external urethral sphincter
- Second narrowest part
- Within the striated external urethral sphincter (slow twitch) and pubourethral or puboprostatic part of levator ani (mixed and fast twitch) to resist surges of raised intr-abdominal pressure
- The external urethral sphincter is actually shaped like an inverted pear with its base on the perineal membrane and its apex pushing up into the prostatic urethr
88
Are pubourethral and puboprostatic fibres voluntarycor involuntary?
Voluntary (part of levator rami)
89
What part of the urethra is the longest?
Spongy
90
What are the glands that enter the spongy urethra?
- Bulbourethral gland
| - Plus many scattered glands epecially in navicular fossa (lacuna magna)
91
What is the navicular fossa?
Expansion of the urethra in the glans of the penis
92
What are the 2 curvatures in the spongy urethra?
Dissapear during erection
- Infrapubic curvature: Between membranous and bulbar urethra
- Prepubic curvature: In the spongy urethra
Must be straightened when passing catheter
93
What artery are the prostate gland and male urethra supplied by?
Inferior vesicular artery
94
What is the venous drainage of the prostate gland and male urethra?
Prostatic venous plexus
- Drains into internal iliac vein
- Has connections with vertebral veins as well (prostatic cancer)
95
What is the lymphatic drainage of the prostate?
- Internal iliac lymph nodes
| - Prostate may drain to presacral nodes too
96
What is the somatic motor for control of the external urethral sphincter supplied by?
Pudendal nerve (S2-4) and its perineal branches
97
What is the autonomic nerve supply to the male reproductive system?
- Parasympathetics: from S2-4 -> pelvic splanchnic nerves -> pelvic plexus
- Sympathetics from L1-2 -> superior hypogastric plexus -> pelvic plexus
98
What is the visceral afferent nerve supply?
Via sacral parasympathetics (S2-4)
99
What is the somatic afferent nerve supply?
Pudendal nerve (S2-4) and its perineal branches
