Reproductive System Week 4 Flashcards
(153 cards)
1
Q
Where do the testes develop?
A
In extra-peritoneal connective tissue in the superior lumbar region of the posterior abdominal wall
2
Q
What structure connects the primordial testes to the anterolateral abdominal wall at the site of the future deep ring of the inguinal canal?
A
Gubernaculum
3
Q
What is the processus vaginalis ?
A
A peritoneal diverticulum
Which traverses the developing inguinal canal, carrying muscular and fascial layers of the anterolateral abdominal wall before it as it enters the primordial scrotum
4
Q
Where are the testis in the 12th week of development?
A
Pelvis
5
Q
In what week do the testes begin to pass through the inguinal canal?
A
28th week
6
Q
How long does it take for the testes to pass throught he inguinal canal?
A
3 days
7
Q
At approximately which week do the testes enter the scrotum?
A
Week 32
8
Q
How do derivatives of anterolateral abdominal wall muscles and fascia come to be in the adult scrotum?
A
As the testes, ductus deferens, and its vessels and nerves relocate they are ensheathed by musculofascial extensions of the anterolateral abdominal wall
9
Q
What happens to the processus vaginalis?
A
Degenerates leaving behind a distal saccular part - forms tunica vaginalis - serous sheath of the testis and epididymis
10
Q
When does the tunica vaginalis obliterate?
A
By the 6th month of development
11
Q
What is the spermatic cord?
A
Contains structures running to and from the testis and suspends the testis in the scrotum
12
Q
Describe the course of the spermatic cord
A
Begins at the deep inguinal ring lateral to the inferior epigastric vessels
Passes through the inguinal canal
Exits at the superficial ring
Ends at the posterior border of the testis
13
Q
What are the fascial coverings of the spermatic cord and from which anterolateral abdominal wall layer are they derived?
A
Internal spermatic fascia - from transversalis fascia
Cremasteric fascia - from the fascia of both the deep and superficial surfaces of the internal oblique muscle
External spermatic fascia - from teh external oblique aponeurosis and its investing fascia
14
Q
What is the cremaster muscle and where does it lie?
A
The cremasteric fascia contains loops of cremaster muscle
Formed from lowermost fascicles of internal oblique arising from inguinal ligament
15
Q
What is the function of the cremaster muscle?
A
Reflexively draws the testes superiorly in the scrotum in response to cold and relaxes in response to heat- attempt to regulate the temperature of the testes for spermatogenesis and protect the testes during sexual activity
16
Q
What temperature is required for spermatogenesis?
A
Requires constant temperature of around 1 degree below core body temperature
17
Q
Which muscle works in conjunction with the cremaster muscle?
A
The Dartos muscle - smooth muscle of the fat-free subcutaneous tissue (dartos fascia) of the scrotum
18
Q
Describe the function of the dartos muscle
A
Inserts into the skin of the scrotum
Assists in testicular elevation
Produces contraction of the skin of the scrotum in response to the same stimuli (temperature, protective during sexual activity)
19
Q
Which nerve innervates the cremaster muscle?
A
The genital branch of the genitofemoral nerve (L1, L2) - derivative of lumbar plexus
20
Q
What is the main difference between the cremaster and dartos muscle innervation
A
Cremaster - striated - somatic
Dartos - smooth muscle - autonomic
21
Q
What are the constituents of the spermatic cord?
A
Ductus deferens - muscular tube - 45cm long - transports spermatozoa from epididymis to ejaculatory duct
Testicular artery - arises from aorta - supplies testes and epididymis
Artery of ductus deferens - arises from inferior vesicle artery
Cremasteric artery - arises from inferior epigastric artery
Pampiniform venous plexus - network of up to 12 begins - converge superiorly as either right or left testicular vein
Sympathetic nerve fibres on arteries and sympathetic and parasympathetic fibres on the ductus deferens
Genital branch of genitofemoral nerve - supplies cremaster
Lymphatic vessels - draining the testes and other associated structures - passes to lumbar lymph nodes
Vestige of processus vaginalis - fibrous thread in anterior part of spermatic cord - extending between abdominal peritoneum and tunica vaginalis - may not be detectable
22
Q
What is the scrotum?
A
Cutaneous sac consisting of two layers:
Heavily pigmented skin
Closely related dartos fascia - fat-free fascial layer consisting of dartos muscle fibres - responsible for the rugosa (wrinkled) appearance of the scrotum
23
Q
How does contraction of the dartos muscle reduce heat loss?
A
Reduces scrotal surface area
Thickens integumentary layer (skin etc.)
Assists the cremaster in holding the testes closer to the body
24
Q
What is the septum of the scrotum?
A
A continuation of the dartos fascia
Divides the scrotum internally into right and left compartments
25
How is the septum of the scrotum demarcated externally?
Scrotal raphe - cutaneous ridge that marks the line of fusion of labioscrotal swellings
26
As what, is the dartos fascia continuous posteriorly and anteriorly?
Anteriorly - Scarpa fascia (membranous layer abdomen)
| Posteriorly - Colles fascia (membranous layer perineum)
27
From what embryological derivative does the scrotum develop?
Labioscrotal swellings
28
Describe the arterial supply and venous drainage of the scrotum
Posterior scrotal branches of perineal artery - branch of internal pudendal artery
Anterior scrotal branches of deep external pudendal artery - branch of the femoral artery
Cremasteric artery - branch of the inferior epigastric artery
Scrotal veins accompany the arteries
29
Where do the lymphatic vessels of the scrotum drain into?
Superficial inguinal lymph nodes
30
Describe the innervation of the scrotum
Branches of lumbar plexus to anterolateral surface:
Genital branch of genitofemoral nerve (L1,L2) - supplies anterolateral surface
Anterior scrotal nerves - branches of the ilioinguinal nerve (L1) - supply anterior surface
Branches of sacral plexus to posterior and inferior surfaces:
Posterior scrotal nerves - branches of the perineal branch of the pudendal nerve (S2-4) - supply posterior surface
Perineal branches of posterior cutaneous nerve of thigh (S2,3) - supply posteroinferior surface
31
What are the testes?
The male gonads - paired ovoid reproductive glands that produce spermatozoa and male hormones (testosterone)
32
How are the testes suspended?
By the spermatic cord - left testis usually suspended more inferiorly than the right
33
Describe the layer covering the testes
Surface of each testes, parts of the epididymis and inferior part of ductus deferens covered by visceral layer of tunica vaginalis - except where testis attaches to epididymis and spermatic cord
34
What is the tunica vaginalis?
Closed peritoneal sac
Partially surrounds the testes
Represents the closed-off distal portion of the embryonic processus vaginalis
35
What is the sinus of the epididymis?
The slit-like recess of the tunica vaginalis
| Between the body of the epididymis and the posterolateral surface of the testis
36
Where does the parietal layer of the tunica vaginalis lie?
Adjacent to the internal spermatic fascia
| More extensive than the visceral layer - extends superiorly for short distance on to the distal spermatic cord
37
What is the function of the serous fluid in the cavity of the tunica vaginalis?
Allows the testis to move freely in the scrotum
38
What is the name of the tough fibrous outer surface of the testis?
Tunica albuginea
39
What is the mediastinum of the testis?
Thickened ridge of tunica albuginea
| On internal posterior aspect of testis
40
What projects inwards from the medistinum of the testis?
Fibrous septa - between lobules of minute but long and highly coiled seminiferous tubules
Separates it into 250 pyramid-shaped lobules
Each lobule contains between 1 and 4 seminiferous tubules
41
What is the function of the seminiferous tubules?
Spermatogenesis
42
How are the seminiferous tubules joined to the rete testis?
By straight tubules
43
Describe the course of the testicular arteries
Arise from the anterolateral aspect of abdominal aorta just inferior to renal arteries
Pass retroperitoneally in oblique direction - over ureters and inferior parts of external iliac arteries to reach deep inguinal ring
Pass through inguinal canal to scrotum to supply testis
Anastomoses with artery of ductus deferens
44
Describe the venous drainage of the testis
Veins emerging from testis and epididymis form the pampiniform venous plexus (network 8-12veins )
Lies anterior to ductus deferens and surrounds testicular artery in spermatic cord
Part of the thermoregulatory system (along with cremasteric and dartos muscles) - helps to keep gland at constant temperature
Converge to form the right and left testicular veins superiorly
Right testicular vein enters IVC
Left testicular vein enters left renal vein
45
Describe the lymphatic drainage of the testis
Follows the testicular artery and vein to the right and left lumbar (canal/aortic) lymph nodes and preaortic lymph nodes
46
Describe the innervation of the testis
Autonomic nerves arise as testicular plexus of nerves on the testicular artery
Contains vagal parasympathetic and visceral afferent fibres, and sympathetic fibres from T7 of spinal cord
47
What is the epididymis ?
Elongated structure on posterior surface of the testis - transports spermatozoa from efferent ductules to ductus deferens
Formed by minute convolutions of the duct of the epididymis - so tightly compacted they appear solid
48
Describe the epididymis
Efferent ductules transport newly formed spermatozoa to the epididymis from the rete testis
Duct of the epididymis becomes progressively smaller as it passes from the head of the epididymis on superior testis to the tail
Head - superior expanded part - composed of lobules formed by the coiled ends of 12-14 efferent ductules
Body - consists of the convoluted duct of the epididymis
Tail of the epididymis continues as the ductus deferens - transports spermatozoa to the ejaculatory duct for expulsion through urethra during ejaculation
49
What are cryptorchid testes and what are the consequences?
Undescended testis
3% fullterm 30% premature infants
95% unilateral
Usually lies somewhere along the normal path of its prenatal descent - commonly inguinal canal
Germ cells absent - Sertoli and Leydig cells secrete male sex hormones still
Spermatogenesis impaired due to elevated temperature
Increased risk of malignant tumours - problematic because not palpable - not detected until late stages
50
What are oligozoospermia and azoospermia?
Oligozoospermia - abnormally low number of sperm in the semen
Azoospermia - no sperm in the ejaculate
51
What is orchitis and what are the consequences?
Inflammation of the testis
Occurs in some individuals who suffer from mumps after puberty
Impaired spermatogenesis
Occasionally leads to seminiferous tubule degeneration and sometimes infertility
52
What are the causes of an absence of germ cells?
Congenital
| Acquired - drugs, viral infections, irradiation, cryptorchidism
53
Describe testicular tumours and their consequences
Rare
High degree of malignancy
Usually arise in germ cells
Present as swelling or lump in testes
Can spread to lumbar lymph nodes --> from here can metastasise to mediastinal and supraclavicular lymph nodes
Can spread by haematogenous route - bones, lungs, liver, brain
54
What is torsion of the spermatic cord and what are the consequences?
Twisting of the spermatic cord just above upper pole of testis
Surgical emergency
Obstructs venous drainage --> oedema, haemorrhage --> arterial obstruction
May cause necrosis of the testis
To prevent reoccurrence or occurrence on contralateral side both testes are fixed to the scrotal septum
55
What is the cremasteric reflex and how can it be elicited ?
Rapid elevation of the testis
Light stroke the skin on the medial aspect of the superior part of the thigh with an applicator stick or tongue depressor
Extremely active in children - may simulate undescended testes
Hyperactive reflex can be abolished by having the child sit cross-legged in a squatting position - if the testes are descended they can then be palpated
56
Describe ductus deferens
Continuation of the duct of the epididymis
Relatively thick muscular walls
Minute lumen
Cord-like firmness
Begins in tail of epididymis at inferior pole of testis
Ascends posterior to testes medial to epididymis
Primary component of the spermatic cord
Penetrates anterior abdominal wall via inguinal canal
Crosses over external iliac vessels and enters the pelvis
Passes along lateral wall of pelvis - lies external to parietal peritoneum
- maintains direct contact with it
Ends by joining the duct of the seminal glad to form the ejaculatory duct
Crosses over the ureter then posterior to the bladder descends medial to ureter and seminal gland
Enlarges to form ampulla of ductus deferens before its termination
57
Describe the arterial supply and venous drainage of the ductus deferens
Artery to ductus deferens - from superior or inferior vesicle artery - anastomoses with testicular artery posterior to testis
Veins from most of duct drain into testicular vein - including distal pampiniform plexus
Terminal portion drains into vesicular/ prostatic venous plexus
58
What is the seminal gland and what is its function?
Elongated structure lying between fundus of bladder and rectum
Obliquely placed, superior to prostate
Do not store sperm
Secrete a thick, alkaline fluid with fructose (energy source for sperms) and a coagulating agent that mixes with the sperms as they pass into the ejaculatory ducts and urethra
Superior ends covered with peritoneum, lie posterior to ureters, separated from rectum by rectovesical pouch
Inferior ends only separated form rectum by rectovesical septum
Duct of seminal gland joins ductus deferens to form ejaculatory duct
59
Describe the arterial supply and venous drainage of the seminal glands
Arteries to seminal glands derive from inferior vesical and middle rectal arteries
Veins accompany arteries and have similar names
60
Describe the ejaculatory ducts
Slender tubes
Union of ductus deferens and seminal gland
Approx 2.5cm long
Arise near neck of bladder
Run close together as pass anteroinferiorly through posterior prostate and along sides of prostatic utricle
Ejaculatory ducts converge
Open on the seminal colliculus by tiny, slit-like apertures on or within the opening of the prostatic utricle
Prostatic secretions do not join the seminal fluid until ejaculatory ducts terminate in prostatic urethra
61
Describe the arterial supply and venous drainage of the ejaculatory duct
Artery to the ductus deferens
| Veins drain into the prostatic and vesical venous plexuses
62
Describe the prostate
3cm long, 4cm wide, 2cm AP depth
Firm
Surrounds prostatic urethra
Glandular part makes up 2/3
1/3 fibromuscular
Fibrous capsule - dense and neurovascular - prostatic plexuses of nerves and veins
Surrounded by visceral layer of pelvic fascia - fibrous prostatic sheath - thin anteriorly, continuous anterolaterally with the puboprostatic ligaments, dense posteriorly - blends with rectovesical septum
Base of gland related to neck of bladder
Apex - contact with fascia on superior aspect of urethral sphincter and deep perineal muscles
Muscular anterior surface - transversely oriented muscle fibres - vertical, trough like hemisphincter - part of urethral sphincter
Anterior surface separated from pubic symphysis by retroperitoneal fat in retropubic space
Posterior surface related to ampulla of rectum
Inferolateral surface related to levator ani
Separated into physiological lobes:
Isthmus - fibromuscular - anterior to urethra - little glandular tissue
Right and left lobes - separated anteriorly by isthmus and posteriorly by furrow - each subdivided into four lobules - defined by relationship to urethra and ejaculatory ducts:
- inferoposterior - palpable by DRE
- inferolateral - major part of the lobe
- superomedial - deep to inferposterior - surrounds ipsilateral ejaculatory duct
- anteromedial - deep to inferolateral - directly lateral to proximal prostatic urethra
Prostatic ducts (20-30) open chiefly into the prostatic sinuses - lie on either side of the seminal colliculus on the posterior wall of prostatic urethra
Prostatic fluid - thin, milky - 20% volume of semen - plays role in activating sperms
63
Which region of the prostate tends to undergo hormone-induced hypertrophy in advanced age?
The middle lobe (superomedial lobule, anteromedial lobule)/ central zone
Forms a middle lobule that lies between urethra and ejaculatory ducts and is closely related to the neck of the bladder
64
What is semen?
Mixture of secretions produced by testis, seminal gland, prostate and bulbourethral gland that provides the means of transport for sperm
65
Describe the arterial supply and venous drainage of the prostate gland
Prostatic arteries - branches of internal iliac artery (inferior vesical, middle rectal, internal pudendal arteries)
Prostatic venous plexus between fibrous capsule and prostatic sheath - drains into internal iliac vein - continuous superiorly with vesical venous plexus and communicates posteriorly with internal vertebral venous plexuses
66
Describe the bulbourethral gland
Pea -sized
Cowper gland
Posterolateral to intermediate urethra - largely embedded in external urethral sphincter
Ducts of the gland pass through the perineal membrane with the urethra - open through minute apertures in the proximal spongey urethra - in the bulb of the penis
Mucus-like secretion
67
Describe the innervation of the internal genital organs of the male pelvis
Presynaptic sympathetic nerve fibres from T12-L2/3
Traverse paravertebral ganglia
Become components of lumbar splanchnic nerves and the hypogastric and pelvic plexuses
Presynaptic parasympathetic nerve fibres from S2/3
Traverse pelvic splanchnic nerves
Join inferior hypogastric and pelvic plexuses
Synapses with postsynaptic sympathetic and parasympathetic neurones occur within the plexuses
During orgasm - sympathetic nerves stimulate contraction of internal urethral sphincter to prevent retrograde ejaculation - peristalsis of ductus deferens, contraction of and secretion from seminal glands and prostate - provide the vehicle and force for ejaculation
Function of parasympathetic innervation to internal organs unclear but those traversing the prostatic plexus form the cavernous nerves - pass to the erectile bodies of the penis - penile erection
68
What is a vasectomy and what are the consequences?
Part of ductus deferens ligated and/or excised
Ejaculated fluid from seminal glands, prostate and bulbourethral glands contain no sperm
Unexpected sperms degenerate int eh epididymis and proximal part of ductus deferens
69
Can a vasectomy be reversed?
In favourable cases, yes
<30 years of age
<7 years post-op
Ends of sectioned ductus deferens reattached
70
What are the symptoms of BHP?
Nocturia, dysuria, urgency, cystitis, nephritis
71
When is the prostate most palpable?
When the bladder is full
72
How does a malignant prostate feel?
Hard and irregular
73
Where do prostate cancers metastasise to?
Via lymph nodes - internal iliac and sacral lymph node
| Via blood - vesical venous plexus to pelvic structures, internal vertebral venous plexus to the vertebrae and brain
74
Where do the gonads develop?
Mesonephric ridge
75
What is a hydrocoele and what are the clinical consequences?
Presence of excess fluid in a persistent processus vaginalis
Congenital anomaly
May be associated with an indirect inguinal hernia
Excess fluid caused by excess secretion from visceral layer of tunica vaginalis
Size depends on how much of processus vaginalis persists
May communicate with the peritoneal cavity
Detection requires transillumination - bright light shined on side of scrotal enlargement in darkened room - transmission as red glow indicates excess serous fluid
Newborn males - often have residual fluid in tunica vaginalis - usually absorbed in first year of life
Injury or inflammation of epididymis may produce a hydrocoele in adults
76
What is the differential diagnosis of a scrotal swelling?
```
Indirect inguinal hernia - persistent processus vaginalis
Tumour
Hydrocoele
Haematocoele
Spermatocoele
Varicocoele
```
77
What is a haematocoele and what are the clinical consequences?
Collection of blood in tunica vaginalis
Rupture of branches of testicular artery - trauma
Trauma may also produce testicular or scrotal haematoma
Does not transilluminate
May cause scrotal haematocoele - effusion of blood into scrotal tissues
78
What is the difference between a spermatocoele and a epididymal cyst?
```
Both collections of fluid in the epididymis
Spermatocoele:
Sperm are present in the milky aspirate of the spermatocoele
Looks like 3rd testis
Unilocular
Acquired retention cyst
Spermatocoele will not transilluminate
Epididymal cyst:
Congenital
Mutlilocular
Behind body of testis
Bunch of grapes appearance
Clear fluid content
Transilluminates
```
79
What is a varicocoele and what are the clinical consequences?
Pampiniform plexus becomes varicose and tortuous
Defective valve in testicular vein - but kidney or renal problems may also result in this
Usually occurs on left side because more acute angle on right side where right testicular vein enters IVC so more favourable to flow
Usually only visible when man standing up or straining
Bag of worms
80
What is epididymitis and what are the clinical consequences?
Inflammation of the epididymis
Most often caused by bacterial infection or STD - gonorrhoea chlamydia
Most common between 20-39 years of age
81
Which part of the male urethra is the least distensible?
Membranous urethra
82
Describe the penis
Male copulatory organ
Conveys urethra - common outlet for urine and semen
Consists of a root, a body and a glans
Composed of three cavernous bodies of erectile tissue:
-paired corpora cavernosa - dorsally
-corpus spongiosum - ventrally
Anatomical position - penis erect
Each cavernous body has outer fibrous capsule - tunica albuginea
Superficial to this - deep fascia of the penis (Buck fascia) - continuation of deep perineal fascia - forms strong membranous covering
Corpus spongiosum contains spongy urethra
Corpora cavernosa fused in median plane except posteriorly - form crura of the penis
Internally the corpora are separated by the septum penis
83
What makes up the root of the penis?
The crura, bulb, bulbospongiosus, ischiocavernosus
84
Where is the root of the penis located?
Superficial perineal pouch
Between perineal membrane superiorly
And deep perineal fascia inferiorly
85
What is the function of the bulbospongiosus muscles?
Compress the bulb and corpus spongiosum
Aids in emptying of the urethra
Anterior fibres - proximal body - assist in erection - increase pressure on erectile tissue in the root of the penis
Compress deep dorsal vein - impeding venous drainage of cavernous spaces - promote erection
86
What is the function of the ischiocavernosus muscles?
Surround the crura in the root of the penis
Force blood distally from crura into corpora cavernosa --> increases turgidity of erection
Also restricts venous outflow through deep dorsal vein of penis - maintain erection
87
Describe the crura and the bulb of the penis
Consist of erectile tissue
Each crus attached to inferior part of internal surface of corresponding ischial ramus
Enlarged posterior part of bulb of penis penetrated superiorly by urethra
88
Describe the body of the penis
Free pendulous part
Suspended from pubic symphysis
Body of the penis has no muscles - except for few fibres of bulbospongiosus at the root and the ischiocavernosus that embrace the crura
89
Describe the glans of the penis
Distally the corpus spongiosum expands to form the conical glans of the penis
Margin of glans projects beyond the ends of the corpora cavernosa to form the corona of the glans which overhangs an obliquely grooved constriction - neck of the glans - separates the glans from the body
Slit-like opening - external urethral meatus - near tip of glans
At the neck of the glans the skin and fascia are prolonged as a double layer of skin - prepuce (foreskin) - in uncircumcised males covers the glans to a variable extent
Frenulum of the prepuce - median fold that passes from the deep layer of the prepuce to the urethral surface of the glans
90
Describe the skin of the penis
Thin, darkly pigmented relative to adjacent skin
| Connected to tunica albuginea by loose connective tissue
91
Describe the ligaments of the penis
Suspensory ligament of the penis - condensation of deep fascia
Arises from anterior surface of pubic symphysis
Passes inferiorly and splits to form a sling - attached to the deep fascia of the penis at junction of root and body
Fibres are short and taut -anchoring the erectile bodies to the pubic symphysis
Fundiform ligament of the penis - irregular mass or condensation of elastic fibres and collagen - of subcutaneous tissue that descends in the midline from linea alba anterior to pubic symphysis
Splits to surround the penis
Unites and blends inferiorly with dartos fascia - forming scrotal septum
Fibres long and loose
Lie superficial to suspensory ligament
92
Describe the arterial supply of the penis
Branches of the internal pudendal arteries:
-Dorsal arteries of penis - supply fibrous tissue of corpora cavernosa, corpus spongiosum, spongey urethra, penile skin
- Deep arteries of penis - supply the erectile tissue of corpora cavernosa - when penis flaccid - coiled, restricting blood flow- helicine arteries of penis
-arteries of the bulb of the penis - supply bulbous part of corpus spongiosum and urethra within and bulbourethral gland
Superficial and deep branches of external pudendal arteries supply penile skin - anastomoses with branches of internal pudendal arteries
93
Describe the venous drainage of the penis
Blood from cavernous space drained by a venous plexus that joins deep dorsal vein of penis - drains into prostatic venous plexus
Blood from skin and subcutaneous tissue drains into superficial dorsal vein which drains into superficial external pudendal vein
Some blood drains into internal pudendal vein
94
Describe the innervation of the penis
Dorsal nerve of penis - branch of pudendal nerve - sensory and sympathetic - skin and glans penis
Ilioinguinal nerve - skin at root of penis
Cavernous nerves - parasympathetic - innervate helicine arteries of the erectile tissue
95
Describe lymphatic drainage of the penis
Skin - superficial inguinal nodes
Intermediate and proximal spongy urethra and cavernous bodies - internal iliac lymph nodes
Distal spongy urethra and glans - deep inguinal nodes
Some lymph passes to external inguinal nodes
96
What are the causes of erectile dysfunction?
Nerve lesion (prostatic plexus or cavernous nerves)
Hypothalamic, pituitary or testicular disorders --> less testosterone
Nerve fibres fail to stimulate erectile tissues
Blood vessels may be insufficiently responsive to stimulation
Blood vessel disease - atherosclerosis/diabetes - most common cause in old age
Depression and/or anxiety
97
How can impotence be alleviated?
Oral medication or injections to increase blood flow to cavernous sinusoids by relaxing smooth muscle
Or in severe cases surgically implanted semirigid or inflatable penile prosthesis assume the role of erectile bodies
Treat the underlying arterial disease
98
Describe the corpora cavernosa
The corpora are a network-like trabeculae of fibromuscular tissue ramified by spaces which become filled with blood during erection. In the flaccid condition of the organ, the cavernous spaces contain little blood and appear as collapsed irregular clefts.
99
Why is palpate on poor at assessing lymphatic spread from a testicular tumour?
Spreads to lumbar and preaortic nodes first - cant palpate
100
How can you differentiate between hernia and swelling associated with testis?
Cough impulse
101
Which part of the penis is removed in circumcision?
Prepuce (foreskin)
102
What might happen if the internal sphincter does not close during ejaculation?
Retrograde ejaculation (semen into bladder)
103
Why does the corpus spongiosum not become rigid even though it swells with blood?
No tunica albuginea covering
104
How do the tunica albuginea and fascial sheaths effect the erection?
Doesnt allow the tissue to expand
| Build up of pressure - turgidity
105
How can you discriminate between prostatic carcinoma and BPH with PSA?
Steeper levels will be seen in prostatic carcinoma
106
List the accessory glands of the male reproductive system,
identifying the substances they secrete, the functions of such and the percentage volume of secretion the glands contribute to the semen (seminal fluid).
Seminal vesicles - 70-80% - seminal fluid - alkaline, viscous fluid - fructose, prostaglandins, clotting proteins
Prostate - 20-30% - prostate fluid - proteases, zinc, citrate, glucose, PSA, lipids, acidic
Bulbourethral gland -2-5% - preejaculate - neutralises any acidity
107
Describe the structures that contract in emission and how this is controlled
Ductus deferens
Prostate
Seminal vesicles
Sympathetic (L1-2)
108
Why do carcinomas of the testis sometimes spread to cervical lymph nodes?
Lumbar lymph nodes drain into mediastinal and supraclavicular nodes
109
Why does cancer of the prostate often present later than BPH?
75-85% in peripheral zones - dont cause symptoms until in central/transitional zones - compressing urethra
Slow growing
110
Describe the microscope structure of the seminiferous tubules
Each seminiferous tubule is surrounded by a layer of connective tissue with flattened myofibroblasts and an inner basement membrane
tubules are lined by a complex stratified epithelium, the seminiferous epithelium, consisting of two kinds of cells, the Sertoli cells (also called supporting cells) and the spermatogenic cells (the germ cells).
Sertoli cells - fixed to basement membrane - form the blood testis barrier - far less numerous than germ cells - cytoplasm of each cell forms an elaborate system of processes that extend upward to the luminal surface, surround the spermatogenic cells and fill all the spaces between them. Owing to this and the limitations of resolution of the light microscope, the cell boundaries are difficult to visualize.
apical region of each cell - complicated recesses - heads of sperms appear to be embedded.
Spermatogenic cells are arranged in rows between and around the Sertoli cells. The most primitive spermatogenic cells, the spermatogonia, rest on the basement membrane, while the later stages are located at successively higher levels in the epithelium. Primary spermatocytes lie adjacent to spermatogonia but nearer the lumen. The nuclei have variable appearances that represent the stages of the first meiotic division. Secondary spermatocytes (rarely seen in the seminiferous epithelium because of their short half-life) divide rapidly (second meiotic division) to form spermatids, which have a lightly stained round nucleus located nearer the lumen of the seminiferous tubule.
The spermatids mature into spermatozoa the deeply staining heads of which appear to be embedded in the cytoplasm of the Sertoli cells and their tails hang into the lumen of the seminiferous tubule.
111
Describe the microscopic appearance of Leydig cells
Between the seminiferous tubules, there is loose connective tissue containing interstitial (Leydig) cells, which are seen in isolated clusters or in rows along small blood vessels. The cells have large spherical nuclei (containing small amounts of peripherally located chromatin and one or two prominent nucleoli) with eosinophilic (stained red in the section). Although spermatogenesis (in the seminiferous tubules) and steroidogenesis (in the Leydig cells) occur in separate histological compartments within the testis, the compartments are functionally and physiologically interactive.
112
What is the function of the epididymis
Its main function is sperm transport, maturation and storage. During their passage through the epididymis, the sperms undergo structural maturation and become motile, the capabilities that are essential for successful fertilisation. They are then stored in the tail segment until ejaculation.
113
Describe the microscopic structure of the ductus epididymis
The ductus epididymis is lined by a tall, pseudostratified columnar epithelium. On the inner surface of the basement membrane, small basal cells form a discontinuous layer. The tall columnar cells have tufts of non-motile cytoplasmic processes called stereocilia projecting into the lumen. Near the lumen, the cytoplasm of the tall cells contains occasionally dark-staining granules. The basement membrane is surrounded on the outside by a highly developed network of capillaries and a circular layer of smooth muscle fibres.
Sperm maturation is completed here
114
Describe the microscopic appearance of the ductus deferens
the ductus deferens is a thick, muscular tube. The smooth muscle coat consists of inner and outer longitudinal layers and an intermediate layer of circular muscle. The epithelium lining the lumen is pseudostratified, columnar and the cells usually have stereocilia. The epithelium lies on a thin lamina propria containing a large number of elastic fibres. As a result, in fixed preparations, the mucous membrane is thrown into numerous folds.
115
Describe the microscopic appearance of the seminal vesicles
The mucous membrane forms an elaborate system of thin, branched, anastomosing folds which project into the lumen. The large lumen of the gland contains coagulated secretion. The epithelium lining the mucous membrane varies from simple columnar to pseudostratified. The lamina propria is surrounded by a smooth muscle coat divided into an inner circular and a very thin outer longitudinal layer.
116
Describe the microscopic appearance of the prostate gland
It is composed of numerous small, compound alveolar glands from which excretory ducts originate and open independently into the prostatic urethra.
The gland is surrounded by a fibro-muscular capsule from which branching septae divide it into numerous, but separate, compound alveolar glands (30-50). The septae are characterized by discrete bundles of smooth muscle fibres interweaving with the connective tissues - fibromuscular stroma
The epithelium lining the glands is heterogenous - varies from low cuboidal to simple or pseudostratified columnar and the cells have pale-staining cytoplasm. The epithelium rests on a very thin lamina propria. Blebs of secretion may be seen attached to the free cell surfaces and are often seen in the lumen of the glands. Also present in the lumina are concentrically lamellated eosinophilic bodies, the prostatic concretions (corpora amylacea), some of which may be calcified.
117
Describe the microscopic appearance of the bulbourethral glands
These glands are located within the urogenital diaphragm and contain tubular and alveolar-type glands.
118
Describe the epidemiology of prostate cancer
Prostatic cancer is the second most common cause of cancer-related deaths in men; genetic, hormonal, environmental, etc. factors are implicated in its pathogenesis.
119
What epithelium is seen in the rete testis
Simple cuboidal
120
Describe the microscopic appearance of the efferent ductules
Characteristic scalloped epithelium
| Myoid contraction and ciliary action - propel sperm
121
What kind of carcinoma is seen in the prostate?
Prostatic adenocarcinoma
122
Why are testicular tumours very important?
Because a high proportion of them are seen in early life
123
What percentage of testicular cancers are germ cell tumours?
90-95%
Germ cells tumours:
Seminoma (40-50%)
Non-seminoma (teratoma, choriocarcinoma, embryonal carcinoma, yolk sac tumours)
Other:
Lymphoma
Mesothelioma
124
What are the functions of the pelvic girdle?
- Bear the weight of the upper body when sitting and
standing.
- Transfer that weight from the axial to the lower appendic-
ular skeleton for standing and walking.
- Provide attachment for the powerful muscles of locomotion
and posture and those of the abdominal wall, withstanding
the forces generated by their actions.
Consequently, the pelvic girdle is strong and rigid, especially
compared to the pectoral (shoulder) girdle. Other functions
of the pelvic girdle are to:
• Contain and protect the pelvic viscera (inferior parts of the
urinary tracts and the internal reproductive organs) and
the inferior abdominal viscera (intestines), while permit-
ting passage of their terminal parts (and, in females, a full-
term fetus) via the perineum.
• Provide support for the abdominopelvic viscera and gravid
(pregnant) uterus.
• Provide attachment for the erectile bodies of the external
genitalia.
• Provide attachment for the muscles and membranes that
assist the functions listed above by forming the pelvic floor
and filling gaps that exist in or around it.
125
Which bones form the pelvic girdle?
- Right and left hip bones (coxal bones; pelvic bones): large,
irregularly shaped bones, each of which develops from the
fusion of three bones, the ilium, ischium, and pubis.
- Sacrum: formed by the fusion of five, originally separate,
sacral vertebrae.
126
How can the pelvis be divided?
The pelvis is divided into greater (false) and lesser (true)
pelves by the oblique plane of the pelvic inlet (superior
pelvic aperture)
127
What is the pelvic brim?
The bony edge surrounding and defining the pelvic inlet
128
What forms the pelvic brim?
- Promontory and ala of the sacrum (superior surface of its
lateral part, adjacent to the body of the sacrum).
- A right and left linea terminalis (terminal line) together
form a continuous oblique ridge consisting of the:
- Arcuate line on the inner surface of the ilium.
- Pecten pubis (pectineal line) and pubic crest, forming
the superior border of the superior ramus and body of
the pubis.
129
What is the pubic arch?
Formed by the ischiopubic rami (conjoined inferior rami of the pubis and ischium) of the two sides. These rami meet at the pubic symphysis, their inferior borders defining the subpubic angle
130
What is the subpubic angle?
The width of the subpubic angle is determined by the distance
between the right and the left ischial tuberosities, which can
be measured with the gloved fingers in the vagina during a
pelvic examination.
131
What constitutes the pelvic outlet?
- Pubic arch anteriorly.
- Ischial tuberosities laterally.
- Inferior margin of the sacrotuberous ligament (running be-
tween the coccyx and the ischial tuberosity) posterolaterally.
- Tip of the coccyx posteriorly.
132
What is the greater pelvis?
The part of the pelvis that is:
- Superior to the pelvic inlet.
- Bounded by the iliac alae posterolaterally and the antero-
superior aspect of the S1 vertebra posteriorly.
- Occupied by abdominal viscera (e.g., the ileum and sig-
moid colon).
133
What is the lesser pelvis?
The part of the pelvis that is:
• Between the pelvic inlet and the pelvic outlet.
• Bounded by the pelvic surfaces of the hip bones, sacrum,
and coccyx.
• That includes the true pelvic cavity and the deep parts of
the perineum (perineal compartment), specifically the
ischioanal fossae
• That is of major obstetrical and gynecological significance.
134
Describe the pelvic diaphragm
The concave superior surface of the musculofascial pelvic
diaphragm forms the floor of the true pelvic cavity, which is
thus deepest centrally. The convex inferior surface of the
pelvic diaphragm forms the roof of the perineum, which is
therefore shallow centrally and deep peripherally. Its lateral
parts (ischioanal fossae) extending well up into the lesser
pelvis.
135
Why do differences exist between male and female pelvises?
These sexual differences are related mainly to the heavier build and larger muscles of most men and to the adaptation of the pelvis (particularly the lesser pelvis) in women for parturition (childbearing)
136
What is the sacrospinous ligament?
The sacrospinous ligament, passing from lateral sacrum and coccyx to the ischial spine, further subdivides the sciatic foramen into greater and lesser sciatic foramina
137
What is the sacrotuberous ligament?
This ligament passes from the posterior ilium and lateral sacrum and coccyx to the ischial tuberosity, transforming the sciatic notch of the hip bone into a large sciatic foramen
138
What are the differences between male and female pelvises?
General structure: Male - thick and heavy Female - Thin and light
Greater pelvis (pelvis major): Male- Deep Female - Shallow
Lesser pelvis (pelvis minor): Male - Narrow and deep, tapering Female - Wide and shallow, cylindrical
Pelvic inlet (superior pelvic aperture): Male - Heart-shaped, narrow Female -Oval and rounded; wide
Pelvic outlet (inferior pelvic aperture): Male - Comparatively small Female - Comparatively large
Pubic arch and subpubic angle: Male - Narrow (<70°) Female - Wide (>80°)
Obturator foramen: Male - Round Female - Oval
Acetabulum: Male - Large Female - Small
Greater sciatic notch: Male - Narrow (∼70°); inverted V Female -Almost 90°
139
Do all individuals conform to the type of pelvis that is normal for their sex?
No, individuals can have features of each type of pelvis
140
What are the male and female pelvis types called?
Male - android
| Female - gynecoid
141
Which type of pelvis is best for childbirth?
Gynecoid
142
What are the consequences of a woman having an android type pelvis?
May present a hazard to successful vaginal delivery of a foetus
143
Why are the diameters of the lesser pelvis important?
To determine the capacity of the female pelvis for childbearing,
the diameters of the lesser pelvis are noted radiographically or
manually during a pelvic examination
144
How is the minimum anteroposterior diameter of the pelvis measured ?
```
The true (obstetrical) conjugate from the middle of the sacral promontory to the posterosuperior margin (closest point) of the pubic symphysis - is the narrowest fixed distance through which the baby’s head must pass in a vaginal delivery.
This distance, however, cannot be measured directly during a
pelvic examination because of the presence of the bladder.
Consequently, the diagonal conjugate is measured by palpating the sacral promontory with the tip of the middle finger, using the other hand to mark the level of the inferior margin of the pubic symphysis on the examining hand. After the examining hand is withdrawn, the dis-
tance between the tip of the index finger (1.5 cm shorter than the middle finger) and the marked level of the pubic symphysis is measured to estimate the true conjugate, which should be 11.0 cm or greater.
In all pelvic girdles, the ischial spines extend toward each
other, and the interspinous distance between them is nor-
mally the narrowest part of the pelvic canal (the passageway
through the pelvic inlet, lesser pelvis, and pelvic outlet) through which a baby’s head must pass at birth but it is not a fixed distance - Relaxation of Pelvic Ligaments and Increased Joint Mobility During Pregnancy
During a pelvic examination, if the ischial tuberosities are far enough apart to permit three fingers to enter the vagina side by side, the subpubic angle is considered sufficiently wide to permit passage of an average foetal head at full term.
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145
How are joint and ligament flexibility affected during pregnancy?
The larger cavity of the interpubic disc in females increases in size during pregnancy. This change increases the circumference of the lesser pelvis and contributes to increased flexibility of the pubic symphysis.
Increased levels of sex hormones and the presence of the hormone relaxin cause the pelvic ligaments to relax during the latter half of pregnancy, allowing increased movement at the pelvic joints. Relaxation of the sacroiliac joints and pubic symphysis permits as much as a 10–15% increase in diameters(mostly transverse, including the interspinous distance), facilitating passage of the fetus through the pelvic canal. The coccyx is also able to move posteriorly.
146
Do all the diameters of the pelvis change during pregnancy?
The one diameter that remains unaffected is the true
| (obstetrical) diameter between the sacral promontory and the
posterosuperior aspect of the pubic symphysis
147
Why do women get a lordotic posture during pregnancy?
Relaxation of sacroiliac ligaments causes the interlocking mechanism of the sacroiliac joint to become less effective, permitting greater rotation of the pelvis and contributing to the lordotic (“sway-back”) posture often assumed during pregnancy with the
change in the center of gravity
148
Why are joint dislocations more common in pregnancy ?
Relaxation of ligaments is not limited to the pelvis, and the possibility of joint dislocation increases during late pregnancy.
149
What are the pelvic planes?
Pelvic inlet
Plane of greatest diameter
Plane of least diameter
Pelvic outlet
150
How is the pelvic inlet assessed?
AP diameter
151
How is the mid-pelvis assessed?
Straight side walls - do they taper?
| Measurement of bispinous diameter (ischial spines)
152
How is the pelvic outlet assessed?
Infrapubic angle - distance between ischial tuberosities
153
What are the key ligaments of the pelvis that allow expansion of the pelvic outlet?
Sacrotuberous ligament
| Sacrospinous ligament
