15. Reproductive System Flashcards
1
Q
Summarise the layers of the scrotum.
A
From internal to external:
- (Tunica albuginea)
- Tunica vaginalis (visceral and parietal)
- Internal spermatic fascia (continuous with transversalis fascia)
- Cremaster muscle (fascia continuous with internal oblique aponeurosis)
- External spermatic fascia (continuous with external oblique aponeurosis)
- Superficial fascia
- Dartos muscle
2
Q
What is the spermatic cord?
A
The testes and epididymis are suspended within the scrotum by the spermatic cord, a tubular structure that passes through the inguinal canal.
3
Q
What structures are contained within the spermatic cord?
A
A good mnemonic is Papers Don’t Contribute To A Good Specialist Level:
- P = Pampiniform venous plexus (drains to testicular vein)
- D = Ductus (vas) deferens
- C = Cremasteric artery (from inferior epigastric artery)
- T = Testicular artery (from abdominal aorta)
- A = Artery to vas deferens (from the superior/inferior vesical artery)
- G = Genital branch of genitofemoral nerve
- S = Sympathetic/Parasympathetic nerves
- L = Lymphatics
4
Q
What is the blood supply and drainage of the testes?
A
Blood supply:
- Testicular artery from the abdominal aorta.
Blood drainage:
- Each testis is drained by vesicular veins are arranged in a pampiniform venous plexus -> These pass through the inguinal canal that unite to form a single vein
- The left testicular vein drains to the left renal vein, whereas the right testicular vein drains directly into the inferior vena cava.
5
Q
What must you remember about the venous drainage of the testes?
A
The left testicular vein drains to the left renal vein, whereas the right testicular vein drains directly into the inferior vena cava.
6
Q
What are the layers that make up the fascia surrounding the spermatic cord?
A
During the descent of the testes into the scrotum, the layers of the anterior abdominal wall are dragged along, creating three layers of fascia surrounding the spermatic cord. These layers are, superficial to deep:
- External spermatic fascia -> Formed from external oblique aponeurosis.
- Cremaster fascia -> Containing the cremaster muscle, formed from internal oblique muscle and aponeurosis
- Internal spermatic fascia -> Formed from transversalis fascia.
7
Q
Describe the parts of the testis and their functions.
A
- Seminiferous tubules -> Site of spermatazoa production
- Tunica albuginea -> Contains the seminiferous tubules
- Rete testis -> Drain the seminiferous tubules
- Epididymis -> Drains the rete testis
- Tunica vaginalis -> Double-layered serous membrane that covers the testes
- Vasa efferentia -> Connect the rete testis to the epididymis
8
Q
Describe the path of spermatazoa.
A
- Seminiferous tubules
- Rete testis
- Vasa efferentia
- Epididymis
- Vas deferens
- Ejaculatory duct (when vas deferens and seminal ducts join)
- Urethra
9
Q
Where does the vas deferens pass?
A
- Through the inguinal canal.
- Passes between the ureter posteriorly and the bladder anteriorly, before passing along the posterior surface of the bladder.
10
Q
What are the parts of the epididymis?
A
From superior to inferior:
- Head
- Body
- Tail
These become increasingly straight.
11
Q
Where in the testis are spermatozoa produced?
A
Seminiferous tubules
12
Q
What are the vasa efferentia?
A
The ducts that connect the rete testis to the epididymis.
13
Q
Where are spermatozoa stored?
A
In the epididymis.
14
Q
What is the ampulla of the vas deferens?
A
An enlargement of the vas deferens at the fundus of the bladder which acts as a reservoir for sperm.
15
Q
A
16
Q
Where do the products of the prostate gland and seminal vesicles join?
A
- Vas deferens joins with the seminal vesicles just before the prostate.
- This forms the ejaculatory ducts.
- They pass through the prostate, and open into the urethra.
17
Q
What are the seminal vesicles?
A
- Glands that lie behind the urinary bladder, near the prostate.
- They secrete a fluid that is high in fructose and contributes to the semen.
- The seminal vesicles contribute around 2/3rds of the total volume of semen.
18
Q
Describe the structural regions of the prostate.
A
The prostate may be divided into a left and right lobe, separated by a superficial median furrow (or groove) on its posterior surface.
19
Q
What are the different histological zones of the prostate?
A
- Central zone -> Surrounds the ejaculatory ducts, accounting for 25% of the prostate volume.
- Transition zone -> Located anterolateral to the proximal urethra. The site in which benign prostatic hyperplasia occurs.
- Peripheral zone -> Surrounds the more distal prostatic urethra at the apex of the prostate, accounting for around 70% of the prostate volume. The site in which prostate cancer typically occurs.
20
Q
A
21
Q
What is the function of the prostate gland in reproduction?
A
Produces and secretes an alkaline fluid containing simple sugars and proteolytic enzymes that contributes to 30% of the volume of semen.
22
Q
Describe the structure of the penis.
A
- The penis is made up of three columns of tissue:
- Two corpora cavernosa -> Lying adjacent to each other on the dorsum aspect
- Corpus spongiosum -> On the ventral aspect, housing the urethra
- The corpus spongiosum is surrounded by striated muscle called the bulbospongiosus.
- The glans penis, forming the distal end of the penis, surrounds the urinary meatus and is surrounded by the prepuce (foreskin).
23
Q
What are the main muscles involved in the penis? What is their function?
A
- Ischiocavernosus -> Assists in maintenance of the erect penis, as contraction impedes venous return.
- Bulbospongiosus -> Assists with maintenance of erection, but is also important for ejaculation.
24
Q
Describe how erection occurs.
A
- Normally, the helicine arteries of the corpora are contracted, so that little blood flows into the penis
- Parasympathetic contribution to erection (cavernous nerves, S2-S4):
- When achieving erection, the helicine arteries of corpora relax
- Somatic contribution to erection (pudendal nerve):
- Contraction of bulbospongiosus and ischiocavernosus impedes venous return
25
Which nervous system is responsible for emission of semen (not ejaculation!)?
Sympathetic
26
Which nervous system is responsible for ejaculation of semen?
Somatic
27
Describe how emission and ejaculation occurs.
Sympathetic nervous system controls emission:
* Sympathetic fibres initiate contraction of smooth muscle of epididymal ducts, ductus deferens, seminal vesicles and prostate in sequence
* Sperm, seminal and prostatic secretions enter prostatic urethra and penile bulb
* Sympathetic stimulation (L1-L2) of internal urethral sphincter prevents ejaculation into bladder
Somatic nervous system controls ejaculation:
* Rhythmic contraction of bulbospongiosus (pudendal nerve S2-S4) moves semen along spongy urethra resulting in ejaculation
28
What nervous sytem is responsible for erection, emission and ejaculation?
* Erection = Parasympathetic
* Emission = Sympathetic
* Ejaculation = Somatic
A commonly used way to remember the nerves responsible for the male reproductive system reflexes is by using the phrase “Point and Shoot”: Point (erection) = parasympathetic, Shoot (emission) = sympathetic
29
Summarise the lymphatic drainage of the testes and scrotum.
* Testes -\> To the **para-aortic nodes**
* Scrotum and skin of the perineal region -\> To the **inguinal nodes**
30
Summarise the innervation of the testes and scrotum contents.
* Sympathetic fibres (T1-L1) -\> Supply the **testis.**
* Somatic fibres (L1 to scrotum):
* Genitofemoral nerve -\> To thigh (e.g. cremaster)
* Ilio-inguinal nerve -\> To scrotum
* Somatic fibres (S2-S3) -\> Supply the rest of the scrotum.
31
Describe the cremasteric reflex.
* This reflex is triggered by stroking the superomedial aspect of the thigh in a downward direction.
* The normal response is a contraction of the cremaster muscle, pulling up the scrotum and testis on the side stimulated.
* Upper and lower motor neuron lesions can cause an absence of the cremasteric reflex.
* The genitofemoral nerve (L1/L2) is responsible for the afferent and efferent limbs of the reflex arc.
32
Describe hydrocoele and varicocoele.
Hydrocoele:
* A collection of fluid within the scrotum, between the parietal and visceral layers of the tunica vaginalis.
* This may occur in combination with a patent processus vaginalis and thus communicate with the peritoneal cavity.
* Usually presents as a painless, enlarged scrotum and may resolve spontaneously, but typically needs surgical repair if persisting beyond 12 months.
Varicocoele:
* Anormal dilatation of the testicular veins of the pampiniform venous plexus, caused by reflux of blood into the plexus.
* Varicocoeles are more common on the left due to the angle at which the left testicular vein drains into the left renal vein and lack of effective venous valves.
* Patients describe the scrotum as feeling like a bag of worms, and only rarely do they report pain. Treatment may involve surgical ligation of the veins to prevent abnormal blood flow.
33
Describe testicular torsion.
The blood supply to the testis can become compromised if the spermatic cord twists within the tunica vaginalis, which can rapidly lead to ischaemic damage and loss of the testis. Testicular torsion is a medical emergency and causes acute scrotal pain and swelling, nausea and vomiting. Treatment is by immediate manual de-torsion followed by surgical fixation of the testis to prevent further episodes of torsion.
34
Describe mal-descent of testes.
By 28 weeks of gestation, the right and left testes reach the inguinal canals, and by 28-40 weeks, they descend to their final place within the scrotum. An undescended testis is a testis that is absent from the scrotum. This may be due to failure of formation, testicular retraction or failure of descent. Mal-descent may result from an anatomical or hormonal abnormality, although most will descend into the scrotum within the first three months of life.
35
Where does testicular cancer most commonly spread to?
Testicular cancers most commonly metastasise via lymphatic drainage, usually to the retroperitoneal lymph nodes (para-aortic).
36
Where does prostate cancer most commonly spread to?
Via venous channels to the IVC and lungs, as well as spreading to the rich venous plexus of the pelvic bones, sacrum and vertebral column.
37
Describe vasectomy.
Division and ligation of the vas deferens is a surgical method by which male infertility can be achieved for contraceptive purposes. Each vas deferens us divided along its scrotal part, just beneath the superficial inguinal ring. As a result, spermatozoa fail to reach the prostatic urethra and degenerate within the epididymis.
38
What part of the prostate does prostatic hyperplasia most commonly occur in?
Transitional zone
39
What part of the prostate does prostatic cancer most commonly occur in?
Peripheral zone
40
Draw a diagram of the female reproductive system.
41
What are the ovaries covered by and what is this continuous with?
* Cuboidal epithelium
* Continuous with the peritoneum
42
Describe the blood supply and drainage of the ovaries.
* Ovarian arteries -\> Arising from the abdominal aorta at the level of L2.
* Pampiniform venous plexus drains into ovarian vein -\> Drains into the left renal vein on the left and inferior vena cava on the right.
43
What ligaments does the ovary attach to?
* Broad ligament
* Suspensory ligament -\> Suspends the ovary by attaching to lateral abdominal wall
* Ovarian ligament -\> Attaches the ovary to the uterus
44
How can the position of the ovaries be described?
Intraperitoneal, on the posterior aspect of the broad ligament.
45
What are the 4 parts of the Fallopian (uterine) tubes?
* Fimbriae
* Infundibulum
* Ampulla -\> Most common site of fertilisation
* Isthmus
46
What is the infundibulum and what is its function?
It is the end of the Fallopian tube that cups the ovary and collects the ovum that is released.
47
What are the 3 main parts of the uterus that the spec mentions?
* Fundus (top of the uterus)
* Body
* Cervix
48
Label this.
49
What is the top of the uterus called?
Fundus
50
What two important terms describe the alignment of the uterus (relative to the vagina)?
* Anteflexed -\> Body of cervix is bent so as to form a slight n shape
* Anteverted -\> Cervix is bent forward relative to the axis of the vagina
51
Describe the blood supply and drainage of the uterus.
* Uterine artery -\> Arises from internal iliac artery
* Uterine vein -\> Drain to internal iliac vein
52
What are some important relations of the uterine artery?
* Travels via the cardinal ligaments
* Passes anterior to **ureter**
* Arrives at the **lateral fornix of the vagina**
53
What structure is the vagina continuous with and at what point?
Uterus, at the uterine cervix.
54
What is the cervix?
The lower, narrow part of the uterus that joins to the top of the vagina.
55
What are the fornices of the vagina?
* The fornices are superior recesses of the vagina formed by the protrusion of the cervix into the vaginal vault.
* There is a large posterior fornix and a smaller anterior fornix with two small lateral fornices.
56
What are some important relations of the posterior fornix of the vagina?
The posterior fornix is immediately anterior to the rectouterine pouch.
57
Describe the arterial supply to the vagina.
* Superior part -\> Uterine arteries
* Middle and inferior parts -\> Vaginal and internal pudendal arteries.
58
Describe how the different structures in the female reproductive tract are continuous with each other.
The ovaries are cupped by the infundibulum of the Fallopian tubes, which connect to the uterus, the cervix of which joins to the vagina.
59
Which female reproductive structures are intraperitoneal, subperitoneal and perineal?
Intraperitoneal:
* Ovaries
* Fallopian tubes
Subperitoneal:
* Uterus
* Vagina
Perineal:
* Vagina
60
What is the pouch of peritoneum that is anterior to the uterus?
Vesicouterine pouch
61
Label this.
62
Describe the relative positions of the bladder, uterus and rectum in the pelvis.
63
What is the pouch of peritoneum that is posterior to the uterus?
Rectouterine pouch (of Douglas)
64
Draw a sagittal section of the pelvis, showing the bladder, uterus and anus.
65
What are the four important ligaments relating to the uterus?
* Broad ligament
* Round ligament of uterus
* Ligament of ovary
* Suspensory ligament of the ovary
66
What is the broad ligament?
* A double-fold of peritoneum
* It extends from the sides of the uterus medially to the pelvic sidewalls laterally and the pelvic floor inferiorly
67
Which ligament contains the ovarian blood vessels?
Suspensory ligament of the ovary
68
What are the different parts of the broad ligament and what does each cover?
* Mesometrium -\> Uterus
* Mesosalpinx -\> Fallopian tubes
* Mesovarium -\> Ovaries
69
Label this. (Posterior view)
70
What ligament tethers the ovaries to the uterus?
Ligament of ovary
71
Describe the path of the round ligament.
* The round ligament of the uterus passes from the uterine horns, through the inguinal canal, to the labia majora fascia.
* It is the female equivalent of the spermatic cord.
72
What are the pubocervical and uterosacral ligaments?
* Pubocervical -\> Connects the pubic symphysis to the cervix
* Uterosacral -\> Connects the uterus to the sacrum
These are mostly supportive ligaments.
73
Describe the lymphatic drainage of the ovary, uterus and vagina.
* Ovary -\> To the para-aortic lymph nodes
* Uterus:
* Body and cervix -\> To the internal iliac lymph nodes
* Fundus -\> To the para-aortic, superficial inguinal and lumbar lymph nodes
* Vagina -\> To the iliac and superficial inguinal lymph nodes.
74
Describe ovarian cysts.
* Two types of benign cyst may develop within the ovary: follicular cysts from the Graafian follicles and Corpus Luteum cysts.
* Most cysts are \<2cm in diameter, usually asymptomatic and usually resolve without further treatment.
* Rupture of haemorrhagic corpus luteum cysts may cause sudden onset pain and signs of peritonitis.
* Pain from ovarian cyst rupture may occur in the lower abdomen, which is typically unilateral and sharp in character, due to irritation of the parietal peritoneum.
* Patients with polycystic ovary syndrome (PCOS) have multiple cysts within their ovaries, associated with obesity, abnormal menses and signs of excessive androgen production, including acne and abnormal hair growth.
* Treatment for PCOS is typically symptomatic.
75
Describe uterine retroversion and retroflexion.
* A retroverted uterus is posteriorly tilted, which is seen in around 20% of females.
* A retroflexed uterus is where the fundus is pointing backwards (towards the rectum), creating a convex uterus anteriorly. This position may be caused by genetic factors and considered a normal variant, or may be indicative of pathology, such as adhesions, endometriosis or fibroids.
* The position of the uterus can be determined by a pelvic examination or ultrasound scan.
76
Describe uterine prolapse.
* Uterine prolapse refers to the descent of the uterus towards the external genitalia and may be graded on the extent of the descent.
* Symptoms may include a feeling of fullness or pressure within the pelvic region.
* Prolapse typically occurs in old age, particularly if the uterine components have been damaged during childbirth or the supportive ligaments and pelvic floor have become weakened.
* For moderate prolapses, patients may be treated with a pessary which structurally supports the uterus.
* For more severe prolapses, hysterectomy with surgical strengthening of the pelvic support structures may be required.
77
Where can pain from the ovaries be referred to?
Umbilicus
78
Describe the spread of ovarian and uterine cancer.
* Ovarian cancer -\> Spread to para-aortic lymph nodes, liver, lungs and peritoneum.
* Uterine cancer -\> Spread to the bladder, rectum, vagina, oviducts, ovaries and more distant structures.
79
What is the perineum? What are the borders?
The perineum is a diamond-shaped region inferior to the pelvic outlet and pelvic floor muscles.
80
What can the perineum be divided into?
* Urogenital triangle:
* Lies between the pubic symphysis anteriorly, the ischiopubic rami and a line between the ischial tuberosities posteriorly.
* Contains the external genitalia and urethra.
* Has an additional layer of fascia called the perineal membrane, through which the urethra and, in females, the vagina pass.
* Anal triangle:
* Lies between the posterior border of the perineal membrane and body anteriorly and the ischial tuberosities, sacrotuberous ligaments and coccyx posterolaterally.
* Contains the anal canal and the ischioanal fossae (fat filled triangular spaces lateral to the anal canal).
81
State the contents of the anal triangle of the perineum.
* Anal canal
* External anal sphincter
* Ischiorectal fossae (fat filled triangular spaces lateral to the anal canal)
82
What are the ischiorectal fossae?
Fat-filled triangular spaces lateral to the anal canal.
83
What is the importance of the perineal membrane?
Provides attachment to the muscles of the external genitalia.
84
What are the perineal pouches? What do they contain?
* The space in the perineum just above the perineal membrane is called the deep perineal pouch -\> Contains the erectile tissues forming the penis and clitoris
* The space in the perineum below the perineal membrane is called the superficial perineal pouch -\> Contains the external urethral sphincter and bulbourethral gland in males.
85
Where is the perineal body?
At the posterior edge of the perineal membrane.
86
What artery and nerve supply the urogenital triangle?
Pudendal artery and nerve
87
How do the pudendal nerve and vessels pass through the perineum?
* They pass in the pudenal canal
* This is located in the lateral wall of the ischiorectal fossa
It is shown in orange in the diagram.
88
89
90
What structures does the superficial perineal membrane contain in males?
* Penis
* Muscles of erection -\> Ischiocavernosus, Bulbospongiosus
* Urethra
91
Where is the external urethral sphincter found?
It is around the urethra as it passes through the pelvic floor.
92
Describe the different muscles that assist the functioning of the penis.
* Bulbospongiosus -\> Compresses the bulb of the penis and the corpus spongiosum, helping with the emptying of the urethra. Also assists in maintaining penile erection by preventing venous outflow.
* Ischiocavernosus -\> Force blood from the crura into the distal parts of the corpus cavernosum and preventing venous outflow, helping with erection.
93
Is ejaculation parasympathetic, sympathetic or somatic? What nerve is responsible?
* Somatic
* Pudendal nerve
94
What structures are in the urogenital triangle in females?
* Vuvla -\> Labia majora, labia minora, vestibule, mons pubis
* Urethra
* Clitoris
95
Draw the structure of the vulva, urethra and clitoris.
96
What is the mons pubis?
The mons pubis is the soft mound of fatty tissue covering the pubic bone above the vulvar area.
97
98
What is more medial: the labia majora or minora?
Minora
99
What is the vulva vestibule?
The area bounded by the labia minora.
100
Describe the structure of the clitoris.
* **Glans** at the tip
* Erectile bodies:
* Two **corpora cavernosa**, which form from the **crura**
* Two **vestibular bulbs**
101
Describe the importance of the integrity of the perineal body.
* Trauma to the perineum, which often occurs during childbirth, can cause tearing of the perineal body.
* Due to the role of the perineal body in pelvic floor integrity, tearing of this structure can lead to chronic pain and incontinence.
* To avoid this, clinicians may make a deliberate incision into the perineum during childbirth, typically in a diagonal direction, to prevent uncontrolled tearing of the perineal body.
102
What can pelvic floor damage lead to?
* Prolapse of pelvic viscera into the vaginal canal. These may be classified as a rectocoele (rectal prolapse), enterocoele (small bowel prolapse), cystocoele (bladder prolapse) or urethrocoele (urethral prolapse).
* Stress incontinence
103
Describe the position of the breasts.
* The breasts lie over pectoralis major, typically extending between the 2nd and 6th ribs.
* The base of the breast is normally unfixed from the underlying chest wall.
104
Describe the structure of the breast.
* 14-18 lactiferous **lobules** arranged radially around the nipple drain their contents into the lactiferous ducts, which ultimately converge at the nipple-areola complex.
* **Areolar glands** within this complex secrete an oily substance onto the areola and nipple to keep them protected and lubricated.
* **Axillary tail** extends upwards and outwards into the axilla.
* The tissue of the breast is supported by the suspensory ligaments, which pass between the deep fascia overlying pectoralis major to the dermis of the skin.
105
Describe the blood supply and drainage of the breast.
* Medially -\> Intercostal branches of the internal thoracic artery
* Laterally -\> Axillary artery laterally
Venous drainage follows this arterial pattern.
106
Describe the lymphatic drainage of the breast.
* Axillary lymph nodes
* Internal thoracic nodes
107
Describe breast cancer.
* Approximately 1 in 8 women (and 1 in 870 men) will be diagnosed with breast cancer in their lifetime.
* Risk factors include family history, older age, early menarche, late menopause and late first pregnancy.
* Most patients present with an asymptomatic breast lump found during self-examination or screening mammography.
* Breast cancers may be classified as carcinomas in situ, which do not have stromal tissue invasion, and invasive carcinomas.
* Breast cancer typically spreads through the region lymph nodes and bloodstream.
* In order to stage the breast cancer, the lymph nodes draining the breast cancer should be physically examined and biopsied.
* This may be performed using a sentinel lymph node biopsy, where dye and a radioactive substance are injected into the breast tissue to identify the first draining lymph node, or through axillary node dissection.
* Treatment of breast cancer includes surgical resection (mastectomy or breast conserving), radiotherapy and adjuvant systemic therapy.
108
Whatis an important branches of the pudendal artery you need to know?
Inferior rectal artery -\> Supplies the rectum
