Week 4 - Anatomy Tutorial - Anatomy of O&G Surgical Incisions & Male Infertility

Question 1

What is the septum known as that divides the scrotum into two?

Answer 1

This is the fibromuscular septum of the scrotum - dicvides it into two bags each containing a testi

Question 2

The scortum is made up of hear bearing skin and a muscle which contracts to raise the testis closer to the body in cold conditions WHat is this muscle known as?

Answer 2

This is the dartos muscle

Question 3

The testes should both be palpated in order to determine size and exclude abnormalities, such as hydrocele or testicular tumours. What testicular volume are prebuertal testis? What vlume are the testis once entering puberty? What are the adult testicular volume of testis? How are the size of testis measured?

Answer 3

Prebuertal testicular volume - 1-3ml

Once tesis reach 4ml, puberty is entered

Adult testis measure from 12-25mls

This size is measured using an orchidometer

Question 4

Volume may be reduced in any condition that causes testicular failure In which condition may the testis be small an difficult to palpate?

Answer 4

Klinefelter’s sydndrome, post-chemotherapy, orchitis

Question 5

. If you are unable to palpate a testis, consider that it may be very small or not present in the scrotum e.g an undescended testis. What are undescended testis known as? How may it be diagnosed?

Answer 5

Undescended testis - known as cryptoorchidism Ultrasound may be useful in the diagnosis

Question 6

Where does the epididymis and vas deferens lie in relation to the testi?

Answer 6

Epidiymis lies on the posterolateral aspect of the testi and runs inferiorly Vas deferens lies medial to the epidymis on the posterior aspect of the tetsi and runs superiorly

Question 7

The epididymis lies along the posterolateral border of each testis and, if normal, is difficult to palpate. However, if there is obstruction the epididymis becomes distended and can be palpated. Where can the vas deferns be palpated? When may the vas deferens be absent?

Answer 7

The vas deferens can be palpated in the spermatic cord as a strong tubular structure

The vas deferens may be absent in cystic fibrosis (congenital bilateral absence of vas deferens)

Question 8

Testicular functions are spermatogenesis and the secretion of testosterone (which promotes the male secondary sex characteristics and protein anabolism). Each testis is encapsulated in the tough fibrous capsule of the tunica albuginea, which is protective and also maintains a slight pressure within the testis to help transport of sperm. The tunica vaginalis is a double layer of peritoneum that encloses the testis and epididymis within the scrotum. What is the tunica vaginalis derived from?

Answer 8

The tunica vaginalis is derived from the processus vaginalis that should obliterate leaving no connection between the peritoneal cavity and tunica vaginalis in the scrotum

Question 9

If the processus vaginalis does not close completely, what can this cause? Where does the collection of fluid usually form between?

Answer 9

If the processus vaginalis does not close completely this can cause a hydrocele A hydrocele is a collection of fluid between the parietal and visceral layers of the tunica vaginalis.

Question 10

The epididymis receives the sperm from the tubules within the testis and is a hugely coiled tube for transport and maturation of those sperm. . It has a head, body and tail. What does the epididymis become at the inferior pole of the testis?

Answer 10

At the inferior pole of the testis the epididymis becomes the vas deferens

Question 11

The vas (ductus) deferens carries sperm from the testis. It is continuous with the tail of the epididymis, and lies medial to the epididymis on the posterior aspect of the testis. How long is the vas deferens roughly? What does it ascend within?

Answer 11

The vas deferens is apporx 25cm in length and ascends through the abdominal wall within the spermatic cord

Question 12

. The vas ascends within the scrotum (accompanied by the testicular vessels), through the spermatic cord to enter the inguinal canal through the superficial inguinal ring in external oblique aponeurosis. It then passes through the deep inguinal ring, immediately lateral to which artery?

Answer 12

The vas deferns passes immediately lateral to the inferior epigastric artery before heading medially to meet the seminal vesicle

Question 13

Does the vas deferns pass above the ureter or the other way round? What does the vas deferens fuse with to form the ejaculatory duct?

Answer 13

The vas deferens passes above thee ureter before descding to join with seminal vesicle duct to form the ejaculatory duct which opens into the prostatic urethra

Question 14

What is the course that sperm travel during ejaculation?

Answer 14

Sperm are produced in the eseminiferous tubules f the testis and then travel to the rete testis before travelling to the epididymis - then travels up the vas defernes before being propelled into the prostatic urethra which continues to become the membranous urethra then the spongy urethra where it exits via the external urethral orifice during ejaculation

Question 15

What are the accessory glands of the penis?

Answer 15

Epidiymis and vas deferens Seminal vesicle (gland) Prostate gland Bulbourethral gland

Question 16

What is the function of the accessory glands of the penis? Remember the contents of the seminal fluid

Answer 16

Epididymis and vas deferens - exit route from testis and site of sperm maturation Seminal vesicle - secrete seminal fluid into ejaculatory duct to form semen - includes fructose, prostoglandins to help with motility and fibrinogen (clotting) (also contains zinc and vitC) Prostate gland - produces alkaline fluid to neutralize vaginal acidity and clotting factors to clot semen in vagina Bulbourethral glands - produces mucus to act as lubricant

Question 17

Anatomically, the penis is always described as if erect. The skin of the penis is fat-free, loose and mobile. What are the muscles assisting in erection of the penis? What forms the glans of the penis?

Answer 17

* The bulbiospnogiosus - lies oveer the bulb of the penis (coprus spongiosum) * Ischiocavernsus - lies over the crura (corpus cavernosum) * The superficial transvere perineal muscle - acts as a firm base for erection The corpus spongiosum continues onto the ventral aspect of the penis and distally it forms the glans penis, which is a cap over the two corpora cavernosa.

Question 18

What controls erection and ejaculation?

Answer 18

Erection - Point

• Parasympathetics inhibit sympathetics allowing blood flow to erectile tissue of the penis

Ejaculation - Shoot

• Sympathetics causes muscle to contract allowing for ejaculation

Question 19

At what level do the testicular (and ovarian) arteries arise? Where do the testicles drain blood?

Answer 19

The gonadal arteries arise at L2 vertebral level Right testicular vein drains to the IVC Left testicular vein drains to the left renal vein which drains to the IVC

Question 20

As the testes (and ovaries) originate on the posterior abdominal wall, lymphatic drainage is to para-aortic nodes. Where is metastatic tumour spread from the testis therefore?

Answer 20

Metastatic tumour spread is therefore to the para-aortic (lumbar) lymph nodes It is only when the tumour spreads locally to the scrotum that the superficial inguinal lymph nodes are involved.

Question 21

What are common O&G surgical incision on the anterior abdominal wall?

Answer 21

LSCS - lower segment caesarean section Laparotomy Laparoscopy Hysterectomy

Question 22

What are the lines corresponding to the natural orientation of collagen fibres that are used when incising a patient?

Answer 22

These are Langer’s lines - the lines are generally parallel to the underlying muscle which helps with wound healing

Question 23

What are the layers incised during the lower segment caesarean section?

Answer 23

Skin Superficial fascia Rectus sheath anteriorly incised Rectus abdominus pulled apart laterally Fascia and peritoneum incised Retract bladder INcise uterine wall and amniotic sac

Question 24

Why is the posterior rectus sheath not incised during a LCSC?

Answer 24

This is because the posterior rectus sheath does not continue after the arcuate line of the abdomen - between the umbilicus and pubic symphysis

Question 25

The two main types of surgical incisions to have a closer look at the pelvic/abdominal organs through the anterior abdominal wall are a vertical midline incision and the lower segment cesarean section What is the other names for the LSCS?

Answer 25

Pfannenstiel incision Bikini line incision Suprapubic incision

Question 26

Laparotomy use the midline vertical incision when looking through the anterior abdominal wall

• What layers are incised?

Which layers are stitched in both LSCS and midline vertical incision?

Answer 26

Midline vertical incisions

• * Skin
• * Superficial fascia
• * Linea albea
• * Peritoneum - after this, able to see into the abdomen
• Stitched LSCS - skin, rectus sheath (anteiorly), uteirne wall with visceral peritoneum
• Midline - skin, linea albea, peritoneum

Question 27

In order to minimise the risk of damage to the bladder in a LSCS, what is done?

Answer 27

The bladder is catheterized before the procedure to reduce its size

Question 28

The uterine fundus can usually start to be palpated above the pubic symphysis from 12 weeks gestation When does the uterine fundus reach the umbilicus? After reaching the umbilicus it grows at about 1cm per rate until it reaches the xiphisternum at what week?

Answer 28

Uterine fundus reaches the umbilicus at roughly 20 weeks Reaches the xiphisternum at roughly 36 weeks - From this gestation onwards the fundal height may decrease as the head starts to descend into the maternal pelvis.

Question 29

What is the measurement from pubic symphysis to uterine fundus known as? What is the error range given?

Answer 29

Symphysiofundal height - measurement from pubic symphysis to uterine fundus in cm equalling the weeks of gestation +/- 3cm

Question 30

What two main arteries supply the anterior abdominal wall with blood? Where do both of these arteries arise? What muscle do the arteries lie posterior to?

Answer 30

Superior and inferior epigastric arteries

Superior is a direct continuation of the internal thoracic artery (internal mammary artery) Inferior is a branch of the external iliac artery Both lie posterior to the rectus abdominus muscle

Question 31

The inferior epigastric artery is a branch of the external iliac artery. It runs up from above the inguinal ligament, piercing the transversalis fascia to ascend behind the rectus sheath and anastomoses with the superior epigastric artery. Together they supply the central part of the abdominal wall. How does the inferior epigastric artery pass through the abdomen?

Answer 31

The inferior epigastric artery pierces the transversalis fascia at the midpoint of inguinal ligament where the deep inguinal ring is located (halfway between ASIS and pubic tubercle) - it then travel behind the rectus abdominus oblqiue to about 2-3cm lateral to umbilicus where it joins with the superior epigastric artery

Question 32

What type of incision runs the risk of incising the inferior epigastric arteries?

Answer 32

This would be during laparoscopy where lateral ports are made for the keyhole surgery - make sure to be careful to avoid the inferior epigastric arteries which run superomedially

Question 33

What are the advantages and disadvantages of LSCS and vertical midline incsion?

Answer 33

• Advntages of LSCS - * Better cosmetic results, Lower incidence of hernia formation and Less pain
• Disadvantages of LSCS - * Access is slowe and Greater blood loss
• Advantages of midline vertical incision - * Rapid bloodless access
• DIsadvnatage of midline vertical incision - Relatively avascular so poor wound healing, Increased risk of wound dehiscence and Hernia formation

Question 34

Why it is important to suture the rectus sheath on closing the anterior abdominal wall?

Answer 34

It is important to suture the rectus sheath on closing the anterior abdominal wall in order to reduce the risk of wound hernia formation.

Question 35

What does the neurovascular bundle supply to the (antero)lateral abdominal wall run between?

Answer 35

The NVB runs between the internal oblique and transversus abdominus muscles

Question 36

What are the nerve supply to the anterolateral abdominal wall? The nerves arise in the spine and curve round to supply the muscles and skin etc

Answer 36

The 7th to 11th intercostal nerves

T12 - subcostal nerve

L1 - iliohypogastric and ilioinguinal nerves

Question 37

As stated, the blood supply to the anterior abdominal wall is the superior and inferior epigastric arteries What is the blood supply to the lateral abdominal wall?

Answer 37

The intercostal and subcostal arteries