10. Male pelvic viscera

Question 1

Male pelvic viscera, anterior to posterior?

Answer 1

Hladder with prostate and urethra, seminal vesicles (and ejaculatory ducts), rectum and anal canal

Question 2

Bladder fills by its _____ muscle relaxing, empties by its ______

Answer 2

Fills by its detrusor muscle relaxing, empties by its contraction

Question 3

Contents of the perineum?

Answer 3

Anteriorly: Genitalia and urethra
Posteriorly: Anal canal and ischio-anal fossae

Question 4

The side walls and floor of the pelvis are in contact with …..

Answer 4

the central, pelvic viscera i.e. bladder and prostate

Question 5

Location of bladder apex?

Answer 5

At upper aspect of pubic symphysis (5-7cm above when full)

Median umbilical ligament (remnant of embryonic urachus) extends from apex

Question 6

Surfaces of the bladder?

Answer 6

Postero-superior
Infero-lateral x 2
Base (trigone)

Question 7

How is ureteric reflux prevented anatomically?

Answer 7

The ureters pass through the bladder wall obliquely, creating a flap valve that prevents urine that is in the bladder from backing up and returning into the ureter (ureteric reflux)

Pressure of urine in the full bladder, forcing the ureters closed

Question 8

Composition of bladder wall?

Answer 8

Formed by detrusor muscle

Lined by transitional epithelium

Question 9

What does the male have to prevent semen backflow into bladder?

Answer 9

Proprostatic, internal spincter

Question 10

What aspect of the female anatomy contributes to urinary continence?

Answer 10

In the female the bladder neck is above the pelvic floor, so that pressure of pelvic organs, as well as levator ani contribute to urinary continence

Question 11

What structures provide support to the bladder?

Answer 11

Fibromuscular and fascial condensations from bladder, prostate and urethra to pubis, lateral pelvic walls, rectum and sacrum support the bladder
e.g. puboprostatic (male) and pubovesical (female) ligaments

Question 12

Peritoneum at apex….

Answer 12

NO

Question 13

Bladder pouches?

Answer 13

Rectovesical (or vesico-uterine and recto-uterine in female)

Question 14

Suprapubic cathater when?

Answer 14

Safe when bladder has distended up against anterior abdominal wall

Question 15

Male bladder relations

Answer 15

Superior: Peritoneum, ileum, sigmoid
Base: Rectovesical pouch and septum, rectum, vas deferens, seminal vesicle

Question 16

Vascular supply of the bladder?

Answer 16

Arteries:

• Ant trunk from Internal iliac
• Superical vesical
• Inferior vesical (or vaginal in females)

Veins:
-Plexus on infero-lateral surface of the bladder.
–> Drains directly to internal iliac vein
(Also drains to the prostatic plexus that drains to internal iliac vein but communicates with the internal vertebral venous plexus)

Question 17

Lymph drainage of the bladder?

Answer 17

3 plexuses: Mucosa, muscle and serosa

Mainly to the external iliac artery

Question 18

Bladder nerve supply:

• From where?
• Parasympathetic?
• Sympathetic?

Answer 18

From where?
From anterior part of the Pelvic (or inferior hypogastric) Plexus, that passes the rectum to reach the bladder (Surgical risk)

ParaS:
Detrusor has profuse, mainly p’symp. nerve supply (both afferent and efferent) derived from the Pelvic Splanchnic Nerves (S2, 3, 4) that reach detrusor via the Pelvic Plexus

Symp:
Symp. supply to Preprostatic (Internal) Sphincter as well as some to detrusor (to function synergistically with P’symp.)
Derived from T12, L1, 2, then via Pelvic Plexus

Question 19

Two options for catheters>

Answer 19

Suprapubic

Urethrally

Question 20

Presentation of “Injury to the bladder and urethra in particular may lead to urinary extravasation “trapped” by Scarpa’s and Colles’, perineal fascia”?

Answer 20

This fascial layer is shown in purple below and limits the spread of urine and bruising to the lower abdomen, upper thighs, penis and scrotum, but no further posteriorly as Colles’, perineal fascia fuses to the Perineal Body

Question 21

First part of male urethra?

Answer 21

Preprostatic:

• With internal/genital/prepostatic sphincter
• From bladder neck to upper aspect of verumontanum
• Surrounded by smooth muscle from bladder wall that passes into urethra and also into prostaste

Question 22

2nd part of male urethra?

Answer 22

Prostatic

• receiving ejaculatory duct opening into prostatic sinuses
• urethral crest causes crescentic section
• Verumontanum with utricle and ejaculatory ducts either side

Question 23

3rd part of male urethra?

Answer 23

Membraneous surrounded by external sphincter

Question 24

4th part of male urethra?

Answer 24

Spongy in bulb of penis and then corpus spongiosum

Question 25

Prostate function?

Answer 25

Genital (not urinary) function
Slightly acid seminal secretion:
-Acid phosphatase
-Amylase
-Prostate specific antigen (PASA)
-Fibrinolysin

Question 26

Structure of prostate

Answer 26

Fibromuscular and glandular
Upside-down pyramid
In tough capsule
Supported by puboprostatic ligaments

Question 27

Surfaces of prostate?

Answer 27

Base
Apex
Posterior: To denonvillier’s fascia and rectum
Anterior: To pubic symphysis and arch
2 x inferolateral surfaces to pelvic floor

Question 28

Lobes of the prostate?

Answer 28

Lobes only in foetus, 2 lateral and a median may be described in adult. The anterior part of the gland is fibromuscular only

Question 29

Zones of the prostate?

Answer 29

1. Transition 5%, around urethra, ant. to ejaculatory ducts BPH (**benign prostatic hypertrophy)
2. Central 25%, behind transition, contains ejaculatory ducts
3. Peripheral 70%, around transition and central (**Carcinoma)

Question 30

Position and role of the seminal vesicals?

Answer 30

The left and right Seminal Vesicles (glands) lie just above the prostate gland, sandwiched between the bladder and rectum. They secrete seminal fluid to nourish sperm.

Question 31

Formation of the ejaculatory duct?

Answer 31

The dilated, ampullary end of the vas unites with the duct from the seminal vesicle to form the Ejaculatory Duct that passes through the prostate to enter the urethra.

Question 32

Prostate and proximal urethra lymph drainage?

Answer 32

Mainly to internal iliac nodes

Question 33

Requirement for innervation of urethra and prostate?

Answer 33

Require:

1. Somatic motor for control of striated muscle – ext. sphincter
2. Autonomic both sympathetic and parasympathetic
3. Sensation

Question 34

Where is the nerve supply of the urethra and prostate derived from?

Answer 34

S2,3,4
Somatic motor and sensory: From pudendal nerve and its perineal branches

Parasympathetic: From pelvic splanchnics to pelvic plexuses

Sympathetic: From L1 and L2 via superior hypogastric plexus to pelvic plexus

Question 35

Action of sympathetic stimulation of preprostatic sphincter?

Answer 35

Shuts it for ejaculation

Question 36

3 stages of micturition?

Answer 36

1. Storage
Parasympathetic to detrusor “switched off” in spinal cord to allow bladder to relax and fill
Usual volume (male) about 400 ml, if reach 500 ml – pain in lower abdomen and perineum

2. “Full” causes desire to micturate
   Afferents (sensory) to spinal cord, then “M” Centre in pons – stimulates preganglionic, parasympathetic neurones at S 2, 3, 4
3. Void
   1y neurones stimulate 2y neurones in bladder wall ganglia, causing detrusor contraction
   Simultaneous relaxation of levator ani (pelvic floor) and external urethral sphincter (striated muscle) – S 2, 3, 4 (pudendal nerve) and contraction of abdo. wall; sensation of urine in urethra maintains the reflex

Question 37

What is the autonomic stretch reflex?

Answer 37

prevails in the untrained infant so that the bladder empties automatically when full

Question 38

How is the “full” sensation of the bladder detected and responded to particularly in infancy?

Answer 38

When full (usual volume of male about 400 ml) stretch receptors send signals via the parasympathetic pelvic splanchnics (afferents) to cord segments S 2, 3, 4 where they trigger reflexes in the parasympathetic efferents  (pelvic splanchnics to pelvic plexus and then to bladder wall) to cause detrusor (bladder) contraction
AUTONOMMIC STRETCH REFLEX

Question 39

Effect of training on on the autonomic stretch reflex of the bladder?

Answer 39

With training, afferents (sensory) ascend up the spinal cord to trigger cortical inhibition in the frontal lobe. This superimposes cortical control on the “M” (micturition) Centre in the pons that in turn (via reticulospinal and corticospinal pathways) usually controls or stimulates preganglionic, parasympathetic neurones at S 2, 3, 4 cord segments

Question 40

Main location of BPH

Answer 40

Transition 5% of the prostate, around urethra, ant. to ejaculatory ducts BPH (**benign prostatic hypertrophy)

Question 41

Main location of the carcinoma of the prostate

Answer 41

3. Peripheral 70%, around transition and central (**Carcinoma)

Question 42

Vascular supply of the prostate and urethra in males?

Answer 42

From inferior vesical to prostate gland and proximal urethra.
Internal pudendal also to perineum

Venous drainage to vesical and prostatic plexuses, which drain to internal iliac vein.
There are communications with the valveless veins of the vertebral plexuses (Batson) facilitating tumour spread

Question 43

Vascular supply of the urethra in the females?

Answer 43

Utero-vaginal and internal pudendal arteres

Venous drainage to veins equivalent to the arterial supply – vaginal and int. pudendal veins

Question 44

Which clinical scenerios result in detrusor control returning to automatic, infant reflex?

Answer 44

Cord transection above S2

Loss of cortical control following CVA

Question 45

What clinical scenario results in a paralysed detrusor muscle and the bladder distending until there is overflow incontinence?

Answer 45

Destruction of sacral segments 2,3,4