perineums

Question 1

arterial supply of perineum

Answer 1

 Via branches of the internal pudendal artery (a branch of the internal iliac)

 Branches include:

1. inferior rectal artery,
2. perineal artery,
3. artery of the bulb of the penis,
4. deepartery of the penis,
5. dorsal artery of the penis

 It lies alongside the internal pudendal vein and the pudendal nerve in the pudendal canal at the
lower border of obturator internus muscle of the lateral pelvic/perineal wall

Question 2

bulbospongiosus muscle

Answer 2

1. The bulbospongiosus muscle can contract vigorously during orgasm and this allows ejaculation
   to occur.
2. (These muscles also help to empty the urethra completely at the end of micturition in order to expel as much residual urine as possible)
3. Innervated by pudendal S2-4
4. surround corupus spongiosum (bulb)
5. the central one (bulb)

Question 3

muscle that surrounds corpora cavernosa

Answer 3

1. ischiocavernosus
2. covers the crura of penis (& clitoris)

Question 4

corpora cavernosa

Answer 4

1. Placed dorsally
2.  Attached to the pubic symphysis by the suspensory ligament
3.  The erectile tissue of the penis
4.  Invested proximally by the ischiocavernous muscles which restrict venous outflow from the
5. penis during erection
6. gets blood from deep arteries of penis & dorsal artery << both from INTERNAL PUDENDAL
7. filling of the tissue compreses outlet veins> erection

Question 5

glans

Answer 5

from corpus spongiosum

contains external urethral meatus

Question 6

buck’s fascia

Answer 6

deep fascia of penis

condenses around pubic symphysis >> suspensory ligament of penis

Question 7

tunica vaginalis

Answer 7

surrounds testes but defficient posteriorly

Question 8

spermatic cord

Answer 8

1. external spermatic fascia - from e_xternl oblique aponeurosis_
2. cremasteric fascia + muscle - from internal oblique
3. internal spermatic fascia - from transversalis fascia
4. 3 arteries: testicular, cremasteric, vas
5. 3 veins accompanying arteries
6. 3 nerves: ilioinguinal, genitofemoral, sympathetics T10,11
7. 3 otehrs: lympathics, vas, procesus vaginalis remnant (fibrous cord)

Question 9

testicular veins

Answer 9

form pampiniform plexus around the testicular artery
>> countercurrent heat exchange

drain into testicular vein

right testicualr veins goes to IVC at L2

left testicular vein goes to left renal vein

Question 10

bulbourethral glands

Answer 10

These glands are situated in the urogenital diaphragm
 They secrete a substance into the urethra which prior to the arrival of the ejaculate which gives
it a rather viscous consistency >mucous for lubrication of urethra

Question 11

venous drainage of prostate

Answer 11

Venous plexus between the true and false prostatic capsules which drains into the internal iliac
vein on either side
 Some venous blood drains posteriorly around the rectum to the valve less vertebral veins. This
explains why prostatic carcinoma metastasizes early to the bones of the lumbar spine and pelvis

Question 12

prostatic relations

Answer 12

Relations of the prostate:
 Anteriorly – extraperitoneal fat lying deep to the pubic symphysis
 Posteriorly – rectum separated by fascia
 Superiorly – continuous with the neck of the bladder
 Inferiorly – external urethral sphincter (within the deep perineal pouch)
 Laterally – levator ani muscle

Question 13

lymphatics male perineum

Answer 13

** superficial perineum (**lower anal cnaal, scrotal wall, penis) : SUPERFICIAL INGUINAL NODES

testes, epididymis, vas deferens >> PARA-AORTIC NODES AT L2

Question 14

lobes of prostate

Answer 14

median lobe (central zone): between ejaculatory ducts and urethra

lateral lobes (right&left zones) main pass, separated by prostatic urethra

posterior lobe (peripheral zone): can be palpated through rectum (often cancer)

Question 15

scrotal innnervation

Answer 15

anterior skin: L1,2

posterior skin: S3,4

Question 16

erection

Answer 16

spinal cord reflex with higher control

sensory n of glans via pudendal n. travels to lvl of S3 of spinal cord

efferents are PNS S2-4 (pelvic splanchnics)

Question 17

ejaculation

Answer 17

Ph1: contraction of smooth muscle in epididymis, vas by SNS L1,2; also c_loses internal urethral sphinctes_

Ph2: contraction of skeletal perineal muscles, propels semen down the urethra

Question 18

seminal vesicles

Answer 18

alkaline secretion

rich in fructose, protein, yellow pigments

contains prostaglandins

60% semen volume

HCO3- rich

empties in ejacualtory ducts which form where vas deferens &seminal vesicles meet

each is a coiled blid sac, goes upward from prostate, lies between bladder and rectum

Question 19

prostate secretions

Answer 19

adds 20% volume

rich in citric acid

has acid phosphatase

Question 20

ductus deferens

Answer 20

OVER external iliac a

BEHIND inf epigastirc a.

OVER ureter

is a muscular tube lined with pseudostratified columnar epithelium

has stereocilia which are NOT motile but absorb fluids

3 layers:

outer Longitudinals, inner circular, outer Longitudinal

Question 21

pudendal nerve

Answer 21

S2-4

via G sciatic f OUT, via L sciatic F IN

goes via pudendal canal with pudendal artery

has branches: inf. rectal, dorsal n. of penis, perineal

Question 22

pouches

Question 23

clitoris

Answer 23

Corresponds somewhat in structure to the penis
 Contains 2 corpa cavernosa (erectile tissue) attached to the pubic rami
 Its free extremity, the glans, is formed by the corpus spongiosum

Question 24

ischiorectal(anal) fossae

Answer 24

These are the 2 fat‐filled spaces that lie on either side of the midline of the perineum, between
the anal canal and side wall of the pelvis

Medially – levator ani and external anal sphincter

Laterally – ischial tuberosity below and fascia over obturator internus
above
 Anteriorly – perineal body and muscles of the urogenital diaphragm
 Posteriorly – sacrotuberous ligament overlapped by gluteus maximus

 The fossae do not communicate across the midline due to the presence of the anal canal and
sphincter.
 However, they do communicate posteriorly through the retrosphincteric space.
 This provides a horseshoe shaped path for the spread of infection from one fossa to the other

1.  The fossae contain (running along the lateral wall) the pudendal canal of Alcock which contains:
2.  Pudendal nerve – give branches to the anus, perineal skin and labial region
3.  Pudendal vessels – give branches to the anus, perineal skin and labial region

Question 25

nerve supply to pelvic viscera

Answer 25

**Pudendal nerve** – supplies muscles of the pelvic diaphragm, muscle and skin of the perineum and external genitalia  S**ympathetic innervation** – via the i_nferior hypogastric plexus_ which lies medial to the internal iliac vessels  **Parasympathetic innervations** – from S2‐4

Question 26

anterior trunk of internal iliac artery

Answer 26

1. **Obturator artery** ‐ leaves pelvis through obturator canal 2.  **Internal pudendal artery** – leaves pelvis through greater sciatic foramen 3.  **Inferior gluteal artery** 4.  Superior vesical arteries 5.  Inferior vesical artery 6.  Artery to ductus deferens 7.  Middle rectal artery 8.  Vaginal artery 9.  Uterine artery

Question 27

posterior trunk of internal iliac artery

Answer 27

1. Iliolumbar artery 2.  Lateral sacral arteries 3.  **Superior gluteal artery**

Question 28

cervical ligaments

Answer 28

The **fascia of levator ani thickens i**n places and each of these thickenings anchors on to the cervix of the uterus. These thickenings are known as the:  **Pubocervical** ligament  **Transverse cervical** ligament  **Sacrocervical** ligament  These ligaments are u**nder the influence of oestrogen** and after the menopause can become slack which can lead to uterine prolapsed

Question 29

fallopian tubes

Answer 29

**Infundibulu**m – funnel‐shaped distal end from where the fimbriae project, its opening into the peritoneal cavity is called the _abdominal ostium_  **Ampulla** – largest and longest part, begins at the medial end of the infundibulum, it is tortuous and is the _usual site of fertilization_ of the oocyte by the sperm  **Isthmus** – short narrow part  **Intra‐mural/uterin**e – short segment that passes through the myometrium of the uterus and **opens via an ostium** into the uterine cavity

Question 30

ovaries

Answer 30

It is attached to the broad ligament by a fold of peritoneum called the mesovarium  From its superior pole extends the **suspensory ligament of the ovary** which is just an extension of the broad ligament that **carries the ovarian vessels in its free border**  The **ovary develops in the posterior abdominal wall and descends to the pelvis via the gubernaculums,**a fibrous cord connected to its lower pole.  The gubernaculum passes through the broad ligament of the uterus  The ovaries are supplied by the ovarian arteries which descend directly from the abdominal aorta near the origin of development of the ovaries at the level of L2  Veins draining the ovaries form a plexus around the arteries and this plexus is called the pampiniform plexus and from it arise the 2 ovarian veins. The right ovarian veins drains into the IVC whereas the left ovarian vein drains into the left renal vein