Pelvis

Question 1

What does the pelvic girdle comprise of?

Answer 1

Two hip bones and sacrum
Pelvic outlet and inlet
Orientation of the pelvic girdle
Joints and ligaments of the pelvic girdle

Question 2

What are the walls and floor of the pelvic cavity?

Answer 2

One antero-inferior, two lateral, a posterior wall and a floor

Question 3

What is contained within the Antero-inferior wall of the pelvic cavity?

Answer 3

Bodies and rami of the pubic bones
Pubic symphysis
Supports urinary bladder

Question 4

What is contained within the lateral wall of the pelvic cavity?

Answer 4

Hip bones with the obturator foramen closed by the obturator membrane and obturator internus muscles covered with fascia over its upper inner surface
The internal pudendal vessels and pudendal nerve crosses the pelvic surface of the Obturator internus and are enclosed in a special canal—Alcock’s canal—formed by the obturator fascia

Question 5

What is contained within the posterior pelvic wall of the pelvic cavity?

Answer 5

musculotendinous
Piriformis muscles , anterior sacroiliac ligaments of the sacroiliac joint, sacrospinous and sacrotuberous ligaments, the sacral plexuses.
Medial to piriformis origin of sacral plexus.
Anterior surface of the piriformis – rectum, sacral plexus of nerves and branches of the internal iliac vessels

Question 6

What is the Pudendal Canal?

Answer 6

The pudendal canal is formed by the fascia of theobturator internusmuscle, orobturator fascia.
It encloses the following:
Internal pudendal artery.
Internal pudendal veins.
Pudendal nerve.
These vessels and nerve cross the pelvic surface of theobturator internus.

Question 7

What are the properties of a female pelvis?

Answer 7

Bones are lighter and thinner
False pelvis is shallow
Pelvic cavity is wide and shallow
Pelvic inlet round/oval
Pelvic outlet comparatively large
Subpubic angle large
Coccyx more flexible and straighter
Ischial tuberosities are more inverted

Question 8

What are the properties of the male pelvis?

Answer 8

Bones are heavier and thicker
False pelvis is deeper
Pelvic cavity is narrow and deep
Pelvic inlet is heart shaped and smaller
Pelvic outlet is comparatively small
Subpubic angle is more acute
Coccyx is less flexible and more curved
Ischial tuberosities are longer and face more medially

Question 9

What is the pelvic diaphragm?

Answer 9

Muscular sling or hammock in the funnel shaped – supports the abdominopelvic viscera, lies inside the true pelvis, separating the pelvis from the perineal viscera.
Resists increases in intra-abdominal pressure.

Question 10

What are the 2 names that the pelvic diaphragm are split into?

Answer 10

the coccygeus and levator ani

Question 11

What is the coccygeus?

Answer 11

Part of the pelvic diaphragm.
Lateral surface of sacrum and coccyx to the sacrospinous ligament

Question 12

What is the levator ani?

Answer 12

Part of the pelvic diaphragm.
Board muscular sheet, various thickness, muscle subdivided into named portions according to their attachments; iliococcygeus & pubococcygeus. urogenital hiatus

Question 13

What is the Pubococcygeus?

Answer 13

Pubococcygeus: arises from the anterior half of the tendinous arch of the obturator membrane and the posterior surface of the pubic bones. Puborectal sling; It forms a U-shaped muscular sling predominantely from the muscle fibers arising anteriorly that run posterior to the anorectal junction and the external anal sphincter. Most medial fibers go around the urethra and insert on the perineal body bounding the urogenital hiatus. In males it merges with the prostatic tissue and in females forms the Pubovaginalis.

Question 14

What is the Iliococcygeus?

Answer 14

Iliococcygeus: arises from the posterior part of the tendinous arch and pelvic surface of the ischial spine, overlaps the coccygeus muscle and is inserted on the side of coccyx and the anococcygeal body.

Question 15

What are the Peritoneal layers and the Pelvic Fascia?

Answer 15

Supravesical fossa
Rectouterine pouch & Rectouterine folds, As the peritoneum passes up and over the uterus in the middle of the pelvic cavity, a double peritoneal fold, the broad ligament of the uterus, extends between the uterus and the lateral pelvic wall on each side, forming a partition that separates the paravesical fossae and pararectal fossae of each side. The uterine tubes, ovaries, ligaments of the ovaries, and round ligaments of the uterus are enclosed within the broad ligaments
The pararectal fossae
Rectovesical pouch
Pelvic Fascia
Parietal pelvic fascia is a membranous layer of variable thickness that lines the inner (deep or pelvic) aspect of the muscles forming the walls and floor of the pelvis—the obturator internus, piriformis, coccygeus, levator ani, and part of the urethral sphincter muscles.
Visceral pelvic fascia includes the membranous fascia that directly ensheathes the pelvic organs, forming the adventitial layer of each organ.

Question 16

What is an important anatomical landmark for chronic endometriosis?

Answer 16

The vesico-uterine pouch

Question 17

As it is the furthest point of the abdominopelvic cavity in women, it is a site where infection and fluids typically collect. What is it called?

Answer 17

Rectouterine fold

Question 18

What are the names of the pelvic arteries?

Answer 18

Internal iliac artery- divides into an Anterior internal iliac artery and Posterior internal iliac arteries at the upper margin of greater sciatic notch.
Anterior internal iliac is largely visceral and supplies Rectum, Urinary bladder and the reproductive organs.
Posterior internal iliac branches are – Iliolumbar, lateral sacral and the superior gluteal artery

Question 19

Where are the ovarian arteries located?

Answer 19

Ovarian arteries - arises from the abdominal aorta and the renal artery. It then runs medially, dividing into an ovarian branch and a tubal branch, which supply the ovary and uterine tube.

Question 20

Where is median sacral artery?

Answer 20

is a small unpaired artery - vessel runs anterior to the bodies of the last one or two lumbar vertebrae, the sacrum, and the coccyx, its terminal branches participating in a series of anastomotic loops

Question 21

What is the Superior rectal artery?

Answer 21

Superior rectal artery is the direct continuation of the inferior mesenteric artery

Question 22

What are the pelvic veins?

Answer 22

Pelvic venous plexuses are formed by the inter-joining veins surrounding the pelvic viscera forming intercommunicating networks which are clinically very important.
The various plexuses within the lesser pelvis (rectal, vescical, prostatic, uterine, and vaginal) unite and are drained mainly by tributaries of the internal iliac veins, but some of them drain through the superior rectal vein into the inferior mesenteric vein of the hepatic portal system or through lateral sacral veins into the internal vertebral venous plexus .
Minor paths of venous drainage from the lesser pelvis include the parietal median sacral vein and, in females, the ovarian veins.

Question 23

What are the lymph nodes of the pelvic girdle?

Answer 23

Lumbar (caval/aortic)
Inferior mesenteric
Common iliac
Internal iliac
External iliac
Superficial inguinal
Deep inguinal
Sacral
Pararectal

Question 24

What are the main nerves that innervate the pelvis?

Answer 24

the sacral and coccygeal spinal nerves are the main nerves
there is also the obturator nerve, lumbosacral trunk

Question 25

Where is the obturator nerve?

Answer 25

Obturator nerve arises from the anterior rami of spinal nerves L2-L4 of the lumbar plexus in the abdomen (greater pelvis) and enters the lesser pelvis

Question 26

Where is the lumbosacral trunk?

Answer 26

Lumbosacral trunk passes inferiorly, on the anterior surface of the ala of the sacrum, and joins the sacral plexus

Question 27

Where is the sacral plexus?

Answer 27

SACRAL PLEXUS – main two branches are the sciatic and pudendal nerves, lie external to the parietal pelvic fascia. Most branches of the sacral plexus leave the pelvis through the greater sciatic foramen. superior gluteal nerve , inferior gluteal nerve

Question 28

Where is the coccygeal plexus?

Answer 28

COCCYGEAL PLEXUS - small network of nerve fibers, anterior rami of S4 and S5 and the coccygeal nerves that lies on the pelvic surface of coccygeus and supplies this muscle, part of the levator ani, and the sacrococcygeal joint. The anococcygeal nerves arising from this plexus pierce the coccygeus and anococcygeal ligament to supply a small area of skin between the tip of the coccyx and the anus.

Question 29

What are the four pelvic autonomic nerve routes?

Answer 29

Sacral sympathetic trunks: primarily provide sympathetic innervation to the lower limbs.
Periarterial plexuses: postsynaptic, sympathetic, vasomotor fibers to superior rectal, ovarian, and internal iliac arteries and their derivative branches.
Hypogastric plexuses: most important route by which sympathetic fibers are conveyed to the pelvic viscera.
Pelvic splanchnic nerves: pathway for parasympathetic innervation of pelvic viscera and descending and sigmoid colon

Question 30

What are visceral afferent fibres in the pelvis?

Answer 30

Visceral afferent fibers travel with autonomic nerve fibers, although the sensory impulses are conducted centrally, retrograde to the efferent impulses conveyed by the autonomic fibers.

Question 31

What is within the pelvis viscera?

Answer 31

Pelvic portions of the ureters, which carry urine from the kidneys.
Urinary bladder, which temporarily stores urine.
Urethra, which conducts urine from the bladder to the exterior. Pelvic part and perineal part.
Rectum and anal canal in the perineum.
The male internal genital organs - testes, epididymides, ductus deferentes, seminal glands, ejaculatory ducts, prostate, and bulbourethral glands.
The female internal genital organs include the ovaries, uterine tubes, uterus, and vagina

Question 32

What is the rectum?

Answer 32

The teniae of the sigmoid colon spread to form a continuous outer longitudinal layer of smooth muscle, and the fatty omental appendices are discontinued. Rectosigmoid junction lies anterior to the S3 vertebra.
Three internal infoldings (transverse rectal folds): two on the left and one on the right side creates flexures of the rectum.

The rectum is relatively smooth.
Three transverse folds (valves of houston) create flexures within the rectum

The distal end of the rectum is the ampulla which is expandable to receive/hold faecal mass

Question 33

What is the vasculature of the rectum?

Answer 33

Peritoneum covers the anterior and lateral surfaces of the superior third of the rectum, only the anterior surface of the middle third, and no surface of the inferior third because it is subperitoneal.
Superior rectal artery, the continuation of the abdominal inferior mesenteric artery, supplies the proximal part of the rectum.
The right and left middle rectal arteries, which often arise from the anterior divisions of the internal iliac arteries in the pelvis, supply the middle and inferior parts of the rectum
Inferior rectal arteries, arising from the internal pudendal arteries in the perineum, supply the anorectal junction and anal canal. Anastomoses between the superior, middle and inferior rectal arteries provides potential collateral circulation.

Question 34

What are the nerves and veins of the rectum?

Answer 34

Superior, middle, and inferior rectal veins
The rectal venous plexus consists of two parts: the internal rectal venous plexus just deep to the mucosa of the anorectal junction and the external rectal venous plexus external to the muscular wall of the rectum. The superior rectal vein drains into the portal venous system and the middle and inferior rectal veins drain into the systemic system, these anastomoses form portocaval anastomosis
Sympathetic: supply is from the lumbar spinal cord, conveyed via lumbar splanchnic nerves and the hypogastric/pelvic plexuses and through the peri-arterial plexus of the inferior mesenteric and superior rectal arteries.
Parasympathetic: supply is from the S2-S4 spinal cord level, passing via the pelvic splanchnic nerves and the left and right inferior hypogastric plexuses to the rectal (pelvic) plexus. Because the rectum is inferior (distal) to the pelvic pain line, all visceral afferent fibers follow the parasympathetic fibers retrogradely to the S2-S4 spinal sensory ganglia.

Question 35

What is the prostate?

Answer 35

3 cm long, 4 cm wide, and 2 cm in AP depth surrounds the prostatic urethra.
The glandular part makes up approximately two thirds of the prostate; the other third is fibromuscular.
Fibrous capsule of the prostate is dense and neurovascular, incorporating the prostatic plexuses of veins and nerves. All this is surrounded by the visceral layer of the pelvic fascia, forming a fibrous prostatic sheath that is thin anteriorly, continuous anterolaterally with the puboprostatic ligaments, and dense posteriorly where it blends with the rectovesical septum.
The prostate has;
A base closely related to the neck of the bladder.
An apex that is in contact with fascia on the superior aspect of the urethral sphincter and deep perineal muscles.
A muscular anterior surface, featuring mostly transversely oriented muscle fibers forming a vertical, trough-like hemisphincter (rhabdosphincter), which is part of the urethral sphincter. The anterior surface is separated from the pubic symphysis by retroperitoneal fat in the retropubic space.
A posterior surface that is related to the ampulla of the rectum.
Inferolateral surfaces that are related to the levator ani.

Question 36

What are the prostatic ducts?

Answer 36

Prostatic ducts (20-30) open chiefly into the prostatic sinuses that lie on either side of the seminal colliculus on the posterior wall of the prostatic urethra. Prostatic fluid, a thin, milky fluid, provides approximately 20% of the volume of semen (a mixture of secretions produced by the testes, seminal glands, prostate, and bulbourethral glands that provides the vehicle by which sperms are transported) and plays a role in activating the sperms

Question 37

What are the right and left lobes of the prostate?

Answer 37

Right and left lobes of the prostate, separated anteriorly by the isthmus and posteriorly by a central, shallow longitudinal furrow.

Question 38

What is the vasculature of the prostate?

Answer 38

inferior vesical arteries but also the internal pudendal and middle rectal arteries. The veins join to form a plexus around the sides and base of the prostate . This prostatic venous plexus, between the fibrous capsule of the prostate and the prostatic sheath, drains into the internal iliac veins. The prostatic venous plexus is continuous superiorly with the vesical venous plexus and communicates posteriorly with the internal vertebral venous plexus

Question 39

What are the Bulbourethral glands?

Answer 39

two pea-size bulbourethral glands (Cowper glands) lie posterolateral to the intermediate part of the urethra, largely embedded within the external urethral sphincter.
The bulbourethral glands are responsible for producing a pre-ejaculate fluid calledCowper’s fluid, which is secreted during sexual arousal, neutralizing the acidity of the urethra in preparation for the passage of sperm cells

Question 40

What are the seminal gland (vesicle)?

Answer 40

is an elongated structure (approximately 5 cm long but sometimes much shorter) that lies between the fundus of the bladder and the rectum. Obliquely placed superior to the prostate and do not store sperms. They secrete a thick alkaline fluid with fructose (an energy source for sperms) and a coagulating agent that mixes with the sperms as they pass into the ejaculatory ducts and urethra.
The duct of the seminal gland joins the ductus deferens to form the ejaculatory duct.
seminal glands derive arterial supply from the inferior vesical and middle rectal arteries.

Question 41

What is the Ductus deferens (vas deferens)?

Answer 41

Ductus deferens (vas deferens); is the continuation of the duct of the epididymis. The ductus deferens:
Has relatively thick muscular walls and a minute lumen, giving it a cord-like firmness.
Begins in the tail of the epididymis, at the inferior pole of the testis.
Ascends posterior to the testis, medial to the epididymis.
Is the primary component of the spermatic cord.
Penetrates the anterior abdominal wall via the inguinal canal.
Crosses over the external iliac vessels and enters the pelvis.
Passes along the lateral wall of the pelvis, where it lies external to the parietal peritoneum.
Ends by joining the duct of the seminal gland to form the ejaculatory duct.
The Vas deferens plus its surrounding tissue form the spermatic cord.

Question 42

What are the Ejaculatory ducts?

Answer 42

Ejaculatory ducts are slender tubes that arise by the union of the ducts of the seminal glands with the ductus deferentes . The ejaculatory ducts (2.5 cm long) arise near the neck of the bladder and run close together as they pass anteroinferiorly through the posterior part of the prostate. The ejaculatory ducts converge to open on the seminal colliculus by tiny slit-like apertures on the opening of the prostatic utricle. Although the ejaculatory ducts traverse the glandular prostate, prostatic secretions do not join the seminal

Question 43

What is the male urethra?

Answer 43

Male urethra is a muscular tube (18-22 cm long) that conveys urine from the internal urethral orifice of the urinary bladder to the external urethral orifice

Question 44

What are the ovaries?

Answer 44

Almond-shaped and –sized that produce oocytes (female gametes or germ cells) and reproductive hormones. suspended by a mesentery, the mesovarium (subdivision of the broad ligament).

Question 45

What are the uterine tubes?

Answer 45

10 cm long, lie in the mesosalpinx, forming the free anterosuperior edges of the broad ligaments. Extend laterally from the uterine horns and open into the peritoneal cavity near the ovaries. They conduct the oocyte that is discharged from the ovary to periovarian peritoneal cavity to the uterine cavity. They also provide a site of fertilization.
Four parts; Infundibulum, Ampulla, Isthmus, Uterine part

Question 46

What is the vasculature of the ovaries and uterine tubes?

Answer 46

The ovarian arteries arise from the abdominal aorta, The ascending branches of the uterine arteries (branches of the internal iliac arteries) course along the lateral aspects of the uterus to approach the medial aspects of the ovaries and tubes.
Veins draining the ovary form a vine-like pampiniform plexus of veins in the broad ligament near the ovary and uterine tube . The veins of the plexus usually merge to form a singular ovarian vein, which leaves the lesser pelvis with the ovarian artery. The right ovarian vein ascends to enter the inferior vena cava; the left ovarian vein drains into the left renal vein. The tubal veins drain into the ovarian veins and uterine (uterovaginal) venous plexus

Question 47

What is the uterus?

Answer 47

Uterus (womb) is a thick-walled, pear-shaped, hollow muscular organ
Adult uterus is usually anteverted (tipped anterosuperiorly relative to the axis of the vagina) and anteflexed (flexed or bent anteriorly relative to the cervix, creating the angle of flexion) so that its mass lies over the bladder
2 parts; Body and Cervix.
Body of the uterus, forming the superior two thirds of the organ, includes the fundus of the uterus, The body lies between the layers of the broad ligament and is freely movable. Isthmus of the uterus is a 1 cm long, constricted segment demarcating body from the cervix,
Cervix of the uterus is the cylindrical, relatively narrow inferior third of the uterus, 2.5 cm long in an adult non-pregnant woman. Two parts: a supravaginal part between isthmus and the vagina, and a vaginal part, which protrudes into the vagina

Question 48

What makes up the wall of the body of the uterus?

Answer 48

Perimetrium—the serosa or outer serous coat—consists of peritoneum supported by a thin layer of connective tissue.
Myometrium
Endometrium—the inner mucous coat

Question 49

What are the ligaments of the uterus?

Answer 49

Ligaments of Uterus;
Broad ligament of the uterus is a double layer of peritoneum (mesentery) that extends from the sides of the uterus to the lateral walls and floor of the pelvis
Ligament of the ovary attaches to the uterus posteroinferior to the uterotubal junction
Round ligament of the uterus attaches anteroinferiorly to uterotubal junction. These two ligaments are vestiges of the ovarian gubernaculum, related to the relocation of the gonads from its developmental position on the posterior abdominal wall.

Question 50

What is the vasculature of the uterus?

Answer 50

The blood supply of the uterus derives mainly from the uterine arteries, with collateral supply from the ovarian arteries. The uterine veins enter the broad ligaments with the arteries and form a uterine venous plexus on each side of the cervix. Veins from the uterine plexus drain into the internal iliac veins.

Question 51

What is the vagina?

Answer 51

a distensible, musculomembranous tube (7-9 cm long), extends from the middle cervix of the uterus to the vaginal orifice, the opening at the inferior end of the vagina
The vaginal fornix, the recess around the cervix, has anterior, posterior, and lateral parts
Four muscles compress the vagina and act as sphincters: pubovaginalis, external urethral sphincter, urethrovaginal sphincter, and bulbospongiosus

Question 52

What is the vasculature of the vagina?

Answer 52

Arteries supplying the superior part of the vagina derive from the uterine arteries. The arteries supplying the middle and inferior parts of the vagina derive from the vaginal and internal pudendal arteries.
The vaginal veins form vaginal venous plexuses along the sides of the vagina and within the vaginal mucosa. These veins are continuous with the uterine venous plexus as the uterovaginal venous plexus and drain into the internal iliac veins through the uterine vein. This plexus also communicates with the vesical and rectal venous plexuses

Question 53

What are the nerves of the uterus and vagina?

Answer 53

Inferior one quarter of the vagina has somatic innervation through deep perineal nerve, a branch of the pudendal nerve, which conveys sympathetic and visceral afferent fibers but no parasympathetic fibers . Only this somatically innervated part is sensitive to touch and temperature, the somatic and visceral afferent fibers have their cell bodies in the (S2-S4) spinal ganglia.
Most of the vagina (superior three quarters) has visceral innervation derived from the uterovaginal nerve plexus, which travels with the uterine artery at the junction of the base of the (peritoneal) broad ligament and the superior part of the (fascial) transverse cervical ligament. The uterovaginal nerve plexus is one of the pelvic plexuses that extends to the pelvic viscera from the inferior hypogastric plexus. Sympathetic, parasympathetic, and visceral afferent fibers pass through this plexus.
Sympathetic innervation originates in the inferior thoracic spinal cord segments and passes through lumbar splanchnic nerves and the intermesenteric-hypogastric-pelvic series of plexuses. Parasympathetic innervation originates in the S2-S4 spinal cord segments and passes through the pelvic splanchnic nerves to the inferior hypogastric-uterovaginal plexus.
The visceral afferent innervations of the superior (intraperitoneal; fundus and body) and inferior (subperitoneal; cervical) parts of the uterus and vagina differ in terms of course and destination. Visceral afferent fibers conducting pain impulses from the intraperitoneal uterine fundus and body (superior to the pelvic pain line) follow the sympathetic innervation retrograde to reach cell bodies in the inferior thoracic-superior lumbar spinal ganglia. Afferent fibers conducting pain impulses from the subperitoneal uterine cervix and vagina (inferior to the pelvic pain line) follow the parasympathetic fibers retrograde through the uterovaginal and inferior hypogastric plexuses and pelvic splanchnic nerves to reach cell bodies in the spinal sensory ganglia of S2-S4. The two different routes followed by visceral pain fibers is clinically significant in that it offers mothers a variety of types of anesthesia for childbirth. All visceral afferent fibers from the uterus and vagina not concerned with pain (those conveying unconscious sensations) also follow the latter route.