Anatomy - Pelvis Flashcards
1
Q
The sella turcica is located in and directly behind? What are its boundaries?
A
The sella turcica is located in the sphenoid bone behind the chiasmatic groove and the tuberculum sellae (anterior border). It belongs to the middle cranial fossa.
Posterior boundary is formed by the dorsum sellae, the supero-lateral angles of which are raised to form the posterior clinoid process. Anteriorly bound by tuberculum sellae
2
Q
Anatomic boundaries of pelvis cavity
A
● Inferoposterior part of the abdominopelvic cavity
● Continuous superiorly with the abdominal cavity at the pelvic inlet
● Limited inferiorly by the musculofascial pelvic diaphragm that forms a bowl-like pelvic floor.
● Bounded posteriorly by coccyx and inferior sacrum
● Roof formed by superior part of the sacrum
3
Q
Peritoneal coverings of the pelvic cavity
A
● Reflects onto pelvic viscera
● Only fallopian tubes and ovaries covered by peritoneum.
● Pockets
○ pararectal fossa
○ Rectovesicle pouch in males
○ rectouterine and vesicouterine pouch in females.
● Rectum is subperitoneal inferiorly and retroperitoneal superiorly
● Sigmoid colon becomes intraperitoneal.
4
Q
Antero-inferior wall of pelvic cavity
A
○ bodies and rami of pubic bones and pubic symphysis.
○ Bears the weight of the urinary bladder
5
Q
Lateral walls of pelvic cavity
A
○ Formed by right and left hip bones
○ Obturator foramen closed by obturator membrane
○ Padded by obturator internus.
6
Q
Posterior wall (posterolateral wall and roof) of pelvis
A
○ Bony wall and roof in the midline, formed by sacrum and coccyx.
○ Musculoligamentous posterolateral wall:
■ formed by piriformis muscle
■ and sacro-iliac, sacrospinous and sacrotuberous ligaments.
7
Q
Floor of pelvic cavity
A
○ Formed by pelvic diaphragm
○ coccygeus and levator ani muscles. Separates pelvic floor from perineum
○ Levator ani consists of puborectalis, pubococcygeus, iliococcygeus.
8
Q
Transcoelomic spread describes the spread of a malignancy into ……
that occurs via ……
A
Transcoelomic spread describes the spread of a malignancy into
Body cavities
That occurs via penetrating the surface of the peritoneal, pleural, pericardial, or subarachnoid spaces.
9
Q
Histology of the rectum:
What are the implications for direct tumour spread?
A
mucosa, submucosa, muscular propria.
There is no serosal layer - therefore spread past muscularis is into peri-rectal space/fat.
10
Q
There are four articulations within the pelvis:
A
Sacroiliac joints (x2)
Sacrococcygeal symphysis
Pubic symphysi
11
Q
The osteology of the pelvic girdle allows the pelvic region to be divided into two:
A
Greater pelvis (false pelvis) – located superiorly, it provides support of the lower abdominal viscera Lesser pelvis (true pelvis) – located inferiorly. Within the resides the pelvic cavity and pelvic viscera.
12
Q
The junction between the greater and lesser pelvis is known as the ……. …….. The outer bony edges of the ….. …. are called the….. …….
A
The junction between the greater and lesser pelvis is known as the pelvic inlet. The outer bony edges of the pelvic inlet are called the pelvic brim.
13
Q
The borders of the pelvic inlet:
A
Posterior – sacral promontory (the superior portion of the sacrum) and sacral wings (ala).
Lateral – arcuate line on the inner surface of the ilium, and the pectineal line on the superior pubic ramus.
Anterior – pubic symphysis
14
Q
Pelvic outlet borders are:
A
Posterior: The tip of the coccyx
Lateral: The ischial tuberosities and the inferior margin of the sacrotuberous ligament
Anterior: The pubic arch (the inferior border of the ischiopubic rami).
The angle beneath the pubic arch is known as the sub-pubic angle and is of a greater size in women.
15
Q
The hip bone is comprised of the three parts:
Prior to puberty, the ……. cartilage separates these parts – and fusion only begins at the age of 15-17.
A
The hip bone is comprised of the three parts; the ilium, pubis and ischium. Prior to puberty, the triradiate cartilage separates these parts – and fusion only begins at the age of 15-17.
16
Q
The inferior ischial ramus combines with the ……. ……. ……. forming the ischiopubic ramus, which encloses part of the …… foramen. The posterorinferior aspect of the ischium forms the ischial tuberosities and when sitting, it is these tuberosities on which our body weight falls.
A
The inferior ischial ramus combines with the inferior pubic ramus forming the ischiopubic ramus, which encloses part of the obturator foramen. The posterorinferior aspect of the ischium forms the ischial tuberosities and when sitting, it is these tuberosities on which our body weight falls.
17
Q
Two important ligaments attach to the ischium:
A
Sacrospinous ligament – runs from the ischial spine to the sacrum, thus creating the greater sciatic foramen through which lower limb neurovasculature (including the sciatic nerve) transcends.
Sacrotuberous ligament – runs from the sacrum to the ischial tuberosity, forming the lesser sciatic foramen
18
Q
From where in the hip bone does the gluteus medius originate?
A
The external surface of the ileal wing is also known as the ‘gluteal surface’ - as it is the site of origin for the gluteal muscles
19
Q
Course of the ureter Abdo part.
A
Origin ureteropelvic junction, the ureters descend “retroperitonealy” along the anterior surface of the psoas major.
20
Q
Course of the ureter pelvic part.
A
At S1 and SI joints cross pelvic brim, and over the external iliac aa. directly below the bifurcation of common iliac at L5/S1.
Travel down the lateral pelvic walls. At the level of the ischial spines, they turn anteromedially, moving in a transverse plane towards the bladder.
Point A brachytherapy
ureters pierce lateral aspect of bladder in an oblique manner. This creates a one way valve, where high intramural pressure collapses the ureters – preventing the back-flow of urine.
21
Q
In Females as the ureter cross the pelvic brim they are in close proximity to
Approximately 2cm superior to the ischial spine, the ureters run underneath the uterine artery.
A
As they cross the pelvic brim, the ureters are in close proximity to the ovaries.
Approximately 2cm superior to the ischial spine, the ureters run underneath the uterine artery. During a hysterectomy, the uterus and uterine artery are removed, the ureter is in danger of being accidentally damaged. ‘water under the bridge’.
22
Q
In men, instead of the uterine arteries, the ……. cross the ureters anteriorly.
A
In men, instead of the uterine arteries, the vas deferens cross the ureters anteriorly.
23
Q
Rectum anatomical relations
A
● Anteriorly: ○ peritoneum in upper and middle third ○ males: rectovesical pouch, bladder, prostate, seminal vesicles, vas deferens ○ females: rectouterine pouch, uterus and vagina ● Posteriorly: ○ sacrum, coccyx and pelvic diaphragm ● Laterally: ○ peritoneum in upper third ○ ileum ○ Ischiorectal fossa ○ Rectal vessels ● Superiorly ○ Rectosigmoid junction and sigmoid colon ● Inferiorly ○ Anal canal
24
Q
Arterial and venous supply to the rectum
A
● Arterial supply
○ superior rectal artery (continuation of inferior mesenteric artery) supplies proximal part of the rectum
○ Middle rectal arteries (from internal iliac) supply middle and inferior parts of the rectum
○ Inferior rectal arteries (from internal pudendal arteries, also from internal iliac) supply anorectal junction and anal canal.
Venous drainage
○ Superior rectal veins drain into the portal system
○ Middle and inferior rectal veins drain into systemic system
○ anastomoses between portal and systemic system exists in the anal canal.
○ Rectal venous plexus exists at the anorectal junction
25
Innervation of the rectum
● Sympathetic supply from the lumbar spinal cord, via lumbar splanchnic nerves and hypogastric plexus.
● Parasympathetic supply from S2-4 via pelvic splanchnic nerves, inferior hypogastric and rectal plexuses.
26
Lymphatic drainage of the rectum
● Superior part of the rectum drain into pararectal and sacral lymph nodes, then to inferior mesenteric lymph nodes to paraaortic nodes.
● Inferior rectum drains into internal iliac nodes → common iliac
● very distal part of rectum drains to superficial inguinal, then to external iliac nodes.
27
Macroscopic appearance of the prostate
● Conical shaped organ, base at the neck of the bladder.
● Apex directed inferiorly
● Approx 3cm long, 4cm wide, 2 cm depth.
● Covered by a fibrous capsule which is dense and neurovascular
○ incorporates the prostatic plexus of veins and nerves
○ surrounded by visceral layer of pelvic fascia to form the prostatic sheath.
28
To where do the prostatic ducts open?
Prostatic ducts open either side of seminal colliculus
29
Anatomical relations of the prostate
```
○ Anteriorly: pubic symphysis
○ Posteriorly: rectum
○ Superiorly: bladder and seminal vesicles
○ Inferio-laterally: levator ani
○ Internally: prostatic urethra.
```
30
Lobes of the prostate
Two main histologic components
Two main histologic components: of 70% glandular tissue and 30% fibromuscular stroma
● Anterior lobe is fibromuscular, contains little glandular tissue
● Right and left lateral lobes
● Median lobe surrounding the ejaculatory ducts and lateral to urethra
● posterior lobe
31
Parasympathetic innervation of male genital organs is via:
Sympathetic innervation of male genital organs is via:
In both sexes originates in the sacral segments S2–S4 (Sacral splanchnic nerves) and reaches the target organs via the pelvic nerves. Parasympathetic ganglia causes dilation of penile or clitoral arteries, and a corresponding relaxation of the smooth muscles of the venous (cavernous) sinusoids, which leads to expansion of the sinusoidal spaces.
Sympathetic activity -> vasoconstriction -> loss of erection. The lumbar (lumbar Splanchnic nerves) sympathetic pathway to the sexual organs originates in the thoraco-lumbar segments (T11-L2) and reaches the target organs via the corresponding sympathetic chain ganglia and the inferior mesenteric and pelvic ganglia, as in the case of the autonomic bladder control.
32
Arterial and venous supply to prostate
● Arterial supply
○ prostatic arteries, branches of internal iliac artery
● Venous drainage
○ Form the prostatic venous plexus surrounding the prostate, between the fibrous capsule and prostatic sheath.
■ drains into internal iliac veins
■ communicates superiorly with vesical venous plexus.
33
Lymphatic drainage of the prostate
● Superiorly to internal iliac nodes
| ● Inferiorly to presacral nodes.
34
Zones of the prostate
● Central zone surrounding ejaculatory ducts and lateral to urethra
● Anterior zone of fibromuscular tissue
● Peripheral zone, posterolateral aspect of prostate gland (majority of prostate ca)
● Transitional zone surrounding the proximal urethra (most common site of BPH)
○ Contains transitional cell epithelium similar to the bladder
35
Most common zone to find prostate Ca
| Most common zone to find BPH
● Peripheral zone, posterolateral aspect of prostate gland (majority of prostate ca)
● Transitional zone surrounding the proximal urethra (most common site of BPH)
36
Macroscopic appearance of uterus
Thick walled, inverted pear shaped
Divided into the body/fundus and inferiorly the cervix ~2.5cm in length which is narrower and more cylindrical - connected by a narrowing called the ithmus of cervix
Usually the uterus is antiverted and antiflexed
37
Usually the uterus is .......verted and ......flexed
Usually the uterus is antiverted and antiflexed
38
```
Body of the uterus
● Gradually narrows from the fundus to the ......
● Anterior surface lies on ......
● Posterior surface is ........
● Laterally con.....
● Surfaces covered sup and inf in
```
● Gradually narrows from the fundus to the isthmus
● Anterior surface lies on bladder
● Posterior surface is horizontal
● Laterally convex
● Covered in peritoneum
○ Reflects anteriorly onto the bladder to form the vesicouterine pouch
○ Reflects posteriorly onto the anterior rectum to form the rectouterine pouch (of Douglas)
39
The Tubes and ligaments attaching to the uterus and their sites of attachment:
Two uterine tubes enter the superolateral aspect
Anteroinferior to it the round ligament attaches
Posteroinferiorly the ovarian ligament attaches
40
The contents of the broad ligament include the following:
1) Reproductive:
Uterine tubes (or Fallopian tube)
ovary (some sources consider the ovary to be on the broad ligament, but not in it.)
2) Vessels:
ovarian artery (in the suspensory ligament)
uterine artery (in reality, travels in the cardinal ligament)
3) ligaments:
ovarian ligament
round ligament of uterus
suspensory ligament of the ovary
41
The cervix is divided into two parts:
Give the anatomical relations of each:
```
1) Supravaginal part
■ Anteriorly
● bladder, parametrium
■ Laterally
● parametrium, uterine arteries
■ Posteriorly
● peritoneum, rectouterine pouch, rectum
```
2) Vaginal part
■ forms the vaginal fornices
■ has an external os
42
Primary cell types of the testes:
Within the seminiferous tubules
1) germ cells develop into spermatogonia, spermatocytes, spermatids and spermatozoon through the process of spermatogenesis.
2) Sertoli cells – the true epithelium of the seminiferous epithelium, critical for the support of germ cell development into spermatozoa. Sertoli cells secrete inhibin.
3) Peritubular myoid cells surround the seminiferous tubules.
43
Layers of the tests
SDECITTa - Some Dumb English Elite Called Italy Totally Trashy
1) Skin
2) Dartos
- Spermatic Cord -
3) External spermatic fascia
4) Cremaster
5) Internal Spermatic fascia
6) Tunica vaginalis
7) Tunica Albicans
44
Coverings of the testes within the internal sprematic fascia:
● Tunica vaginalis- closed peritoneal sac.
○ parietal and visceral layers separated by a small amount of fluid.
● Tunica albuginea- tough fibrous layer.
○ On its inner surface forms septa that divide the testes internally into lobules.
45
Blood supply of the scrotum
| And lymphatic drainage
Arterial:
Internal iliac -> Internal pudendal
Venous:
Anterior scrotal vv ->External pudendal
Posterior scrotal vv -> Internal pudendal
Lymphatics:
Superficial inguinal -> Deep inguinal ->external iliac.
46
What is the parametria? Why is it useful?
● Tissue encompassed by broad ligament
| ● Borders (for CTV delineation):
47
Borders of the parametrium:
○ Superiorly
■ Top of broad ligament
○ Inferiorly
■ Pelvic floor
○ Anteriorly
■ Post wall of bladder, or
■ Post border of external iliac vessels (in patients with very small bladders)
○ Posteriorly
■ Uterosacral ligaments and mesorectal fascia
○ Laterally
■ Pelvic side wall excluding bone and muscle
48
To where do the testicular arteries drain?
Venous drainage of the scrotum?
Left T.a -> Renal vein ->IVC
Right T.a -> IVC
Venous drainage of scrotum = Internal pudendal -> internal iliac ->IVC
49
Lymphatic drainage of the balls?
follows left and right testicular artery and vein to the para-aortic nodes.
50
Internal structure of the balls?
Wrapped in tunica albuginea, which forms internal septae:
● Divided into lobules formed by seminiferous tubules where sperm are produced.
● Seminiferous tubules are joined by straight tubules to the rete testis.
● Efferent ductules transport sperm from rete testis to the epididymis.
51
Nerve supply to the balls?
Testicular plexus on the testicular artery, carries autonomic nerves from T10-T11
52
Structure of the epididymis:
● Formed by tightly compacted minute convolutions of the duct of the epididymis.
● The duct becomes progressively smaller from head to tail
● At the tail, duct continues as the ductus deferens.
53
Describe the seminal vesicles:
| Give Relations
● Elongated structure between fundus of the bladder and rectum
● Obliquely placed superior to the prostate.
● Superiorly covered by peritoneum and rectovesical pouch.
● Inferoposteriorly related to rectum
● Ducts join vas deferens to form the ejaculatory duct
54
What are splanchnic nerves?
(Give the key exception)
Why are they important?
Paired visceral nerves, carrying fibers of the autonomic nervous system (visceral efferent fibers) as well as sensory - visceral afferent fibres. All carry sympathetic fibers except for the pelvic splanchnic nerves, which carry parasympathetic fibres.
Important to end an exam question on innervation.
55
When does the vagus nerve give up supplying parasympathetic innervation?
What takes over?
At the distal 1/3 of Tv colon.
| Pelvic splanchnic nerves then take over parasympathetic supply.
56
Pelvic splanchnic nerves arise from?
Anterior rami of the sacral spinal nerves S2, S3,S4 and enter the sacral plexus.
57
Pelvic splanchnic nerves supply?
The nerves regulate the emptying of the urinary bladder, control opening and closing of the internal urethral sphincter, influence motility in the rectum as well as sexual functions like erection.
BUT some pelvic organs get other innervation (e.g T10-T11 testicular plexus, Seminal vesicles innervated by lumbar splanchnic nerves)
58
Sympathetic nerve supply to the pelvis:
Sacral splanchnic nerves, sympathetic pravertabral ganglia.
59
Arterial, venous and lymphatic drainage of seminal vesicles:
● Arterial supply via the inferior vesical and middle rectal arteries
● Venous drainage via veins of same name.
Lymphatic drainage
● External and internal iliac nodes
● Presacral nodes
60
What does the spermatic cord contain?
Contents of spermatic cord:
● 3 arteries: testicular, cremasteric, ductus deferens
● 2 nerves: genital nerve (to cremaster), testicular nerve
● vas deferens
● pampiniform plexus of veins (ovaries have the same plexus in the broad ligament)
● lymphatic vessels
● tunica vaginalis
61
What are the coverings of the spermatic cord?
Remember the lining of the balls minus skin+dartos, and tunicas (vag and alb):
External spermatic fascia, cremaster, internal spermatic fascia.
62
Innervation of the cremaster?
The genital nerve - i.e. one of the contents of the spermatic cord.
63
The penis is divided into three parts:
Root
Body
Glans
64
The root of the penis contains:
How arranged?
■ crura - of corpus cavernosa
■ bulb
■ ischiocavernosus muscle
■ bulbospongiosus
Ttriradiate in form, consisting of the diverging crura, one on either side, and the median urethral bulb.
Each crus is covered by the Ischiocavernosus muscle, while the bulb is surrounded by the Bulbospongiosus.
65
The glans penis is formed by?
A continuation of corpus spongiosum
66
Describe the paired cylindrical bodies of the erectile tissue:
Corpora cavernosa
■ covered in tunica albuginea
■ posteriorly separates to form the crura of the penis
● attached to infernal surface of ischial ramus
67
Describe the un-paired cylindrical body of the erectile tissue:
Corpus spongiosum
■ contains spongy urethra
○ Covered by Buck’s fascia
68
The main ligament of the penis
Suspensory ligament
| ○ condensation of deep fascia arising from pubic symphysis
69
What parts of the male genitalia are supplied my the internal pudendal artery?
The scrote and the dick (except the skin, which is ext pudendal from the femoral)
70
Arterial supply of the penis:
Skin: Ext pudendal
The rest are branches of internal pudendal (a branch of the internal iliac):
1) Dorsal arteries (paired)
2) Deep arteries (Spongiosum arteries - paired)
3) Bulb arteries - urethral build and bulbourethral gland
71
Venous drainage of the penis:
Skin: ext pudendal.
The glans penis and corpora cavernous penis drain to DEEP DORSAL which drains to:
1) Prostatic and vesicle plexi
2) also communicates below the pubic symphysis with the internal pudendal vein.
The spongiosum cavernosal veins drain to the internal pudendal.
72
Nerve supply to the penis:
1) Somatic motor, sensory and sympathetic via the PUDENDAL NERVE -> Sacral plexus
2) Erection = Parasympathetic nerves to erectile tissue
CAVERNOUS NERVES
73
What is the pudendal nerve where does it originate?
The pudendal nerve is the main nerve of the perineum. It carries sensation from the external genitalia of both sexes and the skin around the anus and perineum, as well the motor supply to various pelvic muscles, including the male or female external urethral sphincter and the external anal sphincter.
Originates in sacral plexus plexus is L4 to S4 (Pudendal is S2-S4).
74
Path of cavernous nerves:
inferior hypogastric plexus where they receive the pre-ganglionic pelvic splanchnic nerves (S2-S4, same level as pudendal nerve origin)
75
Lymphatic supply of the penis:
Superficial and deep inguinal nodes → external iliac nodes
76
Deep inguinal nodes drain to?
Superficial and deep inguinal nodes → external iliac nodes
77
Where does the vas deferens end?
| What does it become?
Ends where it joins the duct of the seminal vesicle.
These tubes become the ejaculatory duct.
78
Course of the vas deferent:
● Begins in the tail of the epididymis at the inferior pole of the testis
● Ascends in the spermatic cord posterior to the testis, medial to the epididymis
● Penetrating the anterior abdominal wall at the deep inguinal ring.
● Crosses over the external iliac vessels and enters the pelvis
● Passes along the lateral wall of the pelvis in direct contact with the peritoneum
● It crosses superior to the ureters, reaching the fundus of the bladder.
● Posterior to the bladder, it descends medial to the ureter and seminal vesicle, enlarging to form the ampulla before terminating at the ejaculatory duct.
79
Origin, "insertion" and course of the ejaculatory duct:
Joint by the confluence of the vas deferent and seminal vesicles, arising near the bladder neck these paired ducts run closely together as they descend anteriorly inferiorly through the prostate (within the central zone) before going the prostatic urethra via the slit like seminal colliculi.
80
Describe the male urethra:
● muscular tube 18-22 cm long
| ● extends from internal urethral orifice at the bladder to external urethral orifice at tip of glans penis.
81
4 parts of the male urethra:
```
1) preprostatic part
■ extends through neck of bladder
■ surrounded by internal urethral sphincter
2) prostatic part
■ descends through anterior prostate
■ features seminal colliculus
```
3) membranous part
■ surrounded by external urethral sphincter
■ penetrates perineal membrane
4) spongy part
■ courses through corpus spongiosum
■ opens at navicular fossa at glans penis.
82
Most parts of the the male penis/urethra have 2 venous drainage pathways that lead to either?
Which on drains the urethra?
1) Prostatic venous plexus (or vesicle plexus)
2) Internal pudendal which drains to internal iliac.
(In females internal pudendal route for both arterial and venous supply)
○ proximal parts drain into the prostatic venous plexus
○ distal parts drain to Cavernous veins → internal pudendal → internal iliac vein
83
Innervation of the male urethra:
From prostatic plexus
● sympathetic L1-3
● parasympathetic S2-4
84
Describe the female urethra:
Muscular tube - 4cm long.
85
Course and relations of the female urethra:
● 4cm long
● passes from internal urethral orifice to external urethral orifice, at the vestibule of the vagina, anterior to the vaginal orifice.
● Lies anterior to the vagina, and runs with it through the pelvic diaphragm and perineal membrane.
86
Macroscopic description of the vagina (but not the relations, thats another exciting card):
Macroscopic
● Distensible musculomembranous tube
● Extends from the level of the middle cervix to the vaginal orifice
● The arched recesses between the cervix and vagina are the fornices.
87
Relations of the vagina:
Relations:
○ anterior: bladder and urethra
○ posterior: covered with peritoneum superiorly, rectum and rectouterine pouch, inferiorly related with anal canal
○ laterally: levator ani and pelvic fascia. Ureters pass close to lateral fornices.
88
Microscopic appearance of the vagina:
● Mucous membrane
○ non keratinized, stratified squamous
● Muscular layer
● Areolar tissue containing plexus of blood vessels
89
Arterial supply to vagina:
superior 1/3rd = Uterine artery
| Inferior 1/3rd = Internal pudendal and vaginal arteries
90
Internal pudendal and vaginal arteries are both branches of?
Whereas the uterine artery is a branch of?
Internal pudendal and vaginal arteries are both branches of the internal iliac artery.
The uterine artery is a branch of the internal iliac as well (haha)
91
Venous drainage of the vagina:
○ Vaginal venous plexuses along the sides of the vagina and within the mucosa
○ Continuous with uterine venous plexus and drain into internal iliac veins via the uterine vein
○ Also communicates with vesical and rectal venous plexus
92
Lymphatic drainage of the vagina
Lymphatic drainage is divided into three sections:
Superior – drains to external iliac nodes
Middle – drains to internal iliac nodes
Inferior – drains to superficial inguinal lymph nodes.
93
Lymphatic drainage of the cervix:
3 parts (Posterior, poster-lateral, lateral):
1) Posterior drains to sacral nodes
2) Posterior-Lateral drains to internal iliac
3) Lateral cervix drains to external iliac (same as top 1/3rd of vag)
94
Innervation of the vagina:
Predominantly from the autonomic nervous system. Parasympathetic and sympathetic nerves arise from the uterovaginal nerve plexus (in turn a subsidiary of the inferior hypogastric plexus).
Only the inferior 1/5 of the vagina receives somatic innervation. This is via a branch of the pudendal nerve,
95
The parts of the vulva:
```
○ mons pubis
○ labia majora
○ labia minora
○ clitoris
○ bulbs of the vestibule
○ greater (Bartholin’s) and lesser vestibular glands
```
96
Blood supply of the vulva:
● Arterial
○ Internal pudendal artery (branch of internal iliac)
○ External pudendal artery (branch of femoral)
● Venous
○ Internal pudendal vein (internal iliac vein)
○ External pudendal vein (great saphenous vein)
97
Lymphatic drainage of the vulva:
Complex,
| But superficial inguinal nodes do a large part.
98
What is the mesovarium?
Mesovarium is the portion of the broad ligament of the uterus that suspends the ovaries.
The ovary is not covered by the mesovarium; rather, it is covered by germinal epithelium.
99
Macroscopic structure of the ovary:
Almond shaped and sized.
1) Suspended by mesovarium
2) Surrounded in capsule, surface is germinal epithelium
- increasingly scarred/less smith with age after puberty
Internal structure:
Divided into cortex containing ovarian follicles and deeper medulla containing ovarian vessels.
100
Relations of the ovaries:
```
● Superior
○ distal fallopian tubes and its fimbriae
○ left: sigmoid colon
○ right: caecum and appendix
● Lateral
○ pelvic side wall
● medial
○ rectum, uterus, uterine vessels
● Anterior
○ broad ligament
● posterior
○ internal iliac artery and vein, ureters
● Inferior
○ pelvic floor
```
101
At what vertebral level do the ovarian arteries originate
Ovarian arteries generally arise from the anterolateral (or lateral) aspect of the abdominal aorta caudal to the origin of the renal arteries at the level of L2 vertebra.
May also arise from the renal, suprarenal, inferior phrenic, superior mesenteric, lumbar, common iliac, or internal iliac arteries.
102
Course of the ovarian artery:
○ Ovarian arteries from the abdominal aorta
■ Descend along the posterior abdominal wall
■ Cross over the external iliac arteries at the pelvic brim and enter the suspensory ligaments of the ovary
■ Approaches the lateral aspect of the ovaries and fallopian tubes
■ Anastomoses with the ascending branches of the uterine arteries which supply the medial aspect
103
2 arterial supplies to the ovaries:
Ovarian artery supplies lateral side and forms anastomoses with the ascending branches of the uterine arteries which supply the medial aspect
104
Venous drainage of the ovaries:
○ pampiniform plexus of veins in the broad ligament
○ Veins merge to form a single ovarian vein which leaves the pelvis with the ovarian artery
○ Right ovarian vein enters the IVC
○ Left ovarian vein joins the left renal vein which drains into the IVC
105
Lymphatic drainage of the ovaries:
Follows ovarian vessels to para-aortic nodes
106
Course of the anal canal:
● Extends from superior aspect of the pelvic diaphragm to the anus
○ The pelvic diaphragm (pelvic floor) is formed by the levator ani muscle (puborectalis, pubococcygeus, iliococcygeus) and coccygeus muscles.
● The canal is 2.5-3.5 cm long, and descends posterioinferiorly in between the perineal body and anococcygeal ligament
107
The pelvic diaphragm (pelvic floor) is formed by:
The pelvic diaphragm (pelvic floor) is formed by the levator ani muscle (puborectalis, pubococcygeus, iliococcygeus) and coccygeus muscles.
108
The dentate line (aka?) divides the anal canal into?
Why is this anatomically significant?
The dentate line (pectinate line) divides the anal canal into upper two thirds and lower one third.
The superior and inferior parts differ in blood supply, nerve supply and lymphatic drainage.
109
The superior half of the anal canal contains longitudinal ..... ...... which contain?
The superior half of the canal contains longitudinal anal columns which contain terminal branches of the superior rectal arteries and veins
110
The superior/apical part of the anal columns is the location of
The superior/apical part of the anal columns is the location of ano-rectal junction
111
Define anal verge:
the lower edge of the anal canal that marks the junction of the anal canal and the external hair-bearing skin
112
Inferiorly the anal columns are joined by?
Inferiorly the anal columns are joined by anal valves, forming anal sinuses that secrete mucin during defecation.
113
Superior to the dentate line the epithelial lining is?
Inferior to it?
Until?
Superior to the dentate line the epithelial lining is simple columnar.
And inferior to it = stratified squamous, nonkeratinized until the anal verge becomes continuous with the perianal skin.
114
How much of the anal canal is encompassed by the internal sphincter? What is it made out of?
Proximal 2/3, formed by thickening of circular muscularis bowel layer.
115
Contraction of the internal anal sphincter is mediated by?
Sympathetic fibres from the superior rectal plexus and hypogastric plexus
116
Relaxation of the internal anal sphincter is mediated by what nerve?
Relaxation is by parasympathetic innervation from the pelvic splanchnic nerves (of course! parasympathetic innervation of the novel after 2/3rds of the large bowel)
117
Contraction of the external anal sphincter is mediated by what nerve?
Supplied mainly by S4 via the inferior rectal nerve (branch of pudendal)
118
Relaxation of the external anal sphincter is mediated by what nerve?
Supplied mainly by S4 via the inferior rectal nerve (branch of pudendal)
119
The external anal sphincter is derived from
Puborectalis - which it merges with superiorly
120
Arterial supply to anal canal, give course:
Above dentate line:
Terminal branches of superior rectal artery, which is a branch of inferior mesenteric.
Below dentate line:
Inferior rectal aa.
121
Venous drainage of anal canal:
Canal drained by rectal venus plexus, but drainage of this related to dentate line (besides the plexus its like the art supply):
1) Above: Portal system via sup rectal vv->inf mesenteric vv
2) Below: Inferior rectal vein ->internal pudendal ->internal iliac
1) and (2) are anastomosed via the middle rectal vv ->internal iliac.
122
What innervates the anal canal above the dentate line?
What is it sensitive to?
● The nerve supply to the anal canal superior to the dentate line is via the inferior hypogastric plexus involving sympathetic, parasympathetic and visceral afferent fibres from S2-S4.
○ This part is sensitive to stretch
● Inferior to the dentate line, the anal canal receives somatic innervation from the inferior anal nerves, branches of the pudendal nerve.
○ This part is sensitive to pain, touch and temperature
123
Lymphatic drainage of the anal canal:
1) Above the pectinate line:
bilateral drainage from ano rectal nodes to
- internal iliac nodes
- Some sources say IMV nodes also
2) Below:
bilateral drainage to Superficial inguinal nodes.
124
The cervix is composed of two regions:
1) Ectocervix: the part projecting into the vagina
2) Endocervical canal (ends cervix): The canal extending from the external os to the internal os. The endocervical canal ends, and the uterine cavity begins, at a narrowing called the internal os.
125
Describe the normal (pre menopausal) histology of the cervix:
1) Ectocervix is lined by stratified squamous non-keratinized epithelium. The opening in the ectocervix, the external os, marks the transition from the ectocervix to the endocervical canal.
2) endocervical canal (or endocervix) is lined by a mucus-secreting simple columnar epithelium.
126
Functions of the cervix:
2 Functions:
1) Facilitates passage of sperm into the uterine cavity. This is achieved via dilation of the external and internal os.
2) Maintains sterility of the upper female reproductive tract. The cervix, and all structures superior to it, are sterile. This ultimately protects the uterine cavity and the upper genital tract by preventing bacterial invasion. This environment is maintained by the frequent shedding of the endometrium, thick cervical mucus and a narrow external os.
127
Vascular supply to cervix:
Blood is supplied to the cervix by the descending branch of the uterine artery and drains into the uterine vein.
128
Innervation of the cervix:
The pelvic splanchnic nerves, emerging as S2–S3, transmit the sensation of pain from the cervix to the brain. These nerves travel along the uterosacral ligaments, which pass from the uterus to the anterior sacrum.
129
Lymphatic drainage of cervix:
There are different answers but:
1) Anterolateral: Follows course of uterine artery to EXTERNAL ILIAC NODES -> para-aortic
2) Posterolateral: INTERNAL ILIAC ->para-aortic
3) Posterior: PRE-SACRAL/SACRAL
Also implicated are deep inguinal
130
The vulva includes:
```
○ mons pubis
○ labia majora
○ labia minora
○ clitoris
○ bulbs of the vestibule
○ greater (Bartholin’s) and lesser vestibular glands
```
131
Blood supply of the vulva:
● Arterial
○ Internal pudendal artery (branch of internal iliac)
○ External pudendal artery (branch of femoral)
● Venous
○ Internal pudendal vein (internal iliac vein)
○ External pudendal vein (great saphenous vein)
132
Lymphatic drainage of the vulva:
```
Lymphatic drainage
● Skin of the perineum
○ superficial inguinal nodes
● Clitoris, vestibular bulb and labia minora
○ deep inguinal or internal iliac
● Urethra
○ internal iliac or sacral nodes
```
133
Describe the bladder:
● Hollow viscus
● Temporary reservoir for urine
● Distensible, varies in size, shape and position
● Located in lesser pelvis when empty
● Apex points toward the pubic symphysis and is attached to the umbilical lig.
● Fundus formed by the posterior wall
● Neck points downwards
● ureters insert posteriolaterally running obliquely into the trigone forming a valve that closes with increased bladder fullness.
134
Describe the bladder wall:
```
● formed by detrusor muscle
● Superiorly covered by serosa
● lined by transitional cell epithelium.
● Trigone:
○ formed by ureteric orifices and internal urethral orifice
○ smooth epithelial surface
```
135
Blood supply to the bladder:
1) Arterial:
- sup vesicle arteries from internal iliac
Males - inferior vesicle
Females - vaginal artery
2) Venous:
i) Vesicle venous plexus -> inferior vesicle veins ->internal iliac
ii) Sacral veins: to internal vertebral venous plexus
○ in females, communicates with vaginal or uterovaginal venous plexus.
136
Lymphatic drainage of the bladder:
2 Paths:
○ superolateral aspect- external iliac nodes
○ fundus and neck- internal iliac, common iliac and sacral nodes
137
Innervation of the bladder
1) Sympathetic: Hypogastric plexus L1-3
2) Parasympathetic: supply from pelvic splanchnic nerves (S2-4)
3) Somatic (external urethral sphincter, remeber internal is autonomic) via pudendal nerve (S2-4)
138
Anatomical relations of the bladder:
1) Superior: Peritoneum
2) Inferior: urethra
Males: prostate
Females: perineal membrane
3) Posterior:
Males: rectovesicle pouch and rectum
Females: Ant wall vag, vesicouterine pouch, uterus and cervix
4) Posteriolaterally - ureters
5) Laterally: ischioanal fossa
6) Anterior: pubic symphysis, retropubic space.
