Anatomy: Abdomen, Pelvis and Perineum Flashcards
1
Q
Why is ischiorectal fossa important clinically?
A
Infection can results - mainly spreading from boils from perianal skin, lesions within the rectum / anal canal, collections bursting through levator ani
Because fossa can communicate - can easily pass infection from one side to the other
Pudendal nerves in pudendal canal (on the lateral wall of the fossa) can be blocked in forceps delivery
2
Q
Vaginal examination features
A
Inspect during straining = prolapse / stress incontinence
Anterior: pubis, urethra, bladder
Posterior: rectum, pouch of douglas = any invasion into posterior vaginal wall / malignant deposits
Apex: cervix - in anterverted - anterior lip, in retroverted - os or posterior lip can be felt first + cervical neoplasia
Bimanual = assess uterus size, pelvic size, postioin/texture of uterus, ovarian enlargement, abnormalities of fallopian tube
3
Q
Relations of the spleen
A
Anteriorly: stomach
Posteriorly: left diaphragm, separating it from left pleura, lung, ribs 9, 10, 11
Inferiorly: splenic flexure of colon
Medially: left kidney
4
Q
Route of the sperm (+ vas deferens anatomy)
A
Semineferous ducts in the lobules of the testis
Rete testes
Vasa in the epididymis
Into the vas deferens: 45cm, thick muscular tube
Through the scrotum - inguinal canal - lateral wall of the pelvis below the peritoneum - towards the ischial spine - turns medially towards base of bladder
Unites with seminal vesicles to form the common ejaculatory ducts
Enter bladder at the most superior and posterior aspect
Traverses bladder and opens in prostatic urethra at the verumonatnum - either side of the utricle
5
Q
Capsules of the prostate
A
True capsule: thin, fibrous sheath surrounding the prostate
False capsule: condensation of the extraperioenal fascia, continuous with the fascia of the bladder and fascia of denonvilliers
Third capsule: sometimes created in BPH due to condensation of the periopheral part of the prostate gland
In enucleation of the prostate for BPH- the plane between the adenomatous mass and third capsule is enteredbetween te
6
Q
Where is the venous plexus of the prostate?
A
In between the true and false fascia
True: thin fibrous capsule
False: condensation of the extraperitoneal fascia - continuous wiht the fascia around the bladder, and the fascia of denonvilliers posteriorly
7
Q
Contents of the spermatic cord
A
3 layers of fascia
external spermatic (from ext oblique apo) cremasteric (from int oblique apo) internal spermatic (from transversalis fascia)
3 arteries
testicular
cremasteric
artery to the vas
3 nerves
sympathetic
ilioinguinal (lies on the cord)
genital branch of the genitofemoral N (to cremaster)
3 other things
vas deferens
pampiniform plexus of the veins
lymphatics
8
Q
Main tributaries of the IVC
A
Lumbar branches
Right gonadal vein
Right renal vein
Left renal vein
Right suprarenal vein
Phrenic vein
Hepatic vein
9
Q
Internal oblique
Origin
Insertion
Direction of fibres
A
Anterior 2/3 iliac crest, lumbodorsal fascia, lateral 2/3 inguinal ligament
linea alba, ribs 11/12, pubic crest via conjoint tendon
Upwards and medially
10
Q
Parts of the penis
A
Root
Body
Glans
11
Q
Transverse colon features
Relations: anterior, posterior, superior, inferior
A
Covered in mesentery - transverse mesocolon attached to the anterior surface of the pancreas
Becomes descending colon at the splenic flexure
Superiorly: liver, gallbladder, greater curvature of stomach, spleen
Inferiorly: coils of small intestine
Anteriorly: greater omentum
Posteriorly: right kidney, small intestine, left kidney, second part of duodenum, pancreas
12
Q
Devleopment abnormalities in the kidney
A
Metanephric duct structures fails to fuse with metanephros structures = ARPKD
Metanephric duct may branch early - extra ureters; may extend into urethra/vagina - causing incontinence
Metanephros fails to develop one side - congenital absence of kidney
Two metanephric masses may fuse = horseshoe kidney
Kidney fail to migrate = pelvic kidney
Distal arteries may persist = aberrant renal arteries,
13
Q
Subcostal (Kocher’s)
Indications
Process
Structures encountered
Risks
A
Cholecystectomy (right) / elective splenectomy (left) / Anterior approach for kidneys (both connected in middle)
2.5cm below and parallel to costal margin, extending laterally to border of rectus sheath or further
Skin, subcut fat, campers, scarpas, anterior rectus sheath, rectus abdominis, posterior rectus sheath, extraperitoneal fat, peritoneum
9th intercostal nerve near the lateral border of incision - if damaged - weakness and atrophy of upper rectus - predisposing to incisional hernia
14
Q
Iliacus
Origin
Insertion
Nerve supply
Action
A
Greater part of iliac fossa extending onto sacrum
Lateral part of psoas major tendon onto the lesser trochanter
branch of femoral nerve (L2-L3)
Flexion of vetebral column
15
Q
Rectus sheath:
above costal margin
above arcuate line
below arcuate line
A
Fuses in the middle = linea alba - xiphisternum - pubic symphysis
Anterior: External oblique only
Anterior: external oblique + 1/2 internal oblique
Posterior: transversus abdominis + 1/2 internal oblique; transversalis fascia, peritoneum
Anterior: external oblique + internal oblique + transversus; transversalis fascia + peritoneum
16
Q
Distinguishing between jejunum and ileum
A
Jejunum is thicker as valvulae coniventes / plicae circulares are larger and more numerous
Greater diameter
Mesentery at jejunum - less arcades that are longer and straigher (less arches), less fatty and thinner vs lower down
Found at or above level of the umbilicus, whilst ileum more likely below
17
Q
Quadratus lumborum
Origin
Insertion
Nerve supply
Action
A
Iliolumbar ligament and adjacent portion of iliac crest
Into the lower border of 12th rib medially and tendons into L1-L4 transverse processes
T12-L4
Extension and lateral flesion of lumbar vertebrae; fixes 12th rib during inspiration
18
Q
Nerve supply of the oesophagus
Upper third
Below the root of the lung
A
Upper third: parasympathetic via RLN + sympathetic via middle cervical ganglion along inferior thyroid artery
Below root of the lung: Vagus + sympathetic nerves form the oesophageal plexus
19
Q
Stomach
Anatomy: shape, surfaces, curves, orifices
Junction of body and pyloric antrum is called?
Pylorus with duodenum junction?
A
J shape, anterior and posterior surface, greater and lesser curvature, cardia and pylorus orifice
Cardia, body (with fundus at the top - lies above cardia), pylorus (antrum and canal)
Incisura angularis
constant prepyloric veins of Mayo - crosses it vertically
20
Q
Location of the deep inguinal ring
Important structure next to it
A
1cm above the midpoint of the inguinal ligament
Defect in the transversalis fascia
Located laterally to the inferior epigastric vessels
21
Q
Blood supply of the spleen
A
Splenic artery from coeliac trunk (runs along upper border of pancreas)
Splenic vein - behind the pancreas
Splenic vessels + tail of the pancreas in the lieno-renal ligament + lymph nodes
22
Q
Composition of the perineum
A
Anterior triangle (urogenital)
Posterior triangle (anal)
23
Q
Relations of the pancreas
- anterior / posterior
Splenic vessels
A
The stomach and D1 lie in front of the pancreas - separated by mesentery (pancreas is retroperitoneal)
Transverse mesocolon attached to the anterior aspect of the pancreas
Below this is the DJ flexure, splenic flexure, small intestine
Posteriorly in contact with the left crus of the driaphragm, the aorta, left suprarenal gland and left kidney
Splenic artery = along upper border of pancreas
Splenic vein = being pancreas
Main duct from tail to head; accessory duct opens 2cm proximally in duodenum
24
Q
Sites of narrowing of oesophagus
A
Commencement - 17cm from upper incisors
Where its crossed by left main bronchus - 28cm from upper incisors
Termination - 43cm from upper incisors
25
Layers to get to the testes
Skin
Dartos muscle
External spermatic fascia
Cremasteric muscle within cremasteric fasacia
Internal spermatic fascia
Parietal tunica vaginalis
Visceral tunica vaginalis
Tunica albuginea
26
Where does the kidney form and where does it migrate to?
Develops in the pelvis; rises cranially taking its blood supply with it - initially from the iliac arteries, then the aorta
27
How does hypospadias develop?
Failure of fusion of the genital folds = persistence of the urethral groove
Varying degrees = completely open or just a narrow orifice - on the underside of the shaft
28
List of retroperitoneal organs
**Primary**
Kidneys
Ureters
Bladder
Adrenals
Aorta
IVC
Lower rectum
**Secondary**
D2/D3/D4
Ascending colon
Descending colon
Head and body of pancreas
29
Types of inguinal hernias and differences
Purpose and boundaries of hasselbach's triangle
Femoral vs inguinal
Indirect - deep and superficial ring; direct - superficial ring only
Indirect has all 3 layers of spermatic cord
Posterior wall - direct hernias come through; inferior epigastric artery, inguinal ligament, rectus abdominis
Femoral - narrower ring - more likely to strangulate, more common in females due to wider pelvis; more likely below and lateral to pubic tubercle; more likely of the Richter type
30
Relations of quadratus lumborum
**Anteriorly**
Colon
Kidney
Subcostal, ilioinguinal and iliohypogastric lie on the fascia covering it
31
Lymphatic drainage of the pancreas
Nodes at the upper border of the pancres
Nodes at the medial aspect of duodenum/head of pancreas
Nodes in the root of the mesentery
32
What is the ischiarectal fossa and what are its relations?
Fossa between the anal canal and side wall of the pelvis
Medially - fascia over levator ani + external anal sphincter
Laterally - fascia over obturator internus
Anteriorly - deep into urogenital diaphragm
Posteriorly - limited by sacrotuberous ligaments + origin of gluteus maximus
Floor is formed from skin + subcut fat
Contains fat + nerves crossing from lateral to medial + inferior rectal vessels
Fossa communicate behind the rectum
In the lateral wall - there is a atunnel of fascia - pudendal canal (of Alcock) = contains the internal pudendal vessels and the pudendal nerve
33
Anterior and posterior relations of the stomach
Anterior: abdominal wall, left lobe of liver, diaphragm
Posterior: diaphragm, aorta, pancreas, spleen, left kidney and suprarenal gland, transverse mesocolon, colon - separated by lesser sac
34
What are the bony and muscular structures of the posterior abdominal wall?
Bony: Body of vetebrae, sacrum, wings of ilium
Muscular: Psoas major, quadratus lumborum, iliacus, posterior part of the diaphragm
35
Paramedian
Layers
Use is declining, 2.5cm lateral to the midline
Skin, superficial fascia, anterior rectus sheath (external + 1/2 internal oblique) + tendinous intersection (segmental vessels - so will bleed), rectus muscle, posterior rectus sheath (which only consists of transversalis fascia below the arcuate line), extraperitoneal fat, peritoneum
36
What are splenunculi?
What are their significance?
Accessory spleens found in the splenic mesentery
Can cause persistent symptoms following splenectomy eg thrombocytic purpura if not removed
37
Parts of the oesophagus
Start and finish
Length
Cervical
Thoracic
Abdominal
Lower border of the cricoid cartilage - cardiac orifice of the stomach
Approx 25cm long
38
Nerve supply of the stomach
Anterior (left) and posterior (right) - left is close to the anterior surface whilst right is a bit further away
Anterior gives off hepatic and pyloric branch; posterior gives off coeliac branch (for coeliac axis)
Both meet at the cardia to give off the gastric branches - travelling at the anterior and posterior part of the insertion of the lesser omentum - knwon as the anterior and posterior nerves of Latarjet
39
Route of peritoneum in the abdomen
Upwards and towards the right into the liver - falciform ligament
Goes in the groove between the caudate lobe and left lobe, splits into the right (upper layer of coronary ligament) and left (anteiror layer of left triangular ligament)
Ligamentum teres in the free edge
Encloses the liver - goes to porta hepatis then gastrooesophageal junction - lesser omentum
Encloses stomach - then greater curvature forms again - loops down and up to transverse colon - greater omentum
Becomes double layered again to form the transvese mesocolon - then separates - upper layer goes up to reflect onto the liver; lower layer continues onto the posterior abdominal wall
Here there are interupptions - reflection from the DJ flexure to the ileocaecal junction - forming the mesentery of the small intestine
40
Funtional anatomy of liver
Based on portal distribution and hepatic veins
Division is based on a line which passes through the fossa of the gallbladder and IVC - Cantlie's line
Each lobe is then divided into 4 segments
41
Scrotum
Contents
Skin appearance
Muscle
Testicles via spermatic cord; left cavity longer and testicle hangs lower than right; divided by fibrous septum
Skin is thin, pigmented, rugae and numerous sebaceous glands
Subcut tissue has no fat but has dartos muscle - this is continuous with the fascia of abdominal wall and perineum - means that if there is extravasation of blood or urine deep to this layer in the abdomen it can appear in the scrotum (eg following hernia repair)
Laxity + dependent position = oedema if cardiac / renal failure
42
Third part of the duodenum
Longest = 10cm
Horizontal
Relations: Anteriorly: root of the mesentery + superior mesenteric vessels; posteriorly: IVC / aorta / L3 vertebra
43
Lymphatic drainage of the stomach
Follows arteries
Those supplied by splenic vessels - drain into the splenic hilar nodes - then the upper pancreatic nodes then to the coeliac nodes
Cardia - along the left gastric vessels - go to the coeliac nodes
Rest of the stomach - via **nodes along the lesser curve** - go to the coeliac nodes via common hepatic artery route; **nodes along the gastroepiploic artery -** to the subpyloric nodes then the coeliac nodes
44
Broad ligament structure and function
Fold of peritnoeum which connects the lateral body of the uterus to the pelvic wall
Contains
Broad ligament
Round ligament
Fallopian tube in its free edge
Uterine vessels and branches of the ovarian vessels
Mesovarium attaching the ovary to the posterior wall
Lymphatics
45
What structures does the mesentery contain?
Superior mesenteric vessels - enters the mesentery anterior to the third part of the duodenum
lymph nodes draining the small intestine
autonomic nerve fibres
46
Where is the root of the penis attached?
At the perineal membrane
The crura - from the ischiopubic rami
The pubic symphysis via the suspensory ligament
47
Spleen anatomy
Mesentery
Lies in left hypochondrium, size of clenched fist
Left lateral extremity of lesser sac
Gastrosplenic ligament - connects it to the greater curvature of the stomach - contains the short gastric and left gastroepiploic vessels
Lienorenal ligament - attaches to the posterior abdominal wall - contains the tail of the pancreas and the splenic vessels
48
Epiploic foramen relations
Anterior: bile duct (right) hepatic artery (left) portal vein (behind - closest to foramen)
Posterior: IVC
Superiorly: Caudate process of liver
Inferiorly: D1
At the vetebral level T12
49
Bladder anatomy
Relations: anterior, posterior, laterally, neck
Lies in the true pelvis, behind pubic symphysis
Anteriorly: pubic symphysis
Superiorly: peritoneum with coils of small intestine, the sigmoid colon rests above it (important in diverticulitis when colovesical fistulas can form); in females the body of the uterus
Posteriorly: rectum and seminal vesicles (males); vagina and supravaginal part of the cervix (females)
Laterally: separated from levator ani and obturator internus by loose connective tissue
Neck of the bladder: fuses with prostate (males); rests on the pelvic fascia (females)
50
Structure of the suprarenal gland
Comprises a cortex (mesoderm)/ medulla (ectoderm)
Medulla receives **preganglionic fibres** from the **greater splanchnic nerve -** secretes noradrenaline and adrenaline
Cortex supplies hormones (sweeter in the middle)
Zona glomerulosa (outer - mineralocorticoids)
Zona fasciculata (middle - glucocorticoids)
Zona reticularis (inner - sex hormones)
51
What is Calot's triangle?
the cystic artery runs in it
Good for localising anatomy
Made up of the inferior surface of the liver, cystic duct and common hepatic duct
52
Umbilical folds of the peritoneum (below the umbilicus)
Median - urachus remnant
Medial - umbilical artery remnant
Lateral - inferior epigastric artery
53
Female urethra
Length - 4cm
Traverses the sphincter urethrae - lies in front of the vagina
Opening - 2.5cm behind the clitoris between the labia minora
54
Why is long pelvic appendix important?
20%
Can hang down irritate the bladder = frequent micturition
55
What abnormalities can be felt on DRE?
Lumen:
Faecal impaction
Foreign bodies
Wall:
Strictures
Tumours
Thrombosed haemorrhoids
Outside the wall:
Prostatic / ovarian / cervical abnormalities
Pelvic bony tumours
Masses or tenderness (due to peritonitis) in the pouch of Douglas
Foreign bodies in vagina - tampon / pessaries etc
56
What happens during left atrium enlargement for the oesophagus?
Displaced backwards, can be seen on barium swallow
57
Structures that form the anal canal
Hindgut and Proctodeum
Initially separated by the anal membrane - which is formed when the urogenital septum reaches the cloacal membrane
(proctodeum - invagination of ectoderm)
58
Parts of the ureter and relations: anterior/posterior
**Abdominal**
Anterior: peritoneum, colic vessels, ovarian/testicular vessels, ileum/mesentery (R) OR sigmoid/mesentery (L)
Posterior: psoas major ± minor, genitofemoral nerve, bifurcation of common iliac
R = close to the lateral border of the IVC
**Pelvic**
Crosses bifuracation, crosses obturator nerve + anterior branches of internal iliac, goes to the ischial spine, turns medially on to base of bladder
then below vas deferens (M) OR past the lateral fornix of the vagina below the uterine artery
Then enters the base of the bladder
**Intravesical**
59
Anatomy of the anal canal
4cm long; separated from upper and lower by dentate line
Mid canal = vertical column in mucosa = columns of morgagni
Distal end = valve like folds (valves of Ball), behind are the sinuses into which the anal glands open into
Upper= columnar epithelium; lower = squamous epithelium, becomes skin at the anal verge
60
Pancreas
Parts
Which plane does it lie in?
How do you work out this plane?
What level is this plane in?
Head, uncinate process, neck, body, tail
Transpyloric plane
Midpoint between suprasternal notch and pubic symphysis
L1/9th costal cartilage
61
Peritoneal cavity:
Layers of peritoneum
Cavities
Lined by?
Parietal (abdominal and pelvic wall); visceral (organs)
Greater and lesser sac
Mesothelium (simple squamous epitherlium)
62
Blood supply
From splenic artery via arteria pancreatica magna
Head and uncinate process - superior pancreaticoduodenal artery (anterior/posterior) - branch of gastroduodenal artery
and
inferior pancreaticoduodenal artery (anterior/posterior) - branch of superior mesenteric artery - they anastomose
63
Nerve supply
Rectus abdominis
External oblique
Internal oblique
Transversus abdominis
Thoracoabdominal (T7-11)
Thoracoabdominal (T7-11) + subcostal (T12)
Thoracoabdominal (T7-11) + subcostal (T12) + lumbar plexus branches (iliohypogastric and ilioinguinal)
64
Structure of oesophagus
Mucosa - stratified squamous epithelium
Submucosa - mucous glands
Inner muscle - circular
Outer muscle - longitudinal
[Upper 1/3 muscle is striated - for rapid swallowing; lower 2/3 is smooth for peristalsis]
Outer layer loose areolar tissue
65
Mesentery of small intestine
Free edge is where jejunum and ileum are
Approx 15cm long - from DJ flexure left of L2 to right sacroiliac joint
66
Lobes of the prostate
Posterior: posterior to the urethra, on the plane below the course of the ejaculatory ducts
Median: between the ejaculatory ducts and posterior to the urethra
Lateral: lobes separated by a shallow median groove on the posterior surface (felt on a rectal examination)
Anterior: only an isthmus present consisting of a fibromuscular tissue
67
Relations of the prostate
Anterior
Posterior
Superior
Inferior
Laterally
Anteriorly: symphysis pubis; with a layer of extraperitoneal fat in front (cave of Retzius)
Posteriorly: erctum, separated by fascia of denonvilliers
Superiorly: continuous with neck of the bladder
Inferiorly: apex of prostate rests on external urethral spinchter in the deep perineal fascia
Laterally: levator ani
68
Corpora cavernosa
Dorsally located, connected together in the anterior three quarters with septum intervening; fits into the base of the glans
Separate behind to form the two crura
2 groovees - lower surface - dorsal vein of peins; upper suface - corpus spongiosum
Attached to pubic symphysis via suspensory ligament
69
Anal sphincters
and innervation
Internal anal sphincter - conntinuous with the circular muscle of the rectum; covers u[pper 2/3 of anal canal)
External anal sphincter - starts lower down and extends further distally; deep, superficial, subcutaneous; deep is blended with levator ani muscle
Anorectal ring is the deep part of external sphincter (where it blends with levator ani) + internal sphincter = can be palpated on rectal examination
Subcutaneous is traversed by fan shaped structure = continuation of the longitudinal muscle fibres of anal canal
Innervation - S2,3,4
S2,3 - pudendal nerve + inferior rectal nerve
S4 - perineal branch
70
Ascending colon
From caecum to posterior aspect of liver - turns sharply at hepatic flexure
Covered on anterior and lateral surface with peritoneum
Posterior relations: iliacus, quadratus lumborum and perirenal fascia over the lateral aspect of the kidney
71
Ureter in relation to the broad ligament
Ureter passes along the border of the broad ligament
Then passes lateral to and then immediately above the lateral fornix of the vagina
72
Relations of the gallbladder
Duodenum
Transverse colon
73
Formation of the bladder
Proximal part of the allantois (apex of bladder - urachus)
Vesicourethral part of the urogenital sinus (body of the bladder and prostatic portion)
Caudal ends of the mesonephric ducts (trigone and dorsal wall)
74
Hepatic veins anatomy
**3 hepatic veins: right, middle and left**
Right in right portal fissure, drains 5, 6, 7, 8
Middle in main portal fissure (same plane as IVC), drains 4A, 4B, 5, 8
Left in left portal fissure, drains 4B, 2, 3
Divide liver into 4 sectors: right lateral (6,7), right medial (5,8), left medial (3,4), left lateral (2) - each supplied by one portal pedicle
Caudate lobe is segment 1 - but has its owm supply, and produces smaller hepatic veins
75
Inguinal canal location
Starts at the deep ring (1cm above the midpoint of the inguinal ligament - ASIS - PT); ends at the superficial ring (located medial and above the pubic tubercle)
76
Location of the superficial ring
V shaped defect in the inguinal ligament
Above and medial to the PT
77
Anatomy of the gallbladder
Posterior surface of liver - whose fossa divides the left and right lobe of the liver
50mL of bile when full - store and concentrates bile
Fundus, body and neck - which opens into the cystic duct
Ventral surface - Hartmann's pouch where a stone can get lodged
Cystic duct lumen = spiral mucosal valves of Heister - make it difficult endoscopically
78
Appendices epiploicae
What are they?
Where are they found?
Where are they not found?
Fat filled tags, found on the surface of the colon
Not found on the caecum, appendix or rectum
79
Rectus abdominis
Origin
Insertion
Where and how many are the tendinous intersections?
Where do they adhere to?
pubic crest
5, 6, 7 costal cartilages
3 - xiphoid, umbilicus, halfway between the two
Anterior sheath only (not posterior)
80
Parts of the male urethra
Prostatic
Membranous
(Bulbar)
Spongy
81
Midgut development
Pushed out into the umbilical cord as the contents grow rapidly
Sucked back in around the 10th week as the cavity expands
Continues to rotate at to the left 180 degrees - bringing the ascending colon to the right side and the caecum just below it
caecum moves down even further to get fixed in the RIF
82
Portal system
Drains blood from the abdominal oesophagus, spleen, pancreas, gallbladder
Superior mesenteric vein joins the splenic veins behind the neck of the pancreas = forming the portal vein which travels in the free edge of lesser omentum
Inferior mesenteric vein joins the splenic vein behind the body of pancreas
Poral vein splits into right and left hepatic vein which then supplies the 4 functional lobules of the liver
83
Lympahtics of the uterus
Fundus:
along ovarian vessels to para-aortic nodes
via vessels in the round ligament to inguinal nodes [mets from fundus can go to the inguinal nodes]
Body
via broad ligament to iliac nodes
Cervix
laterally via the braod ligament to external iliac nodes
posteriorly via uterosacral ligament to the presacral nodes
posterolaterally via the uterine vessels to the interal iliac nodes
84
Route of the peritoneum in the pelvic cavity
Umbilical folds
Rectum - upper 1/3 (front and sides); middle third (front)
Bladder - reflected onto base and upper part (males); reflected onto posterior vaginal wall, then posterior, upper and anterior surface of uterus and onto base of bladder (females) -- pouch of douglas forms in the rectouterine space; also goes laterally from the uterus onto the fallopian tubes - forming broad ligaments
85
Fourth part of the duodenum
Ascends vertically to end, then turns anteriorly left abruptly to form jejunum
2.5cm
DJ flexure - by moving anteirorly it leaves the posterior abdominal wall and acquires a mesentery
DJ flexure suspended by suspensory ligament of Treitz from the **right crus of diaphragm** to **termination of duodenum**
86
Epididymis in relation to testes
Along the posterior border (lateral side)
Median edge has a groove = the sinus epididymis
Covered by tunical vaginalis - but posterior edge free
87
Transversus abdominis
Origin
Insertion
Deep surface of lower 6 costal cartilages (interdigitating with diaphragm), anterior 2/3 iliac crest, lateral 1/3 of inguinal ligament, lumbar fascia
Linea alba, pubic crest via conjoint tendon
88
Blood supply of the oesophagus in the areas:
cervical
thoracic
abdominal
Cervical
Artererial: inferior thyroid artery
Venous: inferior thyroid vein
Thoracic
Arterial: branches of the aorta
Venous: azygos veins
Abdominal:
Arterial: inferior phrenic artery + left gastric artery
Venous: left gastric vein (portal) + azygos veins (systemic)
89
Portal hypertension
No valves = so any increase in pressure is seen across the system = anastomosis sites most vulnerable = dilate and bleed
Sites of anastomosis
Oesophagus (haematemesis) = oesophageal branch of left gastric vein (portal) --\> oesophageal tributaries of the azygos system (systemic)
Rectum (bleeding) = superior rectal branch of inferior mesenteric vein (portal) --\> inferior rectal vein (systemic)
Mesentery (retroperitoneal bleeding) = portal veins in the mesentery (portal) --\> retroperitoneal veins (systemic)
Anterior abdominal wall (caput medusae) = portal veins in the liver (portal) --\> veins of the abdominal wall (systemic) via veins on the falciform ligament
Portal branches in the liver --\> veins of the diaphragm (systemic) related to bare area of the liver
90
Midline Incision
Benefits (x3)
Structures encountered
Through linea alba skirting the umbilicus
Rapid access + minimal blood loss
Skin, subcutaneous fat, superficial fascia (two layers in lower abdomen - scarpas only below the level of umbilicus), linea alba, extraperitoneal fat, peritoneum
91
Ovary anatomy
Size of almond
In the posterior aspect of the broad ligament - connected to the pelvic wall via mesovarium
Suspensory ligament connected - travels over the pelvic brim and external iliac vessels - merges with peritoneum over **psoas major** - ovarian artery travels through this
Ovarian ligament = connects ovary to the cornu of the uterus, runs within the broad ligament
92
Internal iliac artery route
Travels backwards and downwards between ureter anteriorly and internal iliac vein posteriorly
Divides into anterior (superior gluteal) and posterior (inferior gluteal / obturator) branch at the upper border of greater sciatic foramen
Supplies pelvic organs, perineum, buttock, anal canal
93
Variations of extrahepatic ducts
Cystic duct joins much lower down - behind the duodenum
Cystic duct virtually absent = gallbladder opens directly into common hepatic duct
Cystic duct opens into the right hepatic duct
Accessory hepatic ducts open into the gallbladder/cystic duct
94
Blood supply of the uterus
Uterine artery (branch of the internal iliac artery)
travels in the base of the broad ligament
2cm lateral to the cervix - passes superiorly and anteriorly - entering the uterus at the internal os
Travels up the body of the uterus in a tortuous manner
Goes laterally and inferiorly to the fallopian tube - terminates by anastomosing with the terminal branches of ovarian artery
Uterine artery - gives off descending branch to the vagina and cervix
Uterine veins accompany the artery - draining to the internal iliac vein
95
How is malrotation caused?
Where does the first part fix?
Where does the second part fix?
What happens if they both don't fix?
Incomplete development of the midgut - the **DJ flexure** fails to be fixed **retroperitoneally** (anchored to the SMA via lig of Treitz) - hangs freely from the foregut to the right of the abdomen
OR the **caecum** is not fixed in the **RIF** (goes to RUQ) - can cause small bowel obstruction due to the peritoneal bands (of Ladd) that run across it and fix to the abdominal wall there
If both = whole midgut not fixed - can twist on its blood supply (SMA) = **volvulus neonatorum**
96
Development of the testes
Develops on the posterior abdominal wall - which assocaites with its blood supply, nerves and lymphatic drainage
Descends into the inguinal canal and exits at the superfiical ring into the scrotum
97
Importance of the anastamoses in the distal oesophagus
Portosystemic anastomoses - oesophageal tributary of the left gastric vein (portal) with azygos vein (systemic)
Can results in oesophageal varices in portal hypertension
98
Incorrect formation of the foregut causes?
Oesophageal atresia (8%)
Tracheo-oesophageal fistula (80%) - lower part of the trachea fuses with the distal oesophagus
99
First part of the duodenum
Direction
Relevance of first 2-3cm for peritoneum
Relations: anteriorly and posteriorly
Superiorly and posteriorly
Total 5cm, first 2-3cm has got visceral peritoneum (it is intraperitoneal)
Anterior relations: liver / gall bladder
Posterior relations: portal vein, common bile duct, gastroduodenal artery; behind this is IVC
100
Why is the attachment of Scarpa's fascia to the thigh fascia important clinically?
Rupture of bulbous urethra - urine tracks into penis, scrotum and abdominal wall but not into the thigh
Ectopic testis cannot descend any lower into thigh
101
Duodenum: shape; length (for each part)
C shaped, 25cm: 5, 7.5, 10, 2.5cm
102
Seminal veiscles
Location
Anatomy
Lie on each side in the interval between the bladder and the rectum
Lateral to the vas
Common duct with the vas - common ejaculatory duct
Usually impalpable but if TB / other infection - can be palpable
103
Causes of the different subphrenic abcessess
Subphrenic - perf peptic ulcers, appendicitis, diverticulitis
Subhepatic - right - tacks up the right paracolic gutter into the right subhepatic space - when patient is recumbent
Subhepatic - left - in the lesser sac from perforated posterior gastric ulcer / acute pancreatitis (pseudocyst)
Usually drained percuaneously (image guided) or if surgery is required - posterior (below/through the bed of 12th rib) or anterior (below and parallel to costal margin)
104
Lumbar sympathetic chain route
Starts deep to the medial arcuate ligament (as a continuation of the thoracic chain)
Lies in front of the lumbar vertebrae overlapped by IVC on right and aorta on left
Lumbar arteries are deep, lumbar veins superficial
Continue deep to the iliac vessels to reach the sacrum where it becomes the sacral trunk
Converge in front of the coccyx to form the ganglion impar
105
Membranous urethra
2cm in length
Between the perineal membrane and pelvic fascia
Pierces the enternal urethral sphincter
106
How are retroperitoneal organs attached?
Adeventitia - dense fibrous irregular connective tissue
107
Large intestine
Length
Parts
1.5m
Caecum with vermiform appendix
Ascending colon (hepatic flexure)
Transverse colon (splenic flexure)
Descending colon
Sigmoid
Rectum
Anal canal
108
Hydrocele - formation and types
Failure or partial obliteration of the processus vaginalis
Can be **congenital** (whole), **vaginal** (only of the scrotum) or **cord**
109
Blood supply of the ureters
Renal arteries
Testicular/ovarian artery
Internal iliac
Inferior vesical arteries
110
Corpus spongiosum
arises?
surrounded by?
ends up as what?
in the middle of it?
Arises from bulb (below perineal membrane)
surrounded by bulbospongiosus muscle
in the undersurface of corpora cavernosa - then over their extremities to form the glans
urethra in the middle
111
Contents of femoral canal
Cloquet's lymph nodes
Fat
Lymphatics
112
Vulva - definition and components
External genitalia
Parts: mon pubis (fat over the pubic symphysis);
labia majora (over mon pubis; externally - hair and skin; internally mucous membrane)
labia minora - posteriorly - meet at the fourchette; anteriorly - surround the clitoris: upper side forming the prepuce, lower attaching to the glans via the frenulum
vestibule - area enclosed by minora - contain urethral orifice and vaginal orifice (hymen here naturally - after childbirth on remnants known as carunculae
greater vestibular glands (bartholins - open deep to the labia majora posteriorly external to the hymen; similar to bulbourethral glands in males); they are overlapped by the bulb of the vestibule (similar to erectile tissue) - covered in bulbospongiosus travel to the clitoris
clitoris - two corpa cavernosa - attach to ischiopubic rami; free extremity formed by corpus spongiosum
113
Development of the anal canal
9th week - structures separate within the cloaca
Urorectal septum divides the cloaca into the **bladder** and **rectum (hindgut);** reaches the caudal end - which is the cloacal membrane
Forms the anal membrane and urogenital membrane
Anal membrane separates the hindgut from the anal pit (formed from the invagination of the ectoderm known as proctodeum)
Loss of membrane = continuity between hindgut and anal pit = anal canal
114
Anatomy of the kidney
Location
Relations
Layers and what are they continuous with
R lower than L due to liver; between T12 and L3 with the renal vessels at L1
Sit beneathe costal margin, protected by 11th /12th ribs
Anterior:
R - hepatic, duodenal, colic areas, suprarenal
L - gastric, splenic, pancreatic, jejunal, colic areas, suprarenal
Posterior (medial to lateral):
Psoas major
Quadratus lumborum
Transversus abdominis
Layers (Deep to superficial)
Fibrous capsule
Perinephric fat
Fascia (continuous anteriorly - diaphragm [separating it from suprarenal gland = easily separable], medially aortic/IVC sheath, laterally transversalis fascia, inferiorly open)
115
Subphrenic spaces
4 - can be the point of subphrenic abcesses
Right and left suphrenic spaces (found either side of the falciform ligament between the liver and the diaphragm)
Right subhepatic space (renal well of Rutherford Morrison)
Left subhepatic space (lesser sac)
116
Boundaries of the right subhepatic space
Above: liver attached to gallbladder
Behind: posterior abdominal wall and kidney
Below: duodenum
117
External iliac artery route
Runs along the pelvic brim, along the medial border of psoas major
Goes beneath the inguinal ligament to become the femoral artery
Just before the inguinal ligament it gives off the inferior epigastric artery
118
Dimensions of testis
4cm superior to inferior
3cm AP
2.5cm medial to laterla
119
Clinical points of arteries of the stomach
Ulcer on the lesser curve - erodes into right or left gastric arteries = haematemesis / malaena
Ulcer / carcinoma on the posterior surface of the stomach = erode into the pancreas = pain radiating to the back
120
Anterior triangle borders and structures
Triangle formed by the inferior ischiopubic rami and line joining the ischial tuberosities
Middle of triangle = perineal membrane - strong sheath pierced by urethra (males) or urether+ vagina (females)
Deep to this is **deep perineal pouch** which contains the **external urethral sphincter** - striated muscle surrounding the membranous urethra; other contents are the **bulbourethral glands** - whose ducts pierce the membrane and form the bulbous urethra; also contains **deep transverse perineal muscles**
Above this - superior fascia of urogenital diaphragm (technically the perineal membrane is the inferior fascia)
Superior = superficial perineal pouch
121
Blood supply of the bladder + venous drainage
Lymphatic drainage
Superior and inferior vesical arteries - branches of the internal iliac arteries
Rich venous plexus around the bladder: draining into the internal iliac veins
Drain along the vesical vessels to the internal iliac nodes which drains into the para-aortic nodes
122
Relations of psoas major
Lumbar plexus in between superficial and deep layers
Structures on it - ureters, gonadal vessels, IVC
Psoas sheath - encloses it and is beneath the inguinal ligament (means if there is infection of the lumbar vertebrae eg TTB - pus can spread down below inguinal ligament and present as an abcess)
Tendon lies in front of the hip joint with the bursa intervening and is directly behind the femoral artery (which can be palpated)
Retrocaecal / retrocolic appendix lying anteriorly (if appendicitis can cause psoas sign)
123
Important relations between right and left common iliac arteries
**Right common iliac artery**
Right common iliac vein is just behind and to the right
Left common illiac vein crosses behind it
SMA crosses it anteriorly
**Left common iliac artery**
left common iliac vein is below and medial to it
IMA crosses it anteriorly
124
**Cervical** oesophagus - route and relations - anterior/posterior/left/right
Route: downwards and slightly left
Relations
Anterior: trachea, thyroid
Posterior: lower cervical vetebrae, prevertebral fascia
Left: Left common carotid, left inferior thyroid, left subclavian arteries, thoracic duct, left RLN in the groove
Right: right common carotid, right RLN in the groove
125
What is epispadias?
What is a serious complication?
Dorsal wall of uretha partially / completely absent = failure of infraumbilical mesodermal development (or abnormal migration of genital tubercle caudally instead of cranially)
Ectopia vesica - ureteric openings and trione of the bladder is on the abdominal wall associated with cleft pelvis (no symphysis pubis)
126
Prostate
Structure in relation to the urethra
Glandular tissue
Smooth muscle (about 25%)
Mostly lies posterior and laterally to the urethra, little anteriorly
127
Uterus dimensions
7cm long, 5cm side to side, 3cm AP
Pear shaped
Fallopian tubes enter @ supralateral angle
128
Blood supply of the testes
Arterial - testicular artery (from aorta at level of renal arteries) which anastomoses with the artery of the vas (from the inferior vesical branch of the internal iliac artery) [if you ligate testicular artery its ok]
Venous - pampiniform plexus of the veins - which converge to a singe testicular vein at the deep ring
Right - IVC; left - left renal vein
129
Consequence of anal membrane failing to rupture / anal pit failing to develop
Imperforate anus
130
How is malrotation treated?
Mostly small bowel obstruction due to bands of Ladd
Ladd's procedure is done
- de-torsion
- resection of necrosed bowl
- division of ladd's bands
- expansion of mesenteric base - by placing caecum on left and small bowel on right
- appendectomy
131
Gridiron incision (muscle splitting)
Use + Process
Structures
Appendectomy
Centred on mcburney's point - 2/3 from umbilicus to ASIS
Skin, campers', scarpa's (more towards lower end of incision), external oblique (the aponeurosis), internal oblique, transversus, extraperitoneal fat, peritoneum
132
Superficial perineal pouch contents (male vs female)
Bulb of penis (attached to perineal membrane): corpus spongiosum surrounded by bulbospongiosus
Crura of penis (attached to the angle between perineal membrane insertion and ischiopubic rami): surrounded by ischiocavernosus
Superficial transverse peroneal muscle
Female is same but less well developed; also has bulb of vestibule (for bulb of penis) and bartholin's glands present
133
Abdominal aorta location
Infront of T12 to front and left of L4 - then divides into common iliacs
134
Structure of the gastric mucosa
Surface is composed of columnar epithelial cells secreting mucous and alkaline fluid (necessary to protect the stomach from acid)
3 areas:
Cardiac gland area via GO junction - mucus
Oxyntic gland area (acid-secreting) - parietal (oxyntic) and chief (zymogen)
Pyloric end area (distal 30%) - gastrin from G cells and mucous
135
Anal cushions
Location
Purpose
Located at 3, 7 and 11 o'clock
In upper half
important for continence, air tightness and mucus production
136
Blood supply of the gallbladder
Via the cystic artery - a branch of the right hepatic artery (can also be direct from the main hepatic artery)
usually crosses behind the common bile duct and hepatic artery to reach the upper surface of the neck of the gallbladder
Lies in **Calot's triangle**
Also gets arterial supply from the liver bed - no gangrene if cystic artery thrombosed
Venous drainage - small veins directly into the bed of the liver
137
Branches of the aorta
Anterior unpaired (3)
Lateral paired (3)
Paired branches to the parieties (2)
Terminal brances (2)
**Anterior Unpaired**
Coeliac trunk (left gastric, common hepatic, splenic)
SMA
IMA
**Lateral paired**
suprarenal artery
renal artery
gonadal artery
**Paired parieties**
inferior phrenic artery
four lumbar arteries
**Terminal branches**
Common illiacs
Median sacral artery
138
Abdominal oesophagus - route
Relations: a
Oesophageal opening in the right crus at T10; then lies in the groove on the posterior surface of the left lobe of the liver with the left crus posteriorly
Covered anteriorly and to the left with peritoneum, anterior vagus behind peritoneum, posterior vagus is further away from the posterior wall of the oesophagus
139
Posterior triangle borders and contents
Ischial tuberosities and coccyx
Contents:
levator ani
anal sphincters
ischiorectal fossa
140
Inferior vena cava
At what level is it formed?
What separates it from the aorta at the diaphragm?
What level does it pass the diaphragm?
L5 - from left and right common iliac vein, behind the right common iliac artery
Right crus of diahragm
T8
141
Fallopian tubes
Anatomy
Parts
Fallopian / uterine tubes - 10-12cm long - run from lateral side of the body of the uterus to the pelvic wall - end near the opening of the ovary
Infundibulum - fimbrae to collect egg
Ampulla - wide, thin walled, tortuous
Isthmus - thick walled, straight, narrow
Intramural part - no peritoneum; peritoneum over the rest like a drape
Fertilised ovum - can implant anywhere - most likely ampulla = ectopic - can rupture and bleed = intraperitoneal haemorrahe
142
Spongy urethra
15cm
Passes below the pubic symphysis (esp on erection - which means trauma to pubic symphysis can rupture the urethra)
Bulbourethral glands open on its floor
Just before the external meatus - there is the fossa navicularis - widening of the urethra
Mostly transverse but vertical at meatus = spiral stream of urine
143
Functions of femoral canal
Dead space for expansion of femoral vein
pathway of lymphatics from lower limb to external iliac nodes
144
Posterior relations of the IVC
Vertebral column
Right renal artery
Right suprarenal artery
Right suprarenal gland
Right inferior phrenic artery
Right lumbar arteries
Right sympathetic trunk
Right crus of diaphragm and psoas major
To the left: aorta
145
Formation of the urethra in males
Urethra above the prostatic utricle - from the vesicourethral part of cloaca **AND** incorpporated ends of the mesonephric duct
Urethra below the prostatic utricle (prostatic and membranous urethra) - from the urogenital sinus
Urethra and glans - genital (urethral) folds encompassing the phallic portion of the urogenital sinus
146
147
What happens during foregut rotation?
Rotates clockwise
Liver attaches to the stomach - lesser omentum (ventral mesogastrium); stomach attaches vai the spleen to the posterior wall - greater omentum (dorsal mesogastrium)
**Rotation** means - stomach swings to the left - **right** wall of the stomach becomes **posterior** surface - behind it is the lesser sac
The vagus nerve - **Right** becomes **posterior**; **left** becomes **anterior**
**Duodenum** swings to the **left** - so far the its mesentery **fuses** with the posterior abdominal wall - becomes **retroperitoneal** apart from **D1**
148
Pararectal incision
Lateral border of the rectus below the level of the umbilicus
Can be used for appendicectomy; more commonoly for peritoneal dialysis (tenchkoff catheters)
RISK: extending the incision, can damage the nerves supplying the rectus - causing wasting + predisposition to hernias
149
Anterior relations of the IVC
Mesentery
Third part of duodenum
Pancreas
First part of duodenum
Portal vein
Posterior surface of liver
Diaphragm
Arteries from above down: hepatic, right testicular, right colic, right common iliac
150
Meckel's diverticulum remnant of the duct importance
Can act as a fixed point for the small bowel volvulus
151
Arterial supply of the stomach
Coeliac trunk - giving off left gastric, common hepatic, splenic
Left gastric - lesser curvature of the stomach; anastomoses with the right gastric
Common hepatic - hepatic artery proper, right gastric, and gastroguodenal artery (important as posterior side of duodenum) - becomes the right gastroepiploic artery
Splenic - gives of the short gastric (supplies fundus) and left gastroepiploic supplying the greater curvature (anastomoses with right gastroepiploic)
Gastroduodenal before forming the R gastroepiploic gives off the posterior and anterior superior pancreaticoduodenal artery - which anastomoses with the equivalent inferior PD artery from the SMA; also gives off the supraduodenal supplying its namesake
152
Relation of the pancreas to the superior mesenteric vessels
Head is in the C of the duodenum; attached to the medial border - superior mesenteric vessels run behind it
Neck - posteriorly where the splenic veins meets the superior mesenteric vein to form the portal vein
Body is where the inferior mesenteric vein joins the splenic vein
Tail is in the splenic hilum
Superior mesenteric vessels run **in front** of the uncinate process
Common bile duct passes in a groove behind the head of the pancreas
153
Parts of the glans
External urethral meatus
The corona - edge
The frenulum - fold of mucus membrane attached to the prepuce
Skin of the penis attached to the neck of the glans - foreskin
154
Surfaces of the liver
Superior: dome shaped, related to diaphragm
Posteroinferior: covered with peritoneum (not the gallbladder and porta hepatis and ligamentum venosum); related to the stomach, duodenum, oesophagus, hepatic flexure, right kidney, right suprarenal gland
Posterior: connected to the diaphragm by the coronary ligament, in the middle of which is the bare area
RIght and left lobes are sepated by falciform ligament anteriorly, and the H shapped arrangement posteriorly
H shape:
**L -** ligamentum venosum, ligamentum teres
R - IVC and gallbladder
Middle - caudate and quadrate - separated by porta hepatis
155
Sections of the cloaca
Cephallic - vesicourethral (above the entrance of the mesonephric duct)
Middle - phallic
Lower - pelvic
156
Differences between upper and lower half of anal canal
Surface
Development
Innervation
Lymph
Venous
**Surface**
Columnar epithelium in upper, squamous in lower: can form adenocarcinoma in upper, squamous cell carcinoma in lower
**Development**
Upper from endoderm, lower from ectoderm
**Innervation**
Upper from autonomic - not sensitive to pinprick (important when injecting for haemorrhoids), lower from inferior rectal nerve - sensitive to pin prick
**Lymph drainage**
Upper drains to superior rectal nodes to inferior mesenteric nodes, and also laterally internal iliac nodes
Lower drains into inguinal nodes primarily - carcinoma here can metastasise to the inguinal nodes
**Venous drainage**
Upper drains into the portal system, lower drains into the systemic circulation = site of portosystemic anastomses, can be affected in portal hypertension
157
What structures do the root of the mesentery cross?
D3
aorta
IVC
right psoas major
right ureter
right gonadal vessels
right iliacus
158
Vagina
Muscular tube - approax 7cm long
Cervix projects inwards, vagina surrounds it - with anterior, posterior and lateral fornices
Opens into the vestibule
159
Caecum features
Blind ended pouch, with appendix located posteromedially; 2.5cm below ileocaecal valve
Completely covered by peritoneum
160
Muscles of the abdominal wall
Rectus abdominis
External oblique
Internal oblique
Transversus abdominis
161
What are the taenia coli?
Longitudinal bands of muscle that start at the caecum and end at the recto-sigmoid - converge at the base of the appendix
Shorter than the length of the colon - which causes the characteristic bulges along the colon
Help with peristalsis
No tenia coli on appendix or recturm
162
Left triangular ligament significance?
Formed from left peritoneal covering from falciform ligament
Attaches to the lesser omentum in the fissure of ligamentum venosum
No major blood vessels = can be divided safely to retract the left lobe of the liver to expose the oesophagus
163
Difference between omphalocele and gastrochisis
Omphalocele - bowel covered by peritoneal membrane; failure to retract from the cord
Gastrochisis at the 10th week - herniation without any membrane; likely due to a defect in the membrane
164
Formation of the urethra in females
From the vesicourethral section of the cloaca
165
Surgical approach for a kidney excision
Oblique incision = helfway between 12th rib and iliac crest - extending from lateral border of erector spinae to lateral border of rectus abdominis
Latissimus dorsi + seratus posterior inferior divided
Free edge of external oblique divided
Internal oblique + transversus abdominis divided [reveals peritoneum]
Peritoneum pushed forwards, renal fascial capsule is opened
Subcostal nerve + vessels are left intact
If more room is required: incision extended = quadratus lumborum edge is incised + lateral border of 12th rib excised
Must be careful about medial portion of 12th rib as pleura descends below it
166
Anatomy of testes (not epididymis)
Covered by white fibrous capsure - **tunica albuginea**
Over this the **tunica vaginalis testes** (double layered - parietal and visceral - with a cavity at the top of the testes between the two)
Inside lobules separated by a septum (septa testes - originates from tunica albuginea) - each with 1-3 coils of semineferous ducts - sperm produced here
These drain into rete testes (at the hilum - afferent to drain into head of epididymis)
167
Psoas major
Origin
Insertion
Nerve supply
Action
Deep: Transverse processes of L1-L5; superficial: bodies and discs of T12-L4
Lesser trochanter
L2, L3 (of lumbar plexus between layers of psoas major)
**Flexion** and medial rotation of extended thigh; unilateral causes lateral flexion
168
What is the urogenital sinus?
Made up by two parts of the cloaca - the phallic and pelvic part (middle and caudal)
Formed from the urogenital septum fusing with the cloacal membrane - forming the anal canal and the urogenital sinus
169
Blood supply of the prostate
Via the inferior vesical artery - branch of the internal iliac artery
Venous via the prostatic venous plexus which drains into the internal iliac vein
Some venous blood drains posteriorly: into the vertebral veins of Batson - which is why prostate carcinoma can easily spreadto the bones of the lumbar spine
170
Lymphatic drainage of the vagina
Upper 1/3 = internal and external iliac nodes
Lower 2/3 = superficial inguinal nodes
171
Descending colon features and relations
Splenic flexure to left iliac fossa for sigmoid colon
peritoneum covers its anterior and lateral surface
between the diaphragm and descending colon = **phrenicocolic ligament**
Relations: posteriorly: left kidney, iliacus, quadratus lumborum
anteriorly: small intestine
172
Common iliac artery
Where it starts and bifurcates
What are the 4 anterior relations?
Starts L4; bifurcates at the sacroiliac joint level
Peritoneum, ureters, small intestine, sympathetic nervous system
173
What are the superficial fascia on the anterior abdominal wall?
Camper's - fatty
Scarpa's - membranous / fibrous (thinner) - extends into the perineum as Colle's; attaches with the thigh fascia lata (2.5cm below inguinal ligament)
Scarpa's goes into the penis and scrotum as **dartos**
174
Extrahepatic biliary system
Right and left hepatic duct join at the porta hepatis to form the common hepatic dut
Cystic duct joins to form the common bile duct
starts approx 4cm above the duodenum, travels behind it then on the posterior surface of the head of the pancreas in the groove
Joins with the pancreatic duct to become the ampulla of Vater, controlled by the sphincter of Oddi - opens in D2
Sometimes - can open separately - accessory pancreatic duct - which opens 2cm proximal on the medial surface of the second part of the duodenum
175
Rectum
Length
Route
Peritoneal coverings
Lateral inflexions
approx 12 cm
starts at the distal 1/3 of the sacrum and ends 2.5cm away from the coccyx; where it bends sharply backwards to become the anal canal
**Peritoneum:**
Upper 1/3 - front and sides
Middle 1/3 - front
Lower 1/3 - none (is completely extraperitoneal, below the pelvic peritoneum
3 lateral inflexions; left right left where it has valves of houston at each inflexion
176
Cystocopy
Purpose
Findings of the mucosa/submucosa
Findings of the mucosa/submucosa in the trigone
Ridge between ureters?
Examine the internal meatus and the two ureteric orifices
Loosely adherent to overlying muscle wall, so arranged in folds when empty
Mucosa smooth
Interureteric ridge
177
Where does the glans of the penis develop from?
What develops from the glans?
From the genital tubercle
Terminal part of the urethra develops from the glans
178
Blood supply of the ovary
Artery - ovarian artery, branch of the aorta arising from the level of renal arteries
Veins - right drains into IVC, left into left renal vein
Lymphatic - follows ovarian arteries to para-aortic nodes
179
Levator ani muscles
Types
Origin
Insertion
Nerve supply
Action
Ilicoccygeus, Puborectalis, Pubococcygeus (the medial fibres for the levator prostatae aka puboprostatus / pubovaginalis)
Posterior of pubic body, tendinous arch of the obturator fascia (which runs from pubic body to ischial spine)
Forms a sling around the prostate/vagina (pubococcygeus) and rectum (pubovaginalis); into the sides of the coccyx and the median raphe
Perineal branch of S4 on pelvic surface; branch of inferior rectal and perineal division of the pudendal nerve on the perineal surface
Support of pelvic floor, supports abdominal viscera during raised IAP, controls sphincter action on the rectum and vagina, assists in increasing IAP during defecation, micturition and parturition
180
Relations of the inguinal canal
Anteriorly - skin, campers, scarpas, external oblique aponeurosis internal oblique for lateral 1/3
Posteriorly - Medially - conjoint tendon (aponeurosis of internal oblique and transversus); laterally - transversalis fascia
Superiorly - lower arching fibres of internal oblique and transversus abdominis
Inferiorly - inguinal ligament (recurved edge of external oblique)
181
What structures lie on the posterior wall of the abdomen?
Aorta
IVC
Kidneys
Adrenals
Lumbar sympathetic chain
182
Relations of the ovary (it can be very variable)
Lies along the pelvic wall - in a hall fossa - whose floor is the fascia of obturator internus (with obturator nerve close by)
Anteriorly: external iliac vessels
Posteriorly: ureter and internal iliac vessels
183
Structure of pancreas
Surround by fibrous capsule, whose septae divide the pancreas into lobules
Lobules consist of acini of serous cells - secrete pancreatic enzymes into ducts lined with cuboidal epithelium
Islets of langerhans (pale staining with rich blood supply) scattered across which contain alpha, beta and delta cells which secrete glucagon, insulin and somatostatin
184
Relations of the uterus
Anteriorly; utervesical pouch; lying either on the bladder or the small intersting [cervix lying outside the vagina = related to bladder, cervix within = related to anterior fornix]
Posteriorly: rectouterine pouch (of Douglas)
Laterally: lies to broad ligament; the ureter lies laterally to the supravaginal cervix
185
Blood supply of the vagina
Vaginal
Uterine
Middle rectal
Inferior pudendal - supplying the lower third
Venous drainage - plexus of veins around the connective tissue in the vagina - drains to the internal iliac vein
186
Relations of the abdominal aorta
Anterior
Posterior
Right
Left
Anterior: lesser omentum, stomach, coeliac plexus, pancreas, splenic vein, left renal vein, third part of duodenum, root of mesentery, coils of small intestine, aortic plexus, peritoneum
Posterior: bodies of upper lumbar vertebrae, left lumbar veins, cisterna chyli
Right: IVC, thoracic duct, azygos vein, right sympathetic trunk
Left: left sympathetic trunk
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Venous return of the stomach
Follows arteries - drains into the portal vein
Well supplied stomach - means - 3 of the 4 arteries can be ligated and not have any issue
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Why is appendicitis less common in the extremes of age?
Infancy = very wide lumen
Adults = obliterated
Obstruction can precipitate acute appendicitis; so less common in these age groups
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Clinical points of ureters
How it is detected during surgery?
How is it projected on radiological investigation for a stone?
Readily comes off with the peritoneum, may see worm-like contractions when in cotact with the forceps
At 4 points:
Along the spinous transverse processes
When it crosses sacroiliac joint
When it swings out towards the pelvic wall then reaches the ischial spine
When it turns medially towards the base of the bladder
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Rapidly developing varicoele left side
Left renal tumour - as testicular drainage into the left renal vein is impeded by tumour
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Sigmoid Colon
Start-finish
Mesentery important features
Relations
Pelvic brim to the rectosigmoid junction
Mesentery present - in some places extensive - so allows it to hang down in the pelvis
Root of the sigmoid colon crosses the external iliac vessels and left ureter
Males: rests of the bladder
Females: uterus and posterior fornix of the vagina
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Clinical points of the gallbladder:
Gangrene
Haemorrhage during cholecystectomy
Gallstone ileus
No pain when gallstone in common bile duct
Formation of mucocele of the bladder
Gangrene very unlikely as even if cystic artery is thrombosed - it can get blood supply from the liver bed
Pringle's manoeuvre - compress the common hepatic artery in the free edge of the lesser omentum
Gallbladder fundus close to duodenum = gallstone can ulcerate into duodenum via cholecystoduodenal fistula - causing gallstone ileus
No smooth muscle in the walls of the common bile duct (unlike gallbladder / cystic duct) - so no pain if obstructed
Lots of mucus producing cells - if obstructed duct, bile is absorbed and excess mucus produced = cauing mucocele
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Pelvic fascia types
Parietal - strong, covers muscles, attaches to bone at the margins of muscles
Visceral - loose and cellular over movable structures - levator ani muscles, strong over fixed structures - prostate
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Blood supply of the colon and rectum
**Superior mesenteric artery**
Ileocolic - caecum and start of ascending colon
Right colic - ascending colon
Middle colic - transverse colon
**Inferior mesentery artery**
Left colic - descending colon
sigmoid - sigmoid colon
superior rectal - rectum and upper half of anal canal (lower half by inferior rectal artery)
Each branch anastamoses with its neighbour running the length of the colon - marginal artery of Drummond
Middle rectal - small and only supplies muscle coats of rectum
Superior rectal divides into two when it reaches the rectum - branches run either side
The right branch divides into two branches which descend to the level of **the anal valves** then anastomose with the inferior rectal artery - at 3,7,11 o'clock on lithotomy position;
accompanied by branches of the superior rectal vein --\> SMA portal;
ALSO middle rectal --\> IMA = systemic; inferior rectal --\> pudenal --\> IMA = systemic
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Physiology behind atresia and stenosis
Rapid growth causes obliteration of the lumen of the gut; it then recanalises
If this is incomplete - then atresia / stenosis
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What is the perineal body?
What are the attachments?
Why is it important?
Fibromuscular structure right in the midline between 2 triangles
Attachments are:
bulbospongiosus
superficial + deep transverse perineal muscles
levator ani
anal sphincter
Importnat as if damaged during hildbirth = disrupts levator ani attachment = weakens pelvic floor
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Blood supply of the duodenum
Posterior and anterior superior pancreaticoduodenal artery from the gastroduodenal artery
Posterior and anterior inferior pancreaticoduodenal artery from the superior mesenteric artery
They anastomose, run along the groove between the curve and head of the pancreas - supplying both duodenum and pancreas
Also the supraduodenal artery from the gastroduodenal artery - supplying the superior aspect of the duodenum
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Lesser sac relations
Anterior: lesser omentum and stomach
Superiorly: superior recess whose anterior relation is the caudate lobe of the liver
Inferiorly: projects downwards to transverse mesocolon
Left: spleen, gastrosplenic, lieno-renal ligaments
Right: epiploic foramen of winslow
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Lymphatic drainage of testes
Accompany veins, drain in the **para-aortic nodes**
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What are the muscles of:
Pelvic floor?
Pelvic wall?
Floor: levator ani; coccygeus
Pelvic wall: piriformis (front of sacrum); obturator internus (lateral wall of true pelvis)
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Maldescent of the testes
Can be into an ectopic position - at the root of the penis, the perineum or the thigh
Fail to descend (get stuck along the way) - intraabdominally (within the inguinal canal) or at the external ring
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Where is the arcuate line?
Importance
Halfway between the umbilicus and the pubic symphysis
Inferior epigastric vessels enter the sheath here - rupture of these due to violent contraction = rectus sheath haematoma
Spigelian hernia = lateral portion of rectus sheath @ arcuate line
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Prostatic urethra
Length
Main features
3cm in length
2 urethral crests on the posterior wall - forming a sinus where 15-20 prostatic ducts open
Centre of the sinus is the prostatic utricle - either side are the openings of the ejaculatory ducts (formed from the seminal vesicles + terminal vas deferens)
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Pringle's manoeuvre
Compression of hepatic artery in free edge of lesser omentum
Can be compressed when cystic artery torn during cholecystectomy OR if gross haematoma during liver trauma
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Relations of the vagina
Anterior
Posterior
Superior
Lateral
Anterior: cervix enters the vagina above, base of the bladder and urethra (embedded in the anterior vaginal wall)
Posterior: posterior fornix - covered by peritoneum - rectouterine pouch; below is the rectum; below is the anal canal - separated by the perineal body
Superior: ureter lies superior and lateral to the lateral fornix
Laterally; pelvic fascia and levator ani
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Where is the common hepatic duct and its supraduodenal part of common bile duct lie?
In the free edge of the lesser omentum
Left - hepatic artery; Right - common bile duct
Posterior - portal vein
(epiploic foramen of winslow)
Posterior - IVC
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What are the peritoneal coverings of the liver?
**Falciform ligament** - between right and left lobes, attached to the anterior adominal wall, liver posteriorly - also has the ligamentum teres running in its free edge entering at the hepatic notch
divides to form the left and right peritoneal coverings as well
**Left part of falciform ligament** = forms part of the left triangular ligament - if traced back posteriorly and right - attaches to the lesser omentum in the fissure of ligamentum venosum
**Right part of falciform ligament** = forms the upper leaf of coronary ligament
**Right triangular ligament** formed from the upper and lower leaf of coronary ligament (around the bare area of liver)
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Blood supply of the suprarenal glands
Sup. suprarenal artery: branch of inferior phrenic artery
Middle suprarenal artery: branch of aorta
Inf. suprarenal artery: branch of renal artery
Venous drainage
R - short, directly into IVC
L - long, into left renal vein
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Thoracic oesophagus
Route
Relations- anterior/posterior/left/right
Downwards - through superior and posterior mediastinum
Slightly right at T5 then forwards and left at pass through T10 - oesophageal hiatus
Two vagus nerves form a plexus on the surface - left anteriorly, right posteriorly
Relations:
Anterior: pericardium, left common carotid, trachea, left main bronchus (which constricts it partially)
Posterior: thoracic vertebrae, thoracic duct, hemiazygous vein, descending aorta
Left: left subclavian artery, thoracic duct, aortic arch, left vagus nerve and its RLN, left pleura
Right: right pleura, azygos vein
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Development of the gut - location by blood supply
Foregut - into D2 of duodenum supplied by coeliac trunk
Midgut - into the 2/3 of transverse colon, supplied by superior mesenteric artery
Hindgut - into the ectodermal part of the anal canal; supplied by the inferior mesenteric artery
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Anatomy of the ureters
Approx 25-30cm in length; 3mm in diameter
Start at the renal pelvis where there are 2-4 major calyces, which further branch into up to 12 minor calyces - in each there is a projection of medulla = papilla [outer layer is cortex; inner is medulla]
In the papilla are the collecting ducts
Around the hilum of the kidney is the renal sinus
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Why does scrotal pain refer to abdomen?
Testes develop at L2/3 with its own blood, nerve and lymphatic drainage - migrates down but retains supply
Reciprocal pain from kidneys (eg kidneys stones loin to groin)
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What is the blood supply of the appendix and why is it important?
Appendicular artery which is a branch of the ileocolic artery
It is an end-artery - if it gets thrombosed there is rapid developmment of gangrene in the appendix
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Appendix
Length
Location
Position (x3)
Blood supply
5-10cm
Posteromedial aspect of the caecum; approx 2.5cm below the ileocaecal valve
Can be retrocolic/retrocaecal; pelvic; preiliac/retroileal
Blood supply - appendicular artery - a branch of the ileocolic artery; lies in the free edge of its mesentery - descends behind the ileum as a triangular fold
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Suprarenal glands
Location
Relations
Assymetrical
R = pyramidal, embraces upper pole of kidney
L = crescentic, medial border of kidney above hilum
Anterior:
R - IVC, liver; L - stomach, across lesser sac
Posterior: diaphragm
Inferior: kidney (upper poles)
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Importance of hepatic lymph nodes for gastric cancer
Retrograde spread to the hepatic nodes around porta hepatic - compress the bile ducts causing obstructive jaundice
Complex network aorund the stomach means - if coeliac nodes get involved - treatment is very difficult
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Nerve supply of the bladder
Efferent parasympathetic of S2,3,4 accompany vesical vessels to supply motor fibres to bladder wall + inhibotory fibres to internal sphincter
Efferent sympathetic carry inhibitory fibres to muscle walla nd motor fibres to internal sphincters
External sphincter = striated muscle, by pudendal nerve
Sensory fibres for the distension of the bladder - by both sympathetic and parasympathetic
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Stalked body on testes / epididymis
Appendix testes / appendix epididymis (hydatid of morgagni)
found on upper extremity
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What is the porta hepatis?
Gateway to and from the liver
Contain the common bile duct anteriorly, hepatic artery proper in the middle, portal vein posteriorly
Lymph nodes = enlarge during metastasis cause obstructive jaundice
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What is the femoral sheath?
Propagation of fascia along the femoral artery, vein and canal
anteriorly - transversalis fascia
posteriorly - iliacus fascia
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Structures responsible for forming the urogenital tract
Pronephros (3rd week) - transient and never functions
Mesonephros (4th week) - degenerates but has a duct (mesonephric duct) which persists - forms the **vas deferens** and **epididymis**
Metanephros (5th week) - connected via the metanephric duct (diverticulum of the mesonephric duct) - invaginates the metanephros and branches - forming ureters, calyces, pelvis, **collecting ducts -** this fuses with the proximal part of tubular system + glomeruli formed in the metanephros (others are formed from the duct)
Mesonephric duct loses connection with the renal traact - KIDNEY THEN DEVELOPED
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Formation of Meckel's Diverticulum
Persistence of the communication of the primitive midgut to the yolk sac
It can attach to the back of the umbilicus by a fibrous cord - remnant of the vitellointestinal duct
Important as it can act as a fixed point for small bowel volvulus
Can also open onto the skin via the duct
223
Blood supply of the kidney
Order of structures from hilum of kidney
Renal arteries at L1
Renal vein passes aorta immediately below SMA origin; drains into IVC
Left vein longer than right = received tributaries of gonadal and adrenal vein
Anterior to posterior: vein, artery, ureter
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Lymphatic drainage of the rectum
Along bowel wall - along blood vessels - to the root of SMA/IMA - then to cisterna chyli
Upper 2/3 rectum = superior rectal nodes --\> inferior mesenteric nodes
Lower 2/3 rectum = superior rectal nodes--\> inferior mesenteric nodes + internal iliac nodes
Anal canal **above** dentate line = superior rectal nodes --\> inferior mesenteric nodes + internal iliac nodes
Anal canal **below** dentate line = inguinal nodes primarily
Useful in carcinoma - clearning the blood vessels + resection of the mesentery = remove affected lymph nodes
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Coccygeus
Origin
insertion
Nerve
Action
Spine of ischium
Side of coccyx and lowest part of sacrum; same attachments as sacrospinous ligament
Perineal branch of S4
Holds the coccyx in its natural forward position
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Cellular structure of fallopian tube
Cilliated columnar epithelium - lies in longitudinal ridges
Muscular layers with outer longitudinal and inner circular muscles
Ova is propelled by muscular action, cilia and lubricating fluid
227
Second part of the duodenum
Direction
Main features
Relations
As a curve around the head of the pancreas
Bile ducts and pancreatic ducts open at the duodenal papilla on its posteromedial side (marks the division of the foregut and hindgut)
Above it is the accessory duct of Santorini
Relations: Anteriorly - transverse colon, posteriorly - right kidney and ureter
228
Rotation of the midgut
Pushed into the vitelloinstetinal duct where it rotates around to the left along the axis of the superior mesenteric artery - this causes D2.3.4 to be fixed retroperitoneally
229
Narrowest parts of the ureters
At the pelviureteric junction
At the pelvic brim
Vesicourethral junction
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Relations of the rectum
Anteriorly:
Males: rectovesical pouch, base of bladder, seminal vesicles and prostate (separated here by the rectoprostatic fascia known as fascia of denonviliers - this is key in reducing the spread of prostatic carcinoma posteriorly);
Females: rectouterine pouch (of Douglas), posterior wall of vagina
Upper 2/3 of rectum has peritoneum anteriorly - this relates to coils of small intestine, and in the rectovesical/uterine pouch the sigmoid colon
Posterior: coccycx, sacrum, pre-sacral nerves, middle sacral artery
Laterally: below the peritoneal reflection - levator ani and coccygeus
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Parts of the uterus
Fundus, body, cervix
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Hypermobility of kidneys
Where does blood from a traumatic kidney rupture / pus from a perinephric abcess go?
Can move up/down within fascia but not side-to-side
Tracks down the fasia into the pelvis - as it is open inferiorly
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What do the branches of the sympathetic chain supply?
Why is this important?
Plexuses around abdominal aorta; hypogastric plexus (aka presacral nerves) - to supply pelvic viscera (does this by supplying plexuses distributed along the internal iliac artery
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AAA repair can damage plexuses (aortic and hypogastric) causing ED
Lumbar sympathectomy (2,3,4 ganglia of chain) - to treat plantar hyperhidrosis or vasospastic conditions of lower limb
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Femoral ring composition
**Medial part of femoral sheath**
Anterior: inguinal ligament
Medially: lacunar ligament (abnormal obturator artery can be present - can cause issues during femoral hernia repair
Posterior; pectineal ligament
Laterally: femoral vein
235
External oblique
Origin
Insertion
Direction of fibres
Importance of lower border - landmarks
Outer surface of lower 8 ribs
Anterior portion of iliac crest, pubic tubercle, pubic crest, linea alba
Downwards and medially
Lower border between ASIS and pubic tubercle = inguinal ligament
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What can be palpated on a DRE?
Both:
Anorectal ring
Coccyx
Sacrum
Ischiorectal fossa
Ischial spine
Males:
Prostate
Seminal vesicles (sometimes)
Females:
Perineal body
Cervix
Ovaraies (sometimes)
