Anatomy(The Abdomen, Pelvis and Perineum) Flashcards
Gut developed from what
Primitive endodermal tube
Parts of gut with blood supply
divided into three parts:
• foregut: extends to the entry of the bile duct into the
duodenum (supplied by the coeliac axis)
• midgut: extends to distal transverse colon (supplied by
superior mesenteric artery)
• hindgut: extends to ectodermal part of anal canal (sup-
plied by inferior mesenteric artery).
Rotation of stomach with vagus
Clockwise rotation seen from above
• Rotates so that the right wall of the stomach now
becomes its posterior surface, forming the lesser sac
behind.
• Vagus nerves rotate with the stomach so that the right
vagus nerve becomes posterior and the left anterior.
Peritoneal relation of duodenum
all retroperitoneal.except 1st inch
What is vitellointestinal duct
the vitelline duct, also known as the vitellointestinal duct, the yolk stalk, the omphaloenteric duct or the omphalomesenteric duct is a long narrow tube that joins the yolk sac to the midgut
yolk sac?
yolk sac is far more widely used. In humans, the yolk sac is important in early embryonic blood supply and much of it is incorporated into the primordial gut during the fourth week of embryonic development.
During development position change of caecum
The caecum descends into its definitive position in the
right iliac fossa, pulling the colon with it.
Relation of peritoneum with mesentery
•As the stomach rotates clockwise the duodenum
swings to the right, its mesentery fusing with the peri-
toneum of the posterior abdominal wall
•The mesenteries of the ascending and descending colon blend with the posterior abdominal wall, except for the
sigmoid colon, which retains a mesentery.
Mechanism of gut atresia or stenosis
In early fetal life, growth obliterates the lumen of the
developing gut. It then recanalizes. If recanalization is
incomplete, areas of atresia or stenosis may result.
What is Meckel’s diverticulum?
The communication between the primitive midgut and yolk sac may persist as a Meckel’s diverticulum attached to the back of the umbilicus by a fibrous cord, a remnant of the vitellointestinal duct (this may act as a fixed point for small bowel volvulus).
What is peritoneal band of Ladd
The caecum may also be free and may
obstruct the second part of the duodenum because of
peritoneal bands (of Ladd) passing across it. The base
of the mesentery is then very narrow as it is not fixed
at either end, and the whole of the midgut may twist
around its own blood supply, i.e. volvulus neonatorum.
*A peritoneal band of Ladd, also known as a Ladd’s band or mesenteric attachment, is a fibrous band of tissue that can form in the peritoneum during fetal intestinal rotation errors. The band can stretch from the caecum to the subhepatic region and usually attaches the caecum to the retroperitoneum in the right lower quadrant. Ladd’s bands are the most common type of peritoneal band that can cause intestinal malrotation.
What is exomphalos?
Persistence of midgut herniation at the umbilicus may
occur after birth
Exomphalos vs Gastroschisis
The prefix “ex-“ is a Latin word that means “out of,” “from
*Exomphalos/omphalocele
abdomen doesn’t close around the umbilical cord allowing organs to protrude into the the cord.
*Gastroschisis
defect in the abdominal wall to the side of the umbilical cord, usually the right side.
#The word omphalocele comes from the Greek words omphalos, which means “umbilicus”, and cele, which means “cavity”
#The word “gastroschisis” comes from the Greek words gastro, meaning “stomach”, and schisi, meaning “split”.
Function of urorectal septum
Urorectal septum divides the cloaca into bladder anteri-
orly and rectum (hindgut) posteriorly.
• At its caudal end, the urorectal septum reaches the cloa-
cal membrane and divides it into anal and urogenital
membranes.
• The anal membrane separates the hindgut from the
proctodeum (anal pit).
• Eventually the anal membrane breaks down and conti-
nuity is established between the anal pit and the hindgut.
• Failure of the anal membrane to rupture or anal pit to
develop results in imperforate anus.
Formation of anal canal
Anal canal develops from the end of the hindgut (endo-
derm) and an invagination of ectoderm, the proctodeum.
What is urachus
The connections between cloaca (rudimentary bladder) and allantois. The urachus is the embryonic remnant of this connection.
What is urachus
The connections between cloaca (rudimentary bladder) and allantois. The urachus is the embryonic remnant of this connection.
What gives off epididymis and vas
• Mesonephros develops at the 4th week; this also degenerates but its duct persists in the male to form the epididymis and vas deferens.
Metanephros gives off what
proximal part of the tubular system and glomeruli which are developing from the metanephros
Convention of metanephros and metanephric duct
• Metanephros develops at the 5th week in the pelvis.Metanephric duct arises as a diverticulum from the
lower end of the mesonephric duct.
• Metanephric duct (ureteric bud) invaginates the metanephros, undergoing repeated branching to develop into the ureter, pelvis, calyces and collecting tubules.
Migration of kidney
• The kidney develops in the pelvis, eventually migrating upwards, its blood supply moving cranially with it, initially being from the iliac arteries and eventually from the aorta.
What is ureteric bud
Metanephric duct
Mechanism of forming polycystic kidney
• Failure of fusion of the derivatives of the ureteric bud with the derivatives of the metanephros may give rise to autosomal recessive form of polycystic kidney.
Ureteric cause of urinary incontinence
• The ureteric bud may branch early, giving rise to double ureter. Rarely, the extra ureter may open ectopically into the vagina or urethra, resulting in urinary incontinence.
Primitive parts of urinary bladder
• Urinary bladder is formed partly from the cloaca and partly from the ends of the mesonephric ducts.
• The anterior part of the cloaca is divided into three parts:
• cephalic: vesicourethral
• middle: pelvic portion
• caudal: phallic portion.
• The latter two constitute the urogenital sinus.
• The ureter and mesonephric duct come to open separately into the vesicourethral portion. Lol
• The mesonephric duct participates in the formation of the trigone and dorsal wall of the prostatic urethra.
• The remainder of the vesicourethral portion forms the body of the bladder and part of the prostatic urethra.
• The apex of the bladder is prolonged to the umbilicus as the urachus (where the primitive bladder joins the allantois).
Function of allantois
It helps the embryo exchange gases and handle liquid waste.
Formation of urogenital sinus
Pelvic and phallic portion of anterior part of cloaca
Urorectal septum’s shape change
Fork to spoon
Terminal part of urorectal septum forms what
Perineal body
Cause of ectopia vesicae with cleft pelvis(no symphysis pubis) with Epispadias
Dorsal wall of the urethra is partially or completely absent and is caused by failure
of infraumbilical mesodermal development.
Development germ layer of testes
• Develops as a mesodermal ridge on the posterior abdominal wall medial to the mesonephros (urogenital ridges).
• Links with mesonephric duct, which forms the epididymis, vas deferens and ejaculatory ducts.
Mechanism of formation of hydrocele
• Processus vaginalis may fail to obliterate or may become partially obliterated, resulting in a variety of hydroceles
Layers of fascia on abdomen wall
Only superficial fascia
But 2 layers of it in the lower abdomen
Fatty camper
Fibrous scarpa
Extension of fascia of abdominal wall
• Superficial fascia extends onto penis and scrotum.
• Scarpa’s fascia is attached to the deep fascia of thigh 2.5 cm below the inguinal ligament.
• Extends into perineum as Colles’ fascia.
• Colles’ fascia is attached to the perineal body, perineal membrane and laterally to the rami of the pubis and ischium.
In which part of urethral injury urine tracks into the scrotum, perineum and penis and into abdominal wall deep to Scarpa’s fascia
In rupture of the bulbous urethra
Like hydrocele of the cord in male what is a similar lesion exists in the female?
hydrocele of the canal of Nuck
Origin and insertion of rectus abdominis
• Origin: fifth, sixth, seventh costal cartilages.
• Insertion: Only Pubic CREST.
Origin and insertion of external oblique
• Origin: outer surface of lower eight ribs.
E8
• Insertion: linea alba, pubic crest, pubic tubercle, anterior half of iliac crest.
• Fibres run downwards and medially.(Pocket)
(into Iliac crest and Pubic crest)
Formation of inguinal ligament
• Between anterior superior and iliac spine and pubic tubercle, recurved lower border of external oblique forms the inguinal ligament.
Origin and insertion of internal oblique
• Origin: lumbar fascia, anterior two-thirds of iliac CREST and lateral two-thirds of inguinal ligament.(As Continuous strip)
• Insertion: linea alba and pubic CREST via conjoint tendon
(Iliac crest to Pubic crest)
Origin and insertion of transversus abdominis
• Origin: deep surface of lower sixth costal cartilages (interdigitating with diaphragm-THAT’S WHY LOWER 6) lumbar fascia, anterior two-thirds of iliac CREST, lateral THIRD of inguinal ligament.
• Insertion: linea alba and pubic CREST via the conjoint tendon.
(Iliac crest to Pubic crest)
What is line of Douglas with it’s importance
• The lower border of the POSTERIOR aponeurotic part of the Rectus sheath is marked by a crescentic line halfway between umbilicus and pubic symphysis
the Arcuate line of Douglas
IMPORTANCE
• At this point the inferior epigastric vessels enter the sheath.The epigastric vessels (superior and inferior) are applied to the POSTERIOR surface of the rectus muscle. Rupture of these with violent contraction of the rectus muscle leads to a rectus sheath HAEMATOMA.
• A SPIGELIAN hernia emerges at the LATERAL part of the rectus sheath at the level of the arcuate line of Douglas.
•Aponeurosis of internal oblique doesn’t split below this Arcuate line.
Formation and extension of Linea Alba
• The rectus sheath fuses in the midline to form the linea alba, which runs from the xiphisternum to the pubic SYMPHYSIS.
When both sided Kocher’s incisions are connected? And which nerve is at risk?
For anterior approach to kidneyS
9th coastal nerve, inquiry may lead to incisional hernia
Lanz Incision and Gridiron Incision
McBurney’s point is at two-thirds from the umbilicus to the anterior superior iliac spine.
Gridiron (muscle splitting) is VERTICAL on the joining line
The Lanz (Rockey-Davis) it’s a variation of the traditional Gridiron incision. So it is also made at McBurney’s point,The Lanz incision is more transverse than McBurney’s incision, it is HORIZONTAL to transverse plane, and it extends more medially toward the rectus abdominis
Which muscle is not encountered in grid iron incision
External oblique
(Cause here it has become aponeurotic)
Relation of vessels with tendinous intersections of rectus abdominis
segmental vessels enter here and bleeding will be encountered in case of paramedian incision
What is Battle incision with indication
William Henry Battle is known for a number of medical discoveries, including Battle’s incision, Battle’s Sign, and Battle’s operation. Battle’s Sign is a bruise over the mastoid process that indicates a basilar skull fracture. Battle’s operation is a surgical procedure for femoral hernia.
Pararectus incision (rectus muscle is retracted medially)
Indication
1.more often for open insertion of peritoneal dialysis catheters (Tenckhoff
catheter for continuous ambulatory peritoneal dialysis).
2.occasionally for appendicectomy
Deep Inguinal Ring
• DEFECT in transversalis fascia
• Lies 1 cm above midpoint of inguinal ligament.
• Immediately LATERAL to inferior epigastric vessels.
Superficial Inguinal Ring
• V-shaped DEFECT in inguinal LIGAMENT.
• Lies above and MEDlAL to pubic TUBERCLE
Spermatic Cord contains what?
• Three layers of fascia
• Three arteries
• Three nerves
• Three other structures
What is medial compartment of the femoral sheath?
FEMORAL CANAL
What forms the femoral sheath?
Femoral sheath is prolongation of transversalis fascia anteriorly and iliacus fascia posteriorly
Boundaries of the femoral ring
• anterior:ligament of Poupart
• posteriorly:ligament of Astley Cooper
• laterally: femoral vein(so it’s space for expansion is medically)
• medially:ligament of Gimbernat
inguinal ligament (of Poupart)
pectineal ligament (of Astley Cooper)
lacunar ligament (of Gimbernat)
CAUTION:
Occasionally an abnormal obturator artery runs in close relationship to the lacunar ligament and is in danger during surgery for femoral hernia.
What are the contents and function of femoral canal?
• fat
• lymphatics
• lymph node (Cloquet’s node).
#Cloquet’s node, also known as Rosenmüller’s node, is the topmost lymph node in the deep inguinal lymph node group.
(one of the ring’s functions is dead space for expansion of femoral vein, other function is pathway for lymphatics of lower limb to external iliac
nodes.)
Origin point of direct hernia
A direct hernia BULGES through the POSTERIOR wall of the inguinal
canal medial to the INFERIOR epigastric artery through Hesselbach’s triangle.
Boundaries of Hesselbach’s triangle
• laterally: inferior epigastric artery
• inferiorly: inguinal ligament
• medially: lateral border of rectus abdominis.
Distinction between direct and indirect inguinal hernia at operation depends on what?
depends on relationship of sac to the INFERIOR epigastric vessels:
direct hernia is medial,
indirect lies lateral to the artery.
Clinical distinction between inguinal and femoral hernias depends on what?
Depends on the relationship to the pubic TUBERCLE:
inguinal hernias lie above and medially, femoral hernias lie below and laterally.
Clinical distinction between inguinal and femoral hernias depends on what?
Depends on the relationship to the pubic TUBERCLE:
inguinal hernias lie above and medially, femoral hernias lie below and laterally.
Lining of peritoneum
Lined by mesothelium (simple squamous epithelium).
What is the pouch of Douglas?
It is rectouterine pouch
What is the Falciform ligament?
Falciform ligament passes upwards from umbilicus and slightly to right of midline to liver (containing the ligamentum teres in its free edge).
What is the lesser omentum?
After enclosing the liver the peritoneum descends from
the porta hepatis as a double layer, i.e. the lesser omentum.
What is the greater omentum?
Lesser omentum separates to enclose the stomach, reforming again on the greater curvature, and then LOOPS DOWNWARDS
again, TURNING UPWARDS (so 4 layers of two fold visceral peritoneum) and attaching to the length of the transverse colon, forming the greater omentum.
Describe transverse mesocolon’s position.
The transverse mesocolon is a fold of peritoneum originating from lower lip of greater omentum that surrounds the transverse colon and connects it to the posterior abdominal wall.
Examples of intraperitoneal organs
organs located within the visceral peritoneum of the abdominal cavity. The visceral peritoneum COVERS the organs on BOTH the FRONT and BACK surfaces.
EXAMPLES:
Right surface of abdominal oesophagus
Stomach
Liver
Spleen
Tail of pancreas (within linorenal ligament)
First and fourth parts of the duodenum
Jejunum
Ileum
Caecum
Transverse colon
Sigmoid colon
Upper third of rectum
Dome of bladder
Uterus
Location of he lesser sac
A space in the abdomen BETWEEN the STOMACH and PANCREAS. It’s part of the peritoneal cavity and is formed by the lesser and greater omentum(including space between descending and accenting lips).
The ONLY natural communication between the greater and lesser peritoneal sacs is the omental foramen, also known as the foramen of Winslow or the epiploic foramen.
The omental foramen is a small window with clear borders that define it:
Anterior: Hepatoduodenal ligament
Posterior: Inferior vena cava and the right crus of the diaphragm
Superior: Caudate lobe of the liver
Inferior: Superior part of the duodenum
The lesser sac, also known as the omental bursa, is located behind the stomach and lesser omentum, and in front of the pancreas and duodenum. Its function is to allow the stomach to move without restriction.
Which artery is pinched in Pringle’s manoeuvere?
Hepatic artery
Which is left subhepatic space
Lesser sac
Another name of the right subhepatic space with boundaries.
• Right subhepatic space (renal well of Rutherford Morrison) is bounded by:
• above: liver with attached gall bladder
• behind: posterior abdominal wall and kidney
• below: duodenum.
What separates right and left subphrenic spaces
Falciform ligament
What is Psoas test
An inflamed retrocaecal or retrocolic appendix lies in contact with psoas—the resulting spasm in the muscle leads to persistent flexion of the hip and pain on attempted extension.
Where does the abdominal aorta divide into the common iliac arteries?
left side of front of body at fourth lumbar vertebra
Level of bifurcation of common iliac artery
Sacroiliac joint
Origin of inferior epigastric artery
From external iliac artery just above inguinal ligament
Level of formation of IVC
Formed by junction of two common iliac veins behind the right common iliac artery at the level of the 5TH lumbar vertebra
Why should we take caution for aortic and hypogastric plexuses?
The pelvic plexus receives sympathetic and parasympathetic nerves, which provide deep autonomic innervation to the organs involved in ejaculation.This includes the prostate, seminal vesicles, and vas deferens. Norepinephrine is the neurotransmitter that stimulates the sympathetic nervous system, while acetylcholine is the parasympathetic neurotransmitter.
• Resection of abdominal aortic aneurysm and extensive pelvic dissection may remove aortic and hypogastric plexuses and hence compromise ejaculation.
Surgical treatment for planter hyperhidrosis or vasospastic conditions of the lower limb.
Lumbar sympathectomy.
Usually the second, third and fourth ganglia are excised with the intermediate chain.
Similarity between coccygeus muscle and sacrospinous ligament
Both of them have the same attachments
Nerve supply of levator Ani muscle
Perineal branch of S4 on pelvic surface, and
branch of the inferior rectal and perineal division of the pudendal nerve on the perineal surface.
Something about Pelvic fascia.
• Parietal pelvic fascia is a strong membrane covering the muscles of pelvic wall and is attached to bones at margins of muscles.
• Visceral pelvic fascia is loose and cellular over movable structures, e.g. levator ani, bladder, rectum.
• It is strong and membranous over fixed or nondistensible structures, e.g. prostate.
Parts of levator ani muscle
From before backwards
•A sling from pubis to perineal body (Levator prostate/sphincter vaginae)
•Forms a sling around the rectum and anus inserting into and reinforcing the deep part of the anal sphincter at the anorectal ring called Puborectalis
•Pubococcygeus
•Iliococcygeus
Division of cloaca,cloacal membrane and perineum by urorectal septum
•Cloaca >urogenital sinus+anorectal sinus
•Cloacal membrane >urogenital membrane +anorectal membrane
•Perineum>urogenital triangle+anal triangle
(Horizontal) (30°tilted)
How does genial TUBERCLE is formed?
By proliferation of mesoderm which elevates adjacent ectoderm turning into penis/clitoris.
So this TUBERCLE is part of phallic part of urogenital sinus
Fate of urachus TUBE
median umbilical LIGAMENT
Location of deep perineal pouch and contents
Deep to perineal membrane
Contents
Deep transverse perineal muscle
External urethral sphincter
Bulbourethral gland of Cowper (but it’s counterpart Bartholin’s gland of female is located in superficial perineal pouch)
Passage of urethral, vagina
The location of ischioanal fossae, contents and clinical importance
Clinical Points
Between levator ani superiorly and deep perineal pouch(deep to perineal membrane) inferiorly on each sides of anal canal
Or
Between pelvic diaphragm(levator ani is a part of it) and urogenital diaphragm(anterior part of perineal membrane)
*Contents:
•Mainly fat and is crossed by the inferior rectal vessels and nerves from lateral to medial side.
• The internal pudendal vessel and pudendal nerve lie on the lateral wall of the fossa in the pudendal canal (of Alcock), a TUNNEL of FASCIA which is continuous with the fascia overlying obturator internus.
• Infection of the ischiorectal space may occur from boils or abscesses on the perianal skin, from lesions within the rectum and anal canal, from pelvic collections bursting through levator ani.
• The fossae communicate with one another behind the anus, allowing infection to pass readily from one fossa to another.
• The pudendal nerves can be blocked in Alcock’s canal on either side, giving regional anaesthesia in forceps delivery.Pudendal nerve is seen arising from S2–S4 and exiting pelvis to enter gluteal region through the greater sciatic foramen. The nerve gives rise to the inferior rectal nerve, perineal nerve, and the dorsal nerve of the penis or clitoris.
Location of superficial perineal pouch, it’s important contents and another name
Between PERINEAL MEMBRANE and relevant part of COLLES’ FASCIA [deeper layer (membranous layer) of the superficial perineal fascia. It is thin, aponeurotic in structure, and of considerable strength]
•Bulbospongiosus muscle covers the bulb of the penis and the corpus spongiosum.
•Ischiocavernosus muscle covers the crus of the penis and the corpus cavernosum.
•Superficial transverse perineal muscle
•Erectile tissues(spongiosum,cavernosum)
•Bartholin’s gland(of female)
Colles ligament (1811) – small triangular fascia that springs from the pubic crest and ilio-pectineal line and passes upwards and inwards towards the linea alba under cover of the internal pillar of the external abdominal ring. It is also called the reflected inguinal ligament (triangular fascia) is a layer of tendinous fibers of a triangular shape, formed by an expansion from the lacunar ligament and the inferior crus of the subcutaneous inguinal ring.It passes medialward behind the spermatic cord, and expands into a somewhat fan-shaped band, lying behind the superior crus of the subcutaneous inguinal ring, and in front of the inguinal aponeurotic falx, and interlaces with the ligament of the other side of the linea alba.
Superficial and Deep transverse perineal muscle
•Superficial runs across the superficial perineal space.The deep branch of the perineal nerve innervates this muscle.
•Deep is located in the deep perineal space.The pudendal nerve innervates this muscle.
Which ligament gives origin to gluteus maximus?
Sacrotuberous
Relation between BULB of penis and GLANS of penis
Corpus SPONGIOSUM Commences at the perineal membrane by an enlargement the BULB and Runs forward in the groove on the undersurface of the corpora cavernosa, expanding over their extremities to form the GLANS.
Relation between BULB of penis and GLANS of penis and function of their connection
Corpus SPONGIOSUM Commences at the perineal membrane by an enlargement the BULB and Runs forward in the groove on the undersurface of the corpora cavernosa, expanding over their extremities to form the GLANS.
*Function
The function of the corpus spongiosum in erection is to prevent the urethra from pinching closed, thereby maintaining the urethra as a viable channel for ejaculation. To do this, the corpus spongiosum remains pliable(flexible) during erection while the corpora cavernosa penis become engorged with blood.
Demarcating line between membranous and spinach urethra
The perineal membrane is an anatomical term for a fibrous membrane in the perineum. It is the superior border of the superficial perineal pouch, and the inferior border of the deep perineal pouch. The perineal membrane is triangular in shape. It attaches to both ischiopubic rami of the pelvis.
Location of external urethral sphincter
The membranous urethra is surrounded by the external urethral sphincter, which is made up of an internal lissosphincter(smooth muscle) and an external rhabdosphincter(striated muscle).
Location of external urethral sphincter
The membranous urethra is surrounded by the external urethral sphincter, which is made up of an internal lissosphincter(smooth muscle) and an external rhabdosphincter(striated muscle).
What forms prepuce in female
Labia minora
Why do we use a scrotal suspension bag after hernial surgery?
Scrotal subcutaneous tissue is continuous with the fascia of the abdominal wall and perineum; extravasation of urine or blood deep to this plane gravitates into the scrotum, hence frequent bruising of scrotum following hernia repair..Also it fills with oedema fluid in cardiac or renal failure.
Function of the seminiferous tubules.
Sperm is produced here
Testicular artery anastomoses with which artery? And importance of anastomosis.
• Testicular artery anastomoses with artery to vas (which supplies the vas deferens and epididymis), which arises from the inferior vesical branch of the internal iliac artery.
• Anastomosis between these two arteries means that ligation of the testicular artery is not necessarily followed by testicular atrophy.
Level of formation of testicular vein
•Pampiniform plexus becomes a single vessel, the testicular vein, at the DEEP
inguinal ring.
• Right testicular vein drains into the IVC; the left into the
left renal vein.
Testis arises at which level ?
The testis arises at the level of L2/3 on the posterior abdominal wall.
The common ejaculatory duct opening
• The common ejaculatory duct traverses the prostate to open into the prostatic urethra at the Verumontanum on either side of the Utricle.
Relation of oesophagus and crus of diaphragm
It passes through oesophageal opening in the Right crus of the diaphragm at level T10.
Blood Supply of oesophagus in neck, thorax and abdomen.
•Arterial supply:
• In the neck from the inferior thyroid arteries.
• In the thorax: from branches of the aorta.
• In the abdomen: from the left gastric and inferior phrenic arteries.
:• Venous drainage:
• cervical part to inferior thyroid veins
• thoracic part to azygos veins
• abdominal part to azygos vein (systemic) and partly to the left gastric veins (portal).
Nerve Supply of oesophagus
The PNS stimulates peristalsis through the myenteric plexus. It also decreases the pressure in the LES.PNS increases secretory activity.
• Upper third: parasympathetics via recurrent laryngeal nerve and sympathetic nerves from the middle cervical ganglion along the inferior thyroid artery.
• Below the root of the lung, the
vagi (parasympathetic) and sympathetic nerves contribute to the oesophageal plexus.
#The SNS is part of the thoracic and cervical chain nerves.
SNS can constrict blood vessels in the esophagus,relax the muscle wall of the esophagus ,cause contractions of the upper and lower esophageal sphincters (UES and LES).The SNS can sense pain directly.
Why there is a risk of dysphagia in thyroid surgery
May occur from injury to recurrent laryngeal nerve supplying upper third of oesophagus
Muscle of esophagus
Upper third is striated
Lower 2/3 is smooth
Type of inner and outer lining of esophagus
Inner by stratified squamous
Outer by loose areolar
Level of 3 esophageal constrictions
17 cricoid/commencement
28 left main bronchus
43 diaphragm/termination
In the lower oesophagus there is a site of portosystemic anastomosis by which vessels?
between the azygos vein (systemic)
and the oesophageal tributary of the left gastric vein(portal).
Oesophageal varices may arise at this site in portal hypertension.
Relation of mitral stenosis and esophagus
•Left atrial enlargement owing to mitral stenosis may be noted on a barium swallow, which shows marked BACKWARDS displacement of the oesophagus by the dilated atrium.
What is incisura angularis?
• Junction of body with pyloric antrum marked along the lesser curve by a notch—the incisura angularis.
Importance of prepyloric vein of Mayo
•The prepyloric vein is the final branch that connects to the right gastric vein, which drains the duodenum’s proximal part
•. Junction of pylorus with duodenum is MARKED by a constant prepyloric vein of Mayo, which crosses it vertically.
•The prepyloric vein of Mayo MARKS the distal end of a pyloric tumor.
•During surgery, surgeons stop the myotomy 1–2 mm short of the prepyloric vein to prevent duodenal perforation.
Where does the stomach drain it’s blood
Into portal system
•Left and right gastric veins: Drain into the portal vein
•Short gastric veins and left gastroomental(gastroepiploic) vein: Drain into the splenic vein
•Right gastroomental vein: Drains into the superior mesenteric vein
Ultimate destination of lymph from stomach
Coeliac nodes
Which vagus supplies pyloric sphincter?
Pyloric branch of anterior vagus ( because it is in close proximity to the stomach)
nerves of Latarjet
Gastric divisions of both anterior and posterior vagi descend from cardia along the lesser curve between the anterior and posterior peritoneal attachments of the lesser omentum.These nerves are referred to as the anterior and posterior nerves of Latarjet.
Division of gastric mucosa with function
cardiac gland area -mucus
oxyntic (parietal) gland area with chief-acid, zymogen
pyloric end area -gastrin,mucus
Relation among the second part of the duodenum,transverse colon,right kidney
and ureter.
The second part of the duodenum is crossed by the transverse colon and lies anteriorly to the right kidney and ureter.
Relation among third Part of duodenum, the IVC, the aorta and third lumbar vertebra,root of the mesentery and superior mesenteric vessels.
•Third Part of duodenum crosses the IVC, the aorta and third lumbar vertebra.
• Crossed anteriorly by the root of the mesentery and superior mesenteric vessels.
What is the suspensory ligament of Treitz(ˈtrīts)? And it’s importance.
It is a peritoneal fold descending from the RIGHT crus of the diaphragm (not left) to the termination of the duodenum at the DJ flexure.
The ligament of Treitz can range in length from half an inch to 2.5 inches. It’s made up of skeletal muscle from the diaphragm and smooth muscle from the duodenum.
*Importance
•At surgery the DJ flexure may be identified by the presence of the ligament
•An abnormally long ligament can cause intestinal malrotation.
•Abnormal thickening, hypertrophy/some primary and metastatic tumors can involve the ligament, or shortening of the ligament can RARELY lead to SMAS (Superior mesenteric artery syndrome).Contraction of the ligament pulls the duodenum upward into the vascular angle between the superior mesenteric artery and the aorta.
Importance of posterior relation of gastroduodenal artery to 1st part of duodenum
Erosion
of POSTERIOR duodenal ulcers into the gastroduodenal
artery will cause haematemesis AND melaena.
mesentery vs omentum
A large double layer called the omentum covers the front of your abdomen like an apron. A double layer in the back called the mesentery attaches your intestines to your back abdominal wall.
What is the marginal artery of Drummond?
The marginal artery of Drummond, also known as the marginal arcade, is an anastomotic arterial channel that supplies the entirety of the large intestine. It extends from the ileocecal junction to the rectosigmoid junction. As it runs in close proximity along the inner border of the large intestine, it is sometimes referred to as juxtacolic artery.
