Esophagus, Stomach, Small intestine and Large intestine Flashcards
1
Q
Structure of esophagus
A
- muscular tube
- 25cm long and 2 cm diameter
- cervical part: cricoid cartilage to thoracic inlet
- thoracic part: thoracic inlet to diaphragm
- abdominal part: diaphragm to cardiac opening in stomach
- upper 1/3- striated muscle
- middle 1/3- mixed skeletal and smooth
- lower 1/3 - smooth muscle
2
Q
Constrictors of esophagus
A
- Cervical constrictor:
- at pharyngo-esophageal junction
- caused by cricoid cartilage
- lower constrictor of pharynx form Upper Esophageal sphincter - Thoracic constrictor:
- crossed by aortic arch and left main bronchus - Diaphragmatic constrictor:
- at esophageal hiatus
- Lower esophageal sphincter- by right crus
3
Q
Laimer trigone
A
- triangular V-shaped area on posterior side of esophagus
- area of weakness due to absence of outer longitudinal muscle layer
- potential site of herniation or Zener Diverticulum
4
Q
Z-line
A
where the mucosa abruptly changes from esophageal (stratified non-keratinized squamous) to gastric (simple columnar, glandular) at the cardia
5
Q
Arterial supply of Esophagus
A
- Esophageal branch of Inferior Thyroid artery
- Esophageal branch of Left and Right bronchial a
- Esophageal branches of Thoracic aorta
- Left Gastric artery
- Left Inferior Phrenic artery
6
Q
Venous drainage of Esophagus
A
- Left Gastric vein of stomach into Portal system
- Esophageal veins to Azygos and hemiazygos veins
7
Q
Lymphatic drainage of Esophagus
A
- Left gastric lymph nodes
- Inferior Deep cervical lymph nodes
- Para-tracheal lymoh nodes
- Posterior mediastinal and intercosal lymph nodes
8
Q
Innervation of Esophagus
A
Vagal nerves
sympathetic: cervical and thoracic sympathetic chain
9
Q
Muscular layer of Stomach
A
innermost oblique
inner circular
outer longitudinal
10
Q
Ligaments of stomach
A
- Hepatogastric ligament: from liver into lesser curvature, part of lesser omentum, contains left and right gastric artery and vein
- Gastrocholic ligament: greater omentum to transverse mesocolon, 6 layers, contains left and right gastroepiploic arteries
- Gastrosplenic ligament: continuation of gastrocolic
- Gastrophrenic ligament
11
Q
Arterial supply of stomach
A
- Left gastric a. (celiac trunk)
- Right gastric a. (proper hepatic a.)
- Posterior gastric a. (splenic a.)
- Short gastric a. (splenic a.)
- Left Gastro-omental a. (splenic a.)
- Right Gastro-omental a. (gastro-duodenal a.)
12
Q
Vanous drainage of Stomach
A
- Left gastric vein (⇒portal vein)
- Right gastric vein (⇒portal vein)
- Left Gastroepiploic vein (⇒splenic vein)
- Right gastroepiploic vein (⇒sup. mesenteric vein)
- Prepyloric vein
13
Q
Lymphatic drainage of Stomach
A
- sup 1/3: gastric lymph node ⇒ cisterna chyli
- fundus, corpus: pancreatico-splenic lymph nodes
- right inf: pyloric and gastroomental lymph nodes
- left inf: pancreatico-duodenal lymph nodes
14
Q
Innervation of Stomach
A
parasymp: Anterior /Posterior Vagal trunks + celiac plexus
symp: Th6-Th9⇒ celiac plexus through greater splanchnic nerves
15
Q
Duodenojejunal junction
A
- level of L2
- duodenojejunal flexure
- fixed by Suspensory ligament of Treitz
16
Q
Superior Horizontal part of Duodenum
A
- 5cm long
- anterolateral to L1
- has ampulla - hepatoduodenal ligament attaches
- intraperitoneal
17
Q
Descending part of Duodenum
A
- 7-10 cm long
- right side of L1-L3
- Vater’s papilla + sphincter of Oddi
- minor duodenal papilla + sphincter of Santorini
- retroperitoneal
18
Q
Inferior Horizontal part of Duodenum
A
- 6-8 cm long, crosses L3
- retroperitoneal
19
Q
Ascending part of Duodenum
A
- 5cm long, left side of L3-L2
- retroperitoneal
20
Q
Arterial supply of Duodenum
A
- Superior Pancreaticoduodenal a (gastroduodenal)
- Gastroduodenal a (common hepatic a)
- Inferior Pancreaticoduodenal a (SMA)
VEINS:
Pancreaticoduodenal veins ⇒ SMV
21
Q
Lymphatic drainage of Duodenum
A
- anterior lymph vessels ⇒ pancreaticoduodenal + pyloric lymph nodes
- posterior lymph vessels ⇒ SMLN
22
Q
Innervation of Duodenum
A
parasymp: Vagus
symp: Lesser/greater Splanchnic nerves
23
Q
Jejunum
A
- intraperitoneal
- wider, emptier, thicker walled
- less fat, less prominent arterial arcades, longer vasa recta
24
Q
Ileum
A
- longer than jejunum
- darker, more vertical loops
- contains Payer’s patches
- shorter plica circularis, shorter vasa recta, more mesenteric fat, more prominent arcades
25
Meckel's diverticulum
remains of yolk stalk of embryo, which when persistent abnormally as sac or pouch, located 60-90cm orally from ileocecal junction; may be free or attached to umbilicus
26
Blood supply of Jejunum and Ileum
ARTERY:
- superior mesenteric artery
VEIN:
- superior mesenteric vein ⇒ splenic vein ⇒ portal vein
27
Lymphatic drainage of Jejunum and Ileum
- Juxta-intestinal lymph nodes
- mesenteric lymph nodes
- superior central nodes
28
Innervation of Jejunum and Ileum
symp: Th8-Th10 ⇒ lesser/greater splanchnic nerves
parasymp: vagal trunks
29
Teniae coli
three bands in which the longitudinal muscular fibers of large intestine, except rectum and anal canal, are collected
- mesocholic: transverse + sigmoidal mesocolons attach ⇒ posteromedial tenia
- omental: greater omentum attach to transverse colon ⇒ posterolateral tenia
- libera: opposite to mesocolic, no attachment ⇒ anterior tenia
30
Cecum
- 7,5 cm
- semi-intraperitoneal
- ileocecal junction + ileocecal valve of Bauhin
31
Vermiform Appendix
- blind intestinal diverticulum
- contain lymphoid tissue
- has mesoapendix
- clinically found with McBurney point
- found where all tenia join
32
Blood supply of Cecum and Appendix
ARTERY:
- Ileocolic artery (SME)
VEIN:
- Ileocecal vein (⇒SMV)
LYMPH:
- Ileocecal lymph nodes ⇒ SMLN
33
Ascending colon
- semi-intraperitoneal
- cecum ⇒ right colic flexure
- right paracolic gutter ⇒ recess continuous with sub hepatic recess and Morrison's pouch⇒ infection spread
- Jackson's membrane ⇒ thin vascular membrane on anterior surface, may cause obstruction by kinking the bowel
34
Blood supply of Ascending colon
ARTERY:
- ileocecal, right colic + middle colic arteries (SMA)
VEIN:
- ileocolic, right colic veins ⇒SMV
LYMPH:
- epicolic, paracolic, right colic lymph nodes ⇒ SMLN
35
Transverse colon
- right colic flexure ⇒ left colic flexure
- phrenicocolic ligament attached
- transverse mesocolon: mesentery of transverse colon. forms inferior border of omental bursa, fuses with greater omentum forming 6 layered gastrocolic ligament
- L3 vertebral level
36
Blood supply of transverse colon
```
ARTERY:
- middle colic artery (SMA
- left colic artery (IMA)
⇒ 2nd Riolan anastomosis
VEIN:
- middle colic vein ⇒ SMV
LYMPH:
- middle colic lymph nodes ⇒ SMLN
```
37
Descending colon
- semi-intraperitoneal
- left paracolic gutter- closed upward by phrenicocolic ligament
- thinner than ascending
38
Blood supply of Descending colon
```
ARTERY:
- left colic artery (IMA)
⇒ Marginal artery of Drummond together with right colic artery
VEIN:
- left colic vein ⇒ IMV
LYMPH:
- left colic lymph nodes ⇒ IMLN
```
39
Sigmoid colon
- S-shaped loop, 40cm
- iliac fossa ⇒ S3 vertebra
- Rectosigmoidal junction: termination of teniae
- Mesosigmoidum: freely moving
40
Blood supply of Sigmoid colon
```
ARTERY:
- sigmoidal artery (IMA)
⇒ Sudeck point: anastomosis with superior rectal a
VEIN:
- sigmoidal vein ⇒ IMV
```
41
Innervation of Colon
parasymp: vagus nerve (until 2/3 of transverse colon), sacral plexus (1/3 of transverse colon ⇒ anus)
symp: superior hypogastric plexus
42
Cannon-Böhm point
point were innervation changes from vagus to sacral plexus in colon
43
Rectum
- 15-20 cm long, has no omental appendices or haustra
- sacral flexure + perineal flexure
- 3 lateral flexures: 2 on left side, 1 right- Kohlrausch's fold
- superior 1/3⇒ semi-intraperitoneal, middle 1/3⇒retroperitoneal, inferior 1/3⇒ infra peritoneal
44
Blood supply of Rectum
ARTERY:
- superior rectal artery (IMA)
- middle rectal artery (internal iliac artery)
- inferior rectal artery (internal pudendal artery)
VEIN:
- superior rectal vein ⇒ IMV
- middle, inferior rectal veins ⇒ internal iliac vein
- submucosal rectal plexus
45
Innervation of Rectum
symp: lumbar part of sympathetic trunk + superior hypogastric plexus
parasymp: pelvic splanchnic nerves
46
Anal canal
- 4cm long, pelvic diaphragm ⇒ anus
- internal anal sphincter: involuntary, innervated by parasympathetic nerves
- external anal sphincter: voluntary striated muscle, 3 components⇒ subcutaneous, superficial and deep part
- anal columns of Morgagni
- anal valves of Morgagni
- anal sinuses: pocket like recesses above valves
47
Pectinate line
limit of anal valves that indicates the junction of the superior part of anal canal (hindgut) and the inferior part (proctodeum)
48
Zones of mucosa in anal canal
1. Zona columnaris: anorectal junction⇒ pectinate line, simple columnar epith.
2. Zona Hemorrhagica: pectinate line ⇒ hilton white line, stratified squamous non-keratinized epithelium
3. Zona cutanea: stratified squamous keratinized non-hairy epithelium
49
Blood supply of Anal canal
```
ARTERY:
- superior rectal artery
- 2 inferior rectal arteries
- middle rectal artery
VEIN:
- superior rectal vein
- inferior rectal vein
- middle rectal vein
```
50
Innervation of Anal canal
superior to pectinate line: inferior hypogastric plexus
| inferior to pectinate line: inferior anal nerves (pudendal nerve)
