Anatomy Flashcards
trans umbilical plane
passes through umbilicus at intervertebral disk between L3 and L4
RUQ contents
right lobe of liver gallbladder stomach: pylorus duodenum: parts 1-3 pancreas: head right suprarenal gland right kidney right colic (hepatic) flexure ascending colon: superior part transverse colon: right half
LUQ contents
left lobe of liver spleen stomach jejunum and proximal ileum pancreas: body and tail left kidney left suprarenal gland left colic (splenic) flexure transverse colon: left half descending colon: superior part
RLQ content
cecum vermiform appendix most of ileum ascending colon: inferior part right ovary right uterine tube right ureter: abdominal part right spermatic cord: ab part uterus urinary bladder if full
LLQ content
sigmoid colon descending colon: inferior part left ovary left uterine tube left ureter: ab part left spermatic cord: ab part uterus urinary bladder if full
RUQ abdominal pain ddx
dissecting aneurysm gallbladder disease hepatitis hepatomegaly pancreatitis peptic ulcer disease pyelonephritis kidney stones renal infarct appendicitis
LUQ abdominal pain ddx
dissecting aneurysm esophagitis hiatal hernia esophageal rupture gastritis pancreatitis peptic ulcer disease pyelonephritis kidney stones renal infarct splenic abscess splenic rupture splenic infarction
RLQ pain ddx
appendicitis
cholecystitis
crohns
kidney stones
LLQ pain ddx
diverticulitis IBS lactose intolerance celiac kidney stones constipation crohns ulcerative colitis intestinal obstruction
lower abdomen pain ddx
aortic aneurysm colitis including IBS diverticulitis intestinal obstruction perforated viscus
epigastric region
foregut organs
above L1
paraumbilical region
midgut organs
L1-umbilicus
suprapubic region
hindgut organs
below umbilicus
how many layers are in the anterior abdominal wall
7-9 layers
list layers of anterior abdominal wall from outside to inside
skin superficial fascia (Campers in superior region, Campers and Scarpa in inferior) deep fascia (epimysium) muscle (0,1, or 3) transversalis fascia extraperitoneal fat parietal peritoneum
where is scarpas fascia located
only below umbilicus
superiorly attaches to rectus / external oblique epimysium
may retain fluid underneath due to straddle injury
what is diastasis recti
abdominal separation
gap of roughly 2.7 cm or greater between the sides of the rectus abdominus muscle
who gets diastasis recti
newborns and pregnant women
4 variations of diastasis recti
open (split vertically)
open below navel
open above navel
completely open (split vertically and horizontally)
how many layers are in the wall of the linea alba
6 skin superficial (Camper) fascia linea alba transversalis fascia extraperitoneal fat parietal peritoneum
how many layers are in the wall of the rectus abdominis above the umbilicus
8 skin superficial (Camper) fascia anterior rectus sheath rectus abdominis muscle posterior rectus sheath transversalis fascia extraperitoneal fat parietal peritoneum
how many layers are in the wall of the rectus abdominis below the umbilicus
7 skin superficial fascia (Camper and Scarpa) anterior rectus sheath rectus abdominis muscle transversalis fascia extraperitoneal fat parietal peritoneum
how many layers are in the wall lateral to the rectus abdominis
8 skin superficial (Camper) fascia external oblique muscle internal oblique muscle transversus abdominis muscle transversalis fascia extraperitoneal fat parietal paeritoneum
where is the inguinal canal
above inguinal ligament
formed by descending of testis or round ligament of uterus
describe the movement of the testis
was located inside abdominal cavity between parietal peritoneum and transversalis fascia
retroperitoneal
transversed obliquely during embryogenesis through the layers of anterolateral abdominal wall just above inguinal ligament
contents of male inguinal canal
spermatic cord- ductus deferens, testicular artery and vein
go into scrotum
contents of female inguinal canal
round ligament of uterus
attaches to subcutaneous tissue of labium majus
what is an abdominal hernia
protrusion of parietal peritoneum and/or abdominal viscera (small intestine) through a normal or abnormal opening from the cavity
what % of abdominal hernias are inguinal
80-90%
what determines if emergency treatment is required for a hernia
if it is strangulated
direct (acquired) inguinal hernia
herniating bowel passes medial to inferior epigastric vessels
pushes through peritoneum and transversalis fascia in inguinal triangle
enters inguinal canal
indirect inguinal hernia
herniating bowel passes lateral to inferior epigastric vessels to enter deep inguinal ring
predisposing factor for direct inguinal hernia
weakness of anterior abdominal wall in inguinal triangle
frequency of direct inguinal hernia
less common
1/3 to 1/4
older men
layers that exit from abdominal cavity in direct inguinal hernia
peritoneum plus transversalis fascia
course of direct inguinal hernia
through or around inguinal canal, usually transversing only medial third of canal, external and parallel to vestige of processus vaginalis
direct inguinal hernia exit from anterior abdominal wall
via superficial ring
lateral to cord
rarely enters scrotum
predisposing factor for indirect inguinal hernia
patency of processus vaginalis in younger persons
frequency of indirect inguinal hernia
2/3 to 3/4
common in newborns
layers that exit from abdominal cavity in indirect inguinal hernia
peritoneum of persistent processus vaginalis plus all 3 fascial coverings of cord/round ligament
course of indirect inguinal hernia
transverses inguinal canal (entire canal if sufficient in size) within processus vaginalis
indirect inguinal hernia exit from anterior abdominal wall
via superficial ring inside cord
commonly passes into scrotum/labium majus
umbilical abdominal hernia
around umbilicus
common in newborns
epigastric abdominal hernia
midline along linea alba above umbilicus
semilunar abdominal hernia
along semilunar line
where external transverse connect to rectus abdominis
diaphragmatic abdominal hernia
typically posterior and left sided
sex differences in groin hernias
men 8x more likely to get one and 20x more likely to need a repair
lifetime risk is 25% in men and 5% in women
women median age 60-79
men median age 50-69
what is the etiology of caput medusa
superficial veins anastomose with deep veins
when deep veins are blocked superficial veins are enlarged
when do you see caput medusa
hepatic portal vein hypertension or obstruction
causes embryonic umbilical vein to reopen and carry blood away from the liver onto the anterior abdominal wall veins (superior and inferior epigastric veins)
why do you get hypothesia instead of anesthesia when a dermatome isn’t working
segments overlap with one another
xiphoid process dermatome
T7
umbilicus dermatome
T10
inguinal ligament dermatome
L1
common abdominal surgical incisions
anterior subcostal upper midline laparotomy (stomach, pancreas) periumbilical midline laparotomy pararectal incision (sigmoid colon) lower midline laparotomy mcburnery (appendix) inguinal incision (inguinal canal) pfannenstiel incision (pelvic organs)
what is the peritoneum
transparent serous membrane that lines the abdominopelvic cavity and wraps around the organs
2 peritoneum layers
parietal- lines internal surface of the walls of the cavity
visceral- wraps around organs
parietal peritoneum pain sensation
served by same blood and lymphatic vessels and nerves in the region that it is adjacent to
sensitive to all general somatic sensations
pain well localized
visceral peritoneum pain sensation
served by the same blood and lymphatic vessels and nerves as the organ it covers
not sensitive to general sensations
sensitive to stretch and chemical irritation
pain poorly localized, may be referred to surface
cell type in the peritoneum
simple squamous epithelial cells
mesothelium
intraperitoneal organs
completely covered by peritoneum and has a mesentary
retroperitoneal organs
partially covered by peritoneum
mesentary
2 layers of peritoneum adhere together connecting intraperitoneal organs to abdominal wall
why is the female peritoneum not closed
opens through uterine tubes, uterus, and vagina
greater omentum
starts from greater curvature of the stomach and proximal duodenum
drapes down like an apron and folds back upwards to attach to transverse colon
lesser omentum
connects lesser curvature of stomach and duodenum to liver
function of greater omentum
prevents visceral peritoneum adherence to parietal peritoneum
stores excess calories
cushions abdominal organs
insulates against heat loss
adheres to inflamed organs to localize infection
can herniate
what are peritoneal ligaments
double layer peritoneum that connects ne organ with another organ or to the peritoneal wall
peritoneal folds
reflection of peritoneum raised from the internal abdominal wall by underlying structures (usually blood vessels and ducts)
peritoneal lesser sac
space posterior to lesser omentum and stomach
peritoneal greater sac
main and larger part of peritoneal cavity
2 compartments of greater sac
supracolic
infracolic
supracolic compartment of greater sac
above transverse colon, including stomach, liver and spleen
infracolic compartment of greater sac
below transverse colon, including small intestine, ascending and descending colon
typical peritoneal fluid volume
20 ml
increases to 50 ml during ovulation
typical peritoneal fluid color
clear and/or slightly yellowish
cloudy, turbid peritoneal fluid
infection
milky peritoneal fluid
inflammatory condition
peritonitis, pancreatitis, appendicitis
red peritoneal fluid
traumatic tap or malignancy
green peritoneal fluid
ruptured gall bladder, pancreatitis, or intestinal perf
what is peritonitis
infection and inflammation of peritoneum
etiology of peritonitis
traumatic penetration or rupture of abdominopelvic organs
gas, fecal matter, bacteria enters peritoneal cavity
exudation of serum, fibrin, cells, pus into cavity
symptoms of peritonitis
pain, fever, gas under diaphragm when standing, paralyzed bowel movement, ab wall guarding
what is ascites
excess fluid accumulation in peritoneal cavity
several liters of fluid
resp and bowel movements can be affected
etiology of ascites
internal bleeding, portal hypertension, cancer metastasis, starvation
starvation ascites in children
Kwashiorkor
severe malnutrition caused by deficiency in dietary protein
lack of protein causes osmotic imbalance in GI and causes swelling of the gut
abdominal paracentesis
surgical puncture of the peritoneal cavity for the aspiration and drainage of fluid
typically for diagnostics
therapeutic to reduce intra-abdominal pressure
intraperitoneal injection
peritoneum is semipermeable and lies over blood vessels and lymphatic ducts
fluid injected into peritoneal cavity is absorbed rapidly
some ovarian cancer treatments involve this type of admin
peritoneal dialysis
helps renal failure patients
what are peritoneal adhesions
healing from infection, inflamm, or surgery causes fibrous tissue to form between visceral peritoneum or between visceral and parietal peritoneum
result of peritoneal adhesions
limit normal movement of viscera causing ab pain, gut twisting, or volvulus
treatment for severe peritoneal adhesions
surgical separation of adhesions
overview of GI tract
mouth > pharynx > esophagus > stomach > small intestine (duodenum, jejunum, ileum) > large intestine (cecum, ascending, transverse, descending, sigmoid, rectum) > anal canal
organs associated with GI tract
liver, gallbladder, pancreas, spleen, kidneys, adrenals
what is the significance of the primitive GI tract separations
each region gives rise to organs that share the same primary blood supple, nerve innervation, and lymphatic drainage route
foregut organs
mouth pharynx esophagus stomach superior half of duodenum
midgut organs
inferior half of duodenum jejunum ileum cecum appendix ascending colon right 2/3 of transverse colon
hindgut organs
left 1/3 of transverse colon
descending colon
sigmoid colon
rectum
3 constrictions of esophagus
cervical- junction w pharynx
thoracic- crossing w aortic arch/ L main bronchus
diaphragmatic- junction with stomach
muscle makeup of esophagus
internal circular and external longitudinal muscles
superior 1/3 = voluntary striated
mid 1/3 = mix of smooth and striated
inferior 1/3 = all smooth muscle
another name for pyrosis
heartburn
etiology of pyrosis
regurgitation of small amounts of food or gastric fluid into lower esophagus
common perception of pyrosis
chest pain
describe the venous drainage of the lower esophagus
dual venous drainages- to systemic veins via azygous vein system and to the liver via portal vein
etiology of esophageal varices
during portal hypertension, most venous blood flows through lower esophageal region toward azygous veins causing varices
outcome of esophageal varices
can be ruptured by food resulting in extensive internal bleeding into stomach
may vomit fresh blood (not exposed to stomach acid)
what is Zenker diverticulum
a posterior evagination off the upper portion of the esophagus just below the lower pharynx
symptoms of zenker diverticulum
often asymptomatic found in older adults dysphasia/ lump in throat food trapped in outpouching, leading to: -regurgitation -cough -halitosis -infection
stomach cardia
part surrounding the cardial orifice (connection w esophagus)
fundus of stomach
dilated superior part, reaches left 5th intercostal
body of stomach
major part between fundus and pyloric antrum
pyloric part of stomach
pyloric antrum
pyloric canal
pylorus (sphincter)
pyloric orifice
gastric rugae
gastric folds
longitudinal ridges of gastric mucosa on the interior of the stomach
3 nonpaired arteries to the abdomen
- celiac trunk/axis
- superior mesenteric artery (SMA)
- inferior mesenteric artery (IMA)
what arteries come off the celiac trunk to the stomach?
celiac trunk at T12 -left gastric (left lesser curvature) splenic artery: -left gastro-omental (left greater curvature) -short gastric (fundus) common hepatic artery: -right gastric (right lesser curvature) -right gastro-omental (right greater curvature)
where do veins of stomach drain to
hepatic portal vein
where do lymph nodes of stomach drain to
celiac lymph nodes
what is a hiatal hernia
protrusion of part of the stomach into the mediastinum through esophageal hiatus
two types of hiatal hernia
sliding (95%)
paraesophageal (5%)
sliding hiatal hernia
abdominal portion of esophagus + cardia + part of fundus all herniated
regurg possible
paraesophageal hiatal hernia
cardia remains in normal position
part of fundus herniated
usually no regurg
congenital diaphragmatic hernia
1/2200 newborns
poor development of diaphragm
may have pulmonary hypoplasia
high mortality
incidence of hiatal hernias
increases w age
60% of people aged 50 or older
9% are symptomatic
symptoms of hiatal hernia
heartburn
difficulty swallowing
nausea, vomiting
usually worse after meals or when laying flat
pylorospasm
spasmodic contraction of pylorus
food stays in stomach, resulting in overfilling and vomiting
congenital hypertrophic pyloric stenosis
1/150 males
1/750 femals
carcinoma of stomach
most common in body or pyloric part of stomach
associated with feeling full and vomiting
gastric ulcer
an open lesion of stomach mucosa, associated with infections of H.pylori
ulcer erodes arteries, causes bleeding and can cause wall perforation
referred pain from stomach
epigastric region pain
afferent fibers from stomach and 1st part of duodenum, via splanchnic nerve, go to T7-T8 level
dermatome sensation from T7, T8
4 parts of duodenum
superior- L1
descending - L2
horizontal- L3
ascending- L3-L2
overview of duodenum
25 cm
retroperitoneal
C-shaped around head of pancreas
what is inside the lumen of the duodenum
plicae circularies
major duodenal papilla
minor duodenal papilla
what significant structure enters the posteromedial wall of the duodenum
hepatopancreatic ampulla (common bile duct + pancreatic duct coming together) ampulla surrounded by the hepatopancreatic sphincter (smooth muscle)
what arteries supply the duodenum from the celiac trunk?
common hepatic > gastroduodenal, which branches into:
- supraduodental artery
- posterior superior pancreaticoduodenal
- anterior superior pancreaticoduodenal
what arteries supply the duodenum from the superior mesenteric artery?
- posterior inferior pancreaticoduodenal
- anterior inferior pancreaticoduodenal
where do duodenal veins drain?
hepatic portal vein
what is a duodenal/peptic ulcer?
inflammatory erosion of duodenal mucosa
can cause inflammatory adhesion to surrounding organs
perforations cause peritonitis
where do peptic ulcers occur?
65% occur on the posterior wall of the 1st part within 3 cm of the pylorus
what is a significant symptom of peptic ulcers?
erosion to gastroduodenal artery causes severe bleeding into duodenum, retroperitoneum, or lesser sac of peritoneal cavity
referred pain of duodenum
lower epigastric region and occasionally umbilical
if irritates the diaphragm, upper right shoulder
jejunum
2/5 small intestine
mostly in LUQ or around umbilicus
ileum
3/5 small intestine
mostly in RLG or inguinal region
what is the mesentery
fan shaped peritoneal fold that attaches jejunum and ileum to the posterior abdominal wall
what are 3 differentiating factors between jejunum and ileum
wall thickness
vascular supply pattern
plicae circulares
jejunum wall
thick and heavy
ileum wall
thin and light
jejunum vascular supply
long vasa recta with a few large loops
ileum vascular supply
short vasa recta with many short loops
jejunum circular folds (plicae circulares)
large, tall, closely packed
ileum circular folds (plicae circulares)
low and sparse, absent in distal parts
peyers patches in jejunum vs ileum
few in jejunum
many in ileum
bloody supply to jejunum and ileum
superior mesenteric artery gives of to the left 15-18 branches of mesenteric arteries to both jejunum and ileum
SMV collects blood to hepatic portal vein
ileal (meckels) diverticulum
most common congenital anomaly of the gut due to a remnant vitelline duct
contains 2 ectopic tissues- stomach mucosa and pancreatic
on opposite side of the mesentery
ileal (meckels) diverticulum rule of 2s
2% of the population
2” long
2 ft from ileocecal junction
symptoms of ileal (meckels) diverticulum
bleeding (consider for lower GI bleeding in children < 2)
GI track obstruction
when inflamed, pain mimics appendicitis
ileus
small bowel motility disorders that mimic obstruction (no mechanical obstruction)
paralytic ileus
paralysis of small bowel movement mostly due to surgery
stagnations = no peristalsis
ab distention, nausea, malaise
can be from unknown causes such as systemic illnesses
intussesception
part of intestine has invaginated into another section
happens in kids under 5
result in obstruction
diagnose w ultrasound (bulls eye)
can cut off blood supply and cause tissue of wall to die
symptoms of intussesception
sudden pain that comes and goes every 20 min vomiting stool w blood and mucus nausea cramping pain
treatment of intussesception
barium or air enema
laparotomy
surgery
small intesting referred pain
T10 periumbilical
unique anatomical characteristics of large intestine (OETHS)
omental (epiploic) appendices - small fatty omentum like projections
taenia coli- 3 longitudinal muscle bands, not present in the appendix and rectum
haustra- saccular protrustion between transverse folds
semilunar folds- separate haustra on interior
cecum
blind pouch
RLQ
intraperitoneal, no mesentery
orifice for appendix
vermiform appendix
blind intestinal diverticulum off of cecum
6-10 cm long, contains lymphoid tissue
has its own mesentery
epidemiology of appendicitis
common in young people
300,000 cases/year
most common cause of acute ab pain requiring surgery
pain associated with appendicitis
vague pain around umbilicus (T10)
may transfer to RLQ with time to “mcburneys point” due to direct inflammation of parietal wall of the anterior wall peritoneum
rupture of appendix
peritonitis
ab rigidity
nausea
vomiting
mcburneys point
right side of abdomen
1/3 distance from anterior superior ileac spine to umbilicus
appendix function
trap for heavy particles that are ingested
peritoneal status of colon sections
cecum- intra ascending- retro transverse- inta descending- retro sigmoid- intra rectum/anal canal- retro ALTERNATE transverse and sigmoid have their own mesenteries
volvulus
a loop of bowel and mesentery abnormally twisted on itself
cause obstruction and vascular ischemia
volvulus epidemiology
occurs most frequently in middle aged and elderly men
2-3/100,000 people per year
most common volvulus
sigmoid volvulus most common (8% of all intestinal obstructions)
cecum second
treatment for sigmoid volvulus
sigmoidoscopy
barium enema
perianal abscess
pus accumulation in the ischioanal fossa
cryptitis
inflammation of anal sinuses
anal fissure
slit like lesion
12 o clock below anal valves
once one develops, internal anal sphincter goes into spasm, causing further separation of the tear constricting blood flow in the area, impairing healing, and causing pain
anal fistula
channel connects anal canal and perianal abscess
hemorrhoids
4-5% of the population with peal incidence from 45-65 yo
internal - above pectinate line (painless)
external - below pectinate line (painful)
diverticulosis
external evagination (out pocketing) of colon mucosa mostly in middle aged or elderly age dependent prevalence 85% in sigmoid colon infection and rupture can happen
colectomy
removal of ileum, colon, rectum, and anal canal
ileostomy
establish an opening between the ileum and the skin
colostomy
establish an opening between the colon and the skin
sigmoidostomy
establish an opening from the sigmoid to the skin
colonoscopy
endoscopic exam of large bowel and distal part of small intestine with a CCD camera
visual diagnosis of ulceration and polyps
biopsy/removal of suspected colorectal cancer lesions
colonoscopy complications
1/200 have a serious complication
1/2000 perforations
2.6/1000 bleeding
3/100000 death
causes of upper GI bleeding
esophageal varices
gastric or duodenal ulcer
causes of lower GI bleeding
meckels diverticulum crohns colonic diverticulum colorectal cancer hemorrhoid anal fissure arteriovenous malformation
stats of lower GI bleeding causes
40% diverticuli
21% IBS
10-15% cancer, coagulopathy, anal disease
2% arteriovenous malformation
