Abdomen I: Abdominal wall and Cavity Flashcards
What are the boundaries of the abdomen
superior: diaphragm (5th intercostal space)
posterior: lumbar vertebrae and quadratus lumborum muscle
anterolateral: abdominal muscles
inferior: pelvic brim
What are the functions of the abdomen?
- to protect the abdominal viscera: digestive organs, kidneys, spleen
What are the functions of the abdominal muscles?
- protection of abdominal contents
- movement of the trunk
- compression of the abdominal visceral
- expansion of abdominal cavity
- expelling abdominal contents (mictruition, defacation, parturition, vomiting) - increase intra-abdominal pressure
What separates the four abdominal quadrants?
- the transumbilical plane (horizontal at the umbilicus)
- the median plane (vertical from the pubic symphysis)
RUQ, LUQ, RLQ, LLQ
how many abdominal quadrants are there? How many abdominal regions are there?
quadrants: 4
regions: 9
What lines separate the abdominal regions?
Vertically: midclavicular plane that runs through the midinguinal point
Horizontally:
a) subcostal plane (under 10th costal cartilage)
b) transtubercular plane at the anterior superior ishial spine
List the layers of the anterolateral abdominal wall from superficial to deep.
skin –> superficial fascia –> deep fascia –> muscle –> transversalis fascia –> extra peritoneal fat/fascia –> peritoneum
List the muscles of the anterolateral abdominal wall
- rectus abdominus
- external oblique
- internal oblique
- transversus abdominus
what are the muscles of the posterior abdominal wall?
- quadratus lumborum
2. iliopsoas - psoas major + iliacus
what is the innervation of the anterolateral abdominal wall?
Anterior rami of spinal nerves T7 to L1.
- Intercostal nerves T7-T11; 2. subcostal nerve T12 and 3. iliohypogastric & ilioinguinal nerve (L1)
What arteries supply the anterolateral abdominal wall?
from internal thoracic vessels:
- superior epigastric artery
- branches of musculophrenic vessels
from external iliac
- inferior epigastric artery
- deep circumflex iliac artery
What important structure develops in the abdominal cavity and descends down into the scrotum through the inguinal canal?
testis
is the inguinal canal found in males or females?
both
What is the inguinal canal
- It is a 4cm long tube-like space within the lower part of the anterior abdominal wall
- it beings at the deep inguinal ring and ends at the superficial inguinal ring
describe the boundaries of the inguinal canal
floor: inguinal ligament
anterior wall: external oblique aponeurosis
roof: arched fibres of internal oblique and transverses abdominis muscles
posterior wall: transversalis fascia (laterally) and conjoint tendon (medially)
what is inside the inguinal canal in males?
- the spermatic cord and its coverings + the ilioinguinal nerve
in the spermatic cord:
a) vas deferens
b) testicular artery and vein
c) genital branch of genitofemoral nerve
d) lymphatic vessels
what is found in the inguinal canal in females?
- round ligament of the uterus
2. the ilioinguinal nerve
What does the parietal peritoneum cover?
lines the abdominal wall
what does the visceral peritoneum cover?
covers the viscera
What are the 2 main divisions of the peritoneal cavity?
- greater sac: largest part of the cavity
2. lesser sac: smaller part, situated posterior to the stomach and liver
Where does the greater omentum attach?
stomach and transverse colon
What is the purpose of the greater omentum?
to prevent organs from sticking to the anterior abdominal wall
What are the different parts of the greater omentum?
- gastrophrenic ligament
- gastrosplenic ligament
- gastrocolic ligament
what are the different parts of the lesser omentum?
- hepatogastric ligament
2. hepatoduodenal ligament
what is another name for the lesser sac?
omental bursa
where is the lesser sac found?
It is a pounch dorsal to the stomach
What is the epiploic foramen?
it is an opening from the greater sac to the lesser sac beside the hepatoduodenal ligament
What is important about the hepatoduodenal ligament?
it contains important blood and bold vessels going to and from the liver
what ligament attaches the liver to the anterior abdominal wall?
the falciform ligament
What is the mesentery?
- It is a double layer of peritoneum that attaches organs to the posterior abdominal wall (mainly small intestine) that contains blood/lymph, vessels, fat, nerves
- makes the organs mobile
what does retroperitoneal mean in terms of retroperitoneal organs?
retroperitoneal organs lie between the parietal peritoneum and the posterior abdominal wall
what does intraperitoneal mean?
intraperitoneal organs are covered by visceral peritoneum
What are the retroperitoneal organs?
- stomach
- spleen
- liver & gallbladder
- small intestine (jejunum, ileum, and small part of duodenum
- large intestine (transverse colon, sigmoid colon)
- Kindeys & suprarenal glands
- pancreas
- most of the duodenum
- large intestine (ascending and descending colon)
