1- abdominal wall + omentum Flashcards
what are the quadrants of abdomen?
line divided along median and then line along trans-umbillical plane
there is right and left upper quadrant
there is right and left lower quadrant
what are the regions of of abdomen?
= take 2 lines down midclavicular planes, 1 horizontal (subcostal plane) and the other horizontal is trans-tubercle plane
→divides into 9 regions:
- have right + left hypochondrium
- epigastric (around stomach)
- Right/Left Lumbar (also called flank)
- Umbilical (area around belly button)
- Right/Left Inguinal (iliac fossa)
- Pubic (also called suprapubic)
what is linea alba?
(white line) = groove down the midline →formed by aponeurosis coming in middle
what is linea semilunaris?
(half moon) = groove in anterolateral abdominal wall - marks end of lateral part of abdominal wall and beginning of anterior of abdominal wall)
what is inguinal region?
runs from ASIS (anterior superior iliac spine - bumpy bit at top of pelvis) down to tubercle
what are layers of anterolateral abdominal wall muscles?
external obliques (fibre direction like pockets), internal oblique muscle (opposite fibre direction) and transversus abdominis muscle (horizontal fibre direction)
they turn to flattened tendon (aponeurosis) and form rectus (straight) abdominis muscle
what is inguinal ligament?
landmark that separates abdomen from lower limb (thigh) = thickened free edge of external oblique muscle
what makes the subingual space?
the inguinal ligament stretch from free edge of external oblique muscle and to pubic tubercle
- underneath this is the sublingual space
what is in subingual space?
lots of things like nerves etc that communicate with thigh
what is inguinal canal?
4 cm long passageway through anterior abdominal wall in inguinal regions = helps communicate between abdomen and perineum
- it’s formed embyryologically
what is clinical importance of inguinal canal + inguinal ligament?
very important→does mean weakness in the anterior abdominal wall = can lead to herniations (internal body part pushes through weakness)
where is inguinal canal?
it is passageway that runs between a deep ring and superficial ring (openings at each end)
deep ring = superior to midpoint of inguinal ligament
superficial ring = superolateral to pubic tubercle
what is inguinal canals floor?
the medial half of the inguinal ligament
is inguinal canal in both sexes?
yes - more clinically important in males as bigger in males since it forms embryologically and inguinal canal has to travel further to get to scrotum in males = means males more likely to herniate
where do gonads form?
posterior abdominal wall - they are descended into pelvis (for ovaries) and scrotum (for testes) by birth
what is gubernaculum?
gelatinous cord that guides the gonads to final positions (in both male + female)
what is outpouching of abdomen?
vaginal process →pushes through anterior abdominal wall helping form inguinal canal so in scrotum outpouching that allows testes to move without friction
what contributes to spermatic cord formation?
as testes descend they pull all layers of abdominal wall along with it which contribute to layers of spermatic cord (only one that doesn’t is transversus abdominus)
what forms anterior wall of inguinal canal?
- formed by aponeurosis (tendon) of external oblique = forms most of anterior wall
- internal oblique also contributes a bit
what forms posterior wall of inguinal canal?
- transversalis fascia (small layer of fat that)
- conjoint tendon (internal oblique + transversus abdominis aponeurosis)
what forms roof of inguinal canal?
- transversalis fascia
- arches of internal oblique and transversus abdominis aponeurosis
- External oblique aponeurosis
what forms floor of inguinal canal?
Gutter of infolded inguinal ligament
what can cause increased intra-abdominal pressure? (which can lead to hernia)
- chronic cough
- chronic constipation
- occupational lifting of heavy weights
- athletic effort
what is peritoneum?
lining of inside of muscles = thin, transparent, semi-permeable, serous membrane that lines the walls of abdominopelvic cavity and organs
what is the peritoneum in contact with
a) body wall
b) organs
a) parietal
b) visceral
it is continuous membrane just changes it’s name depending on what touching
does peritoneum have nerve supply?
yes - nerve supply related to whether it is parietal or visceral
what is peritoneal fluid?
small amount of lubricating fluid secreted by peritoneum
what are intraperitoneal organs?
example = 1st part of duodenum, stomach, jejunum , ilium, transverse colon, sigmoid colon, liver, spleen
- Almost completely covered in visceral peritoneum
- Minimally mobile
what are retroperitoneal organs?
example = pancreas and kidneys, ureter & rectum= organs only found behind peritoneum
- only has visceral peritoneum on anterior surface
- located in retroperitoneum
- usually fixed position
what are organs with mesentery?
example = have parts of intestine
= when double layer of peritoneum coming together, in double layer of mesentery you would have nerves. vessels, lymphatics etc going to organ
organs are covered in visceral peritoneum which wraps around behind organ to form double layer = mesentery. this mesenetery suspends organ from posterior wall so very mobile
what are peritoneal condensations?
layers of peritoneum come close together or fuse forming structures that attach organs to each other ot to abdominal wall
- specialised structure providing support & creating compartments
how do peritoneal condensations form?
secondary to growth and rotation of GI tract during embryology - depends on how organs rotate around each other as form
what is difference between peritoneal condensation and mesentery?
Peritoneal condensations are areas of fused peritoneum that attach organs to each other or to the abdominal wall, while the mesentery is a fold of peritoneum that specifically supports and suspends the intestines within the abdominal cavity
what is greater omentum?
= also known as policeman of abdomen
→hangs down and loops up to transverse colon, and one from stomach = making 2 double layers →it will move towards organ where infection and tries to close off infection
what is function of greater and lesser omentum?
divide peritoneal cavity into greater + lesser sac - the 2 sacs communicate through omental foramen
where does the portal tried lie?
in the free edge of the lesser omentum = 3 structures that pass into liver
what pouches does peritoneum form?
at its inferior aspect the peritoneum “drapes over” the superior aspect of the pelvic organs
Forms pouches
- one pouch in the male = rectovesical
- two in the female = because uterus in between - vesicouterine and rectouterine (pouch if douglas)
what is ascitic fluid?
excess fluid that can collect within peritoneal cavity
how can ascitis fluid be drained?
by a procedure called ‘paracentesis’ where the needle must be placed lateral to rectus sheet (because you must avoid the inferior epigastric artery = important big artery)
what components of GI occur after stomach?
duodenum that goes to jejunum then ileum then caecum then appendix (looks like tail) then ascending colon then transverse colon then descending colon then sigmoid colon then rectum then anal canal then anus
where is spleen?
behind stomach
where are adrenal glands?
on top of kidneys
how long is small intestine?
around 7m long and, from proximal to distal, made up of:
- The duodenum (short)
- The jejunum (~3m)
- The ileum (~4m)
where is caecum and appendix found?
right iliac fossa
appendix is retrocaecal (behind caecum) but lots of variation
what is place that usually in most pain in appendicitis?
appendiceal orifice on posteromedial wall of caecal = part that is sore and in pain for appendicitis
- the McBurneys point on anterior abdominal wall in theory is place of max tenderness
what is movement like in sigmoid colon?
sigmoid colon has long mesentart which means it can move around a lot which is good for getting rid of faeces but it means it can wrap around itself (sigmoid volvulus) which obstructs the bowel and left untreated can become inflamed and rupture so risk of infarction
