abdominal wall and GI tract overview Flashcards
identify the regions and the lines
orange = midclavicular
green = subcostal
purple = transtubercular
A = epigastric
B = umbilical
C = hypogastric/suprapubic
D = right hypochondriac
E = right lumbar/flank
F = right inguinal/iliac
G = left hypochondriac
H = left lumbar/flank
I = left inguinal/iliac
what are the 4 quadrants of the abdomen and what divides them?
right and left upper quadrants, right and left lower quadrants
median plane and umbilical plane
name things in the right upper quadrant
- right kidney
- right suprarenal gland
- right lobe of liver
- hepatic flexure
- gallbladder
name things in the right lower quadrant
- right ureter
- right ovary
- right uterine tube
- caecum
- appendix
name things in the left upper quadrant
- left kidney
- left suprarenal gland
- left lobe of liver
- spleen
- splenic flexure
name things in the left lower quadrant
- left ureter
- left uterine tube
- left ovary
- left sigmoid colon
what are the functions of the abdominal wall?
• forms a firm yet flexible boundary which keeps the abdominal viscera in the abdominal cavity and assists the viscera in maintaining their anatomical position against gravity
• protects the abdominal viscera from injury
• assists in forceful expiration by pushing the abdominal viscera upwards
• is involved in any action (coughing, vomiting, defecation) that increases intra-abdominal pressure
the anterolateral abdominal wall extends from the _____ to the _______. roof is diaphragm. thoracic cage contributes to superior part of the abdominal wall. inferiorly there is no floor as the abdominal cavity is continuous with the_______. it is bounded by the _____ and _____ crests, _________ and _______ ligament
the anterolateral abdominal wall extends from the thorax to the pelvic inlet. roof is diaphragm. thoracic cage contributes to superior part of the abdominal wall. inferiorly there is no floor as the abdominal cavity is continuous with the pelvic cavity. it is bounded by the iliac and pubic crests, pubic symphysis and inguinal ligament
from superficial to deep, what are the 4 main layers of the anterolateral abdominal wall?
skin, superficial fascia, muscles and associated fascia, parietal peritoneum
describe the superficial fascia of the anterolateral abdominal wall above the umbilicus
- a single sheet of connective tissue
- it is continuous with the superficial fascia in other regions of the body
describe the superficial fascia of the anterolateral abdominal wall below the umbilicus
divided into 2 layers — the fatty superficial layer (Camper’s fascia) and the membranous deep layer (Scarpa’s fascia)
what runs between Camper’s fascia and Scarpa’s fascia?
the superficial vessels and nerves
what are the flat muscles of the abdominal wall?
external + internal obliques and transversus abdominis
in the anteromedial aspect of the abdominal wall, each flat muscle forms an ___________ which covers the vertical _________
- aponeurosis (a broad, flat tendon)
- rectus abdominis
the aponeuroses of all the flat muscles become entwined in the midline, forming the what?
the linea alba
what is the linea alba?
a fibrous structure that extends from the diploid process of the sternum to the pubic symphysis
describe the external oblique
• most superficial
• muscle fibres run downwards and forwards
• origin = external surface of lower 8 ribs
• insertion = linea alba, pubic tubercle, anterior half of iliac
crest
what does the free lower border of the external oblique form?
inguinal ligament
describe internal oblique
• intermediate muscle
• muscle fibres run forward and upwards
• origin = thoracodorsal fascia, anterior 2/3rds of iliac crest,
lateral half of inguinal ligament
• insertion = inferior border of lower 3 ribs, linea alba,
pubis via conjoint tendon
describe transversus abdominis
• deepest
• fibres run horizontally
• origin = internal surface of lower 6 costal cartilages,
thoracodorsal fascia, iliac crest, lateral third of inguinal
ligament
• insertion = linea alba, pubic crest, pubic via conjoint
tendon
• lower thoracic nerves leave the intercostal spaces and run
anteriorly, superficial to this muscle
what are the vertical muscles of the abdominal wall?
rectus abdominis and pyramidalis
the rectus abdominis is a long, paired muscle split into 2 by what?
the linea alba
the lateral borders of rectus abdominis create a surface marking known as what?
the linea semilunaris
what gives rise to the ‘six pack’
at several places the muscle is intersected by fibrous strips, knows as tendinous intersections — the tendinous intersections and the linea alba give rise to the ‘six pack’
origin, insertion and function of rectus abdominis
• origin = crest of pubis bone
• insertion = xiphoid process of the sternum and the costal
cartilage of ribs 5-7
• function = flexes trunk, compresses abdominal viscera,
stabilises the tilt of the pelvis
describe pyramidalis
• superficial to rectus abdominis
• small and triangular
• origin = pubic crest
• insertion = linea alba
• function = tenses linea alba
• only present in 80% of the population
what makes up the rectus sheath above the level of the ASIS?
skin, external oblique, internal oblique, transversus abdominis, transversalis fascia
what makes up the rectus sheath below the level of ASIS?
external oblique, internal oblique, transversus abdominis, transversalis fascia
label A-G
A = parietal peritoneum
B = transversalis fascia
C = trans versus abdominis
D = internal oblique
E = external oblique
F = linea alba
G = rectus abdominis
what form the anterior wall of the rectus sheath at H and I?
H = the aponeurosis of external oblique and anterior lamina of internal oblique
I = aponeurosis of external oblique, inner oblique and transversus abdominis
where is the arcuate line formed?
where the posterior wall of the sheath thins out (as the aponeurosis of the muscles pass anterior to the rectus abdominis)
what are the contents of the rectus sheath?
• rectus abdominis
• pyramidalis
• superior and inferior epigastric vessels
• lymphatic vessels
• ventral rami of nerves T7-T12
The rectus sheath is a tendon sheath (______) which encloses the __________ and ________ muscles. It is an extension of the tendons of the external abdominal oblique, internal abdominal oblique, and transversus abdominis muscles. In addition to these muscles, the rectus sheath also contains __________ of the anterior abdominal wall. Its function is to ______ the contents it encloses.
The rectus sheath is a tendon sheath (aponeurosis) which encloses the rectus abdominis and pyramidalis muscles. It is an extension of the tendons of the external abdominal oblique, internal abdominal oblique, and transversus abdominis muscles. In addition to these muscles, the rectus sheath also contains neurovasculature of the anterior abdominal wall. Its function is to protect the contents it encloses.
inferior epigastric artery anastomoses with the __________ artery which arises from the _________ artery. it enters the _______ aspect of the sheath, posterior to ____________
inferior epigastric artery anastomoses with the superior epigastric artery which arises from the musculophrenic artery. it enters the superior aspect of the sheath, posterior to rectus abdominis
label A-D
A = pyramidalis
B = rectus abdominis
C = tendinous intersections
D = inferior epigastric artery
what does inferior epigastric artery arise from?
external iliac
what run horizontally within the sheath from lateral to medial?
thoracic nerves
what structures contribute to the posterior wall of the sheath at A and B?
identify C and D
A = posterior lamina of internal oblique and aponeurosis of trasnversus abdominis
B = transversalis fascia
C = arcuate line
D = superior epigastric vessels
which nerves supply the anterolateral abdominal wall?
T7-11, T12 (subcostal), and L1 (ilioinguinal and iliohypogastric)
between which muslces do the nerves of the abdominal wall run?
internal oblique and transversus abdominis
where do the lateral cutaneous branches of the abdominal wall nerves pass through the subcutaneous tissue to reach the skin?
at the level of the anterior axillary line
through which structure do the anterior cutaneous branches pass before entering the subcutaneous tissue?
rectus sheath
which dermatomes supply the regions labelled a,b and c?
A = epigastric region - T5-T9
B = umbilical region - T10-T11
C = hypogastric region - T12-L1
what is the inguinal canal?
oblique passage through the abdominal wall just above the medial end of the inguinal ligament
what does the inguinal canal extend from and to?
deep inguinal ring to superficial inguinal ring
what are the anterior, posterior, floor and roof boundaries of the inguinal canal?
anterior = external oblique and internal oblique
posterior = transversalis fascia and conjoint tendon
floor = inguinal ligament and lacunar ligament
roof = archiving fibres of internal oblique and transversus abdominis and transversalis fascia
what does the inguinal canal contain?
the spermatic cord (or round ligament in female), blood and lymphatic vessels, ilioinguinal nerve
identify A-D
A = aponeurosis of external oblique
B = inguinal ligament
C = superficial inguinal ring
D = spermatic cord
where is the deep ring found?
above the midpoint of the inguinal ligament, lateral to the epigastric vessels
where is the superficial ring found?
superolateral to the pubic tubercle
what form the deep and superfical rings?
deep ring = created by the transversalis fascia, which invaginates to form a covering of the contents of the inguinal canal
superficial ring = triangle shaped opening, formed by the invagination of the external oblique, which forms another covering of the inguinal canal contents
the superficial ring contains ___________, whcih run perpendicular to the aponeurosis of the external oblique and prevent the ring from _______
- intercrural fibres
- widening
during periods of increased intra-abdominal pressure, the abdominal viscera are pushed into the ________. to prevent herniation, the muscles of the anterior and posterior wall ______, and ‘clamp down’ on the canal
- inguinal canal
- contract
what is the name of the fibrous cord of tissue that attaches the inferior portion of the gonad to the future scrotum or labia, and guides them during their descent?
gubernaculum
in the embryological stage, the inguinal canal is flanked by an out-pocketing of the peritoneum (____________) and the abdominal musculature
processus vaginalis
the processus vaginalis normally __________, but a failure to do so can cause an _______ inguinal hernia, a hydrocele, or interfere with the ______ of the tests
- degenerates
- indirect
- descent
the gubernaculum, once it has shortened in the process of the descent of the testes, becomes what? function?
a small scrotal ligament, tethering the testes to the scrotum and limiting their movement
in women, the gubernaculum attaches the ovaries to the ______ and future __________. because the ovaries are attached to the _______, they are prevented from descending as far as the testes, instead moving into the pelvic cavity. the gubernaculum then becomes 2 structures in the adult = the ____________and the _____________
in women, the gubernaculum attaches the ovaries to the uterus and future labia majora. because the ovaries are attached to the uterus, they are prevented from descending as far as the testes, instead moving into the pelvic cavity. the gubernaculum then becomes 2 structures in the adult = the ovarian ligament and the round ligament of uterus
at what level is the transpyloric line and what is it crossed by?
- L1
- crossed by pancreas
at what level is the subcostal line?
L2
passes through the inferior border of the 10th costal cartilage
what level does the trasntubercular level lie at?
L4 - passes through iliac tubercles
where is the swallowing centre?
medulla
what is the anterolateral wall bounded superiorly by?
the costal margin and the xiphisternum
what is the abdominal wall bounded inferiorly by?
iliac and pubic crests, pubic symphysis and the inguinal ligament
which layer of fascia forms the deep membranous layer which blends with the fascia of the inner thigh and extends into the scrotum and labia majora as Colles’ fascia?
Scarpa’s fascia
which layer of fascia is the outer fatty layer which is continuous with the superficial fat over the rest of the body?
Scarpa’s fascia
what muscle originates from the lower 6 costal cartilages, lumbodorsal fascia, iliac crest and inguinal ligament?
transversus abdominis
the inguinal ligament is formed by the free lower border of what muscle?
external oblique
what muscle originates from the lower 8 ribs?
external oblique
what muscle inserts into ribs 10-12, linea alba and pectin pubis?
internal oblique
what muscles insert into the linea alba?
external oblique, internal oblique, pyramidalis, transversus abdominis
the conjoint tendon is formed from the tendons of what 2 muscles?
internal oblique and transversus abdominis
true or false?
the anterolateral abdominal muslces contract during inspiration
false
when do the anterolateral abdominal muscles contract?
defacation, urination, vomiting and parturition
true or false?
the anterolateral abdominal wall muslces extend the trunk
false — they laterally flex and rotate
what name is given to the endoabdominal fascia that is located in the region of the anterolateral abdominal wall?
transversalis fascia
b
c
a
d
inguinal ligament attachments
ASIS to pubic tubercle
the internal aspect of the anterior abdominal wall presents 5 peritoneal folds that extend towards the umbilicus, what are they and what do they cover?
- median umbilical fold x1
- medial umbilical fold x2
- lateral umbilical fold x2 — covers inferior epigastric artery
