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