anterior and posterior abdominal wall and diaphragm Flashcards
what are the components of the abdominal wall?
musculoaponeurotic walls anterolaterally
diaphragm superiorly
pelvic floor muscles inferiorly
lumbar section of vertebral column posteriorly
what does the diaphragm cover?
the anatomical thoracic outlet serving as a partition to separate the abdominal and thoracic cavities
what do the pelvic floor muscles attach to?
the bony ring of the pelvic girdle- important because shows abdomen and pelvis are continuous cavities
what is internal pressure (intra-abdominal pressure) controlled by?
either voluntarily or reflexively by the contraction/relaxation of the diaphragm and anterolateral muscular walls
for generalized localization how many quadrants are there and what divides them?
4 divided by the median plane and the transumbilical plane
for specific localization how many regions are there and what divides them?
9 regions by the 2 vertical midclavicular lines and the 2 horizontal lines (subcostal plane and transtubercular plane)
where does the subcostal plane run?
touching the inferior border of the 10th costal cartilage on both sides
where does the transtubercular plane run?
the tubercle of the ilium on the iliac crest going through the body of the 5th lumbar vertebrae
what are the functions of the anterolateral abdominal wall?
(1) form a strong expandable support for the abdominal wall
(2) protect the abdominal viscera from injury
(3) oppose the diaphragm in respiration
(4) move the trunk/maintain posture
what is the anterolateral abdominal wall bounded superiorly by?
the cartilages of the 7th-10th ribs and the xiphoid process
what is the anterolateral abdominal wall bounded inferiorly by?
the inguinal ligament and superior margins of the anterolateral aspects of the pelvic girdle
what does the anterolateral abdominal wall consist of?
skin and subcutaneous tissue (which contains fat, muscles and their aponeuroses and deep fascia), extraperitoneal fat and parietal peritoneum
what are the four major pairs of muscles that compose the anterolateral abdominal wall?
external abdominal oblique
internal abdominal oblique
transverse abdominal
rectus abdominis
which muscle is the principle vertical muscle of the anterior abdominal wall and is much wider superiorly tapering inferiorly?
rectus abdominis
which muscle is often absent but it very small paired muscle most anteriorly and inferiorly that draws the linea alba downward towards the pelvis?
pyramidalis
what does the linea semilunaris represent?
the lateral limit of the rectus sheath
what is the inguinal ligament?
a retinacular structure – it holds down the structures passing between the pelvis and the thigh. It represents a thickening of external oblique aponeurosis running from the ASIS to the pubic tubercle. The deeper two flat muscles attach to it laterally
what is the rectus sheath?
a strong, incomplete fibrous compartment of the rectus abdominis and pyramidalis muscles. It contains some nerves and vessels too, most notably the inferior (and superior) epigastric arteries and veins. It is formed by the crossing and splitting of the aponeuroses of the more transverse muscle layers
which aponeurosis splits superiorly and surrounds the rectus muscle?
the internal oblique aponeurosis
what covers the posterior part of the rectus muscle?
the transverslais fascia
what is the arcuate line?
the line of demarcation represents the inferior limit of the posterior layer of the rectus sheath.
the internal thoracic artery splits into what two arteries?
musculophrenic and superior epigastric a
the abdominal aorta gives off which branch that travels with anterior rami of lower thoracic spinal nerves along inferior edges of ribs?
posterior intercostal a
the external iliac/femoral artery give off what 3 branches?
superficial epigastric, cicrumflex iliac, and inferior epigastric a
what do the anterior rami of spinal nerves T7-T12 travel within?
the posterior thoracic wall
what do the lower intercostal nerves continue as when then reach the costal margin and continue traveling anteromedially?
thoracoabdominal nerves
do the thoracoabdominal nerves participate in the plexus formation?
NO
where do the intercostal nerves travel between?
the innermost and internal intercostal muscles and continue between the internal oblique and transverse abdominal muscles
what structure does the anterior cutaneous branches pierce?
the rectus sheath
what is the inguinal canal?
formed to permit the descent of the testes during fetal life. In adults, both male and female, the canal is an oblique passage about 4cm long directed inferomedially through the inferior part of the anterior abdominal wall. It is parallel and superior to the medial half of the inguinal ligament – the thickened, inferior edge of the external oblique aponeurosis. It represents successive deficiencies in the three muscular layers of the wall, staggered medial to lateral
what are the openings to the inguinal canal?
deep inguinal ring and superficial inguinal ring