The Anterior Abdominal Wall and Peritoneal Cavity Flashcards
What are the borders of the abdominal cavity?
Separated from the thorax by the diaphragm
pelvic cavity lies inferior to the abdominal cavity and is continuous with it
What systems does the abdominal cavity contain organs from?
gastrointestinal tract
hepatobiliary system
endocrine system
spleen is haematopoietic and lymphoid system
defecation
pooping
What lines the internal abdominal wall
parietal peritoneum
What are aponeuroses
tough flat sheet of fibrous tissue that connects muscles with bones or with fascia of other muscles//a sheet of pearly white fibrous tissue that takes the place of a tendon in flat muscles having a wide area of attachment.
How many lumbar vertebrae make up the posterior abdominal wall? Which?
5 lumbar vertebrae. All 5 you stoopid <3
Functions of the abdominal wall?
protect the abdominal viscera
increase intra-abdominal pressure
maintain posture and move trunk
Name the 4 quadrants of the abdomen?
Right Upper Quadrant
Left Upper Quadrant
Right Lower Quadrant
Left Lower Quadrant
Name the 9 regions of the abdomen?
Right hypochondrium
Epigastrium
Left hypochondrium
Right flank
Umbilical region
Left flank
Right iliac fossa
Suprapubic region
Left iliac fossa
What are the 3 central regions of the abdomen superior to inferior?
Epigastrium
Umbilical region
Suprapubic region
What is the transpyloric plane?
Horizontal line
Passes through tips of l/r 9th costal cartilages
halfway between superior border of manubrium and pubic symphisis
What is the pylorus?
opening between the stomach and the duodenum
What is the transumbilical plane?
unreliable as it depends on amount of subcutaneous fat present
Approximately at L3 in a slender individual
What is the intercristal plane?
Horizontal line drawn between the highest points of the l/r iliac crests - used to guide procedures on the back
Which 4 pairs of muscles make up the anterolateral abdominal wall?
External oblique
Internal oblique
Transversus abdominis
Rectus abdominis
Describe the position, appearance attachments and action of the rectus abdominis
The l/r lie either side of the midline(linea alba), surrounded by an aponeurotic rectus sheath
Muscle segments separated by tendinous bands - 4 or 5 segments normally
Attached to sternum and costal margin superiorly and to pubis inferiorly
Acts vertically - is a flexor of the lumbar spine
Describe the orientation of the fibres of the external oblique muscles…
How superficial are they?
Diagonally arranged fibres - running medially and inferiorly(down) towards the midline
Most superficial to the internal obliques and transversus abdominis
Describe the orientation of the fibres of the internal oblique muscles…
How superficial are they?
Diagonally arranged fibres - perpendicular to external obliques - running medially and superiorly(upwards)
Deep to EO, superficial to transversus abdominis
Describe the orientation of the transversus abdominis…
How superficial are they?
Fibres are arranged and act horizontally
Deep to internal and so also external obliques
External obliques, internal obliques and transversus abdominis
What happens when they contract individually? Together?
Together they contract to increase the intra-abdominal pressure
Alone the oblique muscles act as lateral flexors of the spine
What is the linea alba and how is it formed?
A tough midline raphe - white line between l/r rectus abdominis
Anteriorly, obliques and transverse become aponeurotic(flat tendon) - fibres of apneuroses fuse with each other, and in the midline fuse with those of the opposite side to form the linea alba (also rectus sheath)
What is the rectus sheath and how is it formed?
Rectus sheath contains rectus abdominis, made up of apneuroses of obliques and transversus. It has anterior and posterior walls.
Approaching midline, IO apneurosis splits into anterior and posterior layers. EO and anterior layer of IO apneuroses form anterior wall of rectus sheath. Posterior wall formed by posterior layer IO and apneurosis of transversus abdominis
What does the transversalis fascia lie deep to?
What lies deep to the transversus fascia?
Transversalis lies deep to transversus abdominis.
Parietal peritoneum lies deep to the fascia.
What vessels are in the anterior abdominal wall?
musculophrenic artery
superior epigastric artery
inferior epigastric
All accompanied by deep veins - also network of superficial veins in anterolateral abdominal wall
Musculophrenic artery - where is it from, where does it go to?
Branch of the internal thoracic
Supplies anterior abdominal wall
Superior epigastric artery - where is it from, where does it supply?
Continuation of the internal thoracic artery
Descends in the rectus sheath, supplies anterior abdominal wall
Inferior epigastric artery - where is it from, where does it supply?
Branch of the external iliac artery
Ascends in the rectus sheath and anastomoses with the superior epigastric
Describe innervation of the anterior abdominal wall (muscles and skin)
Thoraco-abdominal nerves
T7-T11 - continuation of thoracic nerves t7-11 - somatic nerves cont sensory and motor fibres
Subcostal nerve originating from T12 spinal nerve
Iliohypogastric and ilioinguinal nerves - both branches of L1 spinal nerve
What are the borders of the inguinal canal?
Anterior - external oblique aponeurosis
(internal oblique aponeurosis - laterally only)
Posterior - transversalis fascia (conjoint tendon medially only)
Roof - transversalis fascia, arching fibres of internal oblique and transversus abdominis
Floor - inguinal ligament (lower border of external oblique aponeurosis)
What is the inguinal canal?
- Oblique passageway through muscles of anterior abdominal wall
- Travels medially and obliquely so passes through each layer of the abdominal wall
- About 5cm long in adults
- Extends from deep inguinal ring laterally to superficial inguinal ring medially
Abdominal wall hernias
Laparotomy
Abdominal aortic aneurysm (AAA or triple A)
Inguinal hernias
How is pain felt in the parietal peritnoneum?
