Abdominopelvic cavity Flashcards
General function of abdominopelvic cavity
-contraction of muscular roof, floor, walls of “container”
-increases intra-abdominal pressure
-aids in expiration
-aids in expulsion of fluid, flatus, feces, and fetuses
Respiratory diaphragm
-closes inferior thoracic aperture
-separates abdominopelvic cavity from thoracic cavity
Respiratory diaphragm attaches to:
-osteological boundaries of inferior thoracic aperture (costal margin, xiphoid process, floating ribs)
-superior lumbar vertebrae
Structure of resp diaphragm
-Right dome contains liver and pushes upwards
-Left dome is pushed down by heart
-Contains central tendon, sternal muscle, costal muscle, lumbar muscl
-Right and left crus
-Apertures
Crus
Musculoteninous bands arising from lumbar vertebrae and anchor resp diaphragm to lumbar vertebrae
Caval opening
-Inferior vena cava
-Most anterior
-Level T8
Esophageal hiatus
-Esophagus
-Middle
-Level T10
Aortic hiatus
-Aorta
-Located between crus
-Opening posterior to diaphragm
-Not a true opening
-Level T12
Respiratory diaphragm during inspiration
-Contracts, flattening domes
-Domes descend
-Increases vertical dimension of thoracic cage
-Allows inspired air to fill lungs
Respiratory diaphragm increasing intra-abdominal pressure
-Contraction increases IA pressure
-Increases IA pressure pushes diaphragm back upwards
-Results in forced expiration
Inferior vena cava and central tendon during inspiration
-IVC adheres to caval opening
-Central tendon pulls and widens caval opening
-Dilates inferior vena cava
-Facilitates blood flow back to heart
What happens to esophagus during inspiration?
-Muscular lumbar part contracts and constricts esophagus
Superficial to deep: layers of abdominal wall
-Skin
-Subcutaneous tissue
-Muscles and aponeuroses, deep fascia
-Transversalis fascia
-Extraperitoneal fat
-Parietal peritoneum
Flat muscles of abdominal wall
-External obliques
-Internal obliqyes
-Transversus abdominis
Vertical muscle of abdominal wall
-Rectus abdominis
-Pyramydalis
Aponeurosis
sheet of white fibrous tissue that takes the place of a tendon in flat muscles having a wide area of attachment
Rectus sheath
encloses vertical muscle (rectus abdominis)
Inguinal ligament
-ASIS to pubic crest
-Folding of EO aponeurosies
-Serves as flexor retinaculum
Linea alba
-midline raphe (suture, seam)
-intersection of bilateral aponeuroses from all 3 flat muscles
-xiphoid process to pubic symphyses
What makes up the anterior wall of the rectus sheath?
Above arcuate line:
-External oblique
-Internal oblique
Below arcuate line:
-External oblique
-Internal oblique
-Transversus abdominis
What makes up the posterior wall of the rectus sheath?
-Internal oblique
-Transversus abdominis
Parietal peritoneum
the lining that is around the abdominal cavity
Tendinous intersections
-anchors rectus abdominis to rectus sheet
-creates 6 pack look
Function of abdominal muscles
-Support and protect adnominal viscera
-Maintain or increase intra-abdominal pressure
-Elevates diaphragm during expiration
-Compresses abdominal viscera for expulsion and blood flow (IVC)
-Relaxes to accomodate movement of diaphragm during inspiration
-Moves trunk (RAL flexion of trunk, EO/IO: rotation, lateral flexion)
What does the pelvic diaphragm close? What does it separate?
-The pelvic outlet
-Separates abdominopelvic cavity from perineum
Where is the pelvic diaphragm found?
-Within the lesser (true) pelvis
What is the tendinous arch of obturator fascia?
Thickening of fascia on muscle
What are the two different muscles in the pelvic diaphragm?
-(Ischio)coccygeus
-Levator ani
What are the three parts of the levator ani?
-Iliococcygeus
-Pubococcygeus
-Puborectalis
Of the different muscles of the pelvic diaphragm, which muscle is tapered medially and broad laterally?
Iliococcygeus
Of the different muscles of the pelvic diaphragm, which muscle is tapered laterally and broad medially?
(Ischio)coccygeus
Sustained contraction of pelvic diaphragm does:
-Supports abdominopelvic viscera
-Maintains urinary and fecal continence
Active contraction of pelvic diaphragm?
Primarily: increases support to abdominopelvic viscera during moments of increase IA pressure (coughing or sneezing)
Secondarily: increases IA pressure to aid expulsion
Rectal hiatus
space for rectum/anus
Urogenital hiatus
passage of urogenital viscera
What is the roof, walls and floor of the abdonminopelvic cavity?
Roof: respiratory diaphragm
Walls: anterolateral and posterior abdominal walls
Floor: pelvic diaphragm
The esophageal hiatus allows the travel of the esophagus from the ________ to the ________
thorax to abdomen
The caval opening allows the travel of the inferior vena cava from the _________ to the ___________
Abdomen to thorax
The aortic hiatus allows the travel of the aorta from the ________ to the __________
Travel to and from above the abdomen posterior to the diaphragm
What conveys blood to the respiratory diaphragm?
Pericardiacophrenic artery
The aponeuroses of the external obliques, internal obliques, and transversus abdominis form the _________, __________, and _________
Linea alba, inguinal ligament, rectus sheath
Inferior to the arcuate line, the ___________________ lines the posterior aspect of rectus abdominis.
Transversalis fascia
