Abdomen Lecture Questions Flashcards
What are the demarcations/borders of the abdomen?
-Inferior margin of the thorax
-Superior margin of the pelvis and lower limb
What is the inferior thoracic aperture?
Forms the superior opening to the abdomen
What is the deep abdominal wall continuous with?
Continuous with the pelvic wall at the pelvic inlet
How does the abdomen communicate with the pelvic cavity?
Through the peritoneal cavity
How are abdominal viscera suspended?
They are suspended either by the mesentary or between the cavity and the wall
What type of fluid is in the peritoneal cavity? How much is in there?
-Peritoneal fluid only
-50mm of fluid
What happens if there is too little peritoneal fluid?
-Parietal peritoneum has sensory input
-If there is too little fluid, the organs can stick together and someone will get referred pain
What are the 3 main functions of the abdomen?
-Protection of major viscera
-Breathing
-Changes in intrabdominal pressure (which favors child birth and defacation)
What organs in the abdominal cavity are protected by the thoracic wall?
-Most of the liver
-Gallbladder
-Stomach
-Spleen
- Parts of the colon
What organs of the abdominal cavity are supported by the muscular wall of the abdomen and iliac fossa?
-Small intestine
-Colon
-Appendix
What does the diaphragm do during respiration?
-Contracts during inspiration
-Relaxes during expiration
What do people have trouble with if they do not use their abdomen for breathing? Why do they have those issues?
-They have more issues with concentration, anxiety, and sleeping
-This is because serotonin is stored in the gut and is released during diaphragmatic breathing
What are components of the abdomen?
-Wall
-Abdominal cavity
-Inferior thoracic aperture
-Diaphragm
-Pelvic inlet
What does the abdominal wall consist of?
-Muscles
-Bones
What are the skeletal elements of the bony portion of the abdominal wall?
-Lumbar vertebrae
-Superior expanded parts of the pelvic bones
-Inferior thoracic wall (costal margins, ribs 11-12, xiphoid process)
What muscles make up the posterior aspect of the abdominal wall?
-Quadratus lumborum
-Psoas major
-Iliacus
What muscles make up the lateral aspect of the abdominal wall?
-Transverse abdominis
-Internal oblique
-External oblique
What muscles make up the anterior aspect of the abdominal wall?
Rectus abdominis
What is the general organization of the abdominal cavity?
A central gut tube is suspended from the posterior abdominal wall and partially from the mesentary that is attached to the anterior abdominal wall
What are the 2 sub portions of the mesentary?
-Ventral mesentary for proximal regions of the gut
-Dorsal mesentary that spans the entire system
What is the function of the mesentary?
-Suspends abdominal organs
-Provides a “road” for blood vessels & nerves
-Stores fat
What is peritoneum? What are the two types?
-Epithelial-like single layer of cells that provides lining in the abdominal cavity
-Parietal peritoneum (lines the abdominal wall)
-Visceral peritoneum (covers suspended organs)
What are the two types of abdominal viscera?
-Intraperitoneal
-Retroperitoneal
What is intraperitoneal?
-Structures that are suspended from the abdominal wall by the mesentary
-Completely surrounded by peritoneum
What is retroperitoneal?
-Structures that are not suspended in the abdominal wall by the mesentary
-Lie between the parietal peritoneum & abdominal wall
-Only one surface is covered by the peritoneum
What are secondary retroperitoneal structures?
-Structures that start off as intraperitoneal during development
-They later fuse with the abdominal wall and become secondary retroperitoneal structures
What are some of the secondary retroperitoneal structures?
-Duodenum
-Ascending and descending colon
What is the inferior thoracic aperture? What is it closed by?
-Superior aperture of the abdomen
-Xiphoid process
-Ribs 11-12
-T12
-Closed by the diaphragm
Where does the diaphragm attach to?
-The margin of the inferior thoracic aperture
-Each side has a muscular extension/tendon, called the crus, that anchors the diaphragm to the anterolateral surface of the vertebral column (L3 on the right, L2 on the left)
What structure passes through the diaphragm and in between each crus?
The aorta
What are the arch shaped ligaments that the posterior diaphragm is anchored to? Where do these ligaments attach to?
-Median arcuate ligament
-Medial arcuate ligaments
-Lateral arcuate ligaments
-They attach to the transverse processes of L1 and rib 12
What structure is attached to the diaphragm where the aorta passes through? What happens if this structure is tight?
-Median arcuate ligament
-If this ligament is tight, it can compress the artery that supplies gut to the GI tract and can cause GI issues
What structures are found in the pelvic inlet?
-Rectum
-Bladder
-Uterus
-Ureters
-Peritoneum
What structures pass from the abdomen to the thigh?
-External iliac artery
-Femoral nerve
-Femoral artery
-Psoas major
-Iliacus
How does the abdomen communicate with the lower limb?
Through the inferior margin of the abdominal wall that is marked by the inguinal ligament and the pelvic bone
What are the 2 schemes most often used to describe the regions of the abdomen?
-4 quadrant pattern
-9-region organization
What are the 4 quadrants of the abdomen? How are they divided?
-Upper & lower, right & left quadrants
-Divided w/ a vertical line from the xiphoid process
-A transverse line through the umbilicus
What are the 9 regions of the abdomen? How are they divided?
-R/L hypochondrium
-Epigastric region
-Umbilical region
-Pubic region
-R/L flank
-R/L groin region
-Vertical lines going down from mid-clavicle
-Transverse line from tubercles of iliac crest
-Transverse line inferior to costal margins (ribs)
What are the flank regions also known as?
Lumbar region
What are the groin regions also known as?
Inguinal region
What are the layers of the abdominal wall?
-Skin
-Camper’s fascia
-Scarpa’s fascia
-External oblique
-Internal oblique
-Transverse abdominis
-Transversalis fascia
-Parietal peritoneum
-Extraperitoneal fascia
What is the umbilicus? Where is it situated?
-A scar represenation of the site of attachment of the umbilical cord
-Situated in the linea alba
What are the two superifical fascial layers in the abdominal wall?
-Camper’s (fatty fascia)
-Scarpa’s (deeper membranous fascia)
Where does the camper’s fascia continue to in men?
-It continues into the penis
-After losing its fat, it fuses with scarpa’s fascia
What is the dartos fascia? What is its function?
-Where the camper’s and scarpa’s fascia fuses near the penis and continues into the scrotum
-It contains smooth muscle fibers and contracts according ot the temperature (if its cold, it brings the testes closer to the body)
What are the 5 muscles in the anterolateral abdominal wall?
-External oblique
-Internal oblique
-Transverse abdominis
-Rectus abdominis
-Pyramidalis
What percent of the population has a pyramidalis?
80% of the population has a pyramidalis (20% do not)
What is the function of the pyramidalis muscle?
It stabilizes the linea alba during trunk rotation
What is the transversalis fascia?
-Thin aponeurotic membrane
-Between the inner surface of the TA and extraperitoneal fascia
What is the extraperitoneal fascia?
-Deep to the transversalis fascia
-Separates the transversalis fascia from the peritoneum
What nerves innervate the abdominal muscles? Where are they located?
-Thoracoabdominal nerves T7-T11
-Located between the 2nd and 3rd layers of muscle
What is the rectus sheath? What is it formed by?
-Enclosed the rectus abdominis & pyramidalis
-Formed by the aponeurosis of the external oblique, internal oblique, and TA
What is diastasis recti? Why does it happen more often inferior to the umbilicus?
-When the rectus abdominis gets separated from the linea alba
-It happens more often inferior to the umbilicus because the linea alba is a lot thinner in that region
What forms the inguinal ligament?
The aponeurosis of the external oblique
What ligaments are found in the lower abdominal region?
-Inguinal ligament
-Lacunar ligament
-Pectineal ligament
What is the lacunar ligament?
-An extension of the inguinal ligament at the medial end
-Attaches the inguinal ligament to the pectin pubis on the superior ramus of the pubic bone
What is the pectineal ligament?
An extension of the lacunar ligament along the pectin pubis line
What is the inguinal canal? Where is it located?
-Slit-like passage
-Located just above & parallel to the inguinal ligament
-Begins in the deep inguinal ring and ends at the superficial inguinal ring
What structure passes through the superficial inguinal ring?
Spermatic cord
What is the superficial inguinal ring?
A whole in the external oblique aponeurosis for the spermatic cord to pass through
What is the deep inguinal ring?
A whole in the transversalis fascia that the spermatic cord passes through
What passes through the deep inguinal ring in females?
A round ligament of the uterus
What does the spermatic cord consist of?
-Artery of ductus deferens
-Testicular artery
-Testicular veins
-Sympathetic & afferent nerve fibers
-Lymphatics
What is the round ligament of the uterus? What is its function?
-Cord-like structure that passes from the uterus to the deep inguinal ring and enters the inguinal canal
-After exiting the superficial inguinal ring, it turns into a few strands of tissue and attaches to a connective tissue associated with the labia majora
-Helps keep the uterus in tilted position
-Maintenance of the anteflexion of the uterus
What are the types of inguinal hernias?
-Direct: through the posterior wall of the inguinal canal
-Indirect: through the deep inguinal ring
What are the main vessels of the anterolateral abdominal wall?
-Branches of the internal thoracic artery (intercostal, musculophrenic, superior epigastric)
-Branch from the femoral artery (superficial circumflex iliac)
-Branch from the external iliac artery (inferior epigastric, deep circumflex iliac)
What area does the celiac trunk supply blood to?
The foregut
Where do the gonadal vessels supply blood to?
Ovaries and testes
Where does the superior mesentaric artery supply blood to?
Mesentary
What can the median arcuate ligament do to the celiac trunk? What is this condition called?
-It can compress the celiac artery and can cut off blood supply to the foregut
-This is called compression syndrome
What is the posterior abdominal region? What does it consist of?
-Posterior to the GI tract, then spleen, and the pancreas
-Bound by bones and muscles
-Aorta
-Inferior vena cava
-Sympathetic trunks
-Lymphatics
-Kidneys
-Esophagus
-Ureters
-Gonadal vessels
What bone strutctures make up the posterior abdominal wall?
-Lumbar vertebrae
-Sacrum
-Pelvic bones (medial side of each ilium)
-Ribs 11-12
What muscles make up the posterior abdominal wall?
-Diaphragm
-Psoas major & minor
-Quadratus lumborum
-Iliacus
What muscle in a cow is the filet mignon?
Psoas major
What is the psoas muscle abscess? Why does it occur?
-It is a pus filled sac and infection of the psoas major muscle
-It occurs when tuberculosis or other harmful bacteria infect the intervertebral discs and this infection can spread to the psoas major since there isn’t many other structures in the region for the infection to go
What percent of people have a psoas minor?
Only 40% of people have a psoas minor
What structure passes over the top of the rigth crus?
Inferior vena cava
What lobe of the liver surrounds the inferior vena cava?
Caudate lobe
What is the tendon in the middle of the diaphragm called?
Central tendon
What structures pass through the diaphragm?
-Right and left phrenic nerve
-Aorta
-Inferior phrenic artery
-Thoracic duct
-Anterior and posterior vagus trunks
-Inferior vena cava
-Esophagus
What are the domes of the diaphragm? What are they formed by?
-The domes are rounded portions of the diaphragm that are formed by abdominal contents pushing the lateral portions upward that causes a flattening of the diaphragm in this area
-Right dome is formed by stomach and spleen
-Left dome is formed by the liver
What level of the ribs are the domes located?
-The right dome is at rib 5
-The left dome is in intercostal space 5 (below rib 5)
What happens to the diaphragm/domes during inspiration?
-The muscular part of the diaphragm contracts causing the central tendon to be drawn inferiorly
-This results in flattening of the domes and enlargement of the thoracic cavity
What happens to the heart during inspiration? What does this favor?
-Since the pericardium is attached to the pericardium, during inspiration, the heart/R atrium gets pulled downward
-This favors venous returns because it is opening up the atria more
What is the blood supply to the superior portion of the diaphragm?
-Internal thoracic artery
-Musculophrenic (branch of internal thoracic)
-Pericardiophrenic (branch of internal thoracic)
-Superior phrenic artery (branch of thoracic aorta)
-Thoracic aorta
What is the blood supply to the inferior portion of the diaphragm?
-Abdominal aorta
-Inferior phrenic (branch of abdominal aorta)
What is the innervation of the diaphragm?
-Primarily by phrenic nerves
-Sensory fibers are supplied by intercostal nerves
