Biol 313 Exam 3

3 major sub-cavities of the ventral body cavity

• thoracic, abdominal and pelvic

What is the thoracic cavity defined by inferiorly

the diaphragm

is there a physical divide between the abdominal and pelvic cavities

no

what is the abdominal cavity walled by

musculoaponeurotic walls (anterolaterally), diaphragm (superiorly) and the pelvic floor muscles (inferiorly)

what are the two bony rings that support/protect the abdomen

• inferior margin of the thoracic skeleton (superiorly)

• pelvic girdle (inferiorly)

what is the serous membrane that covers the anterolateral abdominal wall and the visceral organs

peritoneum

what part of the peritoneum goes with the abdominal wall

parietal peritoneum

what part of the peritoneum goes with the visceral organs

visceral peritoneum

region 1

right hypochondrium

region 2

epigastric

region 3

left hypochondrium

region 4

right lateral (flank)

region 5

umbilical

region 6

left lateral region

region 7

right inguinal (groin)

region 8

pubic

region 9

left inguinal (groin)

body plane 1

semilunar lines

body plane 2

midclavicular line (MCL)

body plane 3

transpyloric plane

body plane 4

subcostal plane

body plane 5

transtubercular plane

body part 6

iliac tubercle

body plane 7

interspinous plane

body plane 8

jugular line

body plane 9

pubic symphysis

Right Upper Quadrant (RUQ) Organs

• liver (right lobe)

• gallbladder

• stomach (pylorus)

• duodenum (pts 1-3)

• pancreas (head)

• R suprarenal gland

• R kidney

• R colic (hepatic) flexure

• Ascending colon (superior pt)

• Transverse colon (R half)

Right Lower Quadrant (RLQ) Organs

• cecum

• appendix

• most of ileum

• ascending colon (inferior)

• R ovary

• R uterine tube

• R ureter (abdominal pt)

• R spermatic cord (abdominal pt)

• uterus

• urinary bladder

Left Upper Quadrant (LUQ) Organs

• liver (L lobe)

• spleen

• stomach

• jejunum and proximal ileum

• pancreas (body and tail)

• L kidney

• L suprarenal gland

• L colic flexure

• Transverse Colon (L half)

• Descending colon (superior pt)

Left Lower Quadrant (LLQ) Organs

• sigmoid colon

• descending colon (inferior pt)

• L ovary

• L uterine tube

• L ureter (abdominal pt)

• L spermatic cord (abdominal pt)

• Uterus (if enlarged)

• Urinary bladder (if full)

what does the hypodermis of the anterolateral abdominal wall contain

• variable amounts of adipose tissue

3 muscle layers of the deep hypodermis

• superficial fascia, muscle then peritoneum

five muscles of the anterolateral abdominal wall

• external and internal oblique

• transversus abdominis

• rectus abdominis

• pyramidalis (not found on everyone)

external oblique

• fibers = inferomedial

• external surfaces of lower ribs (5-12)

• aponeurosis inserts on linea alba

• linea alba = place of intramuscular exchange of superficial and deep fibers

internal oblique

• fibers run superomedially

• origin at thoracolumbar fascia and iliac crests

• insertion of aponeurosis on linea alba

• intermuscular exchange of fibers with contralateral external oblique muscles

transversus abdominus

• deepest muscle layer

• origin at internal surfaces of lower ribs, thoracolumbar fascia

• insertion: aponeurosis inserts on linea alba

rectus sheath

• formed by merger of aponeuroses of all three flat muscles

• inferior border thickens = forming inguinal ligament

• rectus abdominus embedded in this

• pierced by inguinal canal

where do all layers of the anterolateral wall fuse

the umbilicus

what does the rectus sheath converge inferiorly to create in males

fundiform ligament

rectus abdominus

• divided vertically by linea alba

• divided horizontally by tendinous intersection

• eight bellies

• origin at pubic crest

• insertion at xiphoid process and inferior costal cartilages

pyramidalis muscle

• absent in 20% of people

• origin at pubic crest

• insertion at linea alba

• no real function

Causes of protuberance of the abdomen

6 F’s

• food, fluid, fat, feces, flatus (gas), fetus

venous flow reversal

• happens when flow through superior or inferior vena cava is obstructed

• blows through anastomoses collateral pathways

• blood is basically flowing backwards because of a blockage and finds alternate routes to get back

what are the gutters of the posterior abdominal wall occupied by

• kidneys, perirenal fat and pararenal fat

what is the most powerful muscle in the body called and what is it composed of

iliopsoas muscle

• composed of iliacus and psoas muscles

what muscle causes hip flexion

iliacus

Iliacus muscle

• large, triangular muscle

• major and minor

• originates on iliac crest and inserts on lesser trochanter of femur

Quadratus lumborum

• originates on iliac crest

• inserts on tips of transverse processes of L1-L4 and inferior margin of rib 12

• flexes vertebral column and fix ribcage during inspiration

abdominal aorta

• 13cm (2.5cm in diameter)

• begins at aortic hiatus and ends by dividing into common iliac arteries at L4 level

• can sometimes see/feel pulsations when wall is relaxed

Inferior vena cava

• begins at level L5 with merging of common iliac veins

• leaves abdomen through caval opening at level T8

• 20cm in length

• largest vein in body

• no valves

• to the right of the aorta

where does the Inferior vena cava drain blood from

• abdominal wall, lower limbs, portal blood and non-portal blood from abdomen and pelvis

• most blood from digestive tract goes through hepatic portal system then drains into IVC

where does the thoracic duct drain into

junction of left subclavian and internal jugular veins

lymphatic drainage

• cisterna chyli → thoracic duct → Left subclavian vein

cisterna chyli

where all lymphatics from abdomen and lower limbs converge, and where everything drains through

Rupture of Diaphragm

• frequently from car accidents

• 95% on left side (because liver protects the right hemidiaphragm)

• stomach, small intestine, mesentery, transverse colon or spleen may enter thorax

Congenital Diaphragmatic Hernia

• 1 in 2200 newborns

• almost always affects left side owing to liver on right

• left lung usually fails to inflate at birth

• high mortality rate (76%)

Posterior Abdominal Pain

• if kidneys, ureters, cecum, appendix, sigmoid colon, lumbar lymph nodes and lumbar nerves are diseased movement of iliopsoas can be painful

• test = lying patients on unaffected side and asking them to extend thigh, pain means positive sign

Abdominal Aortic Aneurysm

• can be congenital or acquired weakness in arterial wall

• deep palpations of mid-abdomen can detect it

• severe pain and high mortality (90%) due to blood loss

peritoneum

• mesothelium lining abdominopelvic cavity

• moist with peritoneal fluid, allows movement without friction

• cavity is completely closed in males, but open to exterior in females (through uterine tubes, uterus and vagina)

three compartments of the peritoneum

• supracolic (greater sac)

• omental bursa (lesser sac)

• infracolic (greater sac)

Peritoneal formations

• mesentery

• mesocolon

• omentum (greater and lesser)

greater omentum

attached to greater curvature of the stomach

lesser omentum

attached to lesser curvature of the stomach

Peritonitis

• infection and inflammation in the peritoneum

• often caused by rupture of the GI tract (ulcer perforation or appendix rupture)

• widespread can be fatal due to rapid absorption of bacterial toxins

ascites

• excess fluid in the peritoneum

Peritoneal adhesions

• peritoneum is damaged and surfaces become inflamed and sticky with fibrin

• when healing, fibrin can be replaced with connective scar tissue binding visceral peritoneum to parietal peritoneum (sticks organs together)

Adhesiotomy

• surgical separation of adhesions

how can the peritoneum be used during renal failure

• a ‘dialysis machine’ which by injecting saline into the peritoneal cavity and then draining them a few hours later will, by using the fluids, absorb toxins by concentration gradient diffusion

falciform ligament

• divides the liver into right/left lobes

• attaches to diaphragm and anterior abdominal wall to the level of the umbilicus

• keeps the liver in place

what are the intestines largely covered by

the greater omentum

celiac trunk

• serves stomach, spleen and liver

• goes to the phrenic artery, gastric artery and hepatic artery

superior mesenteric artery

• serves small intestine, cecum, ascending colon and transverse colon

interior mesenteric artery

• serves descending colon, sigmoid colon and rectum

inferior mesenteric vein

• drains rectum, sigmoid colon and descending colon

superior mesenteric vein (right and middle colic veins)

• drains small intestine, cecum, ascending colon and transverse colon

splenic vein (left colic vein)

drains spleen and inferior mesenteric vein

where do all veins drain

hepatic portal vein to the liver

esophagus

• 10 in long

• surrounded by smooth muscle (2/3rds) and skeletal muscle (1/3)

• follows curvature of vertebral column

  • terminates at z-line inferior to GI sphincter

stomach

• between esophagus and duodenum of small intestine

• food blender and reservoir

• mechanical, chemical and enzymatic digestion

• mixes bolus with gastric juice producing chyme

• can hold 2-3L of food, and is able to change size

• only place that does mechanical, chemical and enzymatic digestion

point 1

cardiac notch

point 2

fundus

point 3

body

point 4

greater curvature

point 5

pyloric antrum

point 6

duodenum

point 7

pyloric canal

point 8

lesser curvature

point 9

pylorus

point 10

angular incisure

point 11

cardia

point 12

esophagus

what is the stomach closed by

pyloric sphincter and GI sphincter

What is the interior of the stomach lined with

rugae (folds)

• not always there if a person is full

point 1

Left gastric artery

point 2

celiac trunk

point 3

common hepatic artery

point 4

gastroduodenal artery

point 5

splenic artery

point 6

splenic branches

small intestine

• primary digestion and nutrient absorption site

• divided into three regions (duodenum, jejunum and ileum)

• begins are pyloric sphincter

• ends at ileocecal valve (opening to large intestine)