Anatomy Exam 3

Regarding surface anatomy, describe the two patterns used to break up the abdomen into different regions

quadrants - RUQ, LUQ, RLQ, LLQ

regions - right hypochondriac, epigastric, left hypochondriac, right lumber, umbilical, left lumbar, right iliac, hypogastric, left iliac

Describe the layers of the anterior abdominal wall (superficial to deep)

skin, Camper’s fascia (fatty layer), Scarpa’s fascia (membranous layer), external oblique muscle, internal oblique muscle, transversus abdominis muscle, transversalis fascia, extraperitoneal fascia, parietal peritoneum

What muscles are located on the anterior abdominal wall? (superficial to deep)

anterolateral: external oblique muscle, internal oblique muscle, transversus abdominis muscle

anteriormedial: pyramidalis, rectus abdominis

Action and Innervation of External Oblique Muscle

Action: compress abdominal contents, flex trunk (bilateral), rotation of trunk (unilateral)

Innervation: anterior rami of T7-T12

Action and Innervation of Internal Oblique Muscle

Action: compress abdominal contents, flex trunk (bilateral), rotation of trunk (unilateral)

Innervation: anterior rami of T7-T12

Action and Innervation of Transversus Abdominis

Action: compress abdominal contents

Innervation: anterior rami of T7-T12

Action and Innervation of Rectus Abdominis

Action: compress abdominal contents, flex trunk (bilateral)

Innervation: anterior rami of T7-T12

Action and Innervation of Pyramidalis

Action: tenses linea alba

Innervation: anterior ramus of T12 (subcostal nerve)

How is the rectus sheath formed?

Formed by the aponeuroses of the external, internal and tramsversus abdominis muscles

Above arcuate line, anterior: external+internal

Above arcuate line, posterior: internal+transversus

Below arcuate line, anterior: external+internal+transversus

At what point is the rectus sheath not present? What is posterior to the rectus sheath at this point?

Not present below the arcuate line, posterior

transversalis fascia

What is the arterial supply of the anterior abdominal wall? What is their parent artery? Where are these arteries located?

Superior Wall: superior epigastric artery, musculophrenic artery (branches of internal thoracic artery)

• if superior to arcuate line, superior epigastric artery is between the posterior restus sheath and rectus abdominis

Inferior Wall: inferior epigastric artery (branch of external iliac artery)

• If inferior to arcuate line, inferior epigastric artery is between the transversalis fascia ad rectus abdominis

Why is the abdominal wall weakened in the inguinal region?

because of the inguinal canal

What is the processus vaginalis?

a pouch that protrudes through the layers of the anterior abdominal wall during the descent of the testis

What is the gubernaculum?

In males: a tether that attaches the inferior end of the gonad to the scrotum

In females: a tether that attaches the inferior end of the gonad to the labia majora

What structures demarcate the beginning and end of the inguinal canal?

begins at the deep inguinal ring, ends at the superficial inguinal ring

What structures pass through the inguinal canal?

genitofemoral nerve (genital branch), ilioinguinal nerve, spermatic cord (men), round ligament (women)

What are the borders of the inguinal canal?

Roof: transversalis fascia, internal oblique muscle, transversus abdominis muscle

Posterior: transversalis fascia

Anterior: aponeurosis of external oblique, internal oblique muscle

Floor: inguinal ligement, lacunar ligament

What is the difference between an indirect and direction inguinal hernia?

Indirect: herniated contents pass thru deep and superficial rings, occurs lateral to inferior epigastric vessels

Direct: herniated contents pass thru only the superficial ring, occurs medical to inferior epigastric vessels

What are the three fascial coverings that surround the spermatic cord or round ligament of the uterus? From what structure does each fascial layer originate from?

External spermatic fascia (superficial): from external oblique muscle

Cremasteric fascia (middle): from internal oblique muscle

Internal spermatic fascia (deep): from transversalis fascia

Describe the spermatic cord. Where does it begin and end? What are its contents?

begins at the deep inguinal ring and ends at the scrotum

contents: pampiniform plexus of veins, ductus deferens, cremasteric artery, testicular artery, artery of the ductus deferens, genital branch of genitofemoral nerve, sympathetic nerve fibers, lymphatic vessels

What is the cremaster muscle and cremaster reflex?

Cremaster muscle: a thin muscle that surrounds the testicles and spermatic cord in males, is responsible for raising and lowering the testicles, which regulates temperature and offers protection

Cremasteric reflex: superficial reflex triggered by stroking the inner thigh, causing the cremaster muscle to contract and elevate the testis

Describe the round ligament of the uterus. Where does it begin and end?

remnant of the gubernaculum, has the same fascia coverings as the spermatic cord, begins at the uterus to the skin of the labia majora

Describe the peritoneum.

2 layers: parietal peritoneum (lines the abdominal wall) and visceral peritoneum (adheres to abdominal structures) + peritoneal cavity

What are the two divisions of the peritoneal cavity? What structure connects the two divisions?

Greater sac and lesser sac

Epiploic foramen

What are the different types of peritoneal folds?

Omenta, mesenteries, ligaments

What are the attachments of the greater and lesser omentum?

Greater: attached to greater curvature of stomach

Lesser: attached to lesser curvature of stomach, 1st part of duodenum, liver

Why is the greater omentum considered the policeman of the abdominal cavity?

because of its ability to move around the abdominal cavity, look for foreign objects, and physically wall off areas of inflammation to prevent the spread of infection

What two ligaments are found within the lesser omentum? What structures pass through these ligaments?

hepatogastric ligament = gastric vessels

hepatoduodenal ligament = proper hepatic artery, portal vein, bile duct

What is the role of omenta?

act as double layer of peritoneum

What is the function of mesenteries?

Attach viscera to posterior abdominal wall

What is the difference between intraperitoneal and retroperitoneal? Which organs are intraperitoneal? Which organs are retroperitoneal?

intraperitoneal = within the peritoneum

esophagus, stomach, jejunum, ileum, cecum, appendix, transverse colon, sigmoid colon

retroperitoneal = outside the peritoneum

duodenum, pancreas, kidneys, ascending and descending colon

What are the four regions of the stomach?

What structure separates the stomach, and which stomach region, from the esophagus?

What structure separates the stomach, and which stomach region, of the duodenum?

cardia, fundus, body, and pylorus

lower esophageal sphincter

pyloric sphincter

What are rugae? Where is it found and what is its function?

wrinkles or folds in the stomach, helps stomach to increase in size and surface area to accommodate food

What are the three parts of the small intestine? Which is their correct order, and therefore, which structures do they connect to?

duodenum (connects to stomach), jejunum, ileum (connects to cecum of large intestine)

Which organ is found nestled into the curvature of the duodenum?

pancreas

What are the four parts of the duodenum?

What is found within the second part of the duodenum?

What structure is attached to the fourth part of the duodenum and jejunum? What is the point called? What is the function of this structure?

superior, descending, inferior and ascending

minor and major duodenal papilla

ligament of Treitz, widen the angle of the duodenojejunal flexure during contraction

What are some features that allow you to differentiate the jejunum from the ileum?

Jejunum: long vasa recta, less rows of arterial arcades

Ileum: short vasa recta, more rows of arterial arcades

What structure separates the ileum from the cecum?

Ileocecal valve

What are the different parts of the large intestine? What are three characteristics that are unique to the large intestine?

ascending colon, transverse colon, descending colon, sigmoid colon

taeniae coli, haustra of colon, omental appendices

What structure hangs off the cecum?

appendix

What are the four lobes of the liver?

What structure separates the right and left lobes on the anterior aspect? What is on the inferior aspect of this structure?

What structures border the quadrate and caudate lobes?

right, left, caudate, quadrate

falciform ligament, rough ligament of the liver (ligamentum teres)

caudate: inferior vena cava and ligamentum venosum

quadrate: gallbladder and ligamentum teres

What is the porta hepatis? Where is it located? What enters/exits this structure?

where structures are going to enter or exit the liver

posterior side of the liver, in the center

enter: hepatic portal vein and right and left hepatic artery - proper hepatic artery

exit: right and left hepatic duct - common hepatic duct

Bile leaves the gallbladder and liver through which ducts? These ducts combine to form what duct? Where does the duct empty into?

Bile from the liver through the left and right hepatic ducts= merge to form the common hepatic duct

Bile from the gallbladder travels through the cystic duct

common hepatic duct + cystic duct = form the common bile duct, which empties into the duodenum through the major papilla

What is the relationship of the pancreas to the duodenum?

head of pancreas nestled in the curvature of duodenum

neck of pancreas is anterior to the superior mesenteric vein and artery

Where does the main and accessory pancreatic ducts empty into?

main pancreatic duct drains into the major papilla of duodenum

accessory pancreatic duct branches off of main and drains into the minor papilla

What structure forms when the main pancreatic duct and common bile duct combine?

hepatopancreatic ampulla

Where is the spleen located in the abdominal cavity? Why is the spleen not considered a digestive organ?

located behind the stomach, next to pancreas

because it is part of the immune system where its function is to recycle old RBCs

What are the main three arteries branching off the abdominal aorta?

celiac trunk, superior mesenteric artery, inferior mesenteric artery

What is the primitive gut? What organs belong to each region?

Foregut = esophagus, stomach, proximal duodenum, liver, pancreas, gallbladder

Midgut = distal duodenum, jejunum, ileum, cecum, appendix, ascendin colon, 2/3 transverse colon

Hindgut = 1/3 transverse colon, descending colon, sigmoid colon, rectum, upper anal canal

What are the branches of the celiac trunk? What pathway do they take? Which organs do they supply?

left gastric artery

common hepatic artery

splenic artery