Anatomy Exam 5: Overview Of Digestive System

Front 1

Obj.
List and describe the components of the digestive system.

Back 1

-oral cavity
-pharynx
-esophagus
-stomach
-small intestine
-large intestine
-accessory digestive organs: salivary glands, liver, gallbladder, & pancreas

Front 2

Describe the function and subdivisions of the pharynx

Back 2

function- transports bolus of food from oral cavity to esophagus during swallowing

subdivisions-
nasopharynx (part of resp. system only)
oropharynx
laryngopharynx

Front 3

Describe the esophagus

Back 3

upper 1/3= skeletal muscle
middle 1/3= smooth & skeletal
lower 1/3= smooth muscle

upper sphincter- prevents entrance of air
lower sphincter- guards against gastriesophageal reflux (w/i esophageal hiatus)

Front 4

What may occur as a result of a sliding hiatal hernia?

Back 4

reflux of gastric contents into esophagus
-stomach herniates upward through esophageal hiatus

Front 5

Obj.
Describe the location of each part of the digestive tract within the body.

Back 5

oral cavity: w/i head, opens into pharynx
pharynx: extends from base of skull to cricoid cartilage, continuous w/ esophagus
esophagus: connects pharynx w/stomach
stomach: ends at pyloric sphincter which opens to duodenum of small intestine
small intestine: continues into large intestine
large intestine: empties into descending colon
sigmoid colon: connects descending colon and rectum
*anal canal ends digestive tract

Front 6

What happens in Barrett's esophagus?

Back 6

stratified squamous epithelium undergoes metaplastic changes into columnar epithelium, which is prone to ulceration & strictures may develop, causing obstruction
--> may further progress into adenocarcinoma

Front 7

What occurs in the stomach?

Back 7

food accumulates and undergoes partial enzymatic digestion into semi-liquid chyme

(via HCl acid & digestive enzymes)

Front 8

Describe the 4 parts of the stomach

Back 8

1. cardiac- at gastroesophageal junction
2. fundus- superolateral part below diaphragm
3. body- main part
3. pyloric- funnel part, pyloric antrum--> pyloric canal
(contains pyloric sphincter, contracted normally)

Front 9

Describe the orientation of the stomach surfaces

Back 9

lesser curvature faces superior/right
angular incisure (notch)= junction btwn body & pyloric
greater curvature faces inferior/left

Front 10

Know the common type of stomach ulcers, what factors cause them, & what complications they may lead to

Back 10

-peptic ulcer (mucosal erosion)
(*gastric ulcers less common than duodenal ulcers)

cause:
-Helicobater pylori (bacterial infection)
-chronic anxiety
-chronic used of NSAIDS

lead to:
-Bleeding
-Perforation (2/3 of ulcer death)
-Obstruction

Front 11

What are some early signs of stomach cancer/ adenocarcinoma?

Back 11

-early satiety (fullness)
-epigastric pain that doesn't improve w/ eating or taking antiacids

*5 yr survival rate <30%

Front 12

Obj.
Discuss the functions of the digestive system.

Back 12

-oral cavity: food ingested, chewed, mixed w/ saliva
-pharynx: transports food (bolus) to esophagus
-esophagus: prevents air in GI & transports bolus to stomach
-stomach: partial enzymatic digestion of food into chyme
-small intestine: primary site of nutrient absorption
-large intestine: water absorption, converts chyme to feces
-accessory digestive organs:
--salivary glands: secretes saliva
--liver: produces bile, emulsifies fat for digestion, stores glycogen, detoxification, receives nutrients
--gallbladder: stores & releases bile
--pancreas: secretes digestive enzymes & hormones

Front 13

Describe function, composition of small intestine

Back 13

function-
-primary site for nutrient absorption
-receives bile from common bile duct & pancreatic enzymes from the main pancreatic duct
^plicae circulares, vili, & microvili increase surface area for absorption

consists of-
-duodenum
-jejunum
-ileum

Front 14

Function & location of duodenum

Back 14

function- receives chyme from stomach

location- first part of small intestine, forms C-shaped loop around head of pancreas, continuous w/ duodenojejunal

4 parts-
superior
descending
inferior/horizontal
ascending

Front 15

Where is the most frequent location of peptic ulcers?

Back 15

duodenal cap/ampulla
superior first 2 cm of duodenum

-distinct radiographic appearance

Front 16

What is the narrowest part of the biliary passages?

Back 16

the hepatopancreatic ampulla
-btwn the bile duct & the main pancreatic duct, drains into major duodenal papilla
*common site for gallstone impaction

Front 17

Where is the junction btwn upper & lower GI bleeding?

Back 17

duodenojejunal junction, suspended from diaphram by suspensory muscle of duodenum (ligament of Treitz)

*surgical landmark

Front 18

Describe the location and function of the ileum

Back 18

location: distal 3/5 of small intestine, right lower quadrant, opens into the large intestine at ileocecal junction
*may contain ileal (Meckel's) diverticulum

Front 19

Describe the clinical relevance of ileal (Meckel's) diverticulum

Back 19

-remnant of the embryonic vitelline duct
-contains all layers of intestinal wall
**may contain ectopic gastric or pancreatic tissue & cause hemorrhage, bowel obstruction, perforation, and/or pain (mimicks appendicitis)

Front 20

Describe the location of the jejunum

Back 20

location: proximal 2/5 of small intestine, left upper quadrant,

Front 21

Function of the large intestine & distinguishing features

Back 21

-site for water absorption

features:
-omental appendices, small fatty projections
-teniae coli, 3 bands of longitudinal smooth muscle
-haustra, sacculations

parts:
-cecum (receive contents of ileum) & appendix
-colon (ascending, transverse, descending, sigmoid)
-rectum
-anal canal

Front 22

Clinical importance of ileocecal junction & cecum

Back 22

Possible sites of intestinal obstruction via:
-intussusception (telescoping of priximal segment into distal)
-volvulus (twisiting of intestine on itself)
-gallstone ileus (blocks ileocecal junction)

Front 23

The ______________ is a vestigal, intestinal diverticulum that contains lymphoid tissue, and is variable in position

Back 23

appendix

*can be retrocecal in position
*20% of appendicitis cases misdiagnosed
*acute appendicitis may develop into peritonitis

Front 24

Obj.
List intraperitoneal and retroperitoneal organs.

Back 24

intraperitoneal-
abdominal esophagus
stomach & proximal duodenum (cap)
jejunum & ileum
cecum
transverse colon
sigmoid colon
liver & gallbladder
tail of pancreas
spleen

retroperitoneal-
duodenum (NOT cap)
ascending colon
descending colon
pancreas (NOT tail)
kidney & ureters
abdominal aorta
inferior vena cava

Front 25

Obj.
List and describe the three branches of the abdominal aorta that supply the digestive tract, including the organs supplied by each branch.

Back 25

Digestive tract consists of derivatives of embryonic gut supplied by unpaired ventral branches of abdominal aorta

celiac trunk/artery: abdominal esophagus, stomach, duodenum, liver, gallbladder, pancreas
(caudal foregut)

superior mesenteric artery: duodenum, jejunum & ileum, cecum & appendix, ascending colon, R 2/3 transverse colon
(midgut)

inferior mesenteric artery: L 1/3 transverse colon, descending colon, sigmoid colon, rectum & upper anal canal
(hindgut)

Front 26

Differentiate btwn right & left colic flexure

Back 26

right colic (hepatic flexure- btwn ascending & transverse colon

left colic (splenic) flexure- btwn transverse & descending colon

Front 27

The larges body in the gland is......
what are its functions?

Back 27

Liver
functions:
bile production
storage of glycogen
receives all nutrients from GI except lipids
detoxification

Front 28

What are the two surfaces of the liver separated by the sharp inferior border?

Back 28

diaphragmatic & visceral surfaces

Front 29

Differentiate btwn the functional and anatomical lobes of the liver

Back 29

functional- divides R & L lobes by imaginary R sagittal fissure, passing through the gallbladder fossa & fossa for inferior vena cava, each lobe has own portal triad

anatomical- divides R & L lobes by L sagittal fissure formed by the fissure for the round ligament of liver (ligamentum teres hepatis) and the fissure for the ligamentum venosum

Front 30

What is the portal triad?

Where does it enter the liver?

Back 30

hepatic artery + portal vein + hepatic (bile) duct

Enters at transverse fissue, porta hepatis

*each functional liver lobe has its own portal triad

Front 31

What is cirrhosis?

What may cause it?

Back 31

destruction of hepatocytes, replaced w/ fibrosis

Chronic alcoholism & hepatitis B & C may cause

Front 32

Describe the function and compartments of the gallbladder

Back 32

function- releases bile when fat enters duodenum

compartments-
-fundus, blunt end at R 9th costal cartilage
-body, main contact w/ viscera
-neck, makes an S turn to become continuous w/ cystic duct

Front 33

Due to its close relation w/ the superior duodenum, what common conditions arise from the gallbladder?

Back 33

Cholelithiasis- gallstones, may be asymptomatic
Cholecystitis- gallstones that obstruct the passage of bile causing inflammation
Fistula- opening may develop into superior doudenum
Cholecystenteric fistula- opening in transverse colon
Gallstone Ileus- a gallstone in the small intestine that obstructs ileocecal valve

Front 34

Where do the following ducts carry bile:
common hepatic duct-
cystic duct-
common bile duct-

Back 34

common hepatic duct- formed by the union of R & L hepatic ducts from respective lobes of liver, carries bile from liver
cystic duct- carries bile from gallbladder
common bile duct- formed by union of cystic & common hepatic duct, joins pancreatic duct at hepatopancreatic ampulla & drains into duodenum

Front 35

what is the difference btwn the exocrine and endocrine components of the pancreas?

Back 35

exocrine- secretes digestive enzymes into duodenum

endocrine- secretes hormones carried in bloodstream to target organs

*pancreas is an accessory digestive gland that lies transversely across L1 & 2

Front 36

what are the 4 parts of the pancreas?

Back 36

-Head, lies w/i C-shaped concavity of duodenum
-Neck, overlies superior mesenteric artery & vein
-Body, longest part
-Tail, close to spleen

Front 37

What are the 2 ducts of the pancreas and where do they drain?

Back 37

main- begins in tail and runs through body, neck, & head, joins bile duct in hepatopancreatic ampulla to drain into the descending part of the duodenum at the major duodenal papilla

accessory- drains part of the head of the pancreas at the minor duodenal papilla

Front 38

Cancer of the pancreatic head may obstruct the _________________, due to its location.

What characteristic symptom would this cause?

Back 38

bile duct


Jaundice (painless), due to retained bile that yellows tissues

Front 39

__________ is the 4th leading cause of cancer death in the US with a 5 year survival rate <5%


What is the first symptom?

Back 39

pancreatic cancer
*cancer of the body & tail do not present until metastasis has occured

PAIN, w/ wieghtloss, anorexia, malaise, weakness

Front 40

Obj.
Describe the organization of the abdominal cavity.

Back 40

-consists of abdominal wall enclosing abdominal cavity
-part of abdominopelvic cavity
-enclosed by muscular abdominal wall, vertebral column, lower thoracic rib cage, upper hip bone
-contains
-peritoneum surrounds peritoneal cavity containing organs of digestive & urinary system

Front 41

Obj.
Describe the peritoneal sac and the different possible relationships of abdominal organs to it (i.e., intraperitoneal, retroperitoneal).

Back 41

intraperitoneal:
-invaginating from peritoneal sac from behind, suspended by mesentary, lining of body wall is parietal peritoneum
-organs covered by visceral peritoneum, suspended in mesentary, blood vessels & nerves reach through mesentary to supply organs

retroperitoneal- located posterior to peritoneum btwn abdomen & parietal peritoneum, organs partially covered by parietal peritoneum, usually on anterior surface

Front 42

The peritoneal sac is closed in (males/females)

Back 42

males

-uterine tubes open into and connect peritoneal cavity to outside world in females (pathway for infection)

Front 43

the peritoneal cavity normally contains only a thin film of peritoneal fluid but fluid may accumulate w/ some pathologies, this is known as _________________ and may be removed by _______________

Back 43

ascites

paracentesis

Front 44

Bacteria may infect the peritoneum causing inflammation (peritonitis). How might this occur?

Back 44

-perforation of a peptic ulcer
-penetrating wound
*potentially life threatening due to peritoneums rapid absorption of toxins

Front 45

Why is a patient with bacterial peritonitis propped in a seated position?

Back 45

peritoneal fluid normally flows superiorly toward diaphram, however if seated it will flow downward into pelvic cavity where absorption is slower, likelihood of spreading through diaphram to pleura is reduced

Front 46

Peritonitis due to trauma or infection may result in the formation of what ?

These will cause what symptoms?

Back 46

peritoneal adhesions (fibrous bridges)


chronic pain & bowel or uterine tube obstruction

Front 47

Peritoneal formations consisting of double layers of peritoneum include ______________, _______________, and ______________

What do these formations join to subdivide the peritoneal cavity into?

Back 47

mesentaries,
omenta (connect stomach to other organs),
and
peritoneal ligaments (connect abdominal organs to each other or to wall)

greater sac (main large part) & lesser sac/omental bursa (posterior to stomach & lesser omentum)

Front 48

What does the greater peritoneal sac contain?

Back 48

sac is subdivided by transverse colon & transverse mesocolon into-
supracolic compartment: spleen, stomach, liver
infracolic compartment: small intestine, ascending colon, descending colon
^infracolic subdivided by mesentary of small intestine into R & L infracolic space

Front 49

What are the two omenta?

Back 49

greater omentum- suspended from the greater curvature of the stomach, mobile, moves to wall off infections to prevent generalized peritonitis

lesser omentum- connecting the lesser curvature (hepatogastric ligament) & the proximal duodenum (hepatoduodenal ligament) to the liver)

Front 50

What are the two types of peritoneal ligaments?

Back 50

gastrosplenic ligament- part of the greater or lesser omentum that connects an abdominal organ w/ another or w/ the wall

splenorenal ligament- connect an organ to and adjacent organ or body wall

Front 51

What is the omental (epiploic) foramen?

Back 51

communication btwn greater peritoneal sace & omental bursa

Bound:
anteriorly- hepatoduodenal ligament
posteriorly- inferior vena cava
superiorly- caudate lobe of liver
inferiorly- superior (first) part of duodenum

Front 52

Why is an internal hernia within the omental foramen difficult to treat?

Back 52

-none of the boundaries can be incised
-must be decompressed w/ need to free it

Front 53

How can infection/cancer spread from the abdominal to pelvic cavity?

Back 53

via
R paracolic gutter- lateral to ascending colon, connects the supracolic compartment & pelvic cavity
or
L paracolic gutter- lateral to descending colon

Front 54

The lowest part of the abdominal peritoneal cavity in the supine position is the ____________________

This structure communicates medially w the __________
and anteriorly w the ________________

Back 54

hepatorenal recess (Morison's pouch)

omental bursa (through omental foramen)

subphrenic recess (btwn liver & diaphragm)

Front 55

Branches of the celiac trunk (from abdominal aorta):

Back 55

left gastric artery: (stomach & lower esophagus)

splenic artery: (neck, body, tail of pancreas, spleen)
-left gastro-omental (stomach)
-short gastric (stomach)

common hepatic artery:
-gastroduodenal (stomach, head of pancreas, duodenum)
>R gastro-omental
>Superior pancreaticoduodenal
-proper hepatic (liver, gallbladder)
>R hepatic
>>cystic (gallbladder)
>L hepatic
>R gastric (stomach)

Front 56

In what cases may an aberrant of accessory hepatic artery occur?

Back 56

-abberant right hepatic artery branching from superior mesenteric
-aberrant left hepatic branching from left gastric

*accessory=additional, aberrant= instead of

Front 57

Branches of the superior mesenteric artery (from abdominal aorta):

Back 57

*Inferior pancreaticoduodenal (head of pancreas & duodenum)

*Intestinal (Jejunal & Ileal) arteries

*Middle colic (transverse colon)
-R & L

*Right colic (ascending colon)
-ascending & descending

*Ileocolic (terminal ileum, cecum, ascending collon)
-appendicular artery (appendix)
-ascending & ileal branches

Front 58

Branches of inferior mesenteric artery (from abdominal aorta):

Back 58

*Left colic artery (descending colon)
-ascending branch
-descending branch

*Sigmoid arteries (sigmoid colon)

*superior rectal artery (rectum & anal canal)

Front 59

What artery may provide collateral circulation if the inferior or superior mesenteric arteries become occluded?

Back 59

marginal artery

Front 60

Why is the left colic (splenic) flexure a "watershed area"?

Back 60

-marginal artery may be absent of insufficient, leading to systemic hypotension
or
-inferior mesenteric artery stenosis may result in ischemia & ulceration (ischemic bowel disease)

Front 61

Where does venous blood from the GI system & spleen drain into for transport to liver?

Back 61

hepatic portal vein

****unlike blood flow from rest of body, which passes directly into tributaries of the superior or inferior vena cava

Front 62

What vessels come together to form the hepatic portal vein?

Where do hepatic veins drain blood from the liver into?

Back 62

formed posterior to neck of pancreas by union of superior mesenteric vein & splenic vein

liver into inferior vena cava

*inferior mesenteric vein drains into splenic vein