Lab 10: Abdomen

Question 1

abdominal skeleton

Answer 1

• bounded superiorly by the abdominal diaphragm and inferiorly by the upper margin of the bony pelvis
• consists of a large cavity that is walled by muscle and serous membrane
• abdominal cavity is continuous inferiorly with the pelvic cavity which is enveloped by the bony pelvis
• structure of rib cage and tilt of pelvis cause the thoracopelvic gap between them to be higher in front than behind
• dome of abdominal diaphragm is very high -> from margins of 12th ribs up to the level of 5th ribs
• some abdominal organs are covered by the lower 5 or 6 ribs and their costal cartilage

Question 2

relationship of abdominal viscera to the rib cage

Answer 2

• several ab organs are partially, largely, or entirely covered by the rib cage
• liver- deep to rib cage, covered anteriorly by the bottom of the sternum and some of the inferior costal cartilage to the left, on the right -> covered by the 5th to 11th ribs and their costal cartilage, posteriorly it is deep to the 9th to 11th ribs
• stomach- covered anteriorly on the left side by the 5th to 8th ribs
• spleen- entirely covered by the 9th to 11th ribs
• kidneys- deep to ribs -> both adrenal (suprarenal) glands are covered by the 12th ribs

Question 3

roof of the abdominal cavity

Answer 3

• abdominal diaphragm forms the roof of the abdominal cavity

- innervated by phrenic nerve (C3-C5)

Question 4

anterolateral walls of the abdominal cavity

Answer 4

• cover by 4 muscles on each side

- one is strap-like longitudinal muscles in the front and 3 sheet-like muscles more laterally

Question 5

anterior abdomen muscle: rectus abdominis

Answer 5

• rectus abdominis- strap-like muscle that arises from the xiphoid (and 5th to 7th costal cartilage)
• runs from superior (xiphoid process), 5th-7th costal cartilages -> to the pubis
• 2 sheets
• inserts on the superior edge of the pubis
• flexes the trunk
• in between each muscle belly there is a tendinous intersections muscle section
• 3 (sometimes 4) connective tissue tendinous intersections that interrupts the muscle belly
• recuts sheath- encloses the rectus abdominis
• formed by aponeuroses of 3 lateral wall muscles
• arcuate line (bellow belly bottom)- below this line the rectus sheath is only in the front (not behind)
• semilunar line- where it stops
• tendinous sheath of lateral wall muscle - make up the layers of rectus abdominis
• innervated by spinal nerves T7-T12

Question 6

3 layers of rectus abdominis

Answer 6

external oblique aponeuroses

• internal oblique aponeuroses
• transversus abdominis

Question 7

anterolateral wall: external oblique

Answer 7

• external oblique- most superficial layer
• arises from the lower 8 ribs and the iliac crest
• fibers run inferiorly and medially and become tendinous anteriorly to form the linea alba
• inguinal ligament
• thick inferior edge of aponeurosis -> stretches between the anterior superior iliac spine and the pubic tubercle -> inguinal ligament
• superficial inguinal ring- hole in the aponeurosis above the pubic tubercle (testes exit here)
• inguinal canal passes though the inguinal ligament- testes originate here and drop)

Question 8

anterolateral wall: internal oblique

Answer 8

• middle layer
• arises from the front of the iliac crest and the inguinal ligament
• fibers run superiorly and medially -> insert onto ribs 10-12
• inferior edge form an arc above the inguinal ligament that is deep to and slightly lateral to the superficial inguinal ring
• above the umbilicus -> aponeurosis splits into superficial and deep layers around rectus abdominis
• below umbilicus -> aponeurosis runs superficial to rectus abdominis to mesh with the linea alba
• runs the opposite direction of external oblique

Question 9

anterolateral wall: transversus abdominis

Answer 9

• running horizontally
• deepest muscle layer
• arises posteriorly form an aponeurosis that passes behind quadratus lumborum
• attaches to transverse processes of L1-L5
• also attaches to the lower 6 costal cartilages -> iliac crest and inguinal ligament
• fibers run anteriorly to become aponeurotic and mesh with the linea alba
• above the umbilicus -> aponeurosis passes behind rectus abdominis
• below umbilicus -> its aponeurosis passes in front of rectus abdominis

Question 10

transversalis fascia

Answer 10

• fascial layer
• below the three layers of muscle in the anterolateral wall
• internal aspect of the abdominal wall is lined with a layer of tissue known as the transversalis fascia

Question 11

rectus sheath

Answer 11

• formed from the aponeuroses of the obliques and transversus abdominis
• arcuate line- inferior margin of posterior rectus sheath
• below arcuate line -> the rectus abdominis sits directly on transversalis fascia
• weak spot in abdominal wall
• aponeuroses of the left and right external oblique muscles cover the rectus abdominis muscles anteriorly and fuse to the midline to form the linea alba

Question 12

above arcuate line: superficial to deep

Answer 12

• external oblique aponeurosis
• first half of internal oblique aponeurosis
• rectus abdominis
• second half of internal oblique
• transversus abdominis
• transversalis fascia
• parietal peritoneum
• first and second half enclose

Question 13

below arcuate line: superficial to deep

Answer 13

• external oblique aponeurosis
• internal oblique aponeurosis
• transversus abdominis
• rectus abdominis
• transversalis fascia
• parietal peritoneum

Question 14

pyramidalis

Answer 14

• arises from the pubis and inserts into the linea alba

- 80% of people have this small muscle

Question 15

linea alba

Answer 15

• left and right muscles (anterior abdomen muscle) are separated by a longitudinal band of connective tissue called the linea alba
• tendinous intersections and linea alba create the six pack
• aponeuroses of the left and right external oblique muscles cover the rectus abdominis muscles anteriorly and fuse to the midline to form the linea alba

Question 16

posterior wall of abdomen: quadratus lumborum

Answer 16

• forms most posterior wall
• laterally flexes trunk
• forms the bulk of the posterior abdominal wall
• originates on the iliolumbar ligament and iliac crest
• inserts onto the transverse process of L1-L4 and the lowermost rib

Question 17

posterior wall of abdomen: psoas major

Answer 17

• originates on vertebral column from T12-L5
• runs down to iliacus and merges -> forms iliopsoas m.
• hip flexor, laterally flexes trunk
• forms the medial part of the posterior abdominal wall adjacent to the vertebral column
• arises from the bodies and intervertebral discs of T12-L5
• fibers merge with those of iliacus to form a conjoint iliopsoas tendon that inserts onto the lesser trochanter of the femur

Question 18

posterior wall of abdomen: psoas minor

Answer 18

• only present in 50-60% of people
• runs along the front of psoas major
• very small
• arises from the bodies and disc of T12-L1 and runs along the front of psoas major
• inserts onto the iliopubic eminence of the pelvis

Question 19

posterior wall of abdomen: abdominal diaphragm

Answer 19

• forms the superoposterior wall of the abdominal cavity

- where all the posterior abdominal wall muscles end

Question 20

peritoneum

Answer 20

• serious membrane, like pleura and pericardium
• parietal peritoneum- outer layer
• visceral peritoneum- inner layer, lies against walls of organs
• retroperitoneal organs- not enclosed by peritoneal cavity
• mesentery- reflected peritoneum that folds around an organ
• greater omentum- fat flap, double layer of visceral peritoneum (specialized mesentery)

Question 21

retroperitoneal organs

Answer 21

• suprarenal glands
• aorta/inferior vena cava
• duodenum (2nd and 3rd parts)
• pancreas
• ureter
• colon (ascending and descending)
• kidneys
• esophagus
• rectum
• SAD PUCKER

Question 22

mesenteries

Answer 22

• small intestine is suspended by the mesentery (proper)
• transverse colon suspended by the transverse mesocolon
• omentum- lesser and greater
• connects to transverse colon and hangs of the greater portion of stomach -> greater omentum

Question 23

digestive canal organs

Answer 23

• esophagus
• stomach
• small intestine
• large intestine

Question 24

accessory organs

Answer 24

• liver
• gallbladder
• pancreas
• spleen

Question 25

biliary tree

Answer 25

-carries bile and digestive enzymes from these organs to the small intestine

Question 26

stomach

Answer 26

- made up of walls of muscle layers: circular, longitudinal, oblique - mixes food with acids to make chyme - rugae- rough ridges for mechanical digestions - 3 parts: fundus, body, pylorus - 2 sphincters: cardiac and pyloric - cardiac sphincter- between esophagus and stomach (prevents regurgitation of acid) - pyloric sphincter- between stomach and duodenum

Question 27

stomach

Answer 27

- made up of walls of muscle layers: circular, longitudinal, oblique - mixes food with acids to make chyme - rugae- rough ridges for mechanical digestions - 3 parts: fundus, body, pylorus - 2 sphincters: cardiac and pyloric - cardiac sphincter- between esophagus and stomach (prevents regurgitation of acid) - pyloric sphincter- between stomach and duodenum (discharge chyme)

Question 28

stomach: mesenteries

Answer 28

- intraperitoneal - attached to posterior - lesser omentum- connects stomach and liver, runs in lesser curvature - greater omentum- hangs down from the stomach, connects with transverse colon -> runs along greater curvature

Question 29

small intestine

Answer 29

- responsible for digesting food and absorbing nutrients - 3 regions: duodenum (mainly retroperitoneal), jejunum (freely mobile, suspended by mesentery), ileum (suspended by mesentery) - ileum opens into the cecum of the large intestine

Question 30

duodenum

Answer 30

- most proximal part of small intestine - c-shaped - curves around head of pancreas - pierced by: main pancreatic duct + bile duct through major duodenal papilla

Question 31

jejunum

Answer 31

- wide lumen - thick walls - numerous circular folds - superior mesenteric artery supply - few arcades, long vasa recta - shorter

Question 32

ileum

Answer 32

- narrower lumen - thin walls - fewer circular folds - superior mesenteric artery supply - many arcades, short vasa recta - longer

Question 33

small intestine: mesenteries

Answer 33

- jejunum and ileum are intraperitoneal - attached to posterior abdominal wall by mesentery - mesentery- surrounding the blood vessels that go to the organs - mesentery proper - encroaches on intestinal walls in the ileum, not in the jejunum

Question 34

large intestine

Answer 34

- responsible for water absorption - storing undigested material - 8 regions: - cecum - vermiform appendix - ascending colon - transverse colon - descending colon - sigmoid colon - rectum - anal canal

Question 35

haustra and taeniae coli

Answer 35

- differentiates large intestine - haustra- pouches of the large intestine - taeniae coli- longitudinal thin muscle that goes throughout the entire large intestine - omental (epiploic) appendages- fat blobs that hang

Question 36

large intestine: mesenteries

Answer 36

- partly intraperitoneal - ascending and descending colon, rectum etc. are retroperitoneal - transverse colon is intraperitoneal - greater omentum- attaches the transverse colon to the stomach - transverse mesocolon- attaches transverse colon to posterior abdominal wall

Question 37

liver

Answer 37

- produces bile - filters blood from GI trace - produces bile - metabolizes carbs, fats, and proteins - lobes (4)- right lobe, left lobe, quadrate lobe (next to gallbladder!), caudate lobe (next to IVC) - round ligament of the liver (ligamentum teres)- used to be umbilical vein - falciform ligament- separates the right and left lobe - falciform ligament splits into 2- top portion (posterior) of the liver is bare (no peritoneum) - hepatic portal vein, hepatic artery proper, and common bile duct (portal triad) going into the liver -> porta hepatis

Question 38

porta hepatis

Answer 38

- where blood vessels enter and exit the liver - hepatic artery- carries oxygenated blood to tliver - portal vein- drains blood from GI tract to liver - common bile duct- drains bile from the liver (joins cystic duct from gallbladder to form common bile duct - deoxygenated blood drains from the liver into the inferior vena cava

Question 39

biliary tree

Answer 39

- right + left hepatic ducts -> common hepatic ducts - cystic duct + common hepatic duct -> common bile duct - bile ducts and the main pancreatic duct both drain into the duodenum, via the major duodenal papilla - bile helps break down lipids

Question 40

kidneys

Answer 40

- excrete metabolic waste - maintain water and electrolyte balance - blood vessels: renal arteries, renal veins - hilum of kidneys transmit the renal artery, renal vein, and ureter - regions: pelvis (collection chamber for urine) -> major and minor calyces; medulla (urine ducts) -> renal pyramids - renal pyramids- receive urine form collecting ducts of the nephron - renal papilla (opening to minor calyx) - renal pyramids -> renal papilla -> minor calyx -> major calyx -> renal pelvis -> ureter -> bladder

Question 41

adrenal glands

Answer 41

- endocrine glands, secrete hormones including adrenaline - blood vessels- suprarenal arteries (3) suprarenal veins - superior suprarenal artery branches off inferior phrenic artery (which supplies the diaphragm) - middle suprarenal artery off aorta - inferior suprarenal artery off renal artery

Question 42

renal artery and veins relationship

Answer 42

- renal veins are superficial to renal arteries - left renal vein is much longer than the right (bc it must cross over aorta) - inferior mesenteric artery (IMA) comes off the aorta over the left renal vein

Question 43

nephron: tubular component

Answer 43

- glomerular (bowmans) capsule - proximal convoluted tubule - loop of henle - distal convoluted tubule - collecting duct - urine leaves through collecting duct - things that are moved into the blood leave through efferent arteriole

Question 44

nephron: vascular component

Answer 44

- afferent arteriole - glomerulus - efferent arteriole - peritubular capillary network

Question 45

arteries of abdomen

Answer 45

- 3 major branches of abdominal aorta: - celiac trunk (T12-L1)- emerges near aortic hiatus -> supplies foregut - superior mesenteric artery (L1)- supplies midgut - inferior mesenteric artery (L3)- supplies hindgut (splenic flexure, ascending and descending colon, rectum) - also note that paired visceral branches from the aorta: middle suprarenal arteries, renal arteries, gonadal arteries

Question 46

celiac trunk

Answer 46

- main branches: 1. left gastric artery: supplies stomach, esophagus 2. splenic artery: supplies pancreas spleen (gives off left gastroepiploic artery) 3. common hepatic artery: splits into gastroduodenal artery and proper hepatic artery - gastroduodenal artery- supplies duodenum (gives off right gastroepiploic artery) - proper hepatic artery- supplies liver (gives off right gastric artery to stomach and cystic artery to gallbladder)

Question 47

anastomoses

Answer 47

- 2 different sources of blood join and form one artery - lesser curvature gets blood from left gastric artery and right gastric artery -> they combine - left side

Question 48

superior mesenteric artery

Answer 48

-L1 -enters mesentery of small intestine -supplies distal 1/3 of duodenum, remaining small intestine, proximal large intestine 1. jejunal branches 2. ileal branches 3. middle colic artery: gives blood to transverse colon and some ascending colon, 4.

Question 49

inferior mesenteric artery

Answer 49

- supplies distal large intestine and proximal rectum - branches: 1. left colic artery- supplies distal transverse colon and proximal descending colon 2. sigmoid branches- supply descending colon, sigmoid colon 3. superior rectal artery-

Question 50

venous drainage

Answer 50

- systemic venous system drains blood from the whole body (except the GI tract) - portal venous system drains blood from the GI tract - passes through liver before continuing to the heart

Question 51

portal venous system

Answer 51

- inferior mesenteric vein drains into splenic vein - splenic vein meets up with superior mesenteric vein -> forms hepatic portal vein - portal vein enter the liver via the porta hepatis

Question 52

gonadal vessels

Answer 52

- gonadal arteries- testicular artery in males and ovarian artery in females - gonadal veins are not symmetrical - left gonadal vein drains into left renal vein - right gonadal veins drains into inferior vena cava

Question 53

peritoneum

Answer 53

- cavity that is enclosed by the abdomen and pelvis is lined with a serous membrane -> peritoneum - peritoneal sac has an outer parietal and inner visceral component that lies against the walls of organs that have pushed into it

Question 54

peritoneal cavity

Answer 54

-membranous sac that some of the abdominal organs protrude

Question 55

retroperitoneal

Answer 55

- sit between the parietal peritoneum and the posterior wall of the abdomen - kidneys and adrenal glands, ascending colon, descending colon, rectum, parts of the pancreas and duodenum

Question 56

mesentery

Answer 56

-push into the peritoneal sac from behind -push into the sac so deeply that the peritoneum stretches out behind them becoming bilaminar between the organ and the posterior abdominal wall -permits the organ a degree of movement and it is the conduit for blood vessels and nerves to the organ -small intestine is suspended by the mesentery -> mesentery proper -transverse colon is suspended by a mesentery -> transverse mesocolon -

Question 57

omentum or ligament

Answer 57

- some organs push into the peritoneal sac even more deeply - one organ may push into the sac in front of another, so the first becomes suspended by a bilaminar sheet of peritoneum that is reflected off of the second - suspensory fold such as this is referred to as either a ligament or omentum

Question 58

lesser omentum

Answer 58

-stomach is suspended from the liver

Question 59

greater omentum

Answer 59

- stomach and transverse colon are connected by a large flap of peritoneum known as greater omenutm - hangs down like an apron to cover the front of most of the intestinal tract - it will adhere to the surface of the gut around a site of infection or perforation which helps seal off and localize such conditions

Question 60

digestive system

Answer 60

- consists of alimentary canal and the abdominal organs of digestion that are associated with it - alimentary canal begins with the oral cavity and includes the oropharynx and pharynx in the head and beck and the esophagus through the neck and thorax - esophagus passes through the abdominal diaphragm to enter the gut - gut is contained with the abdominopelvic cavity - about 1/2 inch below the diaphragm the esophagus opens into the stomach - stomach leads to small intestine (21 ft) - small intestine opens into the large intestine (4ft) - digestive organs associated with alimentary -> liver, gall bladder, pancreas

Question 61

small intestine

Answer 61

- duodenum - jejunum - ileum - most of the digestion of food and the absorption of nutrients - 2 layers of smooth muscle: longitudinal and circular (superficial to deep) - longitudinal- peristaltic - circular- segmenting contractions

Question 62

large intestine

Answer 62

- cecum - vermiform appendix - ascending colon - transverse colon - descending colon - sigmoid colon - rectum - anal canal[ - absorption of water and storage of undigested material until it can be expelled as feces - 4 ft - shorter but larger diameter than small intestine - forms frame around small intestine

Question 63

spleen

Answer 63

- lymphatic organ primarily | - produces a substance used by the liver to make bile which is digestive

Question 64

bile

Answer 64

- liver produces and gallbladder stores bile - delivered into the small intestine by a network of tubes -> biliary tree - biliary tree opens into the duodenum - liver also filters blood from the intestines and metabolizes the carbohydrates, fats, and proteins that are carried to it by that blood

Question 65

pancreas

Answer 65

- produces the hormone insulin -> key role in carbohydrate metabolism - most of substance manufactures digestive enzymes - delivered to the small intestine by tubes that are linked to the biliary tree

Question 66

gut

Answer 66

- foregut - midgut - hindgut - receive blood from separate vessels form the abdominal aorta -> celiac, superior mesenteric, inferior mesenteric

Question 67

portal venous system

Answer 67

- blood from the GI has to be filtered by the liver before it reaches the heart - carries blood from the gut to the liver

Question 68

stomach

Answer 68

- large, dilated portion of the alimentary canal - stores food for processing and mixes the foot with acidic secretion from glands in its walls to form semifluid -> chyme - delivers chyme to the small intestine - esophagus is continuous with the stomach just below the abdominal diaphragm - opening into the stomach is known as the cardiac orifice - greater curvature- longer left margin - lesser curvature- shorter right margin - 3 parts: fundus, body pylorus - fundus- dome-shaped region that extends upward from the cardiac orifice - body- extends from the level of the cardiac orifice to the end of the lesser curvature - pylorus- extends to the point at which the stomach becomes continuous with the small intestine

Question 69

cardiac sphincter

Answer 69

-circular band of smooth muscle that surrounds the cardiac orifice prevents the regurgitation of food and drink

Question 70

pyloric orifice

Answer 70

- stomach opens into the small intestine at the pyloric orifice - walls of this orifice are thickly muscles forming the pyloric sphincter -> regulates the discharge of chyme into the small intestine

Question 71

stomach wall

Answer 71

- mucous membrane that lines the inside of the stomach wall is thick - numerous folds -> rugae - rugae- mainly longitudinal oriented, flatten out as the stomach become distended with food - stomach can expand to accommodate a bit more than a quart of ingested material - walls of stomach comprise of three layers of smooth muscle: longitudinal, circular, oblique (superficial to deep)

Question 72

duodenum

Answer 72

- retroperitoneal- fixed in place - C-shaped - curves around the head of the pancreas - continuous with the second part of the small intestine -> jejunum - vertical portion is pierced by the conjoined main pancreatic duct and bile duct -> forms the major duodenal (hepatopancreatic) papilla - the orifice of this small projection on the inner surface is guarded by a smooth muscle sphincter -> sphincter of oddi - accessory pancreatic duct- opens a little proximal sphincter of oddi it through minor duodenal (hepatopancreatic) papilla - muscous membrane lining the inside has numerous transverse permanents fold -> plicae circulares -> serve to increase SA for absorption

Question 73

jejunum

Answer 73

- long coils- freely movable - attached to the posterior abdominal wall by a fold of the peritoneum -> mesentery - lies primarily in the upper left of the peritoneal cavity - wide lumen and thick wall - supplied by the superior mesenteric artery -> branches of which form anastomosing arcades - branches form only one or two arcades and heir terminal portions are long - numerous closely set plicae circulares - shorter than ileum -> 7 1/2 ft

Question 74

ileum

Answer 74

- lies mostly in the lower right part of abdomen - opens into the cecum of the large intestine - long coils- freely movable - attached to the posterior abdominal wall by a fold of the peritoneum -> mesentery - narrow lumen and thin wall - supplied by the superior mesenteric artery -> branches of which form anastomosing arcades - branches form several arcades and their terminal portions are short - plicae are set farther apart in the proximal part and are absent from its distal part - 11 ft

Question 75

cecum

Answer 75

- forms a pouch below its junction with the ileum at the ileocecal orifice - orifice is guarded by the ileocecal valve - hanging from the end of the cecum is the vermiform appendix -> opens into the cecum alittle below the ileocecal orifice - base of appendix lies directly behind a point on the anterior abdominal wall (McBurney's point) -> 1/3rd of the way up a line drawn between the right anterior superior iliac spine and the umbilicus

Question 76

ascending colon

Answer 76

- extends up the right side of the abdomen form the cecum to the liver - turns to the left at the right colic (hepatic) flexure - at this flexure the ascending colon becomes the transverse colon - transverse colon hangs down a bit as it crosses the abdomen to a point just below the spleen - turns downward at the left colic (splenic) flexure -> becomes the descending colon

Question 77

descending colon

Answer 77

- runs downward along the left side of the abdomen to become the sigmoid colon at the brim of the pelvis - sigmoid colon leads to the rectum

Question 78

rectum

Answer 78

- beings at the level of the 3rd sacral vertebra (S3) - runs downward along the sacrum to the level of the top of the coccyx - pierces the pelvic diaphragm to become the anal canal

Question 79

taeniae coli

Answer 79

- longitudinal layer of muscle that completely surround the outside of the small intestine is retricted to 3 separate band in the large intestine -> taeniae coli - they cause regular bulges and constrictions along most of the large intestine - bulges-> haustra - haustra can be visualized by x-rays when the colon is coated internally with radiopaque material such as barium - taeniae coli and haustra extend the entire length of the colon up to the rectum -> rectum and anal canal lack - circular muscle fibers of the anal canal form an anal sphincter which is aided by a ring of skeletal muscle around it - anal canal opens at the anus

Question 80

liver

Answer 80

- digestive- filters blood from the GI, metabolizes carbs, fats, and proteins carried by the blood -> produces bile - pyramidal shape - covered by rib cage - convex upper (diaphragmatic) surface is molded to the inferior surface of the abdominal diaphragm - inferior (visceral) surface is slightly concave - surface are separated in form by the sharp inferior border - 4 lobes: right (large), left (smaller), quadrate, caudate - quadrate and caudate lobes are central placed on the visceral surface -> left side of the liver - left and right lobe are separated by the mesentery that attached the liver to the middle of the anterior abdominal wall -> falciform ligament - falciform ligament is a thickened inferior free edge of ligamentum teres - ligamentum teres- extends from the liver to the umbilicus -> remnant of the fetal umbilical vein - peritoneum reflect off the livers visceral surface between the quadrate and caudate lobes as the lesser omentum - liver is covered with peritoneum except for the bare area of the diaphragmatic surface around the inferior vena cava

Question 81

gallbladder

Answer 81

- peeks out from the visceral surface of liver under the inferior border at a point just behind the tip of the 9th costal cartilage - pear shaped sac - 3 parts: fundus, body, neck - fundus- rounded end that projects below the inferior margin of the liver - body- lies against the visceral surface of liver - neck- extends from the body to a tube known as the cystic duct - tubes that carry bile connect the liver to the gallbladder and connect the liver and gallbladder to the duodenum -> tubes comprise the biliary tree - left and right hepatic duct- drain bile from the left and right lobes of the liver - left and right hepatic duct joint -> form common hepatic duct -> exits the liver through the porta hepatis - common hepatic duct is joined by the cystic duct from the gallbladder -> forms bile duct - bile duct runs inferiorly and joins main pancreatic duct from the pancreas just before opening into the duodenum of the small intestine -> these 2 ducts enter the duodenum through hepatopancreatic orifice (ampulla) that is guarded y the sphincter of oddi

Question 82

porta hepatis

Answer 82

- place through which the blood vessels and ducts enter and exit the liver - hepatic artery- supplies the liver with oxygenated blood - portal vein- drains blood from the entire GI tract to the liver - common hepatic duct- drains bile from the liver

Question 83

inferior vena cava

Answer 83

-deoxygenated filtered blood is drained from the liver into the inferior vena cava by 2 very short hepatic veins that emerge from its posterior surface

Question 84

pancreas

Answer 84

- transverse the posterior abdominal wall behind the stomach at the level of L2-L3 - extends from the vertical part of the duodenum to the spleen - retroperitoneal - 4 parts: heads, neck. body, tail - head- fits into the C shape bend of the duodenum - neck- connects the head to the body - tail- contacts the spleen - digestive enzymes are drained from the pancreas by the main pancreatic duct -> runs the length of the organ - joins with the bile duct to open into the duodenum at the hepatopancreatic orifice or major duodenal papilla - main pancreatic duct has a branch in the head of the pancreas known as the accessory pancreatic duct - opens into the duodenum a little proximal to the hepatopancreatic orifice through the minor duodenal papilla

Question 85

blood vessels of the gut

Answer 85

- alimentary and associated digestive organs are supplied by 3 arteries that arise from the front of the abdominal aorta - venous blood from the gut contain products absorbed from digested food, so it must be processes by the liver before it can be added to the general circulatory system - blood is taken to the liver by the portal venous system -> bypasses the inferior vena cava - after filtering and processing it -> liver returns the blood to the inferior vena cava for general circulation

Question 86

foregut: blood supply

Answer 86

- gives rise to the esophagus stomach and duodenum - also contains the liver, gallbladder, pancreas, and spleen - celiac artery (trunk) serves the foregut

Question 87

midgut: blood supply

Answer 87

- gives rise to the rest of the small intestine, the cecum, and the vermiform appendix as well as the ascending colon and most of the transverse colon - supplied by the superior mesenteric artery

Question 88

hindgut: blood supply

Answer 88

- gives rise to the terminal portion of the transverse colon together with the descending colon, sigmoid colon, rectum and anal canal - supplied by the inferior mesenteric artery

Question 89

abdominal aorta

Answer 89

- aorta enters the abdominal cavity through the aortic hiatus at the back of the abdominal diaphragm - aorta enters the abdominal cavity at the level of T12 and runs along the front of the vertebral column -> bifurcates at the level of L4 into the left and right common iliac arteries - between the common iliac arteries is the thin terminal branch of the aorta known as the median sacral artery -> runs across L5 and the front of the sacrum - abdominal aorta gives off 3 large, unpaired median branches to abdominal (and pelvic) viscera and 3 paired lateral branches to abdominal (and pelvic) viscera - abdominal aorta also gives off 5 paired lateral branches to the muscles of the abdominal wall - uppermost of these 5 is the inferior phrenic artery -> supplies the abdominal diaphragm - other 4 are known as lumbar arteries -> run across the bodies of the lumbar vertebrae

Question 90

unpaired median visceral branches

Answer 90

- celiac artery (trunk) - superior mesenteric artery - inferior mesenteric artery

Question 91

celiac artery branch

Answer 91

- first branch to arise from the abdominal aorta, soon after it emerges through the diaphragmatic hiatus - comes off at the level of T12-L1

Question 92

superior mesenteric artery

Answer 92

- arises from the abdominal aorta immediately below the celiac artery - comes off at the level of L1

Question 93

inferior mesenteric artery

Answer 93

-somewhat lower, arising from the front of the abdominal aorta at the level of L3

Question 94

paired lateral visceral branches

Answer 94

- middle suprarenal arteries - renal arteries - gonadal arteries - gonadal arteries: ovarian arteries and testicular arteries

Question 95

middle suprarenal arteries

Answer 95

- left and right middle suprarenal arteries arise from the sides of the abdominal aorta at about the same level as the superior mesenteric artery - supply the suprarenal (adrenal) glands with blood - each gland receives blood from 3 arteries - superior suprarenal arteries is a branch of the inferior phrenic artery, and the inferior suprarenal artery is a branch of the renal artery

Question 96

renal arteries

Answer 96

- left and right renal arteries arise from the sides of the abdominal aorta just below the level of the superior mesenteric artery - supply the kidneys with blood

Question 97

gonadal arteries

Answer 97

- left and right gonadal arteries arise from the sides of the abdominal aorta just below the level of the renal artery - supply the gonads with blood - depending upon the sex the gonadal arteries are properly referred to as either ovarian or testicular arteries - gonadal arteries arise at this level bc embryologically the gonads begin to develop high in the abdominal cavity - descend along the back wall of the abdominal cavity during prenatal development to reach their final positions in the 4th month (ovaries) or just before birth (testes)

Question 98

celiac artery

Answer 98

- very short - arises from the aorta just below the abdominal diaphragm and behind the head of the pancreas - divides into 3 branches: left gastric artery, splenic artery, common hepatic artery

Question 99

celiac artery: left gastric artery

Answer 99

- branch of celiac artery | - ascends towards the junction of the stomach and esophagus -> supplying each

Question 100

celiac artery: splenic artery

Answer 100

- branch of celiac artery - runs to the left along the top of the pancreas into the spleen, supplying both - just before entering the spleen, it gives off the left gastroepiploic (gastro-omental) artery - runs back to the right along the greater curvature of the stomach

Question 101

celiac artery: common hepatic artery

Answer 101

- branch of celiac artery - runs to the right toward the liver - divides into the hepatic artery (proper) and the gastroduodenal artery - after the gastroduodenal artery comes off -> there are 2 other branches from the hepatic artery -> right gastric and the cystic artery - gastroduodenal artery- comes off behind the duodenum and supplies it -> gives off a branch -> right gastroepiploic artery - gastroepiploic artery- which runs to the left along the greater curvature of the stomach to anastomose with the left gastroepiploic artery - right gastric artery- comes off the hepatic artery and runs to the left and upward along the lesser curvature of the stomach to anastomose with the left gastric artery - cystic artery- arises from the hepatic artery just before the porta hepatis of the liver to supply the gallbladder

Question 102

superior mesenteric artery

Answer 102

- arises from the aorta just below the celiac artery - runs between the pancreas and the top of the horizontal part of the duodenum - enter the mesentery of the small intestine - supplies the distal third of the duodenum, the entire intestine, and the proximal part of the large intestine - as it runs through the mesentery it gives of 12 to 15 branches to the jejunum and ileum - jejunal branches form one 1 or 2 anastomosing arcades and their terminal portions are long - ileal branches by comparison have several arcades and their terminal portions are short - the superior mesenteric artery supplies the proximal half of the large intestine by 3 large branches: middle colic, right colic, and ileocolic - middle colic artery- first to arise and supplies the terminal portion of the ascending colon and most of the transverse colon - right colic artery- second to arise and supplies most of the ascending colon - ileocolic artery- last to arise and supplies the cecum and appendix

Question 103

inferior mesenteric artery

Answer 103

- arises at the level of L3 (about 1 1/2 inches above the bifurcation of the aorta into the left and right common iliac arteries) - has a smaller diameter than diameter than either the celiac artery or the superior mesenteric artery - supplies the distal part of the large intestine and the proximal part of the rectum - gives off the left colic artery -> supplies the end of the transverse colon and beginning of the descending colon - gives off several sigmoid branches -> supply the descending colon and sigmoid colon - terminal portion of the inferior mesenteric artery changes its name to the superior rectal artery as it crosses over the left common iliac artery - superior rectal artery supplies the proximal third of the rectum

Question 104

venous drainage

Answer 104

-nutrient rich blood from the GI is transported to the liver for filtration and processing by a network of veins that comprise the hepatic portal venous system -portal venous system is defined as originating in 1 capillary bed and terminating in a 2nd capillary bed -hepatic portal system originates in the capillaries of the GI and terminates in the capillaries of the liver -veins that drain blood from the digestive organs merge to form the short (Hepatic) portal vein -> enters the liver -veins that drain blood from the digestive organs have the same names as the arteries they feed from (spleen is supplied by the splenic artery and drained by splenic vein) -distal parts of the veins also follow the paths taken by the arteries of the same name -more proximal portions of the veins have somewhat different courses -(hepatic) portal vein is formed behind the pancreas by the union of the splenic vein and the superior mesenteric vein -

Question 105

superior mesenteric vein

Answer 105

- drains the small intestine, cecum, ascending colon, and transverse colon - it is fed by about a dozen jejunal and ileal veins and by 3 large tributaries: middle colic vein, the right colic vein, and the ileocolic vein - superior mesenteric vein also receives blood from the pancreaticoduodenal vein and gastroepiploic vein -> drains the duodenum and greater curvature of the stomach

Question 106

splenic vein

Answer 106

-drains the spleen and has a large tributaries: inferior mesenteric vein

Question 107

inferior mesenteric vein

Answer 107

- drains the descending colon, sigmoid colon, and the proximal third of the rectum - fed by 3 principal tributaries: left colic vein, sigmoid veins, and the superior rectal vein

Question 108

(hepatic) portal vein

Answer 108

- formed by the union of the superior mesenteric and splenic veins - 3 veins drain into it: left gastric vein and right gastric vein, and cystic vein - left gastric and right gastric veins drain the lesser curvature of the stomach - cystic vein drains the bladder - portal vein enters the liver via the porta hepatis and then splits into the left and right branches that take blood to the livers lobules - blood that is filtered through the lobules is collected by numerous central veins that merge to form the 2 hepatic veins - hepatic veins drain directly into the inferior vena cava

Question 109

lymphatic draingage

Answer 109

- abdomen, pelvis, and lower limbs are drained of lymph by 2 sets of trunks that run along the posterior abdominal wall - trunks merge to form the thoracic duct - largest lymphatic structure in the body is the spleen - lymph from the anterior abdominal wall and lower limbs drain into very large inguinal nodes that lie in the femoral triangle just below the inguinal ligament -> these nodes are easily palpated even in the absence of infection - lymph ducts from retroperitoneal abdominal organs (e.i. kidneys) drain into nodes that lie along either side of the abdominal aorta -> these lumbar nodes are connected by large ducts known as lumbar trunks - gut is drained by ducts that follow one of the 3 arteries that arise from the front of the abdominal aorta to supply it -> these ducts lead to preaortic nodes that lie along the front of the aorta -> connected by a large duct known as the intestinal trunk - lumbar and intestinal trunks merge at the level of L1-L2 to form the thoracic duct which is dilated here as the cisterna chyli - thoracic duct ascends through the thorax to empty into the left brachiocephalic vein - spleen is the principal lymphatic organ -> composed mainly of lymphatic tissue that filters blood passing through it - spleen also involves production of bilirubin, a constituent of bile - transported to the liver by the splenic and hepatic portal veins

Question 110

spleen

Answer 110

- lies behind and to the left to the stomach between the 9th and 11th ribs - resides above the left colic flexure and anterior to the left kidney - blood and lymph vessels enter its concave visceral surface via the hilum - spleen receives blood from the splenic artery (primary branch of the celiac artery) - blood from the spleen is drained by the splenic vein - splenic vein is joined by the inferior mesenteric vein to drain into the hepatic portal vein

Question 111

kidney and adrenal glands

Answer 111

- kidneys excrete most of the bodies metabolic waste product and help maintain water and electrolyte balance - waste and products leave the kidney as urine which passes down down a muscular tube, the ureter, to the bladder - lying on the superior pole of each kidney is an adrenal (suprarenal) gland - each gland consists of 2 separate masses of tissue: the cortex secretes over 20 steroid hormones - medulla secretes amine hormones - kidneys and adrenal glands are retroperitoneal - each kidney is covered with 4 protective layers of tissue: fibrous capsule, a layer of perirenal fat, renal fascia, and layer of pararenal fat (superficial to deep) - medial, concave aspect of the kidney has a vertical slit called the hilum - transmits the renal artery, the renal vein, the renal pelvis, and autonomic nerve fibers

Question 112

arteries of the kidneys

Answer 112

- each kidney is supplied by a renal artery - arise from the left and right sides of the abdominal aorta a bit below the origin of the superior mesenteric artery - right renal artery passes behind the inferior vena cava

Question 113

arteries of the adrenal glands

Answer 113

- adrenal glands are richly supplied with blood by 3 arteries - first is the superior suprarenal artery - its is a branch of the inferior phrenic artery, which arises from either side of the aorta immediately below the diaphragm - second artery is the middle suprarenal artery - arises from either side of the aorta just below the level of the celiac artery - third artery is the inferior suprarenal artery- runs upward to the gland from the renal artery

Question 114

veins of the kidneys

Answer 114

- each kidney is drained by a renal vein - these empty into the inferior vena cava - left renal vein crosses anterior to the aorta just below the root of the superior mesenteric artery - because the left renal vein has to cross the aorta to reach the kidney, it is longer than the right renal vein

Question 115

veins of the adrenal glands

Answer 115

- each adrenal gland is drained by the suprarenal vein - on the right it enters the inferior vena cava directly - on the left, it enters the left renal vein

Question 116

structure of the kidney

Answer 116

- the medial, concave aspect of the kidney has a vertical slit called the hilum - transmits the renal artery, renal vein, and renal pelvis - the renal pelvis is the enlarged beginning of the ureter - hilum extends into the substance of the kidney for a short distance, creating the renal sinus - longitudinal section through the kidney reveals that it is composed of 3 distinct regions around the renal sinus - first region comprises the collection chambers for urine - renal pelvis branches into several chambers called major calyces - each major calyx branches into several smaller, funnel-shaped chambers known as minor calyces - there are about a dozen minor calyces - urine drains from the renal pyramids into the minor calyces - renal medulla is composed of about a dozen renal pyramids - each pyramid is cone shaped structure that contains numerous straight urine collecting ducts - the ducts open at the apex, or papilla, of the renal pyramid into the minor calyx - renal cortex contains numerous twisted (convoluted) tubes and capillaries and the renal corpuscles - between adjacent renal pyramids is a pillar of tissue that descends from the renal cortex - this pillar is called the renal column -> contains arteries and veins - renal pyramid together with the renal cortex capping it constitutes a renal lobe - nephrons are contained within the renal lobes - nephrons are the functional units of the kidneys - they are responsible for the production of urine

Question 117

nephron

Answer 117

- functional unit of the kidney - each nephron lies within the renal medulla, and part lies within the adjacent renal cortex - most of the nephron is located within the renal cortex above a renal pyramid - produces urine by a 2 stage filtration process - blood plasma filters from a capillary bed into the end of a tube that ultimately drains into a minor calyx - it is desirable to conserve water, salt, and sugar -> reabsorbed back into blood vessels from the tube - excreted urine is hyperosmotic and largely devoid of salt and sugar - each nephron has a tubular component and a vascular component

Question 118

tubular component of the nephron

Answer 118

- comprised of a renal tubule that is closed at one end and open at the other - closed beginning of the tubule has a cup-shaped expansion known as the glomerular (bowmans) capsule - surrounds a tightly twisted capillary bed, known as the glomerulus - together glomerular capsule constitute the renal corpuscle - short distance from the glomerular capsule, the renal tubule becomes twisted as the proximal convoluted tubule - then straightens out and loops into and out of the renal pyramid as the loop of henle - loop of henle is also known as the nephron loop - limbs of the loop of henle descend into and ascend from the renal pyramid - after ascending the tubule becomes twisted again as the distal convoluted tubule - a short distance from the glomerular capsule, the renal tubule becomes surrounded by a second capillary network - renal tubule opens into a collecting duct which drains several nephrons - collecting duct opens at the papillae of the renal pyramid into the minor calyx

Question 119

vascular component of the nephron

Answer 119

- consists of 2 capillary networks connected by an arteriole -> portal system - first capillary bed is the glomerulus - blood reaches the glomerulus through a small vessel called an afferent arteriole - about 20% of the blood plasma moving through the afferent arteriole filters through the glomerulus - blood that passes through the glomerulus leaves it by another small vessel called an efferent arteriole - this leads to the 2nd capillary network, where reabsorption of water, salt, and sugar takes place - 2nd network is intertwined around the renal tubule -> peritubular capillary - small vessels lead from the peritubular capillary to the renal vein

Question 120

gonadal blood vessels

Answer 120

- gonads are within or below the pelvis - their vasculature originates high up in the abdomen - vessels that supply and drain their blood are the same, whether the gonads are ovaries or testicles

Question 121

gonadal arteries

Answer 121

- left and right gonadal arteries arise from the front of the abdominal aorta just below the level at which the renal arteries come off - gonadal arteries descend to the left and right to supply the respective gonad

Question 122

gonadal veins

Answer 122

- right gonadal vein follows the course of the right gonadal artery for much of its length - enters the front of the inferior vena cava just below the level at which the renal veins come off - left gonadal vein follows the course of the left gonadal artery for much of its length, but as it approaches the kidney, it departs company from the artery - runs straight upward to drain into the left renal vein

Question 123

nerves in the abdomen

Answer 123

- skeletal muscles of the abdomen are supplied by spinal nerves - spinal nerves that emanate from the spinal cord in the abdomen also innervate muscles of the lower limb - GI tract and organs of digestion, as well as the spleen, kidneys, and adrenal glands, are supplied by autonomic nerves

Question 124

spinal nerves in the abdomen

Answer 124

- skeletal muscles of the abdominal wall are supplied by spinal nerves T7-L1 - muscles of the lower limb are innervated by the ventral rami of L1-L4, which form the lumbar plexus - lowermost lumbar spinal nerve (L5) contributes to the sacral plexus - these plexuses are connected by the lumbosacral trunk between L4 and L5

Question 125

cranial nerve in the abdomen

Answer 125

- vagus nerve (CN X) is the only cranial nerve to enter the abdominal cavity - recall that the left vagus nerve enters the abdomen in front of the esophagus as the anterior vagal trunk - it gives branches to the liver, gallbladder, stomach, and duodenum and to the kidneys and adrenal glands - right vagus enters the abdomen behind the esophagus as the posterior vagal trunk - its fibers are distributed with the branches of the celiac and superior mesenteric arteries - innervates the pancreas, the spleen, the stomach, the small intestine, and the large intestine as far as the left colic (splenic) flexure

Question 126

sympathetic chain in the abdomen

Answer 126

- sympathetic chain also runs through the abdomen into the pelvis - only spinal nerves L1-L2 contribute preganglionic fivers to the chain - sympathetic ganglia below L2 have gray rami communicantes, but no white ones - sympathetic chain below L2 is similar to the sympathetic chain in the neck