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abdomen, anatomy

Terms

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copy deck
what is the most common pathological process of the anterior abdominal wall?
hernias
what are the boundaries of the anterolateral abdomenal wall?
it is the area between the thorax and pelvis
bound superiorly by right and left costal margins
inferiorly by line connecting each ASIS to pubic symphysis, vertical line through anterior iliac spine
what are the functions of the anteriolateral abdominal wall?
maintenance of posture
movements of limbs
where is the inguinal canal?
inferolateral margin of the abdominal wall
what are landmarks that i should know regarding the anteriolateral abdominal wall?
xiphoid process
costal margin
anterior superior iliac spine
tubercle of iliac crest
pubic symphysis
umbilicus
linea alba
what is the linea alba?
a median fibrous line from xiphoid process to pubic symphysis
how is the abdomen commonly divided?
into quadrants - using median plane and umbilicus
into 9 regions - subcostal plane (right under ribs)
transtubercular plane (most lateral aspect of iliac crest)
and midclavicular lines
areas are
right and left hypochondriac areas
right and left lateral or lumbar areas
right and left inguinal regions
epi and hypogastric and umbilical
what are the three flavors of fascia here in anterolateral abdominal wall?
superficial - has two layers of its own
deep
transversalis fascia
what are the layers of the superficial layer of fascia in the anterolateral abdominal wall?
1. fatty layer (camper's)
continuous with fat of thorax, back, perineum, thigh
in scrotum, is thin layer of smooth muscle - dartos muscle, has various amounts of fat
2. membranous layer (scarpa's)
this fuses with fat of thorax, iliac crest, fascia lata, urogenital diaphragm, linea alba and pubic symphysis

superficial vessels and nerves located tween fatty and membranous layers
describe the deep layer of fascia in the anterolateral abdominal wall - give another name, two qualities, and where it can be found
also called investing
1. thin
2. strong
covers muscles
where is the transversalis fascia?
inner surface of transversus abdominis
behind rectus sheath
crosses median plane
internal to transversalis fascia in peritoneum
what are the four muscles and major aponeurosis that i need to know about in the anterolateral abdominal wall?
1. external oblique
2. internal oblique
3. transversus abdominis
4. rectus abdominis
rectus sheath
what do i need to know about the external oblique? specifically, where is it, what important "ring" or aponeurotic gap is in it, and what 2 ligaments?
location: from middle, lower ribs
runs down and forward in front of rectus abdominis
its aponeurosis forms anterior part of rectus sheath

superficial inguinal ring: triangular gap in aponeurosis
can be palpated lateral and above pubic tubercle

2 ligaments:
1. inguinal ligament - tween ASIS, pubic tubercle
is lowest part of external oblique aponeurosis
at inferior border is deep fascia of thigh = fascia lata
2. lacunar ligament - medial end of inguinal ligament
extends to pectineal line
what do i need to know about the internal oblique? specifically how does its fibers run and where is it?
fibers run upward and forward (superoanteriorly)
is found in intermediate position of muscles of anterior abdominal wall
what do i need to know about the transversus abdominis, specifically where is it, what is it associated with, how does its fibers run and what does it join with to form what?
location: deepest of three muscles of anterolateral abdominal wall
fused with internal oblique
fibers run in transverse direction
joins with lowest tendinous fibers of internal oblique to form conjoint tendon or inguinal falx
what's another name for the inguinal falx, where is it?
also called conjoint tendon and is lowest fibers of internal oblique + transversus abdominis
origin, insertion and layer over rectus abdominis
origin: symphysis pubis and pubic crest
insertion: 5th, 6th, 7th costal cartilages
most of muscle in rectus sheath
what makes up the rectus sheath, what is the arcuate line, and what are the contents of the rectus sheath?
composition of rectus sheath:
aponeurosis of external, internal oblique and transversus abdominis muscles
lateral border of rectus abdominis is where posterior and anterior layers form that cross over both surfaces of rectus muscle
fibers of anterior and posterior walls of sheath interlace in anterior median line, creating linea alba
anterior layer attached to rectus muscle at three or more tendinous intersections
arcuate line:
above where aponeurosis of internal oblique splits to enclose rectus abdominis
below where the aponeurosis of all muscles pass anteriorly and rectus abdomins in contact with transversalis fascia
contents of rectus sheath:
superior and inferior epigastric vessels
parts of lower 5 intercostal and subcostal vessels and nerves, rectus abdominis muscle
functions of anterolateral abdominal wall
1. oblique muscles - laterally flex and rotate trunk
rectus abdominis flexes trunk
2. assists diaphragm during inspiration
3. protects the viscera
4. helps maintain posture
5. when contracts simultaneously with diaphragm (and glottis closed), help in micturition (peeing), defecation, vomiting, and parturition (childbirth)
how many nerve groups and what are their names supply the skin and muscles of ther anterior abdominal wall?
4 nerve groups
1. intercostal nerves - T7-T11
2. subcostal nerve = T12
3. iliohypogastric nerve - L1
4. ilioinguinal nerve - L1
5. branches of cutaneous nerves - for some reason, not included in prof's summary
where are the intercostal nerves and what spinal levels do they come from?
T7-T11
course between internal oblique and transversus muscles to enter rectus sheath
where is subcostal nerve, and what spinal level does it come from?
T12
smilar course to intercostal nerves, but originates below 12th rib
where is the iliohypogastric nerve and what spinal level does it come from?
L1
supplies skin over inguinal region
where is the ilioinguinal nerve and what spinal level does it come from?
L1
enters inguinal canal and accompanies spermatic cord or round ligament of uterus
where are branches of cutaneous nerves and what spinal levels do they come from?
T7-T9 = supply skin above umbilicus
T10 innervates skin around umbilicus
T11, T12, L1 supply skin inferior to umbilicus
what are dermatomes?
skin domains innervated by spinal nerves
blood supply is froms segmental branches off aorta
what's an incisional hernia?
protrusion of organ or tissue through surgical incision
what are the main arteries that supply the anterolateral abdominal wall?
1. epigastric arteries
2. posterior intercostal arteries
how many different kinds of epigastric arteries are there, where are they located, where do they come from, and where do they anastomose?
3 different kinds
1. superficial epigastric artery from femoral artery
2. superior epigastric from internal thoracic artery
3. inferior epigastric from external iliac artery
anastomose between superior and inferior epigastric arteries provide collateral circulation between subclavian and external iliac arteries
what does the anastomoses between the superior and inferior epigastric arteries provide collateral circulation between?
subclavian and external iliac arteries
where is the inguinal canal, what is it? what's in it? what does it look like?
location: through abdominal wall, parallel to and above inguinal ligament
what it is: oblique passage about 3-5 cms long
contents: males - spermatic cord
females - round ligament of uterus
structure: arcade of three arches from three flat abdominal muscles
contraction of external oblique pushes anterior wall of canal against posterior wall of canal
how do testis drop? when?
1. develop in lumbar region, deep to transversalis fascia
2. testes pass through inguinal canal behind gubernaculum
3. processus vaginalis is an outpocketing of peritoneum and forms inguinal canal in male
4. testes descend just before birth
5. processus vaginalis is obliterated
how do the ovaries drop?
1. ovaries form on posterior abdominal wall
2. ovaries descend to point just inferior to pelvic brim
3. gubernaculum attaches to uterus where it divides into round ligament of uterus and ligament of ovary
what are the boundaries of the inguinal CANAL?
entry and exit to inguinal canal:
superficial inguinal ring = triangular shaped space in aponeurosis of external oblique
superior to pubic tubercle
deep inguinal ring = oval opening in transversalis fascia
inferior epigastric artery lies at medial boundary of deep inguinal ring
walls:
anterior = external oblique, internal oblique reinforces laterally
posterior = conjoint tendon and transversalis fascia
roof, cephalic or superior wal = arching fibers of internal oblique and transversus abdominis
floor, caudal or inferior wall = inguinal ligament and lacunar ligament
where does the spermatic cord begin and end?
begins: deep inguinal ring
ends: posterior border of testis
what are the layers of the spermatic cord wall?
internal spermatic fascia from transversalis fascia
cremaster muscle from internal oblique muscle
external spermatic fascia from externa oblique
what's in the spermatic cord?
1. ductus deferens
2. testicular artery
3. pampiniform plexus
4. lymphatic vessels
5. cremasteric artery
6. genitofemoral nerve
7. autonomic sensory nerves
8. remnants of processus vaginalis
9. internal spermatic fascia
10. cremaster muscle
11. external spermatic fascia
what's a vasectomy?
bilateral excision of segments of ductus deferens
produces sterility in males
what's the structure of the scrotum?
is pouch below pubic symphysis
2 compartments with 2 layers each
layers: skin and dartos (or smooth) muscle
superficial fascia has no fat but does have dartos muscle
spermatic fascia are beneath superficial fascia and derived from layers of anterior abdominal wall
describe the cremasteric reflex
is a contraction of the cremaster muscle caused by stroking of medial aspect of thigh
appearance will vary with state of contraction/relaxation
what is the tunica vaginalis? where can it be found? what's in it?
location: around testes - is peritoneal sac
what it's made of: parietal layer next to internal spermatic fascia
visceral layer next to testis and epididymis
contains: small amount of fluid in cavity separating visceral and parietal layers - this allows testis to move freely in scrotum
what's the innervation to the scrotum?
genitofemoral, ilioinguinal, pudendal nerves
what are the testes, what do they do, what surrounds them?
testes are paired oval organs
make sperm and androgens (hormones) after puberty
these produce secondary sexual characteristics in male
testis surrounded by tough, fibrous capsule = tunica albuginea
what's the blood supply to the testes?
1. testicular artery = branch off abdominal aorta
2. pampiniform plexus = venous network that drains the testis, is part of thermoregulatory system
what's a hydrocele?
accumulation of fluid in cavity of tunica vaginalis
what's a varicocele?
enlargement (varicosity) of veins of spermatic cord
results from defective valves in testicular vein
where do testicular tumor cells metastasize? where do scrotal tumor cells metastasize?
testicular tumor cells metastasize to lumbar nodes
scrotal tumor cells metastasize to superficial inguinal lymph nodes
where is the epididymis, what are its parts, where does it lead to, and what does it do?
are at posterior margin of testes
3 parts:
1. head
2. body
3. tail
connects to ductus deferens
efferent ductules transmit sperm from testes to epididymis, where they're STORED
what's a hernia?
an abnormal protrusion of any structure beyond its normal site
where do hernias commonly occur?
3 places
1. inguinal
2. femoral
3. umbilical regions
how does one get an umbilical hernia, what causes it, who tends to get them and why?
are usually congenital, can be acquired
caused by incomplete closure of abdominal wall
common in newborn because anterior abdominal wall weak in umbilical ring
what causes inguinal hernias?
1. relative strength vs. weaker places in abdominal wall when pressure is exerted up on that wall
2. congenital peritoneal sacs
where do indirect inguinal hernias tend to happen, who gets them, why?
location: enters deep inguinal ring
crosses canal
emerges at superficial ring
passes entire length of inguinal canal
who gets them: 20 times more common in men than women
when happens later in life, likely that small remnant of processus vaginalis still present at birth - herniation easily caused then by pushing, coughing, straining, lifting
congenital peritoneal sacs = failure of stail of processus vaginalis to obliterate leads to indirect hernia sometimes
where does a direct inguinal hernia happen, what's it made of, how's it happen?
location: medial to inferior epigastric artery
moves toward superficial ring in inguinal triangle
because of conjoint tendon, is generalized bulge
doesn't pass through deep inguinal ring
emerges through or around conjoint tendon reaching superficial inguinal ring
almost never enters scrotum
rare in women
hernial sac made of peritoneum
acquired from weakness of anterior wall - repeated increased intra-abdominal pressure then induces herniation
what's a femoral hernia? where is it located? who gets them?
is a protrusion of extraperitoneal tissue with or without abdominal viscus?
goes through femoral ring
more common in women
neck of sac below and lateral to pubic tubercle
give overview of abdominal viscera
liver - large, upper part of abdominal cavity
esophagus - short segment in abdomen, connects to stomach
small intestine - continuation of alimentary canal from stomach
consists of duodenum, jejunum, ileum
large intestine - continuation of small intestine
cecum
ascending colon
transverse colon
descending colon
sigmoid colon
rectum
anal canal
pancreas
spleen
kidneys
suprarenal glands
what's the common lining of abdominal viscera (specifically gut)?
1. mucosa modified to reflect functions of organ: epithelial cells lining gut are important for selective absorption of foodstuffs
2. outside mucosa is submucosa, made of loose ct: contains lymphoid tissue
3. thin layers of smooth muscle
outside submucosa: inner circular and outer longitudinal layer of smooth muscle
not completely represented in all areas of intesting
4. outside muscle layers is peritoneal covering = serosa
what's the serosa, where can it be found?
is outside submucosa and smooth muscle layers
is peritoneal covering over mucus membranes of viscera
what's in the submucosa of the abdomenal viscera?
lymphoid tissue and thin layers of smooth muscle
the submucosa itself is loose ct
what's the peritoneum?
thin, serous membrane lining walls of abdominal and pelvic cavity
either partially or completely covers viscera in abdomen
what's the broad definition of the peritoneum?
it's a thin, serous membrane that lines the walls of teh abdominal and pelvic cavities
either partially or completely covers viscera within
what's the parietal peritoneum?
lines walls of abdominal and pelvic cavities
what's visceral peritoneum?
covers organs
forms serosa of walls
what's another function of the peritoneum?
it secretes a small amount of fluid that lubricates and facilitates movement of organs
parietal and visceral layers separated by peritoneal fluid
where's the peritoneal cavity?
potential space tween parietal and visceral layers
completely closed in male
open in female through uterines tubes, uterus and vagina
when organ protrudes into peritoneal sac, takes vessels and nerves with it
located tween two layers of peritoneum forming mesentery
what's ascites?
accumulation of serous fluid in peritoneal cavity which can be result of pathological condition
what are the divisions of the peritoneal cavity?
the greater sac and the lesser sac, also called omental bursa
where's the greater sac?
greater sac is main part of peritoneal cavity
extends from diaphragm to pelvis
surgical incision through anterior abdominal wall enters
where's the lesser sac?
also called omental bursa
is pouch, space, behind lesser omentum and stomach
in front of structures of posterior abdominal wall
right margin of sac opens into greater sac through omental foramen or epiploic foramen
sac projects up to diaphragm and down tween layers of greater omentum
bound anteriorly by stomach and lesser omentum
bound superiorly by liver
bound inferiorly by greater omentum
bound to left by spleen and its ligaments
what's the omental foramen and what's another name for it?
also called epiploic foramen
it's the opening on the right margin of the lesser sac or omental bursa leading to the greater sac
where are retroperitoneal organs?
also called extraperitoneal
have viscera that are covered only in front by peritoneum
located tween parietal peritoneum and posterior abdominal wall
what are some specilized areas of the peritoneum?
1. mesentery
2. omentum
3. peritoneal ligaments
what's a mesentery and where are they and what characterizes them?
they are double layers of peritoneum
attaches part of intestines to posterior abdominal wall
have blood vessels, lymph vessels, nerves, fat and lymph nodes
what's an omentum? what does it do? what are the different kinds of omentum? where are they and what do they do?
an omentum is a two-layered fold of peritoneum that attaches stomach to other viscera
1. greater omentum
attached to greater curvature of stomach and inferior border of transverse colon
prevents visceral peritoneum from adhering to parietal peritoneum lining abdominal wall
2. lesser omentum
from lesser curvature of stomach to liver
has hepatogastric and hepatoduodenal ligament
what are peritoneal ligaments? what different kinds are there?
are two-layers folds of peritoneum that attach solid viscera to abdominal walls or another structure
peritoneal fold is reflection of peritoneum with more or less sharp borders
3 different kinds
1. falciform ligament
2. lienorenal ligament
3. gastrolienal ligament
what does the falciform ligament do?
connects anterior surface of liver to anterior abdominal wall
where's the lienorenal ligament?
peritoneum from kidney to spleen
where's the gastrolienal ligament?
peritoneum from spleen to stomach
what's the nerve supply to the peritoneum?
2 kinds:
1.parietal peritoneum supplied by same nerves that innervate overlying muscle and skin
diaphragmatic peritoneum supplied by phrenic nerve and peritoneum in pelvis by OBTURATOR nerve
sensitive to pain, temperature, touch, pressure
2. visceral peritoneum sensitive to stretch, supplied by autonomic nerve fibers
overdistension of viscera lead to pain sensation
what are the major functions of the peritoneum?
1. make peritoneal fluid - secreted by peritoneum
ensure that mobile viscera can move upon one another
2. localize intraperitoneal infections by fusion of greater omentum and peritoneal coverings
3. storage of fat - in peritoneal ligaments and mesenteries and greater omentum (lots of it there)
what innervates the abdominal wall musculature?
intercostal nerves?
describe the abdominal esophagus:
a. where is it, how much of it is there?
b. name its parts and what they do
c. how is it innervated?
d. what is its blood supply?
a. enters abdomen through opening in diaphragm
enters stomach at cardiac orifice
2-3 cm usually below diaphragm
b. cardiac sphincter - barrier to reflex of contents of stomach to esophagus
physiological sphincter at gastroesophageal junction
heartburn is painful stimulation of lower esophagus
c. vagal trunks, thoracic sympathetic trunks, greater and lesser splanchnic nerves
d. arterial blood supply: left gastric branch of celiac trunk
inferior phrenic artery
what are some clinical considerations involving the esophagus?
1. esphageal varices: small veins of lower esophagus become grossly enlarged in portal hypertension
this is when portal blood is under high pressure and shunted through collateral routes
then rupture with cough and hemorrhage profusely, possibly leading to death
2. pyrosis - burning sensation in abdominal part of esophagus
can be associated with esophageal hiatal hernia
what are the parts of the stomach?
1. cardiac - between abdominal end of esophagus and fundus
2. fundus - above entrance of esophagus
3. body - tween fundus and pylorus
4. pyloric - opens into duodenum
what are the parts of the pyloric region of the stomach?
1. pyloric antrum - location of most of gastrin-making cells of gastric mucosa
2. pyloric sphincter - circular thickened mass of muscle around transition from stomach to duodenum
controls rate of discharge of stomach contents into duodenum
where is the lesser curvature of the stomach?
forms its concave border
where's the greater curvature of the stomach?
forms convex border
which parts of the stomach are fixed, which are moving? what are the relationships of the stomach?
Fixed: cardiac orifice, both ends
Mobile: tween ends
fundus fits into curve of left dome of diaphragm, moving with it
air in fundus causes tympanic note on percussion
anterior surface covered with peritoneum
posterior surface covered with peritoneum except where gastrohepatic ligament attached
anterior to stomach = anterior abdominal wall
posterior = lesser sac
shape and position of stomach varies significantly in person at different times, based on respiration and between people
what are the functions of the stomach?
3 main ones
1. storage of food
2. mixing food with gastric secretions
3. controlling rate of delivery
stores ingested food
prepares it for eventual treatment by small intestine
as pyloric sphincter relaxes, churned food squirted into duodenum
digestion both mechanical and enzymatic
waves of conraction of smooth muscle = peristalsis in muscularis mucosa and outer muscular layers agitate gastric pits, rugae, act like washing machine
this breaks down long-chain molecules into smaller components
protein broken down by pepsin secreted by chief cells in form of pepsinogen
HCl from parietal cells activate pepsin and other enzymes of gastric juices - these would have erosive effect on surface mucosa if not for mucous from surface epithelial, neck mucous cells
little absorption except for what's readily dissolvable, and relatively short-chained
what's the blood supply to the stomach?
arteries
come directly or indirectly from celiac trunk
1. left gastric artery - going to esophagus, upper part of stomach
2. splenic artery - gives off pancreative branches and left gastroepiploic arteries
3. hepatic artery divides into
a. common hepatic
b. hepatic artery proper gives rise to right gastric artery and gastroduodenal artery then branch into right and left hepatic arteries
- right and left gastric arteries anastomose along lesser curvature
right and left gastroepiploic arteries anastomose along greater curvature
VEINS
parallel arteries in position and course
drainage directly or indirecctly into portal vein
what's the nerve supply to the stomach?
sympathetic and parasympathetic
sympathetic:
from celiac sympathetic plexus through plexuses around gastric and gastroepiploic arteries
parasympathetic: from anterior and posterior vagal trunks
what are clinical considerations for the stomach? name them
1. gastric ulcer
2. hiatal hernia
3. visceral referred pain
what causes a gastric ulcer, what types are there, how does one treat them?
gastric ulcers due to excess of acid secretion from vagal nerve issues
bleeding peptic ulcer posterior while perforating type usually anterior
eventually involves peritoneum so that stomach will adhere to neighboring structures
caused by infection with helicobacter pylori
treatment includes antibiotics, reduction of acid secretion or sometimes surgical therapy to remove branches of vagus nerve
what's herniating in a hiatal hernia? how does one get a hiatal hernia?
cardia and portion of fundus can herniate through esophageal hiatus into thorax
is an acquired hernia
common because of higher pressure in abdominal cavity at times compared to pressure in thorax
what causes visceral referred pain? what is it a clinical correlate of?
viscerl referred pain associated with actual or potential tissue damage and is mediated by specific nerve fibers
pain varies from dull to severe, is poorly localized
radiates to dermatome level that receives visceral afferent fibers from organ invovled
give an overview of the duodenum and name its parts.
is area from pylorus to duodenojejunal flexure
has 4 parts
first part = superior or duodenal cap
free
other parts fixed (retroperitoneal)
25 cm long
hepatododenal ligament attached to first part of duodenum
1. descending part = second part
receives bile duct and pancreatic duct
hepatopancreatic ampulla opens at major duodenal papilla
2. horizontal = third or inferior part
crossed by superior mesenteric vessels
3. ascending = fourth part
connects with jejunum at duodenojejunal junction or flexure
a peritoneal fold called the suspensory ligament of the duodenum ascends to diaphragm and holds juntion in position
this supports duodenojejunal flexure and widens its angel
this facilitates movement of intestinal contents
- first part of duodenum, mucous membrane smooth
in rest of duodenum, has numerous circular folds called the plicae circulares
what is the plica circularis?
are numerous circular folds of mucous membrane
in first part of duodenum
where is the greater or major duodenal papilla?
is an opening for pancreatic and bile ducts or ampulla
is guarded by sphincter of the hepatopancreatic ampulla
where is the sphincter of the hepatopancreatic ampulla, and what does it regulate?
is at opening of greater or major duodenal papila, which is where pancreatic and bile ducts or ampulla come out
regulate whatever the hell is coming out of the pancreatic and bile ducts (bile)
what's the blood supply of the duodenum?
arterial branches from celiac trunk and superior mesenteric artery = pancreaticoduodenal artery
venous drainage follows artereis into portal venous system
what's the innervation of the duodenum?
sympathetic and parasympathetic
celiac and superior mesenteric plexuses
what are some clinical considerations to note of the duodenum?
2
1. ulcers resulting from acidity of chyme from stomach that's hitting anterolateral wall of first part of duodenum
ulcers can also occur in posterior wall of first part of duodenum
if the ulcer perforates, its contents can empty into peritoneal cavity resulting in peritonitis (ouch!)
2. can be obstructed by abnormailites or tumors of pancreas
describe the jejunum and ileum - how long are they, how does one compare them, what are their functions, what are they attached to?
together are about 7 meters long
first (proximal) 2/5 is jejunum
distal (end) 3.5 is ileum
begins at dueodenojejunal junction or flexure
ends at ileocecal junction
function of both is absorption - mucosal folds increase absorptive surface
attached by mesentery to posterior abdominal wall of small intestine which allows entrance and exit of branches of superior mesenteric artery, vein, nerves
jenjunum is thicker-walled and redder than ileum (in living)
what's the blood supply to the jejunum and ileum?
branches of superior mesenteric artery
jejunal and ileal branches
superior mesenteric vein drains jejunum and ileum
what's the innervation of the jejunum and ileum?
from vagus and splanchnic nerves
preganglionic SYMPATHETIC fibers synapse in celiac and superior mesenteric ganglia
PARASYMPATHETIC nerves from posterior vagal trunks
postganglionic SYMPATHETIC fibers with preganglionic PARASYMPATHETIC fibers synapse in mesenteric and submucosal plexus in intestinal wall supply smooth muscle
what are some clinical considerations to be aware of in the jejunum and ileum?
1. 2% of people have diverticulum in ileum (Meckel's) present as outpouching of intestinal wall
persistence of omphalomesenteric duct of embryo
2. regional enteritis or crohn's disease
one of most frequent illnesses
symptoms include: abdominal pain, diarrhea, vomiting, weight loss
sometimes requires removal of large portions of small intestine
what are the major functions of the large intestine, how can it be distinguished from small intestine?
functions:
1. absorption of water and electrolytes
2. storage of undigested material until excretion
when parts are removed, people can have imbalances of water and electrolytes
some carbohydrate absorption
forms arch for coils of small intestine
distinguishing features from small intestine:
1. teniae coli = three thickened bands of longitudinal muscle
2. haustra = sacculations of wall
3. appendices epiploica = pouches of peritoneum with fat
where's the cecum, what are some important things to note about it?
is part of large intestine lying below level of junction with ileum
has valve = ileocecal valve
is mobile, but does not have mesentery
important to note: is where vermiform appendix can be found
what's and where's the vermiform appendix?
is narrow blind tube joining cecum about 2-3 cm below ileocecal opening
short mesentery of its own = mesoappendix
lots of movement
base of appendix fairly constant and usually deep
what's appendicitis? what causes it? what does this lead to/ where can pain be found?
appendicitis = inflammation of the appendix
caused by obstruction of appendix from feces usuallly
can lead to vascular congestion, ischemia, bacterial growth, infection, perforation
pain of ACUTE appendicitis starts in periumbilical region, localizes to right lower quadrant
pain felt there because spinal segments innervating appendix same as those innervating periumbilical skin
if process limited to direct irritation only of appendix, pain will be diffuse and moderate
once perforation occurs, pus spills out and sharp pain is felt, localized to abdominal wall, usually in right lower quadrant
where's the ascending colon and what covers it?
extends upward from cecum to right colic flexure
peritoneum covers both front and sides
(not back?)
where's the transverse colon?
begins at right colic flexure
suspended by transverse mesocolon
extends from right to left colic flexures
phrenicocolic ligament = attaches left colic flexure to diaphragm
transverse mesocolon attached to superior border
where's the descending colon
inferiorly from left colic flexure to brim of pelvis
becomes continuous with sigmoid colon
covered with visceral peritoneum where not in direct contact with posterior abdominal wall
where's the sigmoid colon?
within pelvis
suspended from wall by sigmoid mesocolon
has considerable freedom of movement
what's the blood supply to the large intestine?
1. ileocolic and right colic branches of superior mesenteric artery
goes to ascending colon
2. middle colic branch of superior mesenteric artery to transverse colon
3. left colic branch of inferior mesenteric artery to descending colon
4. sigmoid branch of inferior mesenteric to sigmoid colon
5. marginal artery - anatomosis of colic arteries around margin of large intestine
what's the innervation to large intestine?
to ascending and transverse colon arise superior mesenteric plexus
they transmit SYMPATHETIC and PARASYMPATHETIC nerve fibers
SYMPATHETIC supply of descending and sigmoid colon from lumbar part of sympathetic trunk and superior hypogastric plexus
PARASYMPATHETIC supply from pelvic splanchnic nerves
what are some clinical consideration for the large intestine?
1. ulcerative colitis - chronic disease of colon
severe inflammation and ulceration of colon and rectum
2. congenital megacolon - from absence of autonomic plexus
poor contractility of colonic musculature
3. diverticulosis - many small sacculations of colonic wall, can become inflamed and rupture
describe the surfaces of the liver
diaphragmatic - covered by peritoneum except where bare - uh, yeah
separated from diaphragm by part of peritoneal cavity = subphrenic recess
visceral - faces posteriorly, caudally and to left
covered by peritoneum except at gall bladder and porta hepatis
bare area of liver in direct contact with diaphragm
what are the lobes of the liver?
are 4
1. quadrate
2. caudate
3. right
4. left
what's the porta hepatis?
is at hilus of liver
has hepatic ducts and branches of portal vein and hepatic artery
what should i know about the right and left lobes of the liver?
they function separately
they each have their own arterial, portal venous supply and venous drainage
what are the ligaments associated with the liver?
4 of them
1. coronary ligaments
these are reflections of the peritoneum
2. falciform ligament
attaches liver to diaphragm and anterior abdominal wall
3. ligamentum teres
obliterated left umbilical vein
in fetus, oxygenated blood brought to liver in umbilical vein
4. ligamentum venosum
part of ductus venosus
most blood bypasses liver in ductus venosus
what is and where is the portal triad?
consists of
1. portal vein
2. hepatic artery
3. bile duct
travel together through liver
seen in hepatoduodenal ligament
what's important to know about the surface anatomy of the liver?
normal position of liver
mostly under thoracic cage on right side above inferior border of lung
pyramidal in shape with base at right, apex toward left
moves with respiration
moves because is connected to diaphragm by falciform and coronary ligaments
what's the function of the liver?
synthesis of proteins
clotting mechanisms
detoxification
iron, copper, vitamin, glycogen storage
secretion of bile
what's the blood supply to liver?
arterial:
from celiac trunk which divides into
a. splenic
b. left gastric
c. common hepatic arteries
hepatic artery proper from common hepatic artery
30% of blood supply
brings oxygenated blood to liver
near porta hepatis, it divides into right and left hepatic arteries
VEINS
a. portal vein: 70% of drainage
brings venous blood rich in products of digestion to liver
b. hepatic veins
leave posterior surface of liver to open directly into IVC
what's the innervation of the liver?
SYMPATHETIC
from celiac plexus
antagonistic to parasympathetic actions but much of its effect may be result of changes in blood flow
PARASYMPATHETIC
from anterior and posterior vagal trunks
promtoes digestive activity through increased peristalsis, relaxation of sphincters, production of digestive mucus and enzymes
what are some important clinical considerations to note in liver?
1. cirrhosis
atrophy or destruction of hepatocytes and hypertrophy of connective tissue
ct surrounds intrahepatic blood vessels and biliary ducts which impedes circulation of blood flow through liver
2. because of vascularity, many cancers metastasize here from other body sites
3. jaundice - accumulation of bile pigment in blood stream
result of obstruction of duct system
often interpreted as serious sign of liver dysfunction
4. liver transplantation
performed with good success partiallly because of treatment with cyclosporine
5. liver is essential, but needs of body can be met with even 70% of liver gone or dysfunctional
explains why fatal diseases like cirrhosis can progress to point where you can have almost total liver destruction before there are any symptoms or signs
where's the gall bladder? what lines it?
along right edge of quadrate lobe of liver
in depression
caudally is covered by peritoneum
lining typical for digestive tract except that mucosa has complex folds/ridges that create honeycomb appearance
many microvilli suggest absorptive function
what are some extrahepatic ducts?
1. cystic duct merges with
2. common hepatic duct to form
3. bile duct
common hepatic duct comes from right and left lobes of liver
bile duct runs in free edge of hepatoduodenal ligament, ending in duodenum
sphincter of ampulla or hepatopancreatic sphincter are walls of bile duct thickened by smooth muscle
what are the functions of the gall bladder?
stores bile
bile made in liver, sent via bile duct directly to duodenum
when sphincter at duodenal papilla constricted, bile forced back into cystic duct and gall bladder
there the bile will be stored, concentrated and acidified
bile = 97% water + 1% salts/pigments + 2% mineral salts and fatty acids
with meal, sphincter relaxes gall bladder contracts from stimulus by gastrointestinal hormones and vagus nerves
bile is then secreted
yellowish bile renders ingested fats more soluble in water so digestive enzymes can function
bile salts break up masses of fat into emulsion, increasing surface area
water soluble lipases then break it down into units that can be absorbed by lining cells of small intestine
what's the blood supply of the gall bladder?
cystic artery gives 70% and is branch from right hepatic artery
cystic vein drains directly into portal vein
what's the innervation of the gall bladder?
along cystic artery from celiac plexus = SYMPATHETIC
vagus nerve = PARASYMPATHETIC
right phrenic nerve - sensory
what are some clinical considerations to be aware of in the gall bladder?
1. obstruction of biliary ducts
gallstones from backup of bile in ducts
also leads to jaundice
stones can be made of bilirubin metabolites, cholesterol, or various calcium salts
2. inflamed gall bladder = cholecystitis
usually causes pain
if bile can't leave gallbladder, will enter blood causing jaundice
3. cholecystectomy
removal of gall bladder
what's the pancreas?
exocrine gland
secretes substance into lumen of GI tract - compound tubuloalveolar?

endocrine gland via islets of Langerhans
produces insulin and other substances released into bloodstream

consists of head, body, neck and tail
where is the pancreas located and what is it associated with?
retroperitoneal
head in crook of duodenum
tail touches spleen
lies just deep to stomach
extensive pancreatic duct enters major duodenal papilla often with bile duct at dilated hepatopancreatic ampulla

is sphincter around terminal part = pancreatic duct sphincter

sphincter around hepatopancreatic ampulla = hepatopancreatic sphincter

control flow of bile and pancreatic exocrine secretions into duodenum
what are the exocrine secretions of the pancreas and what controls them?
pancreas is exocrine gland
secrete alkaline mix of enzymes
pour into duodenum
aids digestion of proteins, fats, carbs to be absorbed by lining cells of small intestine
pancreatic secretion regulated by hormones, vagus nerves
small intestinal hormones, like secretin and cholecystikinin increase pancreatic exocrine secretions
what are the islets of Langerhans, where are they?
are clusters of endocrine cells scattered throughout pancreas, especially in tail
scattered isolated endocrine cells found throughout pancreas
what's the blood supply to the pancreas?
branches from splenic artery
branches from gastroduodenal artery, also called superior pancreaticoduodenal artery
branches from superior mesenteric artery, also called inferior pancreaticoduodenal artery
veins drain into portal, splenic, superior mesenteric veins
what's the innervation of the pancreas?
sympathetic and parasympathetic fibers reach gland by passing along arteries from celiac and superior mesenteric plexuses
innervation plays limited role in digestive process
vagus nerve causes an increase in exocrine secretions
SYMPATHETIC input increases tone of muscle cells on necks of secretory units
SYMPATHETIC input inhibits release of excretory secretions
what are clinical considerations of pancreas?
1. pancreatitis
serious inflammatory condition of exocrine pancreas
can be caused by blocked duct or reflux of bile from hepatopancreatic ampulla into pancreatic duct

occlusion of pancreatic duct by pancreatic stones produce risk of autodigestion of pancreatic tissue by its own enzymes
2. cancer of pancreas
usually involves head
accounts for most cases of extrahepatic obstruction of biliary system
cancer of head often results in obstruction of bile duct or hepatopancreatic ampulla
if beta cells involved, is excess of insulin and high risk for hypoglycemia
if non-beta cells involved, excess stimulation of acid-producing cells by gastrin may lead to gastric ulceration
3. inadequate amounts of insulin leads to diabetes mellitus
what are the functions of the kidneys?
main function is to make urine, glomerular filtrate of blood
reabsorption of water, electrolytes, other solutes in series of tubules in kidney
keeps body in metabolic, acid-base balance
drugs metabolized actively in kidneys
blood pressure directly regulated by renin-angiotensin enzymes made in kidneys
makes series of hormone-like substances that influence RBC production and activate vitamin D, which then in turn increases calcium absorption from gut
what are the relations of the kidneys?
they are retroperitoneal
each kidney lies in mass of perirenal fat posterior to peritoneum
in living (erect) usually can be found from L1-L4
right kidney may be lower than left
what are the major structures of the kidneys?
fibrous capsule - thin, but strong sheath of dense fibrous tissue
cortex = outer, peripheral part
somewhat darker than medulla
contains renal corpuscles, convoluted tubules
may appear to have groups of striations coursing through it, multitude of pinholes or combination
medulla = inner, central part with group of tubes growing out of ureter
contains straight tubules or collecting ducts
is striated
collecting ducts converge onto apex
both cortex and medulla = made up of uriniferous tubules which consist of nephrons and collecting ducts
these process blood plasma and add to/substract from filtrate, forming urine
tubes = calyces, pelvis
conduct urine passively to ureter
pyramids = in medulla, are 8-18 of them which have apex towards hilus
usually 3 major calyces that open into renal pelvis
renal sinus -
contains renal pelvis, branching calyces, renal vessels all packed in loose ct
is cavity, an inward extension of hilus
what are the blood vessels of the kidneys?
renal arteries and veins
what are the relationships of the kidneys?
posterior, superior = diaphragm
inferior = quadratus lumborum
anterior (on right) and inferior = surface of liver
superior = descending part of duodenum
anterior (on left) = suprarenal glands, stomach, spleen, pancreas, jejunum, descending colon
what's the renal fascia consist of?
is condensation of extraperitoneal tissue that splits near the lateral border of the kidney
fatty tissue also lies tween fascia and surface of kidney
what are some clinical considerations to note with the kidneys?
1. renal transplantations are common for treatment of selected cases of chronic renal failure
transplant site for kidney is lower abdomen
2. adult polycystic disease of kidney
important cause of renal failure
is inherited as autosomal dominant trait
3. numerous potential sources of diminished blood flow
poor cardiac funtion, obstruction of renal artery/vein, dehydration such as from starvation, heat or prolonged vomiting
where are the ureters and how do they move urine through them?
retroperitoneal
from renal pelvis to bladder
anterior to psoas major
propelled along by peristaltic contractions of smooth muscle, coassisted by filtration pressure
what's the blood supply to the ureters?
from renal artery, gonadal artery, superior vesicle artery
what's the innervation of the ureters?
shares innervation with kidneys
renal plexus
sympathetic and parasympathetic fibers
what are some clinical considerations to note with the ureters?
1. congenital malformation of kidney and ureter can be detected radiologically
2. obstruction of ureter at any level leads to dilation of superior parts, including renal pelvis and calyces resulting in hydronephrosis
3. rapid distention of ureter causes severe pain
pain results from kidney stone passing into ureter
kidney stone = ureteric calculus
made of calcium oxalate, calcium phosphate AND/OR uric acid
what are the relations of the suprarenal or adrenal glands?
cranial pole of the kidneys
within renal fascia
structure and function of suprarenal glands
capsule - surrounds each gland
cortex - secretes mineral corticoids, glucocorticoids that regulate stress responses, glucose mobilization and overall metabolism, sex hormones
cortisol, corticosterone, aldosterone, progesterone, estradiol, estrone
essential to life
medulla - central area of each gland
epinephrine and norepinephrine released by chromaffin cells
what's the blood supply to the suprarenal glands?
suprarenal branches (all directly or indirectly from aorta)
what's the innervation to the suprarenal glands?
mostly preganglionic sympathetic fibers derived from spanchnic nerves
major end in medulla
cortex receives only vasomotor supply
what are some clinical considerations to note for the suprarenal glands?
inappropriate growth and metabolic activity of medulla may be associated with pheochromocytoma = high levels of epinephrine or norepinephrine
raises BP, causing lots of other stuff
describe the spleen
what does it consist of
what does it do?
spleen is organ of lymphatic system
consists of organized masses of encapsulated lymphatic tissue, associated with blood sinusoids and other vessels
filters blood
site for lymphocyte and monocyte production
active in immune response in presence of antigens
macrophages remove debris from blood, break down old RBCs
heme portion of Hb converted to bilirubin
bilirubin conducted to liver by hepatic portal vein, incorporated into manufacture of bile
accumulation of bilirubin in blood = jaundice, indicates liver or gall bladder disease
storage of RBCs minimal
enlarged spleens may store too many RBCs, may need to remove some so patient can have normal amounts of RBCs and platelets in blood
where is the spleen located?
left, at ribs 9-11
has 2 ligaments connected to it
1. gastrolineal
2. lienorenal
has diaphragmatic and visceral surface
varies in size and shape, usually fits into cupped hand
what's the blood supply to the spleen/
splenic artery from celiac trunk and splenic vein to portal vein
what are some clinical considerations to note for the spleen?
1. splenomegaly = enlargement of spleen
abnormal, associated with disease
notched border helpful when palpating
when patient takes deep breath, notches can often be palpated as spleen moves inferoanteriorly
2. spleen is most frequently injured organ in abdomen
rupture causes severe intraperitoneal hemorrhage and shock
3. patients with sickle cell anemia usually have destroyed their spleens by 5 years of age
repeated sickling of cells in splenic capillaries and infarction of spleen there damages tissue
patients who've lost spleen may have increased vulnerability to infection, especially from encapsulated bacteria
what are the important arteries of the abdomen that we are expected to know?
abdominal aorta with its parietal and visceral branches including
inferior phrenic
lumbar
common iliac
median sacral
suprarenal
renal
gonadal (testicular or ovarian)
celiac trunk
left gastric
splenic
common hepatic
superior mesenteric
inferior mesenteric
common iliac arteries
external iliac arteries
which arteries in the abdomen come off the aorta and where?
abdominal aorta = T12-L4 where it then divides into right and left common iliac arteries
Parietal branches
1. inferior phrenic - crosses diaphragm
2. lumbar - small segmentals
3. common iliac
4. median sacral - unpaired

visceral branches
1. suprarenal
2. renal
3. gonadal (testicular and ovarian)
4. celiac trunk
a. left gastric
b. splenic
c. common hepatic
5. superior mesenteric
6. inferior mesenteric

common iliac arteries
external iliac arteries
what are the veins that i need to know in the abdomen?
IVC
portal system
what is the portal system?
valves are insignificant or absent here
begins as capillary plexus in organs of GI tract, gallbladder, pancreas, spleen
ends by emptying into sinusoids in liver
portal vein receives blood from superior and inferior mesenteric veins and splenic vein
where are the anastomoses between the portal venous system and the systemic venous system?
1. tween superior rectal and middle and inferior rectal veins
2. tween esophageal branch of left gastric and azygous vein
3. retroperitoneal veins and retroperitoneal portal tributaries
4. tween paraumbilical veins and subcutaneous veins (superficial epigastric); paraumbilical veins travel in falciform ligament, accompanying ligamentum teres
what causes portal hypertension, what's result of it?
results from obstruction of portal vein
causes enlargement of connections tween portal tributaries and systemic veins and reverses flow of blood into systemic veins
anastomosis may be engorged, creating esophageal varicosities, hemorrhoids, varicosities on abdominal wall around umbilicus (caput medusae)
what are the lymphatics related to the vessels of the abdomen?
lymph nodes lie along aorta, inferior vena cava and iliac vessels
cistern chyli = sac-like expansion at inferior end of thoracic duct
usually posterior to right crus of diaphragm
what are teh two types of nerves in the abdominal wall?
somatic nerves of lumbar plexus and its branches
visceral or splanchnic nerves of autonomic nervous system
what's the lumbar plexus consist of, what do those nerves do and where do they come from?
lumbar plexus = network of nerves formed within psoas major muscle by ventral rami of L1-L4
1. iliohypogastric nerve = L1
supplies abdominal musculature
2. ilioinguinal nerve = L1
passes through superficial inguinal ring, supplies skin
3. lateral cutaneous nerve of thigh = L2, L3
supplies skin on anterolateral thigh
4. femoral nerve = L2-L4
nerve of extensor muscles
5. obturator nerve = L2-L4
nerve of adductor muscles of thigh
6. genitofemoral nerve = L1-L2
where's the lumbosacral trunk?
union of inferior part of ventral rami of L4 with L5
where does the vagus nerve go, do?
is parasympathetic innervation
1. anterior vagal trunk formed in thorax from left vagus nerve
enters abdomen on anterior surface of stomach
posterior vagal trunk from right vagus
2. to celiac plexus
branches to stomach, pancreas, liver, small intestine, large intestine to left colic flexure
3. rest of the intestine receives parasympathetic from pelvic splanchnic nerves = S2-S4
what's the autonomic plexus made up of? what does it do?
formed by splanchnic nerves, branches of vagus nerve and ganglion cells embedded in ct.
concentrations of this plexus around origins of celiac, renal, superior and inferior mesenteric arteries
correspond to intermesenteric plexus, superior hypogastric plexus, inferior hypogastric plexus

principal part of abdominal autonomic nervous system is CELIAC PLEXUS
located on each side of celiac trunk
what is the thoracic splanchnic nerve?
preganglionic fibers from spinal cord
main source of SYMPATHETIC innervation in abdomen
sensory to abdominal viscera
branches of 5th to 12th thoracic sympathetic ganglia
what's in the sympathetic trunk? what does it give off?
has four segmentally arranged ganglia
gives off lumbar splanchnic nerves to aortic plexus
intermesenteric, inferior mesenteric, superior hypogastric plexus
what role do afferent fibers play in the abdomen?
sympathetic and parasympathetic nerves are visceral efferent or MOTOR
those nerves also carry some sensory fibers from sense organs in viscera
what does the diaphragm do? what are the parts of the diaphragm?
is most important muscle of respiration
increases volume of thorax
has 3 muscular parts that insert onto central tendon, which is ct, not musculature
1. sternal
2. costal
3. vertebral parts
what's the innervation of the diaphragm?
phrenic nerve
C4 with help from C3, C5
what's the blood supply to the diaphragm?
internal thoracic, inferior epigastric, intercostal arteries, aorta through inferior phrenic arteries
what are hiccups?
spasmodic, sharp contractions of diaphragm
what are the borders of the posterior abdominal wall?
diaphram, vertebral column, psoas major, quadratus lumborum, upper edge of iliac crest
where does the psoas major start and insert?
origin: transverse processes and vertebral bodies of T12-L5
insertion: lesser trochanter of femur
what's the origin and insertion of the quadratus lumborum?
origin: iliolumbar ligament, iliac crest
insertion: 12th rib, transversus processes of upper four lumbar vertebrae
what's the origin, insertion and primary action of the iliacus muscle?
origin: iliac fossa
insertion: lesser trochanter of femur
action: iliopsoas is major flexor of thigh

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