Anatomy Flashcards
Describe the foregut.
Oesophagus to mid-duodenum, liver, gallbladder, spleen, 1/2 pancreas
Describe the midgut.
Mid-duodenum to proximal 2/3 transverse colon, 1/2 pancreas
Describe the hindgut.
Distal 1/3 of the transverse colon to proximal 1/2 anal canal
Muscle guarding tends to occur in what?
peritonitis
What is the peritoneum?
A thin, transparent, semi-permeable, serous membrane that lines the walls of the abdominopelvic cavity and organs
What will blood, pus or faeces in the peritoneal cavity cause?
peritonitis
what is peritonitis?
painful inflammation of the peritoneum
what is the function of the lubricating fluid secreted by the peritoneum?
free movement
what type of organ is the liver?
intraperitoneal
what type of organ is the pancreas?
retroperitoneal
what type of organs are the kidneys?
retroperitoneal
What does intraperitoneal mean?
Organ is almost completely covered in visceral peritoneum
What does retroperitoneal mean?
Organ only has visceral peritoneum on its anterior surface
What attaches the liver to the anterior abdominal wall?
falciform ligament
Which omentum hangs from the greater curvature of the stomach like an apron?
greater omentum
Which omentum comes from the lesser curvature of the stomach and attaches to the liver?
lesser omentum
what is an omentum?
a condensation of peritoneum that attaches organs to each other or the abdominal wall
The greater and lesser sac communicate through what?
the omental foramen
Where do the portal triad lie?
in the free edge of the lesser omentum
What does the portal triad consist of?
hepatic artery, hepatic portal vein and the common biliary ducts
What is the name of the peritoneal pouch found in a male?
rectovesical pouch
sits between the rectum and the bladder
What are the names of the peritoneal pouches found in a female?
uterovesical pouch
(sits between the uterus and the bladder),
rectouterine
(sits between the rectum and the uterus)
What is the pouch of douglas also known as?
the rectouterine pouch
which peritoneal pouch is the lowest part of the peritoneum in a standing female?
rectouterine pouch (aka pouch of douglas)
excess fluid within the abdominal caivty is known as what?
ascites
how can ascitic fluid be drained from the peritoneal cavity?
paracentesis or abdominocentesis
dring paracentesis where must the needle be placed and why?
lateral to the rectus sheath to avoid the inferior epigastric artery
where does the inferior epigastric artery lie?
deep to the rectus abdominis
From which artery does the inferior epigastric artery arise from?
external iliac
where is the external iliac artery?
just medial to the deep inguinal ring
GI obstruction could be present as what type of pain and why?
colicky pain- peristalsis comes in waves
What is the extensive network of nerves found within the walls of the GI tract called? (These can bring about peristalsis)
enteric nervous system
Where are the prevertebral ganglia that abdominopelvis splanchnic nerves synapse at?
anterior surface to the descending aorta
abdominopelvic splanchnic nerves leave the spinal cord between which levels?
T5 and L2
postsynaptic sympathietic nerve fibres pass from the prevertebral ganglia and go where?
onto the periarterial plexuses on the surface of the branches leaving the abdominal aorta
What types of nerves are periartrial plexuses made of?
sympathetic, parasympathetic visceral afferent
how do nerves get from the periarterial plexus to abdominal organs?
‘hitch a ride’ with the arteries towards the smooth muscle and glands of organ
The sympathetic nerve fibres for the adrenal gland leave the spinal cord at what levels?
T10-L1
Presynaptic parasympathetic nerve fibres enter the abdominal cavity where?
on the surface of the oesophagus
(vagus nerve goes through the diaphragm with the oesophagus(
Vagus nerve supplies what abdominal organs?
oesophagus to distal end of the transverse colon
Pelvic splanchnic nerves are what kind of nerves?
presynaptic parasympathetic nerve fibres
what levels of the vertebra do pelvic splanchnic nerves come from?
S2-S4
sacral output
What abdominal organs do the pevic splanchnic nerves supply?
descending colon to anal canal
visceral afferent fibres of the foregut enter the vertebra at what levels?
T6-T9
visceral afferent fibres of the midgut enter the vertebra at what levels?
T8-T12
visceral afferent fibres of the hindgut enter the vertebra at what levels?
T10-T12
what does the iliohypogastric nerve supply?
some body wall areas of the ileum and the hypochondrium
what does the ilioinguinal nerve supply?
some ileal and inguinal body wall
what are thoracoabdominal nerves?
somatic motor, somatic sensory and sympathetic nerve fibres that supply the abdominal body wall.
from what vertebral level do the thoracoabdominal nerves leave/enter the vertebra?
T7-T11
what joint does jaw opening occur at?
temperomandibular joint
what are the 3 pairs of jaw-closing muscles?
Masseter
Temporalis
Medial Pterygoid
What is 1 the pair of jaw-opening muscles?
lateral pterygoid
What cranial nerve supplies jaw-opening and jaw-closing muscles?
the mandibular division of the trigeminal nerve (CN V3)
Where is the masseter muscle?
angle of mandible to zygomatic arch
Where is the temporalis muscle?
coronoid process of mandible to temporal fossa
Where is the medial pterygoid?
medial angle of the mandible to pterygoid plates of sphenoid bone
Where is the lateral pterygoid?
condyle of mandible to pterygoid plates of sphenoid bone
Where does the third branch (mandible branch) of the trigeminal nerve (CN V3) leave/enter the cranium?
Foramen ovale
Where does the third branch (mandible branch) of the trigeminal nerve (CN V3) leave/enter the CNS?
the pons
What are the lymph nodes that the general population refer to as tonsils called?
palatine tonsils
What nerve supplies all sensation (ie general AND taste) to the posterior 1/3 of the tongue?
glossopharyngeal (CN IX)
What nerves supply general sensation and special taste to the anterior 2/3 of the tongue?
General sensation- mandibular branch of the trigeminal (CN V3)
Special ‘taste’ sensation- facial nerve (CN VII)
In the inferior half of the oral cavity, what nerve supplies general sensation to the gingiva and floor of the mouth?
mandibular branch of the trigeminal (CN V3)
[inferior half of the oral cavity is in the mandible]
In the superior half of the oral cavity, wht nerve supplies general sensation to the gingiva and palate?
maxillary branch of the trigeminal (CN V2)
[superior half of the oral cavity is in the maxilla]
The sensory part of the gag reflex in the oropharynx is carried by what nerve?
glossopharyngeal (CN IX)
The motor part of the gag reflex in the oropharynx is carried by what nerves?
glossopharyngeal (CN IX) and vagus (CN X)
Spraying a local anaesthetic will numb the area ready for an endoscope by blocking sensory action potentials in what 4 nerves?
- maxillary branch of the trigeminal (CN V2)
- mandibular branch of the trigeminal (CN V3)
- facial (CN VII)
- glossopharyngeal (CN IX)
Where does the second branch (maxillary branch) of the trigeminal nerve (CN V2) enter/leave the cranium?
foramen rotundum
Where does the second branch (maxillary branch) of the trigeminal nerve (CN V2) enter/leave the CNS?
pons
The facial nerve enters/exits the crainum in what 2 foramina?
- internal acoustic meatus
2. stylomastoid foramen
What branch of what cranial nerve provides special sensory taste to the anterior 2/3 of the tongue?
The chorda tympani branch of the facial nerve (CN VII)
What branch of what cranial nerve provides parasympathetic secretomotor to submandibular and sublingual salivary glands?
the chorda tympani branch of the facial nerve (CN VII)
Where does the glossopharyngeal nerve (CN IX) enter the cranium?
jugular foramen
Where does the facial nerve (CN VII) enter the CNS?
at the junction of the pons at the medulla
Where does the glossopharyngeal nerve (CN IX) enter the CNS?
at the medulla
What nerve provides parasympathetic secretomotor stimulation to the parotid salivary glands?
glossopharyngeal (CN IX)
What are the three pairs of salivary glands?
- parotid
- submandibular
- sublingual
where does the parotid gland release its salivary fluid?
opposite the 2nd upper molar
Where are the sublingual glands?
under the tongue
What are the 4 pairs of extrinsic tongue skeletal muscles?
- genioglossus
- palatoglossus
- styloglossus
- hyoglossus
What do the extrinsic tongue skeletal muscles do?
suspend tongue in ora cavity,
move tongue around during mastication, swallowing and speech
Where are the intrinsic tongue skeletal muscles located?
dorsal and posterior tongue
originate and insert within the tongue
What do the intrinsic tongue skeletal muscles do?
Modify the shape of the tongue during function
What nerve supplies the extrinsic and intrinsic skeletal muscles of the tongue? (except the palatoglossus)
hypoglossal nerve (CN XII)
Where does the hypoglossal nerve (CN XII) enter/exit the cranium?
hypoglossal canal
Where does the hypoglossal nerve (CN XII) enter/exit the CNS?
medulla
What are the two functions of the inner longitudinal layer of muscles of the pharynx?
- contract during swallowing to shorten the pharynx
2. relax the larynx to close the laryngeal inlet
What cranial nerves supply the inner longitudinal layer of muscles of the pharynx?
glossopharyngeal (CN IX) and vagus (CN X)
At what vertebra level is the upper oesophageal sphincter?
C6
the level the pharynx becomes the oesophagus
What are the 3 muscles within the outer circular layer of pharyngeal constrictor muscle?
superior pharyngeal constrictor
medial pharyngeal constrictor
inferior pharyngeal constrictor
What is the function of the outer circular layer of pharyngeal constrictor muscles?
sequentially contract to push the food bolus inferiorly into the oesophagus
What nerve supplies the outer circular layer of pharyngeal constrictor muscles?
vagus (CN X)
what muscle closes the lips?
orbicularis oris
What nerve supplies the orbicularis oris?
facial (CN VII)
what is the upper oesophageal sphincter also known as?
cricopharyngeus muscle
What are the three anatomical constrictions of the oesophagus?
- cervical constriction
- thoracic constiction(s)
- diaphragmatic constriction
what is the cervical constriction of the oesophagus due to?
cricopharyngeus muscle
what is the thoracic contraction(s) of the oesophagus due to?
arch of the aorta or left main bronchus
what is the diaphragmatic constriction of the aorta due to?
the lower esophageal spincter/result of passing through the diaphragm
what is the angle of change in direction of the stomach called?
incisura angularis
What causes icterus?
increased blood levels of bilirubin
what is the normal by-product of RBC breakdown?
bilirubin
Where does the breakdown of RBCs occur?
spleen (mainly)
What does the liver use bilirubin to make?
bile
what connects the liver to the second part of the duodenum?
biliary tree
what is the first midline branch of the abdominal aorta?
the celiac trunk
what type of structure is the celiac trunk?
retroperitoneal
what level does the celiac trunk arise around?
T12
The celiac trunk trifurcates, what are the three branches called?
splenic artery, common hepatic artery, left gastric artery
The supraduodenal artery and the superior pancreaticoduodenal artery branches of what artery?
gastroduodenal artery
the gastroduodenal artery branches off what artery?
the common hepatic artery
Where does the splenic artery run?
along the superior border of the pancreas
What type of organ is the spleen?
intraperitoneal
What ribs protect the spleen?
ribs 9-11
The blood suply to the stomach mainly comes from what 4 arteries?
- right gastric artery
- left gastric artery
- right gastro-omental artery
- left-gastro-omental artery
The right gastric artery branches off what artery?
hepatic artery proper
The right gastro-omental artery branches off what artery?
superior pancreaticoduodenal artery
The left gastro-omental artery branches off what artery?
splenic artery
the right and left gastric arteries run along where?
lesser curvature o the stomach and anastamose
the right and left gastro-omental arteries run along where?
greater curvature of the stomach and anastamose
What are the two blood supplies to the liver?
Hepatic artery (Left and right) Hepatic portal vein
the liver is protected by what ribs?
ribs 7-11
What are the four anatomical segments of the liver?
right lobe
left lobe
caudate lobe
quadrate lobe
what are the right and left lobes of the liver separated by?
falciform ligament
How many functional segments does the liver have?
8
What does each liver segment have?
its own portal triad
What is different about the IVC and hepatic veins when comparing to regular veins?
don’t have valves
what effect can a high central venous pressure have on the liver?
hepatomegaly
what are the smallest functional units of a liver?
hexagonal lobule
what does each hepatic lobule contain in the middle?
central vein
what does each hepatic lobule contain at each corner?
interlobular portal triad
What are the two recesses that are related to the liver?
hepatorenal recess (Morrisons pouch) and subphrenic recess
In which sac are the hepatorenal and subphrenic recess lcoated?
greater sac
When the patient is supine, what is the lowest part of the peritoneal cavity?
hepatorenal recess
Describe the abdominal organs veins transformation into the hepatic portal vein.
First the inferior mesenteric drains into the splenic vein. Then the splenic vein and superior mesenteric vein meet and for the hepatic portal vein.
the inferior vena cava is what type of structure?
retroperitoneal
what attaches the liver to the diaphragm?
coronary ligaments
what is the remnant of the embryological umbilical vein?
ligamentum teres
the gallbladder is anatomically where in relation to the duodenum?
anterior
the neck of the gall bladder narrows to become what vessel?
cystic duct
what is the blood supply to the gallbladder?
cystic artery, which is usually a branch of the right hepatic artery.
what is the name of the surgical removal of the gallbladder
colecystectomy
where does the bile duct join with the main pancreatic duct?
the ampulla of Vater
Where does the ampulla of Vater drain into the 2nd part of the duodenum through?
major duodenal papilla
what are three anatomical sphincters are near to the ampulla of Vater?
bile duct sphincter, pancreatic duct sphincter, sphincter of Oddi
What can obstruction of the biliary tree? (ie post hepatic jaundice)
gallstones, carcinma at the head of the pancreas
Where does the uncinate process of the pancreas sit?
behind the superior mesenteric vessels
The pancreas is supplied by what three arteries?
- superior pancreaticoduodenal (comes from the gastroduodenal)
- inferior pancreaticoduodenal (comes from the SMA)
- pancreatic branches (that come from the splenic artery)
What type of structures are each part of the duodenum?
- superior - intraperitoneal
- descending- retroperitoneal
- horizontal- retroperitoneal
- ascending- retroperitoneal
The duodenum secretes what three peptide hormones?
- gastrin
- CCK
- secretin
The duodenum is suppplied by what two arteries?
- superior pancreaticoduodenal (from the gastroduodenal artery)
- inferior pancreaticoduodenal (from SMA)
the the ascending duodenum meets the jejunum at what flexure?
duodenaljejunal flexure
the ileum ends at what junction?
ileocecal juncion
what are the macroscopic folds in the jejunum and ileum called?
plicae circularis
Is the jejunum or ileum more folded with plicae circularis?
jejunum
what is the ileum is important in absorbing?
vitamins (eg B12)
Compare the vasa recta between ileum and jejunum.
vasa recta are much longer in the jejunal arteries
compare the terminal arterial arcades between ileum and jejunum.
the loops are more complex in ileum than jejunum.
lymph tends to lie where?
along arteries
what are the 4 main groups of lymph nodes draining the abdominal organs?
- celiac (foregut)
- superior mesenteric (midgut)
- inferior mesenteric (hindgut)
- lumbar (kidney, posterior abdo wall, pelvis and lower limbs)
What are the three functions of the large intestine?
- defence (commensal bacteria)
- absorption (of water and electrolytes)
- excretion (of formed stool
What type of structure is the cecum?
intraperitoneal
what type of structure is the ascending colon?
retroperitoneal
what type of structure is the transverse colon?
intraperitoneal
what type of structure is the descending colon?
retroperitoneal
what type of structure is the sigmoid colon?
intraperitoneal
what are the spaces that are part of the greater sac of the peritoneal cavtiy and sit between the lateral edge of the ascending/ descending colon and the abdominal wall?
paracolic gutters
What are the three distinct longitudinal thickened smooth muscle that runs from the cecum to the distal end of the sigmoid colon?
teniae coli
what does McBurneys point correspond to?
the location of the appendiceal orfice,
1/3 of the way from the ASIS to the umbilicus
where is the appendiceal orfice?
on the posteromedial wall of caecum
what supplies the pelvis/perineum and the lower limbs?
right and left common iliac arteries
What are the 4 main arteries that come off the SMA?
- inferior pancreaticoduodenal artery
- middle colic artery
- right colic artery
- ileocolic artery
what arteries come off the ileocolic artery?
appendicular artery, jejunal arteries, ileal arteries
what are the 3 main arteries that come off the IMA?
left colic artery, sigmoidcolic artery, superior rectal artery
What is the arterial anastomose between the branches of the SMA and the branches of the IMA?
the marginal artery of Drummond
What are the name of alternative routes for blood to travel?
collateral vessels
what supplies the distal 1/2 of the anal canal and the anus?
the internal iliac artery
what are the two main branches of the internal iliac artery that supply the distal 1/2 of the anal canal and the anus?
middle rectal artery
inferior rectal artery
what represents the divide of the upper 2/3 and lower 1/3 of the anal canal?
pectinate line
what are abnormal dilated, thin-walled veins?
varcies
what are varices caused by?
pathology affecting the portal venous system
what is the foregut drained by?
splenic vein
what is the hind gut drained by?
IMV
what is the midgut drained by?
SMV
Where are the 3 important site of venous portal systemic anastamoses?
- distal end of the oesophagus
- skin around the umbilicus (ie opening of the ligamentum teres)
- rectum/anal canal
what causes the opening of the ligamentum teres?
portal hypertension due to liver pathology (eg cirrhosis)
Why do the portal systemic anastamoses become dilated? (ie how do varices form)
portal hypertension, causing collateral veins to receive a higher volume of blood
where is the rectum located?
within the pelvic cavity
what is the way into the pelvic cavity from the abdominal cavity called?
pelvic inlet
what must the rectum/anal canal pass through?
pelvic floor
What is the name of the pelvic floor muscles?
levator ani
pelvic diaphragm
when does the sigmoid colon become the rectum?
at the rectosigmoid junction
level- S3
Rectum becomes the anal canal just prior to what?
passing through the pelvic floor
what are the anal canal and the anus contained in?
the perineum
What separates the pelvic cavity from the perineum?
the pelvic diaphragm (levator ani muscle)
where does the rectal ampulla lie?
just superior to the levator ani muscle
how does the rectal ampulla accommodate faecal material?
relaxes its walls
what is the rectal ampulla?
dilated distal part of the rectum
what type of muscle is the levator ani muscle?
skeletal
In what state is the levator ani muscles most of the time?
contracted
why must the levator ani muscle reflexively contract further sometimes?
for situations of intra-abdominal pressure eg sneezing or coughing
when must the levator ani muscle relax?
defecation and urination
what nerve supplies the levator ani muscle?
the nerve to the levator ani, it is a branch of the sacral plexus
What is the part of the levator ani muscle that is particularly important for maintaining faecal continence?
puborectalis muscle
What does contraction of the puborectalis muscle of the levator ani muscle do?
decreases the anorectal angle- acts like a sphincter to maintain continence
what shape is the puborectalis muscle?
U-shaped
where is the internal anal sphincter?
medial 1/3 of the anal canal
where is the external anal sphincter?
distal 1/3 of the anal canal
contraction of the internal anal sphincter is stimulated by what nerves?
sympathetic nerves
relaxation of internal anal sphincter is stimulated by what nerves?
parasympathetic nerves
what does the internal anal sphincter reflexively relax in response to?
filling of the rectal ampulla
The superior part of the external anal sphincter is continuous with what muscle?
the puborectalis muscle of the levator ani muscle
what nerve causes contraction of the external anal sphincter?
pudenal (somatomotor) nerve
sympathetic nerve supply of the rectum and anal canal comes from what vertebra levels?
T12-L2
how do sympathetic nerves that supply the rectum and anal canal synapse?
synapse as abdominosplanchnic nerves
visceral afferent nerve fibres of the rectum and anal canal run along side what nerves? (and therefore enter the verterbral column at what level?)
parasympathetic nerves
S2-S4
what do visceral afferents of the rectum sense?
ischaemia, stretch, fullness of the rectal ampulla
from what level does the nerve to levator ani (somatic motor) come from?
S3,S4
from what level does the pudenal nerve (somatic motor) come from?
S2,3,4 anterior rami
What do the levator ani muscle and the pudenal muscle do?
stimulation the contraction of the external anal sphincter and the puborectalis
from what plexus does the pudenal nerve come from?
the sacral plexus
what does the pectinateline represent embryologically?
endoderm (GI tube) and ectoderm (skin) divide
superior to the pectinate line what type of nerve supply is there?
autonomic nerve supply
inferior to the pectinate line what type of nerve supply is there?
somatic nerve supply
superior to the pectinate line what is the blood supply?
IMA
inferior to the pectinate line what is the blood supply?
internal iliac artery
superior to the pectinate line what is the venous drainage?
IMV to portal vein
inferior to the pectinate line what is the venous drainage?
internal iliac vein to systemic venous system
superior to the pectinate line what is the lymph drainage?
internal iliac nodes to inferior mesenteric nodes
inferior to the pectinate line what is the lymph drainage?
superficial inguinal nodes to external iliac nodes
what is the lymph drainage of the inferior pelvic structures?
internal iliac nodes
what is the lymph drainage of the lower limb and more superior pelvic structures?
external iliac nodes
what is the lymph drainage from the external and internal iliac nodes?
common iliac
what is the lymph drainage from the common iliac nodes?
lumbar nodes
What is lymph drainage from the superficialinguinal nodes?
external iliac nodes
what can prolapse of the external rectal venous plexus due to constipation/pregancny/straining cause?
haemorrhoids
what is the name of the fossae filled with fat and loose connective tissue on each side of the anal canal?
(each side commnicates posteriorly)
ischioanal fossa
what is an infection within the ischiofossa called?
ischoanal abcess
what is the name of the endoscope that views the rectum?
proctoscopy