Anatomy Flashcards
which joints controls jaw opening and closing?
the temporomandibular joints
name the 3 pairs of jaw closing muscles.
masseter
medial pterygoid
temporalis
name the pair of jaw opening muscles.
lateral pterygoid
which nerve supplies the muscles of mastication?
CN V3 (mandibular division of the tirgeminal nerve)
which feature of the skull prevents jaw dislocation?
articular tubercle
Describe the course of CN V3 (mandibular division of the trigeminal nerve) AND what type of fibres it contains.
Course: from pons, through foramen ovale to muscles of mastication and sensory area
Contains sensory AND motor fibres
Name the teeth in the mouth and their numbers.
Inscisors (1&2)
Canine (3)
Premolars (4&5)
Molars (6, 7, 8)
Name the 3 main pairs of salivary glands
Sublingual
Submandibular
Parotid
Which nerve supplies general sensation to the top and bottoms halfves of the mouth.
Top = CN V2 Bottom = CN V3
Describe the course and contents of CN V2 (maxillary division of trigeminal nerve)
Course: from pons, through foramen rotundum to the sensory area (mid-face, inc upper mouth)
Contains sensory fibres
which nerves govern the gag reflex?
Sensory part is CN IX
Motor part is CN IX and CN X
Spraying a local anaesthetic at the back of the mouth blocks senosry action potentials in which nerves?
CN V2, CN V3 (top and bottom of mouth), CN VII (anterior tongue) and CN IX (posterior tongue)
Which nerves supply the anterior 2/3rds of the tongue and what do they contain?
CN V3 = general sensory
CN VII = special sensory (taste)
Which nerve supplies the posterior 1/3rd of the tongue and what does it contain?
CN IX = general and special sensory
what divides the anterior tongue from the posterior tongue?
terminal sulcus
Describe the course of CN VII and what it contains.
Course: from pontomedullary junction, through the temporal bone via internal acoustic meatus THEN stylomastoid foramen WHERE part breaks off (chorda tympani - joins with CN V3 to contain taste axons - tongue - and parasympathetic axons - for salivary glands) The remaining part supplies the muscles of facial expression (as is only motor at this point)
Contains special sensory, sensory, motor and parasympathetic
What does CN VII supply?
REMEMBER = Facial nerve
Taste in the anterior 2/3 of tongue
Muscles of facial expression
Glands in the floor of the mouth
Describe the course of CN IX and what it contains
Course: from medulla, through jugular foramen, to supply area
Contains: special sensory, motor, visceral afferent and parasympathetics
Where does CN IX supply?
Posterior wall of oropharynx (sensory)
Parotid gland (secretomotor)
Posterior 1/3rd tongue (sensation and taste)
Name the 4 pairs of extrinsic tongue muscle.
Palatoglossus
Styloglossus
Hyoglossus
Genioglossus
What are the functions of the extrinsic and intrinsic muscles of the tongue?
Extrinsic: change the postition of the tongue during mastication, swallowing and speech
Intrinsic: modify the shape of the tongue during function
What supplies all the muscle of the tongue except the palatoglossus muscle?
CN XII (hypoglossal nerve)
Describe the course and contents of CN XII.
Course: from medulla, through hypoglossal canal, to extrinsic and intrinsic muscles of tongue (except palatoglossus)
Contains: motor
At what level does the oesophagus begin?
C6
what are the circular constrictor muscles of the pharynx innervated by?
CN X (contract sequentially)
what supplies the longitudinal muscle inner layer in the pharynx?
CN X and CN IX
describe the process of swallowing, highlighting which parts are voluntary and which aren’t AND the innervation.
Lips close to stop drooling (orbicularis oris and CN VII)
Tongue pushed food towards oropharynx (CN XII -voluntary).
Soft palate and larynx elevate (longitudinal muscle contracts) to close the nasal cavity (CN IX and X- involuntary)
At the same time circular layer of pharyngeal constrictor muscles contract (CN X -involuntary)
Bolus enters oesophagus and travels by peristalsis (involuntary)
What controls closing of the lips?
orbicularis oris and CN VII
Which muscle creates the UOS?
cricopharyngeus (at C6)
At which level does the oesophagus begin?
C6
How is the oesophagus innervated?
By the oesophageal plexus which runs on its surface supplying smooth muscle.
Contains para via vagal trunks and symp nerve fibres, these influence the ENS to slow or speed up peristalsis
How is the LOS created (remember it is physiological, NOT anatomical)?
Contraction of diaphragm
Intrabdominal pressure is slightly higher than intragastric pressure
Oblique angle at which it enters the stomach
What is the Z-line?
Describes the aprupt change from non-keratinised stratified squamous epithelium to simple columnar epithelium
Where is the pyloric sphincter?
Between the stomach and duodenum
The lesser omentum attaches to the _________. The greater omentum attaches to the _________.
Lesser curvature
Greater curvature
Which organs are in the foregut?
Oesophagus, stomach, mid-duodenum, liver, gallbladder, spleen and 1/2 of pancreas
Which organs are in the midgut?
2nd half of duodenum, rest of small intestine, large intestine up to 2/3rd of transverse colon AND 1/2 of pancrease
Which organs are in the hindgut?
Distal 1/3rd of transverse colon, rest of colon, rectum and proximal half of anal canal
what are the 9 abdominal regions?
Left and right hypochondrium
Epigastric
Left and right lumbar/flank
Umbilical
Left and right iliac fossa
Pubic/suprapubic/hypogastric
Which 3 line separate the abdomen into its 9 segments?
midclavicular
subcostal (under ribs)
trans-tubercular (across bony hib bit)
which 2 lines divide the abdomen into quadrants?
median and trans-umbilical
which layers of muscle make of the abdominal wall?
rectus abdominis (vertical) external oblique (hands in pockets) internal oblique (opposite - so up and in) transversus abdominis (horizontal)
what is the peritoneum?
a thin, transparent, semi-permeable serous membrane which lines the walls of the abdominopelvic cavity and organs (has parietal and visceral part)
what are the three ways that organs can be arranged within the peritoneum?
intraperitoneal (eg: liver)
retroperitoneal (eg: pancreas - as only the front is coated by it)
with a mesentery (eg: intestines)
what is the falciform ligament?
a ligament which attaches the liver to the front body wall, and separates the liver into the left medial lobe and left lateral lobe.
where do the two omental sacs communicate between?
the omental foramen
where does the portal triad lie in relation to the omentum?
on the free edge of the lesser omentum
which pouches are formed by the inferior aspect of the peritoneum in males and females?
Males: rectovesical (between bladder and rectum)
Females: vesico-uterine (between bladder and uterus) and recto-uterine/Pouch of Douglas (between uterus and rectum) pouches
what procedure is used to drain ascitic fluid from the peritoneal cavity?
paracentesis
where must the needle be inserted during paracentesis and why?
lateral to the rectus sheath to avoid the inferior epigastric artery
where does the inferior epigastric artery arise from?
the external iliac just medial to the deep inguinal ring
which types of nerves supply organs within the abdominal cavity?
visceral afferents (sensory)
parasympathetic
sympathetics
ENS
which types of nerves supply the abdominal wall?
somatic sensory
somatic motor
sympathetics
To supply abdominal organs:
Sympathetics leave the spinal cord between 1.
They then enter ___2____ but do not ___3___.
They leave the chains within _______4_______ nerves.
They synsapse at ____5____ which are found ____6____
Postsynaptic fibres then travel on the surface of _7__ in ___8___ to reach the smooth muscle and glands of the organ
- T5-L2
- sympathetic chains
- synapse
- abdominopelvic splanchnic
- prevertebral ganglia
- anterior to the aorta at exit points of major bracnes of the abdominal aorta
- arterial branches leaving the abdominal aorta
- periarterial plexuses
How do sympathetics get to the adrenal gland (doesn’t follow normal route)?
- Leave spinal cord at T10-L1
- Enter abdominopelvic splanchnic nerves
- DO NOT synapse at prevertebral ganglia, instead travel with periarterial plexuseese and synapse directly onto cells
Where does the parasympathetic innervation of abdominal organs originate from?
CNX (vagus nerve) AND pelvic splanchnic nerves (S2, 3, 4)
Supplying abdominal organs:
The vagus nerve (presynaptic fibres) enters the abdominal canvity on the surface of the ___1__ in __2__.
It then travels into the __3__ around the abdominal aorta
It is carried to the __4__ where they __5__ in ganglia.
- oesophagus
- vagal trunks
- periarterial plexuses
- walls of the organs
- synapse
Where does the vagus nerve supply and where do the pelvic splanchnic nerves supply?
Vagus supplies: GIT and abdominal organs up to the distal end of the transverse colon
Pelvic splanchnic nerves supply: descending colon to anal canal
Pain in the foregut tends to be felt in __1__
Pain in the midgut tends to be felt in ___2___
Pain in the hindgut tends to be felt in __3__.
- epigastric
- umbilical
- pubic
Visceral afferents get from the abdo organs to the CNS by travelling alongside __1__ back to the spinal cord.
Those from foregut structures enter at 2
Those from midgut enter at __3__
Those from hindgut enter at __4__
- sympathetic fibres
- T6-T9
- T8-T12
- T10-L2
Pain from the liver or gallbladder can be referred to 1
Pain from the stomach can be referred to 2
Pain from the pancreas can be referred to 3
- right shoulder
- inbetween the shoulder blades
- mid back
which nerves supply the abdominal body wall?
thoracoabdominal nerves
subcostal nerve
iliohypogastric nerve
ilioinguinal nerve
The thoracoabdominal nerves were origionally the 1 intercostal nerves which have left the intercostal spaces and travelled between 2
The subcostal nerve originated from 3 ___ ramus
The iliohypogastric nerve originated from half of 4 ___ ramus
The ilioinguinal nerve originated from the other half of 5 ___ ramus
- 7th-11th intercostal nerves
- the internal oblique and transversus abdominis
- T12 anterior ramus
- half of L1 anterior ramus
- other half of L1 anterior ramus
what is the portal triad made up of?
hepatic artery (blood supply to)
hepatic portal vein (drainage to)
common bile duct
nerves and lymphatics
at what level does the celiac trunk arise?
T12
Which arteries supply the foregut, midgut and hindgut
Foregut: celiac trunk
what does the celiac trunk trifurcate to produce?
splenic, hepatic and left gastric arteries
which ribs protect the pancreas?
9-11
what does the spleen do?
break RBCs to make bilirubin
which arteries supply the stomach?
right and left gastric arteries (run along lesser curvatures)
right and left gastro-omental (greater curvature)
which ribs protect the liver?
7-11
what are the 4 lobes of the liver?
right
left
caudate
quadrate
why can hepatomegaly occur due to rises in central venous pressures?
the IVC and hepatic veins lack valves so a rise in central venous pressure can engorge the liver with blood due to back pressure
In the centre of a liver lobule a __1__ is found and at each corner an __2__ is found.
- central vein
2. interlobular portal triad
what does the central vein do?
collect cleaned blood and drains into hepatic veins then IVC
Which 2 recesses are found within the greater sac of the peritoneal cavity?
subphrenic recess
hepatorenal recess/Morison’s pouch
The hepatic portal vein drain blood from __1__ to the _2__ for first pass metabolism.
The inferior mesenteric vein drains blood from the __3__ to the 4.
The splenic vein drains the blood from the 5 to the hepatic portal vein.
The superior mesenteric vein drains blood from the 6 to the __7__.
- foregut, midgut and hindgut
- liver
- hindgut
- splenic vein
- foregut (inferior mesenteric drains into it too)
- midgut
- hepatic portal vein
The IVC drains blood from the __1__ to the __2__.
- hepatic veins
2. right atrium
what is the ligamentum teres/round ligament?
a remnant of the embryological umbilical vein (found on inferior part of falciform ligament)
which artery supplies the gallbladder?
cystic artery (a branch of the right hepatic artery in 75% of people)
The right and left hepatic ducts from the liver unite to form what?
common hepatic duct
what is the bile duct formed by?
the common hepatic duct (from the liver) uniting with the cystic duct (from the gallbladder)
where does the bile duct drain into?
the 2nd part of the duodenum along with the main pancreatic duct
The bile duct travels in a groove on the 1 aspect of the __2__.
It then joins with the ___3___ to form the __4__
These both then drain into the _____
- posterior
- pancreas
- main pancreatic duct
- ampulla of Vater
- 2nd part of the duodenum
ERCP stands for what?
endoscopic retrograde cholangiopancreatography
What is ERCP used for?
An investigation to study the biliary tree and pancreas and treat some pathologies. It is a
How does ERCP work?
Endoscope is inserted which reaches to the duodenum. A cannula is placed into the major duodenal papilla and radio-opaque dye is injected back into the biliary tree. Radiographic images are then taken of the dye filled tree
How can obstruction of the biliary tree cause jaundice?
Obstruction causes a back up of bile to the liver, this overspills into the blood.
What are the parts of the pancreas?
head (widest bit - surrounded by the duodenum)
neck
body
tail
Which nerves supply the pancreas?
Symp: abdominopelvic splanchnic nerves
Para: vagus nerve
What do the exocrine and endocrine parts of the pancreas do?
Exocrine: secretes pancreatic digestive enzymes into the main pancreatic duct
Endocrine: secretes insulin and glucagon into the bloodstream
which arteries supply the pancreas?
mainly splenic artery (pancreatic branches)
gastroduodenal (superior pancreaticoduodenal)
superior mesenteric (inferior pancreaticoduodenal)
where would pain from the pancreas present?
epigastric and/or umbilical region
can radiate to the back
Sympathetic innervation promotes ___ of the pyloric sphincter
Parasympathetic innervation promotes ___ of the pyloric sphincter.
contraction
relaxation
The duodenum is supplied by which arteries?
gastroduodenal (superior pancreaticoduodenal)
superior mesenteric artery (inferior pancreaticoduodenal)
The duodenal-jejunal flexure is usually found around which level?
L2 a few cm’s left of midline
what are the folds in the muscosa of the jejunum known as?
plicae circularis
Which arteries supply the jejunum and ileum and what is the venous drainage?
superior mesenteric artery via jejunal and ileal arteries
Drainage from: jejunal and ileal veins to superior mesenteric vein to hepatic portal vein
NOTE: Vessels travel within the mesentery
Bile helps to absorb fats.
Once absorbed fats go into 1 which are specialised 2 vessels of the small intestine.
They then travel via the __3__ to eventually drain into the 4 at the 5
- lacteals
- lymphatic vessels
- lymphatic system
- venous system
- left venous angle
What are the main groups of lymph vessels and where do they drain from?
Celiac (foregut) Superior mesenteric (midgut) Inferior mesenteric (hindgut) Lumbar (kidneys, posterior abdo wall, pelvis and lower limbs)
Lymph drains first into the ___ or ___. Then it will eventually drain into ___.
thoracic duct (3/4)
right lymphatic duct
venous angles
what are the venous angles made by?
junction between subclavian and internal jugular veins
the thoracic duct and right venous angle drain into which ducts?
thoracic duct into left venous angle
right lymphatic duct into right venous angle
which parts of the colon are mobile?
Caecum, transverse, sigmoid
where are the paracolic gutters found?
between the lateral edge of the ascending/descending colon and the abdominal wall (R and L)
what are the teniae coli?
3 distinct longitudinal bands of thickened smooth muscle running from the caecum to the distal end of the sigmoid colon
which lies more superiorly: the splenic or hepatic flexure?
splenic
what are haustra formed by?
tonic contraction of the teniae coli
where does the appendix lie?
in the right iliac fossa, most commonly retrocaecal
Where is McBurney’s point and what is it used for?
1/3 of the way between the right anterior superior iliac spine (ASIS) to umbilicus
will be tender in appendicitis (generally)
Sigmoid mesocolon refers to what? what are the +ve’s and -ve’s of this?
long mesentery
means has movement, but is at risk of twisting causing a sigmoid volvulus resulting in bowel obstruction and potentially infarction
the abdominal aorta bifurcates into what?
common iliacs
what do the lateral branches of the abdominal aorta supply?
kidneys/adrenal glands
gonads
body wall (posterolaterally)
The midline branches of the abdominal aorta are?
celiac trunk
superior mesenteric
inferior mesenteric
what is the blood supply of the hindgut and remainder of GIT?
Hindgut by inferior mesenteric artery
Distal half of anal canal onwards is supplied by the internal iliac artery
where are the 3 clinically important venous anastomosis between the portal and systemic systems?
distal end of oesophagus (varices)
skin around umbilicus (caput medusa)
rectum/anal canal (piles)
The oesophagus drains into which veins?
superior part into azygous vein
inferior into hepatic portal vein
The superior rectal vein drains into 1.
The middle rectal veins drains into 2.
The inferior rectal vein drains into 3.
- inferior mesenteric
- internal iliac
- internal iliac
Which fibres are used to sense the ‘fullness’ of the rectum prior to defecation?
visceral afferent nerve fibres
what can faecal continence be affected by? (3)
neurological pathologies (stroke etc)
medications
age-releated degeneration of nerve innervation of muscle
The pelvic cavity lies within the _1_ It is continious with \_\_2\_\_ It lies between the _3_ and \_\_4\_\_ It contains _5_ The rectum is located here.
- the bony pelvis
- the abdominal cavity above
- pelvic inlet
- pelvic floor
- pelvic organs and supporting tissues
Which muscle forms most of the pelvic floor?
levator ani muscle
At what level does the sigmoid colon become the rectum?
S3
When does the rectum become the anal canal?
anterior to the tip of the coccyx just prior to passing through the levator ani muscle
The rectum is in the ___
The anal canal and anus are in the ___.
pelvis
perineum
where is the rectal amuplla located?
immediately superior to the levator ani muscle
Which muscles make up the levator ani muscle group?
iliococcygeus
pubococcygeus
puborectalis
what do the levator ani muscles form?
most of the pelvic diaphragm which forms most of the floor of the pelvis and most of the roof of the perineum
Levator ani muscles are ___ muscles.
skeletal
which nerves supplies the levator ani muscles?
nerve to levator ani (a branch of the sacral plexus)
AND
pudendal nerve (S2,3,4)
What is the function of the levator ani muscles?
to provide continual support for the pelvic organs (tonically contracted the whole time, relax to allow urination and defaecation, further contract during increase in intra-abdominal pressure - sneezing)
what is the puborectalis particularly important for and how does it work?
maintaining faecal continence, by contracting it decreases the anorectal angle acting like a sphincter (it’s one of the levator ani muscles so is under voluntary control)
The internal anal sphincter is 1 muscle. Its contraction is stimulated by __2__, and inhibited by __3__.
The external anal sphincter is 4 muscle. Its contraction is stimulated by 5.
- smooth
- sympathetic nerves
- parasympathetic nerves
- skeletal
- the pudendal nerve
The internal anal sphinter is contracted __1__ and relexes reflexively in response to __2__.
The external anal sphincter is contracted 3 in response to 4 and 5.
- all the time
- distension of the rectal ampulla
- voluntarily
- rectal ampulla distension
- internal sphincter relaxation
which nerves will supply structures in the pelvis and which will supply structures in the perineum?
pelvis = symp, para and visceral afferent perineum = somatic motor and somatic sensory
structures in the perineum are considered what?
body wall structures
sympathetic fibres supplying the rectum and anal canal come from 1 and travel to __2__ where they 3 then travel via __4__ around branches of the 5 to cause __6__ and __7__
- T12-L2
- inferior mesenteric ganglia
- synapse
- periarterial plexuses
- IMA
- contraction of the internal anal sphincter
- inhibit peristalsis
Visceral afferents from the rectum and anal canal join the spinal cord at which level and what do they hitch a ride with?
S2-S4
parasympathetics
Parasympathetics supplying the rectum and anal canal arise from 1 via 2, they synapse 3 to cause __4__ and __5__
- S2-S4
- pelvic splanchnic nerves
- in walls of rectum
- inhibition of the internal anal sphincter (relaxing it)
- stimulation of peristalsis
Somatic motor nerves supplying the rectum and anal canal arise from 1 and __2__. It causes 3
- pudendal nerve (S2-S4)
- nerve to levator ani (S3,4)
- contraction of external anal sphincter and puborectalis
The two important spinal cord levels for nerve supply to the rectum and anal canal are?
T12-L2 (symp)
S2-S4 (visceral aff, para, part of somatic motor)
The pudendal nerve is formed by and supplies?
a branch of the sacral plexus and S2-4 anterior rami
supplies the external anal sphincter
the pudendal nerve exits the pelvis via and enters the perineum via?
exits: greater sciatic foramen
enters: lesser sciatic foramen
The pectinate line marks what?
the junction between the embriological development which formed the GIT (endoderm) and the part that formed the skin (ectoderm)
Lymph drains from above the pectinate line to? And below the line to?
Above = to inferior mesenteric nodes Below = superficial inguinal nodes
Lymph drainage:
The internal iliac drains?
The external iliac drains?
The common iliac drains ? which then drains to ?
internal iliac: inferior pelvic structures
external iliac: lower limb and more superior pelvic structures
common iliac: lymph from external and internal iliac nodes to lumbar nodes
rectal varices form due to ___
haemorrhoids from due to ___
portal hypertension
prolaspe of rectal venous plexuses (NOT related to portal hypertension, but to raised pressure - eg: chronic constipation, pregnancy)
where do the ischioanal fossae lie and what are they filled with?
lie on each side of the anal canal and communicate posteriorly
filled with fat and loose CT
Protoscopy views?
interior of the rectum
what are the two factors usually needed for a hernia to develop, give examples?
- structural weakness (eg: normal anatomical weakness in diaphragm, umbilicus, inguinal and femoral canal - abnormal eg: surgical scars)
- increased pressure on that part of the wall (eg: repeated increased intra-abdo pressure: chronic cough, pregnancy)
List the common sites of herniation (6)
Epigastric Umbilical Incisional (from surgical scar) Spigelian Inguinal Femoral
where is the inguinal region?
between the anterior superior iliac spine to the pubic tubercle
what is the linea alba?
the midline of the anterior abdominal wall running from the xiphoid process to the pubic synthesis, formed by the fusion of aponeuroses of the muscles of the anterior abdominal wall
what is the linea semilunaris?
a line found on either side of the rectus abdominis muscles
what is the inguinal ligament and what does it mark?
it is an inferior thickening of external oblique muscle
it marks an anterior boundary between the abdomen and thigh
where does the inguinal ligament run between?
ASIS and pubic tubercle
what is the inguinal canal and where does it lie?
an oblique passage between the abdomen and perineum which lies inferomedially running along the superior border of the inguinal ligament
What does the inguinal canal contain?
spermatic cord (males)
round ligamnet of uterus (female)
blood and lymphatic vessels
ilioinguinal nerve
what are the names for the enterence and exit to the inguinal canal?
enterance = deep inguinal ring exit = superficial inguinal ring
How is the inguinal canal formed in males?
the testes are attached to the testicular ligament, as they descend the layers of the body wall move with it, inc peritoneum through the inguinal canal. An open cavity is formed which normally will close off (if not are prone to herniation)
which part of the abdominal body wall does not form part of the covering of the spermatic cord after the testes descent?
transversus abdominis muscle
What are the boundaries of the inguinal canal (remember it lies inferiolaterally)?
Anterior wall: external oblique aponeurosis (total), internal oblique muscle (laterally)
Posterior wall: transversalis fascia (laterally) and conjoint tendon (medially)
Roof: transversalis fascia (laterally) arches of internal oblique and transversus abdominis aponeurosis (centrally) and external oblique aponeurosis (medially)
Floor: gutter of infolded inguinal ligament
What is the significance of Hesselbach’s triangle?
it is a site of direct inguinal herniation
what is Hesselbach’s triangle made up of?
inferior epigastric artery, inguinal ligament and the lateral border of the rectus abdominis
What is the difference in passage between direct and indirect inguinal herniation
Direct passes directly through the abdominal wall to get access to the inguinal canal
Indirect used a pathway already created by the body to get access to the inguinal canal (eg: same pathway testes took)
Direct inguinal hernias pass 1 to the inferior epigastric vessels, pushing through 2 to the 3 inguinal ring, 4 to the spermatic cord.
- medial
- Hesselbach’s triangle
- superficial
- parallel
Indirect inguinal hernias herniate 1 to the inferior epigastric vessels to enter the 2 inguinal ring, 3 the spermatic cord or layers of abdominal wall.
- lateral
- deep
- within
what is the basic difference in pathways of herniation in femoral and inguinal hernias?
inguinal will travel via the inguinal canal
femoral will travel through the subinguinal space/femoral canal (below the canal)
where is the subinguinal space?
posterior and inferior to the inguinal ligamnet
what does the suinguinal space contain?
hip flexors
femoral artery and vein
lymphatics
nerves
where is the femoral canal located?
medial to the vessels in the subinguinal space
