3- clinical anatomy of GI tract herniation & abdominal pain

Question 1

what are 2 requirements to cause herniation?

Answer 1

1. structural weakness
2. increased pressure (intra-abdominal pressure)

Question 2

what are normal structural weaknesses that can lead to hernia?

Answer 2

some parts of diaphragm, a weakness around umbilicus, inguinal canal, femoral canal

Question 3

what are some abnormal structural weaknesses that cause hernia?

Answer 3

congenital diaphragmatic hernia (stomach moving up to thorax due to development issues), surgical scars/incisional hernia (when wound is still weak)

Question 4

what are things that cause increased abdominal pressure?

Answer 4

chronic cough, pregnancy, strenuous activity, straining during defecation or urination

Question 5

what is inguinal canal? (reminder)

Answer 5

• inguinal canal formed embryologically (bigger in males as travel further to get to scrotum so more clinically important)
• formed in medial half of inguinal region

Question 6

what does inguinal canal contain?

Answer 6

spermatic cord or round ligament of uterus

Question 7

can hernia be unilateral or bilateral?

Answer 7

yes - can be unilateral or bilateral

Question 8

what are direct and indirect inguinal hernias?

Answer 8

direct inguinal hernia = directly pushes through anterior abdominal wall (directly pops out)

indirect inguinal hernia = takes a little path through abdominal wall to get out →using inguinal canal as area of weakness to push through

Question 9

what is route causing indirect inguinal hernia?

Answer 9

→to tell apart use inferior epigastric artery (coming off external iliac). just medial to that there’s area of weakness (inguinal triangle) so if medial to epigastric artery, looped bowel can push through abdominal wall (not through inguinal canal) = push through abdominal wall and eventually joins inguinal canal and into scrotum (indirect)

*NOTE - hernial sac lying next (parallel) to spermatic cord

Question 10

what is route of causing direct inguinal hernia?

Answer 10

→loop of intestine push through deep inguinal ring and use inguinal canal to push all the way through and then pops out (hernial sac) within spermatic cord

Question 11

how do you find deep inguinal ring?

Answer 11

in between ASIS and pubic tubercle = half way between is where deep inguinal ring, epigastric artery

Question 12

why would you push deep inguinal ring?

Answer 12

• if push hernia back in at deep inguinal ring and ask to cough then direct inguinal hernia would go back in as pushing through canal
• if indirect inguinal hernia, pushing deep inguinal ring blocks it’s route to get back out where it came from

Question 13

is direct or indirect inguinal hernia more common?

Answer 13

indirect more common

Question 14

what is the site of direct inguinal herniation?

Answer 14

Inguinal triangle = hesselbach’s triangle

Question 15

what arteries line the hesselbach’s/inguinal triangle?

Answer 15

• inferior epigastric artery
• lateral border of rectus abdominis
• inguinal ligament

Question 16

are femoral herniation more common in males or females?

Answer 16

females

Question 17

what is importance of subinguinal space?

Answer 17

important area for things to pass from abdomen to thigh e.g. Hip flexors, Femoral artery and vein, Lymphatics, Nerves

Question 18

where is lump (hernia) of inguinal hernia seen?

Answer 18

usually medial and superior to tubercle

Question 19

where is lump (hernia) of femoral hernia?

Answer 19

lateral and slightly inferior to pubic tubercle

Question 20

what is myopectineal orifice?

Answer 20

area of innate weakness (just all of area, femoral canal, inguinal canal, inguinal triangle etc)

Question 21

what are the 4 main questions to ask about abdominal pain?

Answer 21

1. location = what anatomy lies or refers pain there? is it localised?
2. character = dull, achy, sharp, stabbing?
3. timing = does it come and go?
4. pain referral pattern

Question 22

what nerves supply abdominal organs?

Answer 22

• visceral afferents
• autonomic motor →parasympathetic, sympathetic
• enteric nervous system (only found in GI tract, can work on it’s own to control GI tract but also under influence of autonomic nervous system)

Question 23

what nerves supply body wall of abdomen?

Answer 23

• from skin to parietal peritoneum
• somatic sensory
• somatic motor
• sympathetic nerve fibres

Question 24

what is route of sympathetic nerves?

Answer 24

brain →spinal cord (only exit between T1 and L2) - in abdomen T5-L2 are ones we’re interested in (T1-T4 are for thorax or up to head). they don’t synapse straight away but go through sympathetic trunk and reach abdominal aorta →they form peri-arterial plexus around arteries then leave sympathetic chain as splanchnic nerves and head to ganglia sitting around aorta →they use the arteries to get to organs they need to go to (in plexus also parasympathetic and visceral afferents)

Question 25

what is the exception nerve that doesn't take part in periarterial plexus on abdominal aorta?

Answer 25

adrenal nerves = comes out at same level and move into sympathetic trunks then branch out as splanchnic nerves but then continue to adrenal glands and ole synapse at cells of adrenal glands

Question 26

at what level of spinal cord does the following nerves leave a) abdominal sympathetic nerves b) thoracic sympathetic nerves c) sympathetic nerves for adrenal glands

Answer 26

a) T5-L2 b) T1-T4 c) T10-L2

Question 27

what is route of parasympathetic nerves?

Answer 27

= vagus nerve (only going to distal part of transverse colon), the rest is supplied by sacral division (s2,3,4) *not pudendal nerve but same level

Question 28

what is nerve outflow for a) sympathetic b) parasympathetic

Answer 28

a) thoracolumbar b) craniosacral

Question 29

what is route of vagus nerve once it is in abdominal cavity?

Answer 29

- presynaptic parasympathetic nerve fibres enter abdominal cavity on surface of the oesophagus (“vagal trunks”) - travel into the periarterial plexuses around the abdominal aorta - carried to the walls of the organs where they synapse in ganglia - supply parasympathetic nerve fibres to the GI tract + abdominal organs up to the distal end of the transverse colon

Question 30

what are pelvic splanchnic nerves and what do they supply?

Answer 30

= parasympathetic nerves from sacral region - Presynaptic parasympathetic nerve fibres - supply smooth muscle/glands of the descending colon to anal canal

Question 31

where is pain of foregut felt and what organs are in foregut?

Answer 31

= pain felt in epigastric region foregut = oesophagus to mid-duodenum, liver, gallbladder, spleen and 1/2 pancreas

Question 32

where is pain of midgut felt and what organs are in foregut?

Answer 32

= pain felt in umbilical region midgut = mid-duodenum, proximal 2/3 transverse colon, 1/2 pancreas

Question 33

where is pain of hindgut felt and what organs are in foregut?

Answer 33

= pain felt in pubic region hindgut = distal 1/3 of transverse colon to proximal 1/2 of anal canal

Question 34

what is route for visceral afferent nerve fibres in abdominal cavity?

Answer 34

pain fibres from the vast majority of the abdominal organs run alongside sympathetic fibres back to the spinal cord

Question 35

what level do visceral afferents nerves supplying foregut structures enter spinal cord?

Answer 35

enter the spinal cord at approx T6-T9

Question 36

what level do visceral afferents nerves supplying midgut structures enter spinal cord?

Answer 36

enter spinal cord at approx T8-T12

Question 37

what level do visceral afferents nerves supplying hindgut structures enter spinal cord?

Answer 37

enter the spinal cord at approx. T10-L2

Question 38

why can liver and gallbladder pain have referred pain at shoulder?

Answer 38

liver & gallbladder →right next to diaphragm which can get irritated if they’re irritated →phrenic nerve supplies diaphragm (c3,4,5) which supplies skin at shoulder

Question 39

what nerves are conveyed within thoracoabdominal nerves?

Answer 39

somatic motor, somatic sensory, sympathetic nerve fibers (which supplies abdominal body wall structures)

Question 40

what is route of thoracoabdominal nerves?

Answer 40

7th - 11th intercostal nerves that continue and travel anteriorly then leave intercostal spaces and travel in plane in between internal oblique & transversus abdominis where they're then called thoracoabdominal nerves

Question 41

what nerve supplies body wall from a) T12 anterior ramus b) half of L1 anterior ramus c) other half of L1 anterior ramus

Answer 41

a) subcostal nerve b) iliohypogastric nerve c) ilioinguinal nerve

Question 42

what is pain like for appendicitis?

Answer 42

- appendix found in right iliac fossa (part of midgut) - midgut pain usually first felt in dull achy pain in umbillical region (T8-T10) - then sore, sharp stabbing in right iliac fossa (from visceral to somatic) →started to irritate lining of abdominal cavity (parietal perineum) so can then feel directly in that area