Hernias

Question 1

Describe visceral pain

Answer 1

Pain that results from:
 Visceral stretching
 Visceral inflammation
 Visceral ischaemia

Pain is:
 Diffuse/poorly defined - Cat tell exactly location
 Often midline
Nausea, vomiting, sweating often accompany visceral pain
Very common presentation- can be difficult to diagnose

Question 2

Describe the sympathetic outflow to the gut

Answer 2

T5-L2 (preganglionic)
Pass through (paravertebral) sympathetic trunk without synapsing (preganglionic)
Form (abdominopelvic) presynaptic splanchnic nerves (preganglionic)
◦ Greater (T5-9)
◦ Lesser (T10-11)
◦ Least (T12)
These splanchnic nerves synapse with prevertebral ganglia
 Coeliac, renal, superior mesenteric, inferior mesenteric and others
Extend from prevertebral ganglia to viscera (postganglionic)
Mainly innervate blood vessels

Stynamps in sympathetic chain - then go to structures not in that segment. Gut doesn need sympathetic chain . For gut, the fibres so straight through sympathetic chain without synapsing, they coelesce to form 3 splanchnic nears that cover foregut, midgut and hndgut otrgans - the greater lesser ad least splanchnic nerve

Question 3

How are visceral afterrents related to the sympathetic outflow

Answer 3

Visceral pan fibres (afferents) often follow similar path but opposite direction to sympathetic outflow

Question 4

What organs are innervated by the greater splanchnic nerve

Answer 4

Foregut - organs supplied by celiac trunk

Question 5

What’s innervated by the lesser splanchnic nerve

Answer 5

Midgut (supplied by SMA)

Question 6

What does the least splanchnic nerve innervate

Answer 6

Kidneys ad upper ureter

Question 7

Give an example of how visceral pain follows path o sympathetic outflow

Answer 7

Caecal volvulus
 Distended small bowel
 General visceral afferents activated
 Afferent impulse goes back to superior mesenteric ganglia (prevertebral)
 Continues back along least splanchnic nerve
 Passes back through sympathetic chain (paravertebral)
 Into dorsal horn of spine
 Converge with somatic afferents at that spinal level (T9 & 10)
 Brain interprets visceral afferent to be coming from T9 & 10 dermatomes
 Peri-umbilical pain

Question 8

What is a hernia

Answer 8

A hernia is a protrusion o part of the abdominal contents beyond the normal confines of the abdominal wall. Hernias occur outside the abdomen so could say. Beyond the confines of its normal containing cavity

Question 9

What are the signs and symptoms of hernia

Answer 9

Hernias that are not stuck ◦ Fullness or swelling ◦ Gets larger when intra-abdominal pressure increases ◦ Aches
Hernias that are stuck (incarcerated) ◦ Pain ◦ Cannot be moved ◦ Nausea and vomiting (and other signs of bowel obstruction) ◦ Systemic problems if bowel has become ischaemic

Question 10

What are teh causes of a hernia

Answer 10

Weakness in the containing cavity
o Congenitally related (we will talk about descent of the testis)
o Post surgery where wounds have not healed adequately (incisional hernia)
o Normal points of weakness
Anything that increases intra-abdominal pressure
o Obesity
o Weightlifting
o Chronic constipation/coughing

Question 11

What are the constituents of a hernia

Answer 11

The sac oIs a pouch of peritoneum
o You need to understand Parietal/visceral peritoneum
Contents of the sac oAny structure found within the abdominal cavity
o Commonly
o Loops of bowel
o Omentum
Coverings of the sac oConsist of the layers of the abdominal wall through with the hernia has passed
o You need to know your abdominal layers

Question 12

What is the basis of abdominal hernias

Answer 12

Weaknesses in abdominal wall
◦ Inguinal canal
◦ Femoral canal
◦ Umbilicus
◦ Previous incisions eg due to surgery

Question 13

What is teh ingunal canal

Answer 13

Oblique passage through lower part of the abdominal wall
In males
◦ Structures pass through from abdomen-testis In Females
◦ Round ligament goes from Uterus-labium majus
Potential weak point

Question 14

What are th gubernaculum andtunica aginalis

Answer 14

Connective tissue that condenses - guides the descending estis - get sshorter. As this happens, the process vaginalis expands downwards and acts like a guide, to become he tunica vaginalis. Processus vaginalis should disappear leaving the tunica

Question 15

What happens if processus vaginalis doesnt close

Answer 15

Connection from peritoneal cavity into scrotum - can have complete connectio/path. From abdominal cavity going into scrotum

Question 16

Describe the structure of the inguinal canal

Answer 16

Oblique passage through lower part of the abdominal wall
◦ Therefore the boundaries are also layers of the abdominal wall
See slide

Question 17

What forms the floor of the inguinal canal

Answer 17

Anterior wall fo ingunal canal is aponeuros of sterna oblique Aponeurosis of external oblique rolls and thicker at inferior part to form inguinal ligament

Question 18

What forms the roof of the inguinal canal

Answer 18

Internal oblique - arching musclar fibres form part of the roo of he inguinal canal
Transverse abdominis also contributes to the roof

Question 19

What is the conjoint tendon

Answer 19

Internal oblique and transverse abdomina come together at bone to form Conjoint tendon
Reinforces inguinal canal medically

Question 20

What is the posterior wall of the inguinal cana?

Answer 20

Transversalis fascia ad conjoint tendon medically

Question 21

What are different types of abdomincalhernia s

Answer 21

Comprise approx 75% of all abdominal hernias
 50% Indirect
 M>F (7:1)
 Mainly right sided
 25% Direct

Remaining hernias
 10% Umbilical
 10% Incisional

Question 22

How is the position of a hernia named

Answer 22

Location of a hernia - where it leaves its containing cavity. Important so can talk abt hernia in terms of its neignbouring structures

Question 23

What’s teh difference between direct and indirect hernias

Answer 23

Passes through the deep Inguinal ring
 The inguinal canal
 The superficial Inguinal ring
Then depending on where the Processus Vaginalis was obliterated can potentially descend into the scrotum

Bulges through Hesselbach

Question 24

What are the borders of hesselbachs triangle

Answer 24

-

Question 25

What is a femoral hernia

Answer 25

More common in Females
◦ Pelvic anatomy different
◦ Can easily get stuck (incarcerated)
◦ Strangulate
Through fermibnalring buge out though saphenous ccopening

Question 26

What is an omphalocele

Answer 26

Failure of the midgut to return to the abdomen during development
◦ Viscera persist outside the abdominal cavity within umbilical ring
◦ Abdominal cavity may not grow to correct size to accommodate viscera ◦ Viscera are covered in peritoneum
◦ Gut has a chance to develop relatively normally
◦ Feeding can commence
 Often associated with other genetic problems
 Mortality rate is high
Bowel herniated, can fix, but developmental defects, high mortality

Question 27

What is gastroschisis

Answer 27

Defect in ventral abdominal wall
 Abdominal viscera not covered in peritoneum -exposed to amniotic fluid
 Tend to get problems with gut development (intestinal atresia, short/inflamed gut)
 Problems arise around feeding
 Survival better than Omphalocele because of less genetic complications
 Defect can often be closed at birth
Not other defects

Question 28

What is an umbilical hernia

Answer 28

Commonly found in infants Hernia (bulge) at the site of the umbilicus Not usually painful 80-90% close by age 3
Usuallynot a problem, can be operated. On

Question 29

What is a paraumbilical hernia

Answer 29

Acquired adult
◦ Should be called Para-umbilical
◦ Goes through linea alba in region of umbilicus
◦ F>M
◦ Obesity
◦ Risk of strangulation as defect is often small

Question 30

What are symptoms of hernia

Answer 30

Varied Based around what happens if loops of bowel get trapped
◦ Pain
◦ Vomiting
◦ Sepsis

Question 31

Define incarcerated and stranglated

Answer 31

Incarcerated - stuck, irreducible

Strangulated - blood supply is disrupted, can lead to tissue necrosis

Question 32

What is the afferent pathway of the hindgut

Answer 32

Lumbar splanchnic nerves