Abdominal Wall And Inguinal Canal

Question 1

How do you divide the abdomen into 4 regions? What are the regions called?

Answer 1

Vertical = medial plane line (through midline)
Horizontal = trans-umbilical plane (through belly button)

Left/right upper/lower quadrants

Question 2

How do you divide the abdomen into 9 regions?

Answer 2

Two vertical lines = mid-clavicular lines
Two horizontal lines:
— upper = transpyloric plane (L1; halfway between suprasternal notch and pubicsymphysis) OR subcostal plane (L3; inferior edge of costal cartilage)
— lower = trans-tubercular plane (L5; between the tubercles of the iliac crest)

Question 3

What are the names of the 9 regions?

Answer 3

Upper central = Epigastric
— (L and R) Hypochondrium

Middle central = Umbilical
— (L and R) = Lumbar

Lower central = Pubic or hypogastric
— (L and R) Iliac or inguinal

Question 4

Surface projections of liver?

4 and 9 region model

Answer 4

4: Right lobe in RUQ, left lobe reaches into LUQ
9: right hypochondrium and epigastrium

Question 5

Surface projections of gallbladder?

4 and 9 region model

Answer 5

4: RUQ
9: On the transpyloric plane

Question 6

Surface projections of stomach?

4 and 9 region model

Answer 6

4: LUQ (pylorus might cross into RUQ)
9: left hypochondrium, epigastrium, perhaps some droopage into umbilical

Question 7

Surface projections of caecum?

4 and 9 region model

Answer 7

4: RLQ
9: right lumbar

Question 8

Surface projections of descending colon?

4 and 9 region model

Answer 8

4: LLQ
9: left lumbar

Question 9

Surface projections of sigmoid colon?

4 and 9 region model

Answer 9

4: LLQ
9: Left inguinal, pubic/hypogastric region

Question 10

Attachments of external oblique muscle

Direction of fibres?

Answer 10

Origin: Lateral surfaces of lower eight ribs
Insertion:
— linea alba
— inguinal ligament = free lower border of external oblique, from anterior iliac spine to pubic tubercle

Downwards and forwards

Question 11

Attachment of internal oblique muscle

Direction of fibres?

Answer 11

Origin: lumbar fascia, iliac crest and lateral 2/3 of inguinal ligament
Insertion: lower 3/4 ribs, linea alba, [inferior fibres] attach to pubis as conjoint tendon, fusing with transversus abdominis

Perpendicular to external oblique - forwards and upwards

Question 12

Attachments of transversus abdominis muscle

Direction of fibres?

Answer 12

Origin: inner surfaces of lower six costal cartilages, lumbar fascia, iliac crest, lateral part of inguinal ligament
Insertion: conjoint tendon, anterior aponeurosis

Horizontal fibres

Question 13

Which anterior abdominal muscle(s) increase intrabdominal pressure

Answer 13

External and internal oblique
Transversus abdominis
Rectus abdominis

Question 14

Which abdominal muscle(s) cause(s) lateral flexion and rotation?

Answer 14

Internal and external oblique

Question 15

Which anterior abdominal muscle(s) support the vertebral column and supports the abdominal viscera?

Answer 15

Transversus abdominis

Question 16

Which anterior abdominal muscle(s) cause(s) flexion of the trunk

Answer 16

Rectus abdominis

Question 17

Layers of anterolateral abdominal wall (superficial to deep)?

Where is rectus abdominis located?

Answer 17

Skin —> Superficial fascia —> external oblique —> internal oblique —> transversus abdominis —> transversalis (deep) fascia —> parietal peritoneum

Medial to this, the three muscles and transversalis fascia insert on a large aponeurosis that invests rectus abdominis called the rectus sheath

Question 18

Attachments of rectus abdominis?
What intersects them in midline?
Why is it called the six-pack muscle?

Answer 18

Two sheets of muscle located medially separated by linea albea

Origin: costal margin
Insertion: pubis

Blocks of muscle separated by tendinous intersections which can be seen from the surface

Question 19

How much of rectus abdominis is invested by the rectus sheath? What name is given to the point where is is not covered?
Why no cover here?

Answer 19

Superior 3/4

After arcuate line, posterior part only covered by transversalis fascia, not tendinous sheet from EO, IO and TA

Allows passage of inferior epigastric vessels

Question 20

What dermatome is the umbilicus located in?

Answer 20

T10

Question 21

What nerve(s) innervate(s) the anterolateral abdominal muscles?

Answer 21

T7-T12 provide lateral and anterior branches (cutaneous and motor) to the superior and middle fibres

Ilioinguinal and iliohypogastric (both L1) provide branches (cutaneous and motor) to inferior fibres

Question 22

What dermatome is appendicitis initially referred to?

Answer 22

T10

Question 23

What structure guides the testis from its embryological position through the anterior abdominal wall?

Answer 23

Gubernaculum

Question 24

The testes are intraperitoneal during development true or false?

Answer 24

False - retro, superficial to it

Question 25

Which structures of the anterior abdominal wall do not get brought down with the testis and gubernalculum? What do they form?

Answer 25

Transversalis fascia - instead, forms opening of inguinal canal
Parietal peritoneum - pinches to form double membrane called processus vaginalis which follows adjacent to testis and forms in tunica vaginalis layer around the testis

Question 26

What is likely to develop if the processus vaginalis remains patent after birth?

Answer 26

Development of indirect inguinal hernia

Question 27

What is the structure called where (from inside to outside) the contents of the inguinal canal enters the anterior abdominal wall? And exits?

Answer 27

Deep inguinal ring

Superficial inguinal ring

Question 28

Surface marking of deep and superficial inguinal rings?

Answer 28

Deep = between mid-point of inguinal ligament and mid-inguinal point
Superficial = just superior to pubic tubercle

Question 29

Roof, anterior wall, posterior wall and floor of inguinal canal?

Answer 29

Roof = internal oblique and transversus abdominis fibres
AW = external oblique aponeurosis
PW = transversalis fascia and conjoint tendon medially
Floor = infolding of inguinal ligament

Question 30

Surface markings of inguinal ligament?

Answer 30

ASIS and pubic tubercle

Question 31

Content of female inguinal canal?

Answer 31

Round ligament of the uterus
Ilioinguinal nerve
Genital branch of genitofemoral nerve

Question 32

Contents of male inguinal canal?

Answer 32

Spermatic cord (also containing genital branch of genitofemoral nerve)
Ilioinguinal cnal

Question 33

Location of inferior epigastric blood vessels in relation to deep inguinal ring?

Answer 33

DIR is lateral to inferior epigastric vessels

Question 34

Which type of inguinal hernia passes through the inguinal canal? What does the other one do?

Answer 34

Indirect = through inguinal canal (deep to canal to superficial)
Direct = through Hesselbach’s triangle, directly in through weakened conjoint tendon in anterior abdominal wall out through superficial ring

Question 35

Where is the femoral canal?

Answer 35

Potential space within femoral sheath

Question 36

The femoral nerve, vein and artery are all located in the femoral canal true or false?

Answer 36

False - only femoral vein and artery

Nerve travels laterally?

Question 37

Where is femoral sheath located in relation to the inguinal ligament?

Answer 37

It passes beneath

Question 38

Femoral hernia how?

Answer 38

Abdominal contents through femoral canal

Question 39

What equivalent structure in females is guided through the anterior abdominal wall by the gubernaculum? Where does it end

Answer 39

Round ligament of the uterus, ending at labia majora