Abdomen

Question 1

major classes of fascia of the abdominal wall

Answer 1

Superficial fascia- in lower region of abdominal wall forms two layers: superficial fatty layer and deeper membranous layer
Transversalis fascia- continuous layer of deep fascia that lines abdominal cavity and continues into pelvic cavity
Extraperitoneal fascia- deep to the transversalis fascia separates it from peritoneum

Question 2

What is the deepest layer of fascia of the anterior abdominal wall

Answer 2

Transversalis fascia

Question 3

The abdominal cavity

Answer 3

Largest anatomical cavity
Lies under cover of lower ribs and diaphragm
Some of the abdominal cavity projects backwards into the pelvis in front of buttocks
Continuous with the pelvic cavity = abdominal-pelvic cavity
Cavity for: digestive tract and late pregnancy

Question 4

Prominent visual features of anterior abdominal wall

Answer 4

Epigastric region
Umbilicus
Periumbilical region
Hypogastric region
Anterolateral wall tissues and muscles
Anterior superior iliac spine
Iliac crest
Pubic tubercle
Linea alba

Question 5

Theoretical landmarks of importance

Answer 5

Semilunar line
Transplyoric plane- separates umbilical region from epigastric
Trans-tubercular plane- separates umbilicus from hypogastric
Spino-umbilical line (RHS)
McBurney’s point
Mid-clavicular line
Mid-inguinal point
Arcuate line

Question 6

Mid inguinal point

Answer 6

Important surgical landmark forms midpoint of imaginary line that joins anterior superior iliac spine and pubic symphysis
Marks positions where external iliac artery leaves the abdomen to become femoral artery
Point at which femoral pulse is palpated
Deep inguinal ring is medial to it

Question 7

McBurney’s point

Answer 7

Point over right side of abdomen that’s 1/3 distance from anterior superior iliac spine to the umbilicus
Roughly corresponds to most common location of the base of the appendix where it’s attached to caecum

Question 8

Gross anatomical features of the abdominal cavity

Answer 8

Boundaries:
Diaphragm- superior
Pelvic brim - inferior/imaginary
Anterolateral abdomino-pelvic wall- derivative of body wall
Posterior abdominal wall

Question 9

Tissue layers of anterior abdominal wall

Answer 9

Skin
Superficial fatty layer or subcutaneous tissue (camper fascia)
Deep membranous layer subcutaneous tissue (scarpa fascia)
Superficial layer deep fascia
External oblique
Intermediate layer deep fascia
Internal oblique
Deep layer of deep fascia
Transversus abdominis
Endoabdominal (transversalis) fascia
Extraperitoneal fat
Parietal peritoneum

Question 10

General design of body wall

Answer 10

Skin
Superficial fascia- with or without subcutaneous fat
Deep fascia
Muscles of body wall
Endothoracic or endoabdominal or transversalis fascia

Question 11

Linea alba

Answer 11

Fibrous structure that runs down midline of abdomen

Question 12

Rectus sheath

Answer 12

Also called rectus fascia
Multilayered aponeurosis, fibrous sheath of dense regular connective tissue
Formed by aponeurosis/tendons of the transverse abdominal and internal and external oblique muscles
Rectus sheath envelopes rectus abdominis muscle-abs

Question 13

2 sets of muscles of the anterolateral wall of abdomen

Answer 13

Lateral group= anterolateral muscles, abdominal continuation of muscles of thoracic wall
Midline group= rectus abdominis, pyramidalis, thoracic equivalent must be sternum

Question 14

Arcuate line

Answer 14

Known as the semicircular line of Douglas
Curved line found posterior to the rectus abdominis muscle bilaterally
Occurs about 1/2 distance from umbilicus to pubic crest
Important clinical site in which the anterior wall could herniate
Anatomical landmark that determines the nature of tissue layers of the rectus sheath
Tissue layers of rectus sheath above Arcuate line are different form those below
If one dissects anterolateral abdominal wall the Arcuate line may be difficult to see as all aponeurosis are translucent

Question 15

Tissue layers of the rectus sheath superior to Arcuate line

Answer 15

Aponeurosis of external oblique passes anterior to the rectus abdominis muscle
Aponeurosis of internal oblique splits to surrounded rectus abdominis
Posterior to rectus abdominis is the aponeurosis of the transversus abdominis as well as transversalis fascia

Question 16

Tissue layers of the rectus sheath inferior to Arcuate line

Answer 16

Aponeurosis of the internal oblique and the transversus abdominis pass anteriorly to the rectus abdominis muscle instead of surrounding
Transversalis fascia is only structure located posteriorly

Question 17

Surface map of anterior abdominal wall 2 methods

Answer 17

Abdominopelvic quadrants
9 compartments of abdominopelvic region
Based on physically palpable anatomical structures
Standardises mapping surface of the body between patients
Useful in surface palpation of major abdominal organs

Question 18

Abdominopelvic quadrants

Answer 18

Points of reference are:
Linea alba- vertical line
Xiphoid process
Pubic symphysis
The umbilicus - horizontal line
Divides region into RUQ, LUQ, RLQ, LLQ
RUQ= liver and gall bladder
LUQ=stomach, pancreas, spleen
LLQ=descending colon and part of ilium
RLQ=ascending colon, appendix

Question 19

9 abdominal compartments by surface mapping

Answer 19

2 vertical planes:
-one on each side of midline, a line joining the mid clavicular point to the mid inguinal point, passes just lateral to tip of 9th costal cartilage
2 horizontal planes:
-subcostal plane- a line drawn joining the lowermost bony point of the rib cage- usually 10th costal cartilage, body of L3 vertebra; origin of the inferior mesenteric artery and 3rd part of duodenum lie on this plane
-trans-tubercular plane- a line uniting the 2 tubercles of the iliac crest, upper border of L5 vertebra and the confluence of the common iliac veins (IVC origin) lie on this plane

Right and left hypochondriac regions and epigastric region
Subcostal plane
Right and left lumbar regions and umbilical region
Transtubercular plane
Right and left iliac region and hypogastric region

Question 20

What is peritoneum

Answer 20

Simple squamous epithelium
Also known as pavement epithelium
One cell thick tissue membrane
Lines the:
-interior surfaces of all of abdominal wall: except area of coronary ligament (small area between liver and diaphragm known as bare area of liver)
-surfaces of all viscera of abdomen except bare area of liver
2 types of peritoneum: parietal and visceral, they’re continuations of the same layer of membrane

Question 21

Innervation of peritoneum

Answer 21

Parietal peritoneum: lines inner walls of abdomen, diaphragm and pelvis, innervated by sensory division of the somatic nervous system- pain sensations are sharp and localised
Visceral peritoneum: lines visceral organs of the abdomen, innervated by the sensory division of the autonomic nervous system, pain sensations are not localised but perceived as non defined discomfort e.g. indigestion

Question 22

The bare area of the liver

Answer 22

Part of liver that’s not covered by visceral peritoneum
Occurs when parietal peritoneum on inferior surface of diaphragm dives inferiorly to cover surface of liver
Coronary ligament
Important clinically because it has no sensory or nervous innervation so if there’s a pathological development patient wont be aware

Question 23

Compartments of abdominal cavity

Answer 23

Peritoneal compartment
Intraperitoneal compartment
Extraperitoneal compartment
-retroperitoneal compartment/space

Question 24

Structures of abdomen lie in these locations

Answer 24

Intraperitoneal
Secondary retroperitoneal
Primary retroperitoneal
These locations differ in accessibility and mobility
There’s no organs found within the peritoneal compartment

Question 25

Peritoneal cavity (abdominal cavity)

Answer 25

The cavity created between the parietal and visceral peritoneum Derived from coelomic cavity of embryo: others being the pleural cavities and the pericardial cavity The largest fluid filled cavity in body Secretes ~50ml fluid per day Fluid acts as a lubricant and has anti-inflammatory properties

Question 26

Intraperitoneal cavity

Answer 26

Visceral organs that are completely covered in visceral layer of peritoneum effectively create a compartment in which they’re contained in This is the intraperitoneal cavity Known as intraperitoneal organs

Question 27

What is a mesentery

Answer 27

Double layer of visceral peritoneum Continuous folded band that’s attached to wall of abdomen and encloses the viscera Attaches intestines to the posterior abdominal wall

Question 28

Sub classification of extra-peritoneal organs

Answer 28

Lying in front peritoneal sac: -pre-peritoneal structures -exists only conceptually- normally no structure found in this area -this space can be invaded pathologically at level of pelvis Lying behind peritoneal sac: -post or retro-peritoneal structures

Question 29

Laparoscopic access to the peritoneal cavity

Answer 29

Formally divisible into: The greater sac The lesser sac The omental foramen (epiploic foramen of Winslow) is the window that allows for communication between the greater and lesser sac

Question 30

Double folds of peritoneum can be referred to as

Answer 30

Ligament Omentum Mesentery

Question 31

Omenta

Answer 31

Consist of 2 layers of visceral peritoneum which pass from stomach and first part of duodenum to other viscera Greater omentum- derived from dorsal mesentery Lesser omentum- derived from ventral mesentery

Question 32

Greater omentum

Answer 32

Large double visceral peritoneal fold that attaches to the greater curvature of the stomach and first part of duodenum Drapes inferiorly over transverse colon and the coils of jejunum and ileum Turning posteriorly it ascends to become adherent to the peritoneum on the superior surface of transverse colon and anterior layer of transverse mesocolon before arriving at posterior abdominal wall Contains accumulation of fat, peritoneal fluid and white blood cells. and there’s 2 arteries and accompanying veins= the right and left gastro-omental vessels

Question 33

Lesser omentum

Answer 33

Extends from the lesser curvature of stomach and first part of duodenum to inferior surface of liver Divided into: -A medial hepatogastric ligament which passes between the stomach and liver -a lateral hepatoduodenal ligament which passes between duodenum and liver. Ends laterally as a free margin and serves as the anterior border of the omental foramen Enclosed in this free edge are the hepatic artery proper, bile duct and portal vein The left and right gastric vessels are between layers of lesser omentum near lesser curvature of stomach

Question 34

Mesenteries

Answer 34

Visceral Peritoneal folds that attach viscera to posterior abdominal wall They allow some movement and provide a conduit for vessels, nerves and lymphatics to reach viscera Include: The mesentery: associated with parts of small intestine The transverse mesocolon: associated with transverse colon The sigmoid mesocolon: associated with sigmoid colon

Question 35

Ligaments

Answer 35

Consists of two layers of peritoneum that connect 2 organs to each other or attach an organ to body wall, and may form part of an omentum E.g. splenorenal ligament, gastrophrenic ligament

Question 36

Divisions of the peritoneal cavity

Answer 36

Right subphrenic space left suphrenic space Subhepatic space Right and left paracolic gutter Right and left inframesocolic space Pelvis