MGA 18 and 19, abdominal wall and inguinal region, overview

What is found in the RUQ

liver (right lobe and part of left lobe)

gallbladder

pyloric stomach

duodenum

head of pancreas

right kidney

upper part of ascending colon

right part of transverse colon

What is found in the LUQ

fundus and body of stomach

spleen

left lobe of liver

body and tail of pancreas

left kidney

left side of transverse colon

upper part of descending colon

jejunum

What is found in the LLQ

lower part of descending colon

sigmoid colon

left ureter

lower part of jejunum

left ovary and fallopian tube

What is found in the RLQ

cecum

appendix

ileum

right ureter

right ovary and fallopian tube

lower part of ascending colon

lower pole of right kidney

What is found in the RH (right hypochondriac)

right lobe of liver

gallbladder

right kidney

parts of SI

What is found in the epigastric region

majority of stomach

part of liver

part of pancreas

duodenum

adrenal glands

What is found in the LH

spleen

part of stomach

left kidney

pancreas

parts of colon

What is found in the RL (right later/lumbar)

ascending colon

right kidney

part of the SI

What is found in the umbilical region

parts of SI (jejunum and ileum)

transverse colon

bottom portions of both kidneys

What is found in the LL

descending colon

kidney

part of SI

What is found in RI (inguinal)

cecum

appendix

right ovary and fallopian tube

What is found in the pelvic region

urinary bladder

sigmoid colon

small intestine

What is found in the LI

descending colon

sigmoid colon

small intestine

left ovary and fallopian tube

Transtubercular plane

horizontal plane connecting tubercles of right and left iliac crests

Midclavicular plane

vertical plane that passes through midpoint of clavicle and intersects halfway a line connecting ASIS to pubic tubercle

Subcostal plane

passing through the inferior border of the 10th costal cartilage

Transumbilical plane

passing through the umbilicus and intervertebral disc between L3 and L4 vertebrae

Abdominal layers (superficial to deep)

skin --> campers fascia --> scarpa's fascia --> external oblique --> internal oblique --> transversis abdominis --> exztraperitoneal fat --> transversalis fascia --> parietal peritoneum

Camper's fascia

superficial, fatty layer that is continuous with superficial fat over rest of body and may be thick

Scarpa's fascia

deep, membranous layer on each side, it fuses with fascia lata below the inguinal ligament and in the midline, it is continuous with superficial fascia of penis (or clitoris), dartos tunic/fascia, and superficial perineal fascia

On each side of the anterior midline there is a long, vertical muscle

rectus abdominis

A small muscle anterior to the lower part of the rectus abdominis is called

pyramidalis (absent in 20% of people)

Most medial muscle in the abdomen

linea alba

Insertion for the external oblique, internal oblique, transversus abdominis, and pyrimidalis

linea alba

Insertion for the rectus abdominis

costal cartilages of ribs 5-7 and xiphoid process

Innervation of external oblique, internal oblique, transversus abdominis, and rectus abdominis

anterior rami of T6-T12 (and for internal oblique and transversus abdominis, anterior rami of L1 as well)

Innervation of pyramidalis

anterior ramus of T12

Function of external oblique m

compress abdominal contents

both muscles flex trunk

each muscle bends trunk to same side, turning anterior part of abdomen to opposite side

Function of internal oblique m

compress abdominal contents

both muscles flex trunk

each muscle bends trunk and turns anterior part of abdomen to same side

Function of transversus abdominis

compress abdominal contents

Function of rectus abdominis

compress abdominal contents

flex vertebral column

tense abdominal wall

Function of pyramidalis

tenses the linea alba

Cremaster m is only found in

males

Insertion of cremaster

pubic tubercle and crest

Innervation of cremaster

genitofemoral

Function of cremaster m

retracts testes

The cremasteric reflex

sensory fiber that stimulates the motor fibers carried in the genital branch of the genitofemoral n, resulting in contraction of the cremaster m and elevation of the testis when the upper medial side of the thigh is stroked

Cremasteric reflex is more active in

children

The cremasteric reflex may be absent in certain cases of

testicular torsion or L1-L2 spinal cord injury

Rectus sheath

aponeurotic (of the external, internal, and transversus m) tendinous sheath that encloses the rectus abdominis and pyramidalis

Rectus sheath above arcuate line (upper 3/4 of anterior abdominal wall)

sandwiches the rectus abdominis in the sheath

- aponeurosis of internal oblique splits into 2 laminae

Rectus sheath below the arcuate line (lower 1/4 of anterior abdominal wall)

has the rectus abdominis below the sheath like a person under a blanket

- no posterior aponeurotic wall

Contents of the rectus sheath

rectus abdominis

pyrimidalis (if present)

terminal parts of lower 5 intercostal nerves and subcostal n

superior and inferior epigastric vessels

Arcuate line

curved line that marks lower end of posterior aponeurotic wall of rectus sheath, located halfway between umbilicus and pubic symphysis

Peritoneum

thin serous membrane lining the abdominal cavity, that can reflect onto abdominal viscera providing a complete or partial covering

Peritoneum lining the walls

parietal peritoneum

Peritoneum lining the viscera

visceral peritoneum

Superior epigastric a

terminal branch of internal thoracic a

anastomoses with inferior epigastric a

Inferior epigastric a

originates from external iliac a

enters the rectus sheath and ascends posterior to the rectus abdominis, supplies lower central part of anterior abdominal wall

What supplies the lateral part of the anterior abdominal wall

10th and 11th posterior intercostal ateries, subcostal arteries

What supplies the lower lateral part of anterior abdominal wall

deep circumflex iliac a

originates from external iliac a

Superficial epigastric a

branch of femoral a

anastomoses with inferior epigastric a

Cremasteric a

branch of inferior epigastric a

irrigates the cremaster

Thoracoepigastric veins

v btwn the lateral thoracic vein and the superficial epigastric veins

Innervation of anterior abdominal wall

anterior rami of thoracic spine T7-T12, supply the skin and muscles of abdominal wall

T5 and T6 supply upper parts of the

external oblique m

T6 supplies cutaneous innervation to

skin over xiphoid

Skin and muscle in the inguinal and suprapubic regions of the abdominal wall are innervated by ___ and not by thoracic nerves

L1

Umbilicus landmark and dermatome

T10

McBurney's point

point on the abdomen on RLQ where tenderness is maximal during acute appendicitis

Blumberg's sign

rebound tenderness

Processus vaginalis

transformed into a tubular structure with coverings from the layers of the anterior abdominal wall forming a passage

What is the passage formed from the processes vaginalis called

inguinal canal

The testes descend into the

scrotum

The ovaries descend into the

pelvic cavity

The descending of gonads depends on the ____________, a band of tissue that anchors the gonads and guides their descend into their final location

gubernaculum

2 openings to the inguinal canal

deep inguinal ring

superficial inguinal ring

Passage of the inguinal canal is located through

the lower part of anterior abdominal wall

The inguinal canal lies parallel and immediately above the

medial part of the inguinal ligament

Deep inguinal ring is an opening in the

transversalis fascia, lies lateral to inferior epigastric artery

Superficial inguinal ring is an opening in the

aponeurosis of external oblique, located immediately superior to pubic tubercle

Contents of the inguinal canal

- genital branch of genitofemoral n

- spermatic cord in men, formed by structures running between testis and abdominopelvic cavity and ilioinguinal n

- round ligament of the uterus in women

- ilioinguinal n, exits through the superficial inguinal ring with the other contents

contents of inguinal canal in men

ductus deferens, artery to ductus deferens, testicular artery, pampiniform plexus, cremasteric artery and vein, genital branch of genitofemoral, sympathetic and visceral afferent fibers, lymphatics

Anterior wall of inguinal canal

aponeurosis of the external oblique muscle

Posterior wall of inguinal canal

transversalis fascia

Roof of inguinal canal

transversus abdominis and internal oblique m

Floor of inguinal canal

medial one half of the inguinal ligament

Hesselbach's triangle (inguinal triangle) boundaries

laterally - inferior epigastric artery

medially - rectus abdominis m

inferiorly - inguinal ligament

Fermoral hernias

below inguinal ligament

more common in females

Inguinal hernia

above inguinal ligament

more common in males

passage of peritoneal sac with/without abdominal contents, through a weakened part of abdominal wall in groin

Indirect hernia

passes lateral to the inferior epigastric artery through the deep and superficial inguinal ring and enters the scrotum

Direct hernia

"directly" in the inguinal triangle through posterior wall of inguinal canal medial to inferior epigastric artery

rarely enters scrotum

Abdomen

part of trunk between thorax and pelvis

Anterolateral wall of abdominopelvic cavity

musculoaponeurotic

Posterior wall of abdominopelvic cavity

lumbar vertebral column and the posterior diaphragm that overlies the thoracic vertebrae and lower ribs

Abdominal cavity contains the peritoneal cavity and

houses most of the organs of the alimentary system and part of the urogenital system

Abdominopelvic cavity is formed by a major part from the

abdominal cavity

Abdominal cavity

space bounded by the abdominal walls, diaphragm, and pelvis

Diaphragm is a dome-shaped, musculotendinous partition separation the

thoracic and abdominal cavities

The diaphragm is the

primary muscle of respiration

Parietal peritoneum

outer surface

internal surface of abdominopelvic wall

Visceral peritoneum

inner lining

closer to the viscera such as spleen and stomach

Peritoneal cavity

potential space of capillary thinness between the parietal and visceral layers of peritoneum

contains thin film of peritoneal fluid that keeps the peritoneal surfaces moist

Intraperitoneal organs

almost completely with visceral peritoneum

Retroperitoneal and subperitoneal organs

outside the peritoneal cavity, external or posterior to the parietal peritoneum and are only partially covered with peritoneum

Intraperitoneal organs examples

spleen and stomach

Retroperitoneal organs examples

kidneys and pancreas

Subperitoneal organs examples

bladder and lower rectum

Mesentery is a

double layer of peritoneum because of the peritoneum by an organ and is continuity of the visceral and parietal peritoneum

The mesentery provides

neuromuscular communication between the organ and the body wall