Abdomen lecture

The hind gut structrues are supplied by the

IMA

Splenic flexure —> anus

The mid gut structures are supplied by

SMA

Mid duodenum —> approx splenic flexure

The foregut structures are supplied by the

celiac trunk

(oral cavity —> initial duodenum)

Body of the pancreas is supplied by the _________ which branches off the celiac trunk but the head and neck are supplied by branches from both the _____- and _____

Splenic artery

Gastroduodenal artery (common hepatic —> cel trunk)

SMA

The adrenal glands affect kidney function through the secretion of

aldosterone

Suprarenal medulla secretes

catecholamines (epinephrine and norepinephrine) fight or flight

Suprarenal cortex secretes

corticosteroids in response to stress, and androgens

How is the liver divided functionally?

Right and left based on blood supply and glandular secretions —> portal lobes (R and L )

What exits the porta hepatis?

Right and left hepatic ducts and lymph vessels

What enters the porta hepatis?

Portal vein, right and left hepatic arteries and nerve fibers

What bounds the abdomen superiorly? Inferiorly?

The diaphragm superiorly and the inguinal ligament and pelvic bones inferiorly

Aponeurosis

Flat, broad, tendon-like layers that serve as attachments for muscles

Fascia

A thin sheath of fibrous tissue enclosing a muscle or other organ

Peritoneum

Serous membrane that lines the abdominal cavity and its organs

Peritoneal ligament

A double layer of peritoneum that connects one organ to another organ or to the abdominal wall

Mesentery

A fold of the peritoneum that attaches the stomach, small intestine, pancreas, spleen and other organs to the posterior wall of the abdomen

Omentum

A double layered fatty sheath that supports and protects abdominal organs

Median plane

Divides the body into equal right and left halves

Transumbilical plane

This plane divides the body into upper and lower halves, across the middle of the abdomen

What are the 4 quadrants of the abdomen?

RUQ, LUQ, RLQ, LLQ

What are the 9 regions of the abdomen?

Right hypochondriac region // Epigastric region // Left hypochondriac region

Right lumbar region // Umbilical region // Left lumbar region

Right iliac region // Hypogastric region // Left iliac region

Liver

Gallbladder

Small intestine

Ascending/transverse colon

Right kidney

Right adrenal gland

Right ureter

These organs are found in what region of the abdomen?

Right hypochondriac region

Esophagus

Stomach

Liver

Pancreas

Small intestine

Transverse colon

R/L kidneys

R/L adrenal glands

R/L ureters

These organs are found in what region of the abdomen?

Epigastric region

Stomach

Tip of the liver

Tail of the pancreas

Small intestine

Transverse/descending colon

Spleen

Left kidney

Left adrenal gland

Left ureter

These organs are found in what region of the abdomen?

Left hypochondriac region

Liver

Gallbladder

Small intestine

Ascending colon

R kidney/ureter

These organs are found in what region of the abdomen?

Right lumbar region

Stomach

Pancreas

Small intestine

Transverse colon

R/L kidneys

R/L ureters

These organs are found in what region of the abdomen?

Umbilical region

Small intestine

Descending colon

L kidney

L ureter

These organs are found in what region of the abdomen?

Left lumbar region

Small intestine

Appendix

Cecum/ascending colon

R ovary/fallopian tube

These organs are found in what region of the abdomen?

Right iliac region

Small intestine

Sigmoid colon/rectum

R/L ovaries/fallopian tubed

Urinary bladder

Uterus

Vas deferens/seminal vesicles

Spermatic cord

Prostate

These organs are found in what region of the abdomen?

Hypogastric region

Small intestine

Descending/sigmoid colon

L ovary/fallopian tube

These organs are found in what region of the abdomen?

Left iliac region

What region of the abdomen is the appendix found in?

Right iliac region

What region of the abdomen is the prostate found in?

Hypogastric region

Thin cartilaginous extension off of the sternum that is easily palpated in the depression where the costal margins meet in the upper part of the anterior wall is identified as the _________

Xiphoid process

Where the xiphoid process meets the sternum

Xiphosternal junction

The xiphosternal junction is at which vertebral level?

T9

Small depression located in the upper-most midline abdomen in the infraxiphoid area

Epigastric fossa

Costal margin

The curved lower margin of the thoracic wall formed anteriorly by the cartilage of the 7th, 8th, 9th and 10th ribs and posteriorly by the cartilage of the 11th and 12th ribs

The cartilage of which ribs form the anterior portion of the costal margin?

7, 8, 9 and 10

The cartilage of which ribs form the posterior portion of the costal margin?

11 and 12

Why is the costal margin important?

The diaphragm connects to the costal margin. If there is something wrong with the costal margin, breathing can be interrupted

The superior portion of the diaphragm attaches to this area of the thorax

Costal margin

What is the Linea alba?

Fibrous band that extends from the symphysis pubis inferiorly to the xiphoid process superiorly and lies in the midline

What does the inferior portion of the linea alba connect to?

The symphysis pubis

What does the superior portion of the linea alba connect to?

Xiphoid process (linea alba)

This structure represents the fusion of the aponeuroses of the muscles of the anterior abdominal wall and is represented on the surface by a slight median groove

Linea alba

The linea alba is represented on the surface by a slight median groove. What is this median groove referred to as?

Rhaphe

You are scrubbing into your first surgery of your general surgery rotation. The head surgeon tells you to identify the linea alba when the patient is opened on the table. Explain where it is. What color is this structure?

You tell the surgeon that the linea alba is a fibrous band that extends form the pubic symphysis to the xiphoid process and lies in the midline of the abdomen. It is a pearly white color

Rhaphe

A suture/seam where two structures meet

Umbilicus

Puckered scar at the site of attachment of the umbilical cord in the fetus

The umbilicus lies in the linea alba and is ____ in position

Inconstant

What vertebral level is the umbilicus located at?

L4 (umb)

What vertebral level does the aorta bifurcate into the R and L common iliac arteries?

L4 (aorta)

What does it mean when we say the umbilicus is "inconstant in position"?

It can be found in slightly different spots on different people

The aorta bifurcates behind this structure

Umbilicus

Linea semilunaris

Lateral edge of the rectus abdominis semilunari

Where does the linea semilunaris cross the costal margin?

At the tip of the 9th costal cartilage

This bony structure of the pelvis can be felt along its entire length

Iliac crest

The iliac crest ends anteriorly at the _____

Anterior superior iliac spine (ASIS)

The highest point of the ASIS lies opposite ____

L5

A 56 year old male comes to the ER after a car accident with pelvic instability. You tell your student to check the stability of the patient's pelvis, and they tell you they won't be able to feel the iliac crest because the patient is extremely overweight. Is your student correct?

No they're wrong, throw a shoe at their face and then explain to them that the iliac crest can be palpated in its entirety regardless of the patient's weight

Diaphragm

Dome-shaped, musculotendinous partition separating the thoracic and and abdominal cavities

The diaphragm is made up of a central tendon with muscular attachments to the _____, ___ and ___

Xiphoid process, inferior thoracic cage and superior lumbar vertebrae

Which dome of the diphragm is higher?

Right

What are the 3 openings of the diaphragm, from anterior to posterior?

Caval opening (IVC)

Esophageal hiatus

Aortic hiatus

The IVC passes through the diaphragm through the _____

Caval opening

What does the caval opening allow for passage of?

IVC through the diaphragm

The IVC is adherent to the caval opening in the central tendon of the diaphragm. What happens when the diaphragm contracts during inhalation?

The IVC dilates, facilitating blood flow to the heart

In addition to the IVC, what else passes through the caval opening of the diaphragm?

The right phrenic nerve and some lymphatics

Oval aperture in the diaphragm that allows for the passage of the esophagus

Esophageal hiatus

In addition to the esophagus, what other structures pass through the esophageal hiatus?

Anterior and posterior vagal trunks

Esophageal branches of the left gastric vessels

Lymphatics

Which diaphragmatic aperture is the site of hiatal hernia?**

Esophageal hiatus (hernia)

Protrusion of a part of the stomach upward through the esophageal hiatus in the diaphragm**

Hiatal hernia

This is an opening posterior to the diaphragm through which the aorta passes

Aortic hiatus

Aortic hiatus

This aperture does not pierce the diaphragm, and therefore is not affected by movements during respirations

What structures pass through the aortic hiatus?

Aorta

Azygos vein

Thoracic duct

What groups of arteries supply the superior portion of the diaphragm?

Superior phrenic arteries (from thoracic aorta)

Musculophrenic and pericardiophrenic arteries (from the internal thoracic arteries)

What arteries supply the inferior surface of the diaphragm?

Inferior phrenic arteries (from the thoracic aorta)

Diaphragm

Phrenic = _____

On the superior portion of the diaphragm, the musculophrenic and pericardiophrenicn veins drain into the ______ vein

Internal thoracic vein

On the superior portion of the diaphragm, the superior phrenic vein drains into the _____

IVC

On the inferior surface of the diaphragm, the right inferior phrenic vein drains into the _____

IVC (rt phren drain)

On the inferior surface of the diaphragm, explain the venous drainage on the left side

The left inferior phrenic vein is doubled and drains into the IVC and left suprarenal vein

On the inferior surface of the diaphragm, the left inferior phrenic vein is doubled and drains into the ___ and ___

IVC and suprarenal vein

Which nerve roots provide motor supply to the diaphragm?**

C3, C4, and C5 keep the diaphragm alive! (phrenic nerve)

Centrally, the diaphragm's sensory innervation comes from _____**

The phrenic nerve (C3-C5)

Peripherally, the diaphragm's sensory innervation comes from _______

Intercostal nerves (T5-T11) and subcostal nerves (T12)

Fascia that is the fatty superficial layer continuous with the superficial fat of the rest of the body**

Camper's fascia

This abdominal fascia may become extremely thick in obese patients**

Camper's fascia (ob)

What is the first fascia encountered when cutting into the abdomen?**

Camper's fascia (1s)

Deep membranous layer of fascia of the abdomen. Fades out over the thoracic wall above and along the midaxillary line laterally. Inferiorly, it passes onto the front of the thigh where it fuses with the deep fascia**

Scarpa's fascia

Scarpa's fascia extends over the penis, where it helps to form _______**

Dartos fascia

Extension of scrapa's fascia into the perineum**

Colle's fascia

Fascia that lines the muscle is known as

Investing fascia

What is another name for the investing fascia?

Epimysium

Fascia that lines the organs of the abdomen. Names for the organ it lines

Endoabdominal fascia (transversalis)

The outer layer of the peritoneum that lines the interior of the abdominal wall/abdominal cavity**

Parietal peritoneum

There are 5 muscles of the abdominal wall, ____ flat muscles and ____ vertical muscles

3 flat, 2 vertical

All 3 flat muscles of the abdomen end anteriorly in a strong, sheet-like ______

Aponeurosis

The fibers of each of the 3 aponeuroses from the flat muscles of the abdomen interweave at the linea alba with the corresponding muscle of the opposite side, forming the ______**

Rectus sheath

Rectus sheath

Fibrous sheath formed by aponeuroses of abdominal muscles