Week 6 Content Flashcards
Identify and describe the boundaries of the abdominal wall.
Superior - right and left costal margins, xiphisternal joint
Inferior - a line on either side connecting the ASIS to the pubic symphysis
Lateral - vertical lines ascending from the ASIS on each side
Posterior - lumbar paravertebral musculature
Identify and describe the 4 planes of the abdomen.
Subcostal plane - line through the most inferior parts of the costal cartilage (10th rib), also passing through the body of L3
Transtubercular plane - line passes through the iliac tuberosities at the L5 level
Sagittal plane (2) - mid-clavicular lines, extends inferior from the mid-clavicle to the mid-inguinal point
Describe the transpyloric plane.
AKA Addison’s plane, a transverse plane that is slightly above the subcostal plane, through the body of L1
Describe the interspinous plane.
A transverse plane that is slightly below the transtubercular plane.
Name the 9 quadrants of the abdomen.
Upper region from R to L: R hypochondraic, epigastric, L hypochondraic
Middle region from R to L: R lumbar, umbilical, L lumbar
Lower region from R to L: R inguinal, hypogastric, L inguinal
Describe the contents of the RUQ.
Liver Gallbladder Right suuprarenal gland Right kidney Ascending colon (superior part)
Describe the contents of the LUQ.
Spleen Stomach Pancreas - body and tail Left kidney Transverse colon (left half) Descending colon (superior part)
Describe the contents of the RLQ.
Cecum Veriform appendix Right ovary Right ureter Most of ileum
Describe the contents of the LLQ.
Sigmoid colon Descending colon (inferior part) Left ovary Left ureter Left spermatic cord
Describe the layers of the abdominal fascia.
Just deep to skin is the superficial fascia’s fatty layer (Camper’s fascia) and then deep to that is the superficial fascia’s membranous layer (Scarpa’s fascia). Together the Camper’s fascia and Scarpa’s fascia make up the subcutaneous tissue.
Next deep structures are investing (deep) fascia covering the abdominal muscles: the external oblique, internal oblique, and transverse abdominis
Deep to the abs are transversalis fascia, then extraperitoneal fascia, and finally the parietal perironeum.
Which fascial layer continues as the fascia lata of the thigh?
Scarpa’s fascia, the superficial fascia’s membranous layer
Describe OINA for external oblique.
O: external surface of ribs 5-12
I: linea alba, pubic crest, iliac crest, pubic symphysis
N: inferior 5 thoracic nerves, subcostal nerve (T12), and iliohypogastric nerve (L1)
A: trunk flexion, rotation, lateral rotation; compress abdominal contents
Describe OINA for internal oblique.
O: thoracolumbar fascia, anterior iliac crest, lateral half of inguinal ligament
I: linea alba, pubic crest, inferior surface of ribs 11-12
N: lower 5 thoracic nerves, subcostal (T12) and iliohypogastric (L1) nerves
A: trunk flexion, rotation, lateral rotation; compress abdominal contents
Describe OINA for transversus abdominis.
O: TLF via lateral raphe, iliac crest, lateral 1/3 of inguinal ligament, internal surface of costal cartilages 7-12
I: linea alba, pubic crest, pubic synphysis
N: lower 5 thoracic nerves, subcostal (T12) and iliohypogastric (L1) nerves
A: compress and support abdominal viscera, tightens TLF
Describe OINA for rectus abdominis.
O: pubic symphysis, pubic crest
I: xiphoid process, costal cartilages 5 and 7
N: lower 5 thoracic nerves, subcostal (T12) and iliohypogastric (L1) nerves
A: trunk flexion; tenses anterior abdominal wall
Briefly describe the rectus sheath.
A dense fibrous sheath enclosing the rectus abdominis muscle, formed by the fusion of aponeuroses of the abdominal muscles
Where is the arcuate line?
Roughly at the level of the umbilicus, the point of transition where all 3 abdominal aponeuroses pass anteriorly.
Describe the rectus sheath above the level of the umbilicus, anteriorly and posteriorly.
Anteriorly: aponeuroses of external oblique and 1/2 of internal abdominal oblique
Posteriorly: aponeuroses of 1/2 of other internal oblique and TA
What is the linea alba?
Where the anterior and posterior walls of the rectus sheath meet and fuse in the anterior median line.
Describe the rectus sheath below the level of the umbilicus, anteriorly and posteriorly.
Anteriorly: aponeuroses of all 3 muscles now pass anteriorly over the rectus abdominis with no fascia from the muscles passing posteriorly
Posteriorly: a thin fascial film (transversalis fascia) remains posteriorly that protects the rectus abdominis from rubbing against the abdominal contents
Describe the innervation of the anterior abdominal wall.
Supplied by:
- ventral primary rami of thoracic spinal nerves T6-T11
- ventral primary rami of T12 (subcostal n.)
- ventral primary rami of L1 (iliohypogastric and ilioinguinal nerves)
Describe the cutaneous landmarks for innervation of the anterior abdominal wall.
T10 - umbilical area
T7 - xiphoid area
L1 - pubic area
Describe the arterial supply to the anterior abdominal wall.
Superior epigastric (branch of the internal thoracic artery) and Inferior epigastric (branch of the superficial epigastric artery off of the external iliac) enter the rectus sheath posterior to the rectus abdominis and anastomose with the rectus muscle
Posterior intercostal arteries that accompany intercostal nerves also supply anterior abdominal wall
Additional supply comes from the direct branches of the abdominal aorta and lumbar arteries
Describe caput medusae.
AKA medusa’s head
Distended superficial epigastric veins
Common in portal HTN, can be caused by liver failure
Describe the inguinal canal.
A passage from the abdominal cavity through the anterior abdominal wall that lies right above the inguinal ligament, formed by folds of the external oblique aponeurosis
Openings are called superficial and deep inguinal rings
Contents: inguinal nerve, blood and lymphatic vessels, spermatic cord in males, round ligament of the uterus in females
Where does the inguinal ligament insert?
ASIS to pubic tubercle
Describe the borders of Hesselbach’s triangle.
Medial border - rectus sheath
Lateral border - inferior epigastric artery
Inferior border - Poupart’s ligament (inguinal lig)
RIP
Triangle carries the inguinal canal and the external (superficial) inguinal ring
Compare and contrast acquired and congenital inguinal hernias.
Acquired (direct) hernias are caused by the wear and tear of living, such as childbirth, weight gain, and other muscle strain.
Congenital (indirect) hernias are present from birth and happen at points of weakness in the abdominal wall. Children’s hernias are almost always congenital. In men, the hernia will be within the spermatic cord.
Describe the peritoneum, including its layers and function.
A thin, transparent serous membrane that consists of 2 layers:
- Parietal peritoneum - lines abdominal wall
- Visceral peritoneum - lines the visceral organs
Space between is lined with serous fluid to allow frictionless movement between the wall and the organs and between organs
Not all organs are covered by the peritoneum
What is peritoneal effusion?
AKA Ascites, defined as >25 mL of fluid buildup in the peritoneal cavity
Can be caused by liver cirrhosis, HF, HTN, hepatic vein blockage
Sx: increased SOB
Describe the mesentery.
A double layer of peritoneum that encloses the abdominal organs
Provides a means of neurovascular communication and organ attachment to posterior abdominal wall
Contained with the fibrous tissue of the mesentery are blood and lymph vessels, nerves, lymph nodes, and adipose tissue
Describe the omentum.
A double layer of peritoneum that attaches the stomach to the body wall or to other abdominal organs
Greater omentum - fat-laden fold of peritoneum that connects stomach with transverse colon
Lesser omentum - connects the lesser curvature of the stomach and duodenum to the liver
Describe the location and contents of the abdominal cavity.
Located superior to the pelvic inlet and limited superiorly by the thoracic diaphragm
Contains the peritoneum and abdominal viscera
Describe the esophagus.
Muscular tube extending from the pharynx to the stomach (25 cm long)
Function - transportation of food from oral cavity to stomach
Passes through esophageal hiatus of the diaphragm to enter into the abdominal cavity
Peristaltic action creates rapid food movement from the oral cavity to the stomach
Called the thoracic esophagus superiorly and abdominal esophagus inferiorly
Describe the location and function of the stomach.
Expandable part of the digestive tract that lies between the esophagus and the small intestine
Function - provide enzymatic digestion of food, converting solid food to a liquid mixture called chyme
Capable of holding 2-3 L of food
Describe the 4 parts of the stomach.
Cardia - part surrounding the cardial orifice (the connection
between the stomach and the esophagus)
Fundus - dilated superior aspect of the stomach that is related to the left dome
of the diaphragm
Body - center, lying between the fundus and the pyloric antrum
Pyloric - funnel-shaped region of the stomach at the bottom. The distal aspect
is characterized by the pyloric sphincter which controls discharge of the
stomach contents into the duodenum
Describe the small intestine’s function and name its parts in order.
Function - continue food digestion
3 parts:
- Duodenum
- Jejunum
- Ileum
Describe the duodenum.
First and shortest part of the small intestine; C-shaped
Bile and pancreatic ducts enter into the duodenum for digestive purposes
4 parts: superior, descending, horizontal, ascending
Describe the jejunum and ileum.
Together they are 6-7 meters long
No clear demarcation between jejunum and ileum but surgeons are able to distinguish based on:
- Jejunum is often redder, thicker, and has a greater vascularity than the ileum
Describe the spleen.
Largest lymphatic organ, located in the LUQ, next to the pancreas
Primary function: eliminate old and damaged cells from the circulation, filter antigens, and contribute to the immune response
Its removal does not seriously impair the immune response
Describe the pancreas.
Organ lies posterior to the stomach, points towards the spleen
Functions:
- secreting gastric juices for the small intestine that enters the duodenum via the pancreatic ducts
- endocrine gland supplying the body with insulin and glucagons from the
Islets of Langerhans
For descriptive purposes, it is divided into four parts
- Head, neck, body and tail
Describe the liver.
Largest Gland in the body and is found in the RUQ; has 2 lobes (L and R) separated by falciform ligament
Function: metabolic activities, secretion of bile, and storage of glycogen
It also is responsible for processing the products of digestion as well as
endogenous and exogenous substances like drugs and toxins that enter the
circulation
Describe the portal triad.
Bile duct - formed by the common hepatic duct and the cystic duct (gall bladder)
Hepatic artery - arises from the aorta and delivers well-oxygenated blood to the liver
Portal vein - arises from the mesenteric and splenic veins and empties into the liver, carries nutrient-rich blood
Describe the large intestine.
Cecum - first part of the large intestine, blind intestinal pouch; connected to ileum via the ileocecal valve; attached to vermiform appendix
Colon - described in 4 parts (ascending, transverse, descending, sigmoid); functions to remove fluid from fecal matter
Rectum and anal canal - continuation of the colon, sphincters for control of defacation
Describe the vermiform appendix.
Attached to the cecum of the large intestine
Blind divertculum
Function not well understood
Describe the kidneys.
Lie on the posterior abdominal wall
Function: remove excess water, salts, and wastes of protein metabolism from the blood while returning nutrients and chemicals back to the blood
Superior aspect of kidney contains the suprarenal glands or adrenal glands, which function to produce hormone and steroids for body
Describe the ureters.
Convey the waste products absorbed by the kidneys to the bladder in the pelvis
Run inferiorly from the kidney, over the common iliac arteries to the bladder
Is blood drainage from the left gonads more or less effective than from the right gonads? Why or why not?
Drainage from left gonads is less effective because blood supply to the right gonads come straight off of the abdominal aorta, whereas the left side has a less direct route
Describe the 3 constriction points of the renal system.
1st constriction - ureteropelvic junction, right after kidney
2nd constriction - pelvic inlet, between common iliac artery branches of internal and external iliac arteries
3rd constriction - entrance to bladder
Name the contents of the pelvic cavity.
Bladder
Urethra
Reproductive organs (ovaries, fallopian tubes, uterus, cervix, vagina in women; testis, seminal vesicle, vas deferens, ejaculatory duct, and prostate in men)
Describe the bladder.
Hollow pouch with strong muscular walls with characteristic of distensibility
Functions - temporary reservoir for urine
Urethra - muscular tube that conveys urine from the bladder
Describe the female reproductive organs.
Ovaries - female reproductive glands, produces ova (oocytes) and estrogen
Fallopian tubes or uterine tubes - extend laterally from the uterus and open
near the ovaries. Functions to convey the ovum from the ovary to the uterus.
Uterus - thick walled, pair shaped, hollow muscular organ. Provides
environment for embryo and fetus development
Cervix - neck region of the uterus.
Vagina - musculomembraneous tube extending from the cervix to the
vestibule of the vagina. Functions as a passageway
Describe the male reproductive organs.
Testis - male gonad, one of two reproductive glands found in the scrotum. Functions to produce spermatozoa and testosterone.
Seminal Vesicle -lies between the bladder and the rectum. Function to secrete a
thick alkaline fluid that mixes with the sperm as they pass into the ejaculatory duct.
Ductus Deferens or Vas Deferens - continuation of the duct of the epididymus. It
begins in the epididymis and eventually joins with the duct of the seminal vesicle to form the ejaculatory duct.
Ejaculatory Duct - slender tube that arises by the union of the duct of a seminal
vesicle with the ductus deferens and connects into the urethra
Prostate - accessory gland, secretes fluid that helps to form part of the seminal fluid
What makes up the posterior abdominal wall?
Bones - lumbar vertebrae, sacrum, wings of ilium, ribs 11-12
Muscles - diaphragm, iliacus, psoas major, quadratus lumborum
Describe OINA for psoas major.
O: transverse processes, bodies, and IVDs of T12-L5
I: lesser trochanter with iliacus as iliopsoas tendon
N: ventral primary rami of L2-4
A: hip flexion; trunk flexion and lateral flexion
Describe OINA for psoas minor.
O: bodies of vertebrae T12 and L1 and the IVD in between
I: pubic bone
N: ventral primary ramus of L1
A: pelvis flexion, vertebral column flexion
Describe OINA for iliacus.
O: iliac fossa
I: lesser trochanter with psoas major as iliopsoas tendon
N: femoral n. via nerve to iliacus
A: hip flexion
Describe OINA for quadratus lumborum.
O: iliac crest, iliolumbar ligament, and transverse processes of lower lumbar vertebrae
I: rib 12, transverse process of upper lumbar vertebrae
N: subcostal n. and upper lumbar ventral primary rami
A: trunk lateral flexion; extends vertebral column; elevates hip; stabilizes rib 12 against inhalation
thin, strap-like muscle
Describe the nerves of the lumbosacral plexus.
Lumbar plexus is derived from L2-L4
- Iliohypogastric - L1
- Ilioinguinal - L1
- Genitofemoral - L1-2
- Lateral femoral cutaneous - L2-3
- Femoral - L2-4
- Obturator - L2-4
- part of L4 forms lumbosacral trunk
Sacral plexus is derived from L4-S4
- Superior gluteal - L4-S1
- Inferior gluteal - L5-S2
- Sciatic - L4-S3
- Pudendal - S2-S4
- twigs to piriformis - S1-4
- nerve to obturator internus - L5-S2
- nerve to quadratus femoris - L4-S1
Describe the arterial supply to the posterior abdominal wall.
Descending thoracic aorta enters the abdominal cavity through the diaphragm and
becomes the abdominal aorta
The abdominal aorta divides at the level of L4 vertebra into right and left common iliac arteries
The common iliac arteries divide into internal and external iliac arteries
- Internal iliac supplies the viscera of the pelvic cavity
- External iliac passes under the inguinal ligament and enters the anterior
compartment of the thigh. It changes names to the femoral artery when crossing under the inguinal ligament.
The inferior epigastric artery arises from the external iliac artery before it enters the
anterior thigh compartment. It supplies the inferior aspect of the anterior abdominal wall
Describe the inferior vena cava.
The largest vein in the body
It returns blood from both lower extremities, anterior abdominal wall and abdominal pelvic viscera
It arises about the L5 vertebra from a union of the common iliac veins
It ascends through vena cava foramen in the diaphragm and continues to the heart
Describe the diaphragm generally.
A musculotendinous partition separating the thoracic and abdominal cavities
Major muscle of inspiration
Composed of a central tendon in the shape of a boomerang into which the peripheral muscle portion inserts
Describe the peripheral muscle portion of the diaphragm.
Sternal portion: fibers arising from the xiphoid and inserting into central tendon
Costal portion: arises from internal surface of lower 6 ribs and costal cartilage and lateral and medial arcuate ligaments, inserts into central tendon
Lumbar portion: arises from lumbar vertebrae in the form of a right crus (L1-3 and their discs) and left crus (L1-2 and their discs)
Describe the openings of the diaphragm.
Sternocostal hiatus - passage of the superior epigastric vessels and some lymphatics
Foramen for the inferior vena cava - AKA caval opening; passage for IVC and right phrenic nerve
Esophageal hiatus - passage for esophagus and vagal trunks
Aortic hiatus - passage for aorta and thoracic ducts
Sympathetic trunk passes posterior to the medial arcuate ligament
T/F: Camper’s fascia is a fatty layer that is filled with smaller vessels.
True
T/F: Scarpa’s fascia is a membranous layer that marks the entry into the abdominal cavity.
True
What is the thoracic level of the caval opening, and what structures pass through it?
T8
IVC, right phrenic nerve
What is the thoracic level of the esophageal hiatus, and what structures pass through it?
T10
Esophagus, anterior and posterior vagal trunks, esophageal branches of left gastric artery and vein
What thoracic level is the aortic hiatus, and what structures pass through it?
T12
Aorta, thoracic duct, azygos vein
What is the function of the parietal peritoneum?
It covers the retroperitoneal organs
What are the major organs of the retroperitoneum?
Kidneys
Pancreas
Duodenum
Why are organs termed retroperitoneal?
They have peritoneum on their anterior side only
They are not suspended by mesentery in the abdominal cavity and lie between the parietal peritoneum and posterior abdominal wall
Why does the lesser omental sac exist?
It forms as part of the rotation of the foregut
What is the arterial supply for the spleen, stomach, and liver?
the Celiac trunk
What is the significance of the duodenal-jejunal flexure?
This is where the small bowel transitions from retroperitoneal to intraperitoneal
What is the significance of the terminal ileum?
It marks the transition from the small to large bowel.
Where is the appendix located?
It is attached to the cecum
Which artery supplies most of the ascending and transverse colon?
The superior mesenteric artery
Where is the transition zone of the organs supplied by the superior and inferior mesenteric arteries?
The mid transverse colon, but there’s no exact area where the transition occurs
Which artery supplies the descending and sigmoid colon?
The inferior mesenteric artery
Which artery(s) supply the rectum and distal parts of the sigmoid colon?
Partially supplied by inferior mesenteric artery and branches of the iliac arteries
