Module 2: The Abdomen Flashcards
4 quadrants of the abdomen
Left and right upper and lower
9 divisions of the anterior abdominal wall
- Epigastric
- Umbilical
- Hypogastric
- Left hypochondriac
- Left lumbar
- Left inguinal
- Right hypochondriac
- Right lumbar
- Right inguinal
Layers of the abdominal wall (superficial to deep)
- Skin
- Superficial fascia
- Investing fascia
- External oblique
- Internal oblique
- Transervsalis abdominus
- Extraperiotoneal fat
- Transversalis fascia
- Parietal peritoneum
What is a liposuction?
Surgical suctioning of fat deposits of the body, involves the removal of the superficial facia layer (Camper’s fascia)
Superficial fascia layer divisions
Camper’s fascia (superficial)
Scarpa’s fascia (membranous)
Symptoms of potential liposuction complications
Bruising, swelling, damage to other layers of abdominal wall
What is the rectus sheath?
Protective layer within the anterior abdominal wall that supports and protects the contents of the abdomen
What is the rectus sheath made up of?
The aponeurotic internal oblique, external oblique and transversus abdominus
What is an aponeurosis?
Flat-sheet of tendon like material that anchors a muscle or connects it w the part that the muscle moves
What is rectus abdominus diastasis?
Condition in which the rectus abdominus muscles become separated due to a thinning and widening of the linea alba
Symptoms of rectus abdominus diastasis
Protruding midline and lower back pain
Blood supply to the anterior abdominal wall
- Superior epigastric artery
- Inferior epigastric artery
Superior epigastric artery
Terminal branch of the internal thoracic artery
Enters rectus sheath posteriorly and anastomoses w the inferior epigastric artery
Inferior epigastric artery
Branch of external iliac artery
What is a rectus sheath hematoma?
Result of bleeding of the rectus sheath from damage to the superior and/or inferior epigastric arteries and their branches which could happen from a direct tear of rectus sheath or abdominal muscles
Symptoms of rectus sheath hematoma
Blood collects on anterior abdominal wall causing bruising, tenderness, pain and bulging of abdomen
Lymphatic drainage of anterior abdominal wall
- Superficial
- Deep
Superficial lymphatic drainage
Drainage to axillary nodes from above the umbilicus to the superficial inguinal nodes below the umbilicus
Deep lymphatic drainage
Drainage to external iliac, common iliac and lumbar nodes
Inguinal canal
4-6cm in length located in lower anterior abdominal wall
Imp passageway for structures btwn abdominal and pelvic region
Inguinal rings
Ends of the inguinal canal, act at doorways for contents to enter and exit
Superficial inguinal ring
Opening in external oblique aponeurosis, superior to pubic tubercle
Deep inguinal ring
Invagination of transversals fascia, superior to midpoint of inguinal ligament
Contents of inguinal canal in females
Main structure is the round ligament of uterus
Innervation of inguinal canal in females
Ilioinguinal nerve supplies skin of upper labia majora and mons pubis
Contents of inguinal canal in males
Main structure is spermatic cord
Innervation of inguinal canal in males
Ilioinguinal nerve supplies skin of upper scrotum and root of penis
Ilioinguinal nerve
Passes through canal and exits through superficial inguinal ring; supplies skin of adjacent upper thigh in both males and females
What is an inguinal hernia?
When contents of the abdominal cavity protrude into the inguinal canal; happens at weak spots of abdominal wall
Weak spots of female abdominal wall
Where round ligaments of uterus attaches to the tissue surrounding the pubic bone
Weak spots of male abdominal wall
In inguinal canal where spermatic cord enters the scrotum
Symptoms of inguinal hernia
Bruising, bulging, pain especially when bending over, lifting objects or coughing
What causes weakness in abdominal wall?
Giving birth, injury, aging
Major muscles of the posterior abdominal wall
Divided into superior and inferior portions
What borders the posterior abdominal wall superiorly?
The diaphragm
Major muscles of posterior abdominal wall (superior)
Larger right and smaller left crus of diaphragm
Right cura origin
L1-L3
Left cura origin
L1-L2
Major muscles of posterior abdominal wall (inferior)
Psoas major
Illiacus
Quadratus lumborum
Iliopsoas muscle
Formed by the merging of the psoas major and iliacus and inserts onto the lesser trochanter of the femur
Quadratus lumborum
Thin, flat muscle that originates on iliac crest and lumbar vertebrae and inserts into rib 12
Tight Quadratus Lumborum
Tight muscles on one side of posterior abdominal wall can lift the corresponding side of one’s pelvis leading to a misalignment and can pull at the ribs limiting reaching and breathing
What happens if both quadratus lumborum muscles are tight?
Compression on spine and back pain
Formation of lumbar plexus
Formed in psoas major muscle from the ventral (anterior) rami of lumbar spinal nerves 1-4
Nerves of the lumbar plexus
- Iliohypogastric
- Ilioinguinal
- Genitofermoral
- Lateral femoral cutaneous
- Femoral
- Obturator
- Lumbosacral trunk
Iliohypogastric nerve
Spinal nerve L1
Supplies skin and muscles of lower abdominal wall
Ilioinguinal nerve
Spinal nerve L1
Runs through inguinal canal, supplies skin of upper medial thigh, root of penis and anterior scrotum in males and skin of mons pubis and labium majora in females
Genitofemoral nerve
Spinal nerves L1 and L2
Two branches: genital and femoral
Genital branch
Enters inguinal canal
Femoral branch
Supplies skin of upper anterior thigh
Lateral femoral cutaneous nerve
Spinal nerves L2 and L3
Supplies skin of anterolateral thigh
Femoral nerve
Spinal nerves L2-L4
Supplies muscles of anterior compartment of thigh, hip and knee joints and skin of anterior thigh
Obturator nerve
Spinal nerves L2-L4
Supplies muscles of medial compartment of thigh, hip and knee joints and skin of medial thigh
Lumbosacral trunk
Part of L4 that joins L5
Joins S1-S4 ventral rami to form the sacral plexus
What is a femoral nerve entrapment?
Pinching of femoral nerve
What causes femoral nerve entrapment?
Disc herniation at vertebral level L2/3 or L3/4
Bulging disc impinges femoral nerve
Symptoms of femoral nerve entrapment
Pain, numbness, weakness along front thigh
Sympathetic nerves of posterior abdominal wall
Lumbar sympathetic trunk
Lumbar sympathetic trunk
Runs down posterior abdominal wall lateral to vertebral column
Parasympathetic nerves of posterior abdominal wall
Vagal trunks
Pelvic splanchnic nerves
Vagal trunks
Branches of left and right vagus nerves that carry parasympathetic fibres to the aortic plexus
Pelvic splanchnic nerves
Spinal nerves S2-S4
Carry parasympathetic fibres to the superior hypogastric plexus
The autonomic plexuses (that we focus on)
Aortic (prevertebral) plexus
Superior hypogastric plexus
Aortic plexus
Includes prevertebral ganglia
Innervates organs of abdomen such as stomach, small and large intestine and kidneys
Prevertebral ganglia
Celiac
Superior mesenteric
Inferior mesenteric
Aorticorenal
Superior hypogastric plexus
At bifurcation of descending aorta
Innervates organs of pelvis such as uterus, prostate, bladder, rectum and perineum
What is diabetic gastroparesis?
Impaired innervation to abdominal viscera that can result in dysmotility (disordered peristalsis)
Symptoms of diabetic gastroparesis
Bloating, abdominal pain, nausea and vomiting
NO structural abnormalities in gut and NO inflammation
Bifurcations of the abdominal aorta
Bifurcates at L4/L5 into left and right common iliac arteries which bifurcate into external and internal iliac arteries
What causes an aortic dissection (tear)?
Trauma to abdominal region
Hypertension bc walls of blood vessels are weakened over time
Symptoms of aortic dissection
Abdominal pain, weakness, fainting due to blood loss
Anterior unpaired visceral branches of the abdominal aorta
- Celiac artery
- Superior mesenteric artery
- Inferior mesenteric artery
Celiac artery
Forms at T12 and has three branches Supplies foregut structures
Three branches of celiac artery
Left gastric, common hepatic and splenic arteries
Foregut structures
Distal esophagus to proximal duodenum
Includes pancreas, liver, gallbladder
Superior mesenteric artery
Forms at L1 and supplies midgut structures
Branches of superior mesenteric artery
Inferior pancreaticoduodenal artery
Jejunal and ileal arteries
Middle and right colic arteries
Midgut structures
Extend from distal duodenum to proximal half of transverse colon
Inferior mesenteric artery
Forms at L3 and has three main branches
Supplies hindgut structures
Branches of inferior mesenteric artery
Left colic, sigmoidal and superior rectal arteries
Hindgut structures
Distal third of transverse colon to rectum
Lateral paired visceral branches
- Suprarenal arteries
- Renal arteries
- Gonadal arteries
Suprarenal arteries
Formed at L1
Renal arteries
Formed btwn L1 and L2
Gonadal arteries
Formed at L2
Posterior parietal branches
Supply structures of posterior abdominal wall
1. Right and left inferior phrenic arteries
2. Lumbar arteries