Gross 2 Posterior Abdominal Wall Flashcards
What are the attachments of the Diaphragm?
Inferior margin of thoracic cage
First 3 Lumbar Vertebrae
What are the Apertures in the Superior Boundary?
What level are they in and what goes through them? (4)
- Caval Opening: T8 level, opening for IVC
- Esophageal Hiatus: T10 level, opening for terminal end of esophagus
- Aortic Hiatus: T12 level, opening for abdominal portion of aorta
- Sternocostal Triangle: Opening for Superior Epigastric Vessels
What is the Medial Arcuate Ligament? What is it a passage for?
A thickening of the Psoas Fascia at the diaphragm
- Its a passage for sympathetic trunks and Least Splanchnic nerves
What is the Lateral Arcuate Ligament?
A thickening of the quadratus fascia at the diaphragm
Why are the Apertures of the Curs of the Diaphragm important?
They are a passage for the Greater and Lesser Splanchnic Nerves
What are the Fascias of the Posterior Abdominal Wall?
- Transversalis Fascia (Endoabdominal Fascia)
- Psoas Fascia
- Thoracolumbar Fascia:
–Anterior Layer
–Middle Layer
–Posterior Layer
What are the muscles of the Posterior Abdominal Wall?
- Psoas Major
- Iliacus
- Quadratus Lumborum (QL)
How does the Psoas Major run? (Pathway)
How will the Lumbar Plexus course with the Psoas?
- Runs inferior-lateral
- Passes deep to the Inguinal Ligament
- Lumbar Plexus is embedded with the Psoas
- Nerves of the lumbar plexus will course medial, lateral of through the psoas major/
How does the Iliacus run? (Pathway)
- Its in the abdomen, The anterior surface/fascia is separated from the extraperitoneal tissue and peritoneum
- The fibers then join the lateral side of the Psoas
Is the QL a muscle of the back or the abdomen?
Yes,
- Anteriorly the QL is covered by the anterior layer of the Thoracolumbar Fascia
- The QL lays posterior to the colon, kidney, and Psoas
What is the Unilateral function of the QL?
- Stabilizes the pelvis during walking
–There is a burst of QL activity at heel strike in EMG studies
–Works synergistically with opposite Glute Med. - Ipsilateral flexion of the vertebral column
- Stabilizes the spine when carrying loads on the contralateral UE
What are the Bilateral functions of the QL?
The QL extends the spine
What are the Respiratory functions of the QL?
Stabilizes the 12 ribs to assist with efficiency of inspiration (Helps depress the rib)
What nerve roots make up the Lumbar Plexus?
Ventral Rami L1 - L4
What regions are innervated by the Lumbar Plexus?
Structures of the abdominal walls, pelvic regions, and lower extremities
Where are the divisions found in the Lumbar Plexus?
L2 - L4
What terminal nerves arise from the Anterior Divisions of the Lumbar Plexus?
- Obturator N. (L2-L4)
- Genitofemoral N. (L1 and L2 ant.)
- Lumbosacral Trunk (L4 ant. and L5)
What terminal nerves arise from the Posterior Divisions of the Lumbar Plexus?
- Lateral Femoral Cutaneous N. (L2-L3)
- Femoral N. (L2-L4)
- Accessory Obturator N. (L3-L4)
What are the functions of Iliohypogastric N?
Sensory:
- Lateral Gluteal Region
- Upper Inguinal Region
- Hypogastric/Pubic region of the abdominal wall
Motor:
- Internal/External Abdominal Oblique
- Transverse Abdominis
What are the functions of the Ilioinguinal N.?
Sensory:
- Pubic Symphysis
- Inguinal Region
- Anterior Scrotum
- Anterior Labia Majora
Motor:
- Internal Abdominal Oblique
- Transverse Abdominis
What are the functions of the Genitofemoral N.?
Sensory:
- Femoral Triangle (Femoral Branch)
- Anterior Scrotum (Genital Branch)
- Anterior Labia Majora (Genital Branch)
What are the Classifications of branches/planes of the Abdominal Aorta?
- Anterior Midline
- Lateral
- Posterior lateral
What are the arteries of the Posterior Abdominal Wall and what do they supply?
- Inferior Phrenic A.: supplies the Inferior Surface of the diaphragm
- Subcostal A.: Supplies the muscle and skin along the lateral wall
- Lumbar A.: Supplies the posterior wall, including the vertebral column
What are the arteries of the Anterior Midline?
For Digestive Tract
- Celiac Trunk
- Superior Mesenteric
- Inferior Mesenteric
What are the arteries of the Lateral Abdominal Wall?
These are for the Urogenital and Endocrine Organs
- Superior Suprarenal
- Middle Suprarenal
- Renal
- Gonadal
What veins drain into the Inferior Vena Cava?
- Inferior Phrenic
- Lumbar V.
- Common Iliac (External and Internal Iliac, Femoral)
How does the Inferior Vena Cava connect to the Superior Vena Cava?
Through the Ascending Lumbar or the Azygos V.
Which vein(s) drain blood from the Inguinal Region?
The Deep and Superficial Circumflex Iliac Vein
What is the pathway for the Deep Circumflex Iliac Vein to go to the IVC?
Deep Circumflex Iliac V. -> External Iliac -> Common Iliac -> IVC
What is the pathway for the Superficial Circumflex Iliac Vein to go to the IVC?
Superficial Circumflex Iliac -> Femoral -> External Iliac -> Common Iliac -> IVC
What is the Peritoneum? What are the 2 layers of Peritoneum?
- A serous membrane that covers or envelops and lubricates structures
- Parts of the peritoneum will connect organs to other organs
The 2 layers:
- Parietal
- Visceral
What does the Parietal Peritoneum do?
It lines the internal surface of the abdominal wall
What does the Visceral Peritoneum do?
Invests the stomach and intestines
What it the relationship of the viscera to the peritoneum?
- There is the Intraperitoneal Organs
- There is the Extraperitoneal {Retroperitoneal and Subperitoneal} organs
What are the characteristics of Intraperitoneal Organs?
They are almost completely covered with visceral peritoneum (This includes the stomach, spleen and parts of small intestine)
think pushing hand in balloon
- This does not mean its inside the peritoneum cavity
What are the characteristics of Extraperitoneal organs?
Like intraperitoneal organs they are outside the peritoneal cavity-external to the parietal peritoneum
- They are partially covered with peritoneum (Usually on just one surface)
Where are the Retroperitoneal Organs?
Retroperitoneal Organs such as the kidneys are between the Parietal Peritoneum and the posterior abdominal wall and have Parietal Peritoneum only on their anterior surfaces
*Similarly, the subperitoneal urinary bladder has parietal peritoneum only on its superior surface
What is the Parietal Cavity?
This is formed between the parietal and visceral peritoneum
- This is a potential space
–It contains no organs
–It contains serous (peritoneal) fluid
–Peritoneal fluid can be absorbed by lymphatic vessels
What are the Peritoneal Formations?
- Greater Omentum
- Lesser Omentum
- Mesentery
- Transverse mesocolon
What is the Greater Omentum Peritoneal Formation?
A 4 layer fold of peritoneum, it drapes over the anterior abdomen and extends from the greater curvature of the stomach
What is the Lesser Omentum Peritoneal Formation?
A double layer of peritoneum, it extends form the lesser curvature of the stomach to the proximal duodenum
What is the Mesentery Peritoneal Formation? What is the Mesentery of the small intestine?
A double layer of peritoneum, it connects organs to the body wall. Its a pathway for neurovascular structures.
- The Mesentery of the small intestine attaches the jejunum and ileum to the posterior abdominal wall
What is the Transverse Mesocolon Peritoneal Formation?
This attaches the transverse mesocolon to the posterior abdominal wall
- This separates the abdominal cavity into superior and inferior compartments
– Supracolic and Infracolic compartments
What are the Peritoneal Ligaments of the Liver
- Falciform Ligament
- Hepatogastric Ligament
- Hepatoduodenal Ligament
What are the Peritoneal Ligaments of the Stomach?
- Gastrophrenic Ligament
- Gastrosplenic Ligament
- Gastrocolic Ligament
What is the innervation for the Parietal Peritoneum?
- Regional Somatic
Its sensitive to pressure, heat and cold, and chemical stimuli
- Nociception: Signaling of actual or potential danger
- Its well localized
What is the Vasculature Supply for the Parietal Peritoneum?
Regional Somatic
What is the innervation for Visceral Peritoneum?
Regional Visceral Supply
Its insensitive to touch, heat and cold and laceration
- Its stimulated primarily by stretching and chemical irritation
What is the Vasculature Supply for the Visceral Peritoneum?
Regional Visceral Supply (e.g. Foregut -> via arteries of the Celiac Trunk)
What nerves provide sensation (sensory) to the abdominal viscera and visceral peritoneum?
Visceral Afferents
What nerves provide motor innervation to the Abdominal Viscera?
- Sympathetic and Parasympathetic Nerves
- Sympathetic Innervation via the Thoracic and lumbar Splanchnic Nerves
- Parasympathetic Innervation via the Vagus and Sacral (Pelvic) Splanchnic Nerves
Describe the Digestive Tract Pathway starting at the mouth ending with the anal canal.
Mouth ->Esophagus -> Stomach -> Duodenum -> Jejumun -> Ileum -> Cecum -> Ascending Colon -> Transverse Colon -> Sigmoid Colon -> Anal Canal
Which nerves convey sensory information for the Abdominal Viscera? What additional information does it include?
- Visceral Afferents
- Includes information regarding sudden distention, spasms, chemical irritation, mechanical stimulation and ischemia
(This produces autonomic reflex and visceral pain sensation)
What is Referred Pain?
- Pain felt in a part of the body other than its actual source
- Convergence of these visceral and somatic afferent fibers confuses the relationship between the pain’s origins and its perception
(The area of skin that projects pain may be useful in determining source)
What do the Thoracic and Lumbar Splanchnic Nerves Innervate?
Thoracic Splanchnic
- Greater Splanchnic: T5-T9 (T10) Innervates Foregut
- Lesser Splanchnic: T10-T11 Innervates Midgut
- Least Splanchnic: T12 Innervates Kidney, and Suprarenal glands
Lumbar Splanchnic: L1-L3 Innervates Hindgut
What do the Parasympathetic Nerves of the Abdominal Viscera innervate?
- The Anterior and Posterior Vagal Trunk innervate the esophagus, to most of the transverse mesocolon
- The Sacral (Pelvic) Splanchnic nerves (S2-S4) innervate the terminal part of transverse colon, descending and sigmoid colon, rectum and pelvic viscera.
What is the function of Sympathetic Stimulation of the Digestive Tract?
It INHIBITS peristalsis and constricts BV to digestive tract so the blood is available to skeletal muscles; contracts internal anal sphincter to aid fecal continence
What is the function of Parasympathetic Stimulation of the Digestive Tract?
It PROMOTES peristalsis and secretion of digestive juices. Contracts rectum, inhibits the internal sphincter to case defecation
What is the function of Sympathetic Stimulation of the Liver and Gallbladder?
Promotes BREAKDOWN of glycogen to glucose (For increased energy)
What is the function of Parasympathetic Stimulation of the Liver and Gallbladder?
Promotes BUILDING/conservation of glycogen; increases secretion of bile
What does the Suprarenal Medulla release?
It releases adrenaline into blood via the sympathetic stimulation
