block I: diaphragm and posterior abdominla wall

Question 1

chief muscle of respiration

Answer 1

diaphragm

Question 2

describe the diaphragm

Answer 2

• Double-domed
• Musculotendinous
• It divides the thoracic and abdominal part
• Domes
• (Right & Left)
• Right one is higher and reaches
  the 5th rib during expiration,
  whereas the left reaches the 5th
  intercostal space
• The level of domes varies according to:
• Phase of respiration
  -Inspiration vs Expiration
• Posture
• Size & degree of abdominal viscera’s distension

Question 3

the pericardia; sac fuses with:

Answer 3

central tendon of diaphragm

Question 4

Based on its peripheral attachments, the diaphragm can be divided in three descriptive
parts:

Answer 4

1) Sternal 2) Costal 3) Lumbar

Question 5

Describe the components of the diaphragm

Answer 5

1. Central tendon

• Muscular part:
• Sternal – arises from the xiphoid process
• Costal – inferior six costal cartilages, it forms the right & left domes
• Lumbar – arises from the medial & lateral arcuate ligaments and the L1-L3 vertebrae
  Crura of the diaphragm – musculotendinous bands
• Left crus – L1 to L2
• Right crus - L1 to L3
• Splits to enclose the esophagus

Median arcuate ligament - Aortic
hiatus (T12)

Question 6

What are the diaphragms openings or hiatus?

Answer 6

Allow structures to pass between thorax and abdomen
1. Caval opening (T8) = Vena caval foramen
2. Esophageal hiatus (T10)
3. Aortic hiatus (T12)

Question 7

Describe the caval opening T8

Answer 7

Vena caval foramen
* Inferior vena cava (IVC)
– During inspiration, the diaphragm contracts, widens the opening and dilates the IVC
* Right phrenic (terminal branches)
* Lymphatic vessels (from the liver to the middle phrenic and mediastinal lymph nodes)

Question 8

Describe the esophageal hiatus (T10)

Answer 8

• Esophagus (E)
• Anterior & posterior vagal trunks
• Esophageal branches of left gastric vessels
• Lymphatic vessels

Question 9

Describe the Aortic hiatus (T12)

Answer 9

• An opening to the descending aorta (A)
• Thoracic duct
• Azygous and hemi-azygos vein (occasionally)
• Greater splanchnic nerve (occasionally)

The aorta does not pierce the
diaphragm, therefore, blood flow is not
alter

Question 10

Describe sternocostal triangle (foramen)

Answer 10

• Between the sternal and costal attachments
• Transmits lymphatic vessels from the diaphragmatic surface of the liver and the superior epigastric
  vessels.
  Two small apertures in each crus of the diaphragm; one transmits the greater splanchnic nerve and the other the lesser splanchnic nerve.

Question 11

Diaphragm: Blood Supply and Venous Drainage
to Superior Surface are:

Answer 11

1. Pericardiacophrenic aa
2. Musculophrenic aa - branches from internal
   thoracic artery
3. Superior phrenic aa – from thoracic aorta

Venous Drainage:
The Pericardiacophrenic and Musculophrenic veins drain into the internal thoracic vein, whereas the superior phrenic drains into the IVC.

Question 12

Diaphragm: Blood Supply and Venous Drainage
to Inferior Surface are:

Answer 12

Blood supply:
The inferior surface of the diaphragm is supply by the inferior phrenic artery

Venous Drainage:
Right side: Inferior phrenic to IVC
Left side: 2 Inferior phrenic veins – one drain into the IVC the other to the suprarenal vein

Question 13

Lymphatic Drainage of Diaphragm: Superior Surface

Answer 13

Lymphatic nodes in the diaphragm communicates
freely.

Superior surface:
Diaphragma)c lymph nodes:
1. Posterior
-Posterior Mediastinal Parasternal
2. Anterior
-Parasternal
3. Phrenic

Question 14

Lymphatic Drainage of Diaphragm: Inferior Surface

Answer 14

Inferior surface:
Lymphatic vessels drain
into the:
Ø anterior diaphragmatic
Ø phrenic
Ø superior lumbar (caval/aortic) lymph nodes

In the inferior surface, lymphatic capillaries are dense constitute the primary means for absorption of
peritoneal fluid and substances introduced by intraperitoneal (I.P.) injection.

Question 15

Diaphragm innervation

Answer 15

Motor:
1. Phrenic Nerves (C3 – C5)
Ø Left and right phrenic nerves

Sensory:
Pain & Proprioception
1. Phrenic nerves (Left & Right)
2. Intercostal nerves (T5-T12)
Ø Carries only afferent fibers from the peripheral part of the diaphragm
Ø Intercostal nerves 6-11 & subcostal nerves

Question 16

explain paralysis of diaphragm

Answer 16

During inspiration, the diaphragm contracts,
its convexity is somewhat flattened, the
diaphragm descend pushing the viscera
inferiorly.
^ increases volume of thoracic cavity
v decreases Intrathoracic pressure
Resulting in air going into the lungs

The paralyzed dome ascends as it is pushed
superiorly by the abdominal viscera that are
being compressed by the active contralateral
dome.

Question 17

What are the muscles of the posterolateral wall?

Answer 17

• External oblique
• Internal oblique
• Transversus abdominis
• Latissimus dorsi
• Serratus posterior inferior

Question 18

CONTENTS OF THE POSTERIOR ABDOMINAL WALL

Answer 18

• Lumbar vertebra (5) & IV discs
• Muscles
  ü Psoas
  ü Quadratus lumborum
  ü Iliacus
  ü Transversus abdominis
  ü Oblique muscles
• Diaphragm
• Thoracolumbar fascia
• Lumbar plexus
• Nerves, vessels and lymph nodes

Question 19

describe Psoas major (psoas = muscle of the loin)

Answer 19

Attachments: Transverse process of
lumbar vertebra and side of T12-L5
bodies to lesser trochanter of femur
Action:
* Flexes the thigh (acting with Iliacus)
inferiorly
* Flexes vertebral column laterally,
superiorly
* Balance the trunk
* When sitting it flexes the trunk
(acting with Iliacus)
Innervation: anterior rami of lumbar
L1, L2, L3

Question 20

describe psoas minor

Answer 20

Attachments: Transverse process of
T12 iliopectineal arch and eminence
This muscle does not cross the inguinal
ligament.
Action:
* When present (~60%), its function
jointly with the Psoas major and
Iliacus muscles
Innervation: anterior rami of lumbar L1

Question 21

describe iliacus

Answer 21

Attachments: Iliac fossa (superior 2/3), ala of sacrum and anterior sacro-iliac ligaments
to lesser trochanter of the femur
Action: Flexes the thigh and stabilizes the hip joint (acts with Psoas major muscle)
Innervation: Femoral nerve (L2-L4)

Question 22

describe quadratus lumborum

Answer 22

Attachments: Inferior border of 12th rib
and tips of lumbar transverse process
to iliolumbar ligament and internal lip
of iliac crest
Action:
* Extends and laterally flexes the
vertebral column
* Fix 12th rib during inspiration
Innervation: Anterior branches of T12
and L1-L4 nerves

Question 23

explain quadratus lumborum posterior side

Answer 23

Attachments: Inferior border of
12th rib and tips of lumbar
transverse process to iliolumbar
ligament and internal lip of iliac
crest
Action:
* Extends and laterally flexes
the vertebral column
* Fix 12th rib during inspiration
Innervation: Anterior branches of
T12 and L1-L4 nerves

Question 24

the endo abdominal fascia lies where?

Answer 24

between parietal peritoneum and muscles

Question 25

whoch are the ligaments of the posterior abdominal wall

Answer 25

1 median arcuate ligament 2. medial arcuate ligament (formed by thickened of the psoas fascia sheath) 3. lateral arcuate ligament (froemd by thickened of the quadratus lumborum fascia)

Question 26

What is the thoracolumbar fascia?

Answer 26

an extensive fascial complex attached to the vertebral column medially that, in the lumbar region, has posterior, middle, and anterior layers with muscles enclosed between them.

Question 27

Explain the subcostal n t12

Answer 27

* Anterior rami of T12 * Arises from the thorax and pass posterior to the lateral arcuate ligament into the abdomen * Pass through the transversus abdominis and internal oblique muscles Innervates: * External oblique m. * Skin of the anterolateral abdominal wall

Question 28

Explain the lumbar spinal nerves (L1-L5)

Answer 28

* Anterior and Posterior rami – Anterior rami supply the skin and muscles of the inferior most trunk & lower limb – Posterior rami supply the muscles of the back – White communicating branches (Sosa’s lecture) * Anterior rami of L1, L2 and L3 * Convey presynaptic sympathetic fibers to the lumbar sympathetic trunk Lumbar plexus of nerves * Formed by the union of the ventral rami L1 - L4 * Localized anterior to the transverse process of lumbar vertebrae

Question 29

explain iliohypogastric n & ilioinguinal n (L1)

Answer 29

entering the abdomen posterior to the medial arcuate ligament and passing inferolaterally, anterior to the quadratus lumborum. * It pierces the transversus abdominis muscle close to the ASIS Innervates: * Abdominal muscles * Skin inguinal and pubic region

Question 30

EXPLAIN genitofemoral nerve (L1, L2)

Answer 30

* Genital branch * Enters the inguinal canal (deep inguinal ring) * Spermatic cord * Cremaster mm * Scrotum (Labium major) * Femoral branch * Supply skin of femoral triangle PIERCES THE PSOAS MAJOR

Question 31

Explain lateral cutaneous nerve of the thigh (L2,L3)

Answer 31

* Runs inferolateral on Iliacus muscle and enters the thigh (deep to inguinal ligament/iliopubic tract) Innervation: * Supplies the skin on the anterolateral surface of the thigh

Question 32

eXPLAIN FEMORAL NERVE (l2-l4)

Answer 32

* Emerges from the lateral border of the Psoas major. After innervating the Iliacus muscle this nerve passes deep to the inguinal ligament/iliopubic tract Innervates: * Iliacus * Flexors of the hip (anterior thigh) * Extensors of the thigh

Question 33

Explain obturador (L2-L4)

Answer 33

* Emerges from the medial border of the Psoas major muscle and passes inferior to the superior pubic ramus through the obturator foramen Innervation: * All muscles in the medial compartment of the thigh, except the hamstring part of the adductor magnus.

Question 34

Ex[lain accessory obturador n. (L3,L4)

Answer 34

* Present ~10% of the time * Parallels the medial border of the Psoas * Innervates hip joint and Pectineus muscles

Question 35

THE MUSCLES OF THE POSTERIOR ABDOMINAL WALL ARE MAINLY SUPPLIED BY?

Answer 35

branches of the abdominal aorta that starts at the aortic hiatus (T12) and ends at the level of L4.

Question 36

WHAT ARE TH ETHREE VASCULAR PLANES?

Answer 36

1. Anterior midline - Digestive tract 2. Lateral - Urogenital & Endocrine organs 3. Posterolateral - Diaphragm & Body wall

Question 37

Where does abdominal aorta start?

Answer 37

aortic hiatus (T12) ~13 m lenght -ends at level of L4

Question 38

What is the blood supply of the diapraghm?

Answer 38

-Superior phrenic, Musculophrenic and pericardiophrenic - Inferior phrenic

Question 39

blood supply to posterior mm.

Answer 39

* Inferior phrenic * Lumbar (1-4) * Iliolumbar * Ascending branch of deep circumflex artery

Question 40

Veins if the posterior abdominal wall?

Answer 40

Tributaries of IVC. IVC begins at L5; caval opening T8

Question 41

EXPLAIN THE LYMPHATIC VESSELS AN LYMPH NODE SOF POSTERIOR ABDOMINAL WALL

Answer 41

* Lie along the aorta, IVC, and iliac vessels * The common iliac lymph nodes receive lymph from the external and internal iliac lymph nodes. Lymph from the common iliac lymph nodes passes to the right and left lumbar lymph nodes. Lymph from the alimentary tract, liver, spleen, and pancreas passes along the celiac and superior and inferior mesenteric arteries to the pre-aortic lymph nodes(celiac and superior and inferior mesenteric nodes)

Question 42

What is the intestinal lymphatic trunk?

Answer 42

Efferent vessels from these nodes form the intestinal lymphatic trunks, which may be single or multiple, and participate in the confluence of lymphatic trunks that gives rise to the thoracic duct.

Question 43

what are the anatomical positions of kidneys

Answer 43

The right kidney related to rib 12, whereas the left kidney is related to ribs 11 & 12. transpyloric plane

Question 44

explain psoas abscess

Answer 44

Psoas Abscess (red arrow can result from an infection of the vertebral column, due to tuberculosis (TB) that spread from the vertebral column to the psoas fascia. Pus usually runs over the pelvic brim and deep to inguinal ligament

Question 45

explain posterior abdominla pain

Answer 45

The Iliopsoas test can rule out an intraabdominal inflammation. Usually, movement of the iliopsoas will produce pain if some structures are diseased. For example, an inflammation of the appendix. As Moore and Dalley pointed out, “The person is asked to lie on the unaffected side and extend the thigh on the affected side against the resistance of the examiner’s hand (Bickley, 2009). The elicitation of pain with this maneuver is a positive psoas sign.” Thus, a positive right psoas sign in the right side may indicate an acutely inflamed appendix. In the left side, it could be an inflammation of the sigmoid colon, lumbar lymph nodes, among others