Anatomy Lecture 2 -- Posterior Abdominal Wall

Question 1

Upper attachments of the psoas major

Answer 1

• Sides of vertebrae T12 to L5
  
  • IV discs
  • Transverse processes

Question 2

Lower attachment of the psoas major

Answer 2

Lesser trochanter of the femur with iliacus muscle (iliopsoas)

Question 3

Upper attachment of the psoas minor

Answer 3

• Sides of vertebrae T12 to L1
• IV discs
• Transverse processes

Question 4

Lower attachment of the psoas minor

Answer 4

Superior ramus of the pubic bone (pectineal line)

Question 5

Posterior abdominal wall muscles that cross under the inguinal ligament

Answer 5

• Psoas major
• Iliacus

Question 6

Posterior abdominal wall muscle that passes over the inguinal ligament

Answer 6

Psoas minor

Question 7

Upper attachment of the quadratus lumborum

Answer 7

• Medial 1/2 of inferior border of the 12th rib
• Transverse processes of L1 to L5

Question 8

Lower attachment of the quadratus lumborum

Answer 8

• Iliolumbar ligament
• Iliac crest

Question 9

Upper attachments of the iliacus

Answer 9

• Superior 2/3 of iliac fossa
• Ala (wing) of sacrum
• Anterior sacroiliac ligaments

Question 10

Lower attachment of the iliacus

Answer 10

Tendon of psoas = iliopsoas

Question 11

5 muscles of the posterior abdominal wall

Answer 11

• Psoas major
• Psoas minor
• Quadratus lumborum
• Iliacus
• Transversus abdominus

Question 12

3 origins of the muscle fibres of the diaphragm

Answer 12

• Sternum
• Ribs (costal margin)
• Lumbar vertebrae

Question 13

Diaphragmatic muscle that wraps around the esophagus

Answer 13

Right crus

Question 14

Diaphragmatic muscles on either side of the aorta

Answer 14

Right and left crus

Question 15

Nerve that travels alongside the IVC. How does its corresponding nerve pierce the diaphragm?

Answer 15

• Right phrenic nerve
• Left pierces diaphragm on its own

Question 16

Where do the muscle fibres of the diaphragm converge?

Answer 16

Central tendon

Question 17

Ligament of the diaphragm that forms the hole through which the aorta enters

Answer 17

Median arcuate ligament

Question 18

Ligament of the diaphragm that lets the psoas pass underneath

Answer 18

Medial arcuate ligament

Question 19

Ligament of the diaphragm that lets the quadratus lumborum come through

Answer 19

Laterla arcuate ligament

Question 20

Define the caval foramen

Answer 20

Hole in the central tendon through which the right phrenic nerve and lymphatics pass

Question 21

How does the sympathetic trunk pierce the diaphragm

Answer 21

On either side of the abdominal aorta just inside the medial arcuate ligament

Question 22

Define somatic nerves

Answer 22

Any nerve that is not in the gut (i.e. arms, legs and body wall; motor and sensory)

Question 23

Define a reflex arc

Answer 23

A neural circuit that creates a more or less automatic link between a sensory input and a specific motor output

Question 24

Describe how the simplest spinal reflexes are mediated

Answer 24

3 element chain:

• Sensory neurons
• –> interneurons in the spinal cord
• –> motor neurons

(–> means activate)

Question 25

2 roots that branch from the spinal cord and the structure that the subsequently form

Answer 25

Dorsal and ventral roots --\> spinal nerve

Question 26

What does the spinal nerve branch into?

Answer 26

Dorsal and ventral rami (ramus singular)

Question 27

What do dorsal rami innervate?

Answer 27

The deep muscles of the back (motor) Horizontal strips of skin (sensory)

Question 28

Alternative name for the ventral rami in the thoracic region

Answer 28

Intercostal nerves

Question 29

What are the communicating branches?

Answer 29

Rami communicantes, which go to each ganglion all the way down the sympathetic trunk to a point

Question 30

What do the lumbar nerves form when they join together?

Answer 30

Major nerves that go down the leg

Question 31

Identify these 7 nerves of the lumbar plexus

Answer 31

1. Subcostal nerve 2. Iliohypogastric nerve 3. Ilioinguinal nerve 4. Genitofemoral nerve 5. Lateral cutaneous nerve of the thigh 6. Femoral nerve 7. Obturator nerve

Question 32

Lumbar plexus nerve that crosses the iliacus

Answer 32

Lateral cutaneous nerve of the thigh (5)

Question 33

Lumbar plexus nerve the is on the lateral side of the psoas

Answer 33

Femoral nerve (6)

Question 34

Completely straight nerve of the lumbar plexus that goes down inside the pelvis through the obturator foramen

Answer 34

Obturator nerve (7)

Question 35

Nerve of the lumbar plexus that branches into a Y at the bottom

Answer 35

Genitofemoral nerve (4)

Question 36

How do the right and left vagus nerves enter the abdomen?

Answer 36

As the posterior and anterior vagal trunks, respectively, through the esophageal hiatus of the diaphragm

Question 37

What does the vagus nerve supply?

Answer 37

Motor parasympathetic fibers to all the organs **except the suprarenal (adrenal) glands**, from the neck to the second segment of the transverse colon

Question 38

From where do the pelvic splanchnic nerves arise?

Answer 38

Ventral rami of the S2 - S4

Question 39

Describe the trajectory of the pelvic splanchnic nerves from their origin

Answer 39

1. Arise from ventral rami of S2 - S4 2. Travel from each side of pelvis to corresponding inferior hypgastric plexus 3. Travel to distal 1/3 of transverse colon, sigmoid colon, rectum, bladder and genitalia 4. Preganglionic parasympathetic fibres synapse in walls of organs

Question 40

Location of inferior hypogastric plexus

Answer 40

Bilaterally on the walls of the rectum

Question 41

Where do the white rami stop? What does this mean?

Answer 41

* After L2 * Preganglionic fibers must travel down the sympathetic chain from higher levels

Question 42

6 ganglia of the abdominal region

Answer 42

1. Celiac 2. Aorticorenal 3. Superior mesenteric 4. Inferior mesenteric 5. Superior hypogastric 6. Inferior hypogastric

Question 43

Sympathetic nerves that form the greater splanchnic nerve

Answer 43

T5, 6, 7, 8, 9

Question 44

Sympathetic nerves that form the lesser splanchnic nerve

Answer 44

T10, 11

Question 45

Function of the general visceral sensory (afferent) fibers (GVA)

Answer 45

Conduct sensory impulses (usually pain or reflex sensations) from the viscera, glands and blood vessels to the central nervous system. (Considered to be part of ANS but afferent fibers are not classified as either sympathetic to para)

Question 46

From what is the cortex of the adrenal gland derived?

Answer 46

Mesoderm

Question 47

From what is the medulla of the adrenal gland derived?

Answer 47

Embryonic neural crest cells

Question 48

How are hte cells of the adrenal medulla innervated?

Answer 48

Preganglionic sympathetic fibers (no postganglionic fibers)

Question 49

Define the cisternae chyli

Answer 49

Start of the thoracic duct

Question 50

What nerves do the GVA usually accompany? Which nerves are the exception?

Answer 50

* Sympathetic efferent fibres * Abdominal GVA that DO NOT follow this pathway = those that innervate structures in the distal half of the sigmoid colon and the rectum (follow the path of the parasympathetic efferent fibers back to the vertebral column)