Surface anatomy of the abdomen

Question 1

Describe the midclavicular line

Answer 1

Extends vertically from the midpoint of the clavicle to the midpoint of the inguinal ligament.

Question 2

Describe the transpyloric plane

Answer 2

Runs horizontally across the abdomen from the level of the tip of the 9th costal cartilage, the tip of rib 12

Question 3

Describe the transtubercular line

Answer 3

Runs horizontally across the tubercles of the iliac crest (upper portion of the body of L5 vertebra).

Question 4

How do you palpate the superior boundary of the abdomen?

Answer 4

The thoracic outlet.

Palpate xiphoid process and follow the costal margin.

Pass your fingers beyond the costal angle (rib 9) and to the lowest part of the costal margin (rib 10).

The tip of rib 11 should be palpable just anterior to the midaxillary line, the tip of rib 12 is normally level with the spinous processes of L1.

Question 5

How do you palpate the inferior boundary of the abdomen?

Answer 5

Palpate the iliac crests of the pelvis, the pubic bones form the inferior boundary of the abdomen.

Question 6

How do you palpate the posterior boundary of the abdomen?

Answer 6

The posterior boundary is formed by lumbar vertebrae.

The transverse processes can be palpated 5cm lateral to the spinous processes, just beyond the bulk of the erector spinae muscles.

Question 7

Where would you palpate external oblique?

Answer 7

Palpate the area near the right iliac crest to feel the attachment of external oblique tighten as the person moves against resistance.

Question 8

Where would you palpate internal oblique?

Answer 8

Palpate the area between the left iliac crest and the umbilicus

Question 9

How do you palpate quadratus lumborum?

Answer 9

Ask the person to raise their shoulders and the anterior border of quadratus lumborum can be palpated just posterior to the mid axillary line.

Question 10

What are the superficial nerve branches on the anterior abdominal wall?

Answer 10

Anterior cutaneous branches of the intercostal nerves

Question 11

Describe the surface markings of the abdominal aorta

Answer 11

Marked by a vertical line to the left of the midline of the trunk.

The line runs from 2.5cm above the transpyloric plane to 2.5cm below the supracristal plane

Question 12

What is the supracristal plane?

Answer 12

Where the aorta bifurcates into common iliac arteries at L4

Question 13

Describe the surface markings of the inferior vena cava

Answer 13

Follows a vertical line just to the right of the midline from the union of the common iliac veins (L4/L5) 2.5cm below the supracristal plane to just above the right 6th costal cartilage.

Question 14

Describe the spleen

Answer 14

• Soft organ
• ~10cm long
• ~7cm wide
• ~3-4cm thick
• Lies on the left side posterior to ribs 9-11 near the midaxillary line

Question 15

Describe the liver

Answer 15

• Large organ that fills the right hypochondrium
• Large right lobe, small left lobe which tapers towards the left side of the abdominal cavity
• The upper border of the liver passes 7cm from the xiphisternal joint on the left, and on the right from this joint all the way around the right side of the thoracic cage
• The lower border passes in an oblique line from 7cm to the left of the midline to the 8th costal cartilage on the left, and then follows the border of the costal margin around to the right

Question 16

Describe the gall bladder

Answer 16

• Small sac lke structure approximately 3cm in diameter
• Difficult to palpate, but lies at the midclavicular line on the right 9th costal cartilage.

Question 17

Describe the stomach

Answer 17

• When the stomach is full it can be palpated on the left side below the costal margin, when it is empty it lies completely behind the rib cage and cannot be palpated.
• The fixed portions of the stomach are:
  
  • Cardiac orifice lies along the 7th costal cartilage 2.5cm to the left of the midline, level with the tip of the xiphoid process.
  • Pyloric orifice lies on the transpyloric plane 1.5cm to the right of the midline.
  • The fundus of the stomach may rise as high as the 5th intercostal space 7cm to the left of the midline or be as far down as the 10th costal cartilage.

Question 18

Describe the duodenum

Answer 18

• ~25cm in length and lies between the pyloric valve and the jejunum.
• From the pyloris, it passes 5cm to the right side as far as the costal margin (1st part).
• The duodenum then pases down and to the left for 7.5cm to the 10th costal cartilage (2nd part).
• The 3rd part crosses 10cm to the left side, across the body of L3 vertebra.
• The 4th part ascends 2.5cm to the duodenal junction (L2, 2cm left of the midline).

Question 19

Describe the pancreas

Answer 19

• Glandular organ, ~10cm long and 4cm wide
• Crosses from right to left (head, neck, body, tail) anterior to the vertebral body of L1.
• The head of the pancreas is surrounded by the duodenum and is related to the IVC and the right crus of the diaphragm.
• The body of the pancreas lies on the transpyloric plane and is related to the superior mesenteric and splenic veins.
• The tail of the pancreas abuts onto the hilum of the spleen.
• The pancreas is not normally palpable

Question 20

Describe the small itestine

Answer 20

• ~8cm long
• Attached to the mesentery
• Jejunum begins at L2, just to the left of the midline
• Ends at the iliocaecal junction, which lies at the junction of the right midclavicular and transtubercular lines.

Question 21

Describe the caecum

Answer 21

• Caecum lies in the right iliac region, above the lateral half of the right inguinal ligament.
• The appendix lies in the midclavicular line, 1.5cm medial to the anterior superior iliac spine.
• The caecum and appendix are not normally palpable

Question 22

Describe the kidneys

Answer 22

• Right kidney is protected by rib 12
• Left kidney is protected by ribs 11 and 12
• Each kidney is ~11cm long, ~6cm wide and ~3cm thick, with a hilum at L1.
• Upper margin at T12 and lower margin at L3.
• Each hilum lies ~3cm from the midline and the lateral border of each kidney lies approximately 6.5cm from the midline.
• The lower pole of the right kidney can be palpated using deep pressure, just lateral to the midclavicular line, and just below the level of the right 10th rib.

Question 24

Describe the bladder

Answer 24

• Normally situated behind the pubic bones
• As it fills, it rises approxmately 3cm above the pubic bones.
• A full bladder may then be palpated just superior to the pubic symphysis