Abdomen

Question 1

boundaries of abdominal cavity

Answer 1

inferior thoracic aperture - diaphragm

pelvic brim - continuous with pelvic cavity

anterior and posterior abdominal wall

Question 2

roof of abdominal cavity

Answer 2

is the same as the floor of the thorax

= diaphragm

separates thoracic from abdominopelvic cavity

radiating muscle fibres
central tendon (sternal, costal , lumbar attachments)

Posterior attachments
- musculotendinous cura
- tendinous arches

Question 3

musculotendinous crura

Answer 3

part of posterior attachments of the roof of the cavity

right = L1–>L3
left = L1–>L2

Question 4

tendinous arches

Answer 4

part of posterior attachments of the roof of the cavity

Median arcuate ligament (between crura, forms aortic hiatus)

medial arcuate ligament (to L1 transverse process)

Lateral arcuate ligament (to rib 12)

Question 5

what does the lateral arcuate ligaments allow

Answer 5

allows the diaphragm to pass over the anterior surface of muscles (quadratus lumborum)
- one on left and right

Question 6

anterior abdominal wall muscles and function

Answer 6

rectus abdominis
external and interal obliques
transverse abdominis

function: flexion of trunk, tense anterior wall fo abdomen, compress contents, increase intra-abdominal pressure for cough and sneezing, defecation and child-birth

in respiration: relaxes during inspiration, contracts during expiration

Question 7

posterior abdominal wall (bony elements and muscles)

Answer 7

bony elements: subcostal margin (attachment of diaphragm), 5 lumbar vertebrae, pelvic bones

muscles: psoas major, illiacus, quadratus lumborum

Question 8

quadratus lumborum

Answer 8

part of posterior abdominal wall

quadrilateral shaped
2 sites of attachment: 12th rib, iliac crest, transverse processes of all lumbar vertebrae

functions: lateral flexion of vertebral column, stabilisation of 12th rib in respiration

innervation: anterior branches of lumbar spinal nerves

Question 9

connection between thorax and abdomen

Answer 9

inferior-posterior mediastinum

aorta
vagus nerve
esophagus
thoracic duct
azygous system
sympathetic trunk

Question 10

abdominal esophagus

Answer 10

abdomen:
passes through esophageal hiatus of diaphragm (T10, narrowing)
lower esophageal sphincter (controls entrance to stomach)
ends at cardiac opening into stomach (T11)

Question 11

location of posterior abdominal region

Answer 11

posterior abdominal GI tract
posterior abdominal wall –> paritoneum
structures = retroperitoneal

involved in activities of abdominal viscera
conduit between body regions

Question 12

posterior abdominal region (structures - 5 main)

Answer 12

Viscera
- kidneys, ureters and suprarenal glands

Abdominal aorta
- branches

inferior vena cava
- azygous system

lymphatic system
- thoracic duct

nervous system
- prevertebreal plexuses
- lumbar plexus

Question 13

suprarenal glands

Answer 13

posterior abdominal region - viscera

endocrine system
produce hormones to regulate important body functions including
- metabolism, immune system, blood pressure, stress response

location: superomedial kidneys

glandular tissue

highly vascularised
- renal arteries, superior suprarenal, middle suprarenal, inferior suprarenal
- right/left suprarenal veins –>renal veins

Question 14

kidneys

Answer 14

part of posterior abdominal region - viscera

urogenital system - filters blood, produces urine

paravertebreal gutters, left higher than right - liver overlies right kidney

lies on psoas major, quadratus lumborum, transverse abdominis

hilus - medial aspect
- renal vein, renal artery, renal pelvis (ureter) (anterior to posterior)

Question 15

ureters

Answer 15

part of posterior abdominal region - viscera

urogenital system
transports urine, extends into pelvic region

renal pelvis
- hilum of kidney
- most posterior

abdomen: passes inferiorly over psoas major
pelvis: pelvic brim - passes anteriorly over bifurcation of common iliac arteries
- enter bladder obliqguely: upper angle

Question 16

what are the 3 contrictions - impact of renal (“kidney”) stones

Answer 16

renal pelvis
pelvic brim
entrance to bladder

Question 17

connections between thorax (inferior-posterior mediastinum) and the abdomen (7 - main)

Answer 17

abdominal aorta + branches
inferior vena cava
azygous system
abdominal lymphatics
thoracic duct
nervous system

Question 18

abdominal aorta

Answer 18

continuation of thoracic aorta
aortic hiatus in diaphragm
ends as common iliac arteries (L4-5)

prevertebral plexus (nervous system)

Question 19

main branches of abdominal aorta (3 unpaired, 3 paired)

Answer 19

unpaired:
- Celiac trunk (foregut: spleen, stomach, liver)
- superior mesenteric (midgut: small intestine, first half of large intestines)
- inferior mesenteric (hindgut: rest of GI tract)

paired:
- suprarenal arteries (suprarenal glands)
- renal arteries (kidneys, ureters)
- gonadal arteries

Question 20

inferior vena cava

Answer 20

drains into right atrium

venous return of all blood from below the diaphragm
- suprarenal, renal, gonadal veins

gastrointestinal–> portal vein–> liver to be filtered –>hepatic vein –>IVC

lumbar veins may drain into IVC or azygous sytem

Question 21

abdominal lymphatics

Answer 21

lymph nodes around major arteries in abdominal region
- “pre-aortic lymph nodes” (celiac trunk , superior mesenteric artery, inferior mesenteric artery)

drain into cisterna chyli –> thoracic duct –> left brachiocephalic vein

Question 22

name the 2 main groups of nervous systems that supply the prevertebral plexuses and what specifically contributes

Answer 22

vagus - parasympathetic
- ant + post vagal trunks
- abdominal esophagus + stomach, liver

Sysmpathetic trunk
- Splanchnic nerves
- thoracic and lumbar plexuses

Question 23

prevertebral plexuses

Answer 23

celiac plexus (trunk + SMA)
aortic plexus (SMA + IMA)
superior hypgastric plexus

Question 24

lumbar plexuses

Answer 24

anterior plexus of lumbar spina nerves (L1-4)
–> lumbsacral plexus
- innervation of lower limb
- ant + mid compartments (femoral n., obturator n.)

forms psoas major