GI session 1 Flashcards
Abdominal wall constituents
Sheets of muscle and sheets of tendon (aponeuroses)
Aponeuroses functions
Hold abdominal viscera in cavity. Rotate body. Respiration, coughing, sneezing, micturition, defecation, childbirth
How do aponeuroses carry out functions
By contracting to increase intra-abdominal pressure
Hernia definition and cause
bowel or other organs protruding out of abdomen. weaknesses in muscle wall.
Muscles on side of midline
Pair of muscles on each side of midline - rectus abdominis muscle
Rectus abdominis muscle attachments
Superiorly - sternum and costal margin
Inferiorly - pubis
Surrounded by - rectus sheath
Lateral to rectus sheath
3 sheets of muscle w/ fibres running in different directions.
Directions of 3 muscle fibres
External oblique: obliquely downwards and inwards
Internal oblique: Obliquely upwards and inwards
Transvesus abdominis: transversely
Aponeuroses of muscle layers
Become aponeurotic as they pass towards rectus sheath
Aponeurosis of external oblique
Lowest most extent is aponeurotic throughout length.
Attachments of external oblique
Laterally: anterior superior iliac spine
Medially: pubic tubercle
Inguinal ligament
Inguinal canal
above inguinal ligament. In males, it transmits structures to and from testes - spermatic cord
Bony landmarks of the abdomen
Xiphisternum Costal margin Iliac crest anterior superior illiac spine pubic tubercle pubic symphysis
deliniation of 9 abdominal regions
2 vertical and 2 horizontal lines
Vertical line
extends from mid-clavicular pint to mid-inguinal point
mid-inguinal point
midway between pubic symphysis and anterior superior iliac spine
Lower transverse line
between tubercles of iliac crests
upper transverse line
subcostal plane (line joining lowest part of costal margins on both sides)
3 central regions
epigastric, umbilical and suprapubic (superior to inferior)
3 lateral regions
hypochondrium, flank and iliac fossa
extensions from fossa
towards back: loin, lumbar region
Transpyloric plane of Addison
passes horizontally across epigastrium and reaches costal margin at most lateral part of rectus abdominis muscle. Tip of 9th costal cartilage, where mid-clavicular line crosses costal margin
Organs lying on transpyloric plane of Addison
gall bladder, pancreas, plyorus of stomach and duodeno-jejunal flexure
sub-costal plane
lies at lowest points of costal margin
McBurney’s point
2/3 of way along line joining umbilicus to right anterior superior iliac spine. Marks usual site of base of appendix. Position of caecum.
Umbilicus
insertion of umilical cord during embryonic life and level of L3 vertebra
intertubercular plane
level of tubercles of iliac crests. position of bifurcation of abdominal aorta.
Intercristal plane
highest point of pelvis.
Foregut innervation and pain
Greater sphlanic nerve arising from T5 to T9 spinal level. Anteriorly in midline (epigastrum).
Midgut innervation and pain
Lesser sphlanic nerve from T10 and T11 (periumbilical area)
Hindgut innervation and pain
lowest sphlanic nerve from T12 (suprapubic area)
Peritoneum innervation and pain
same sensory nerve supply as skin overlying abdominal wall
Diaphragm innervation and pain
Phrenic nerve, C3, C4 and C5.
Diseases irritating diaphragm - cholecystitis (inflammation of gall bladder) - pain in C3,4,5 distribution. Pain felt in shoulder.
Cholecystitis
Inflammation of gall bladder
Kidney innervation and pain
Sensory innervation is via sympathetic plexus accompanying renal artery (T10,11,12) (same as gonad).
Pain referred along cutaneous nerves of T10, 11, 12(most common). Radiates from loin to groin.
