Abdominal Wall, Inguinal Region & Hernias Flashcards
what is the abdominal pelvic cavity split into?
- abdominal cavity
2. pelvic cavity
Describe the abdominopelvic cavity?
Abdominal and pelvic cavities are continuous
Diaphragm separates the thoracic and abdominal cavities.
Upper part of the abdominal cavity extends beneath the thoracic cage
Pelvic inlet (pelvic brim) arbitrarily separates the abdominal from the pelvic cavity
The abdomen is a large cylinder extending from the superior margin of the pelvis to the inferior margin of the thorax
The inferior thoracic aperture (hole at the bottom of the ribcage) forms the superior opening of the abdomen
Closed by the diaphragm
what are the visceral structures?
Stomach, duodenum, small and large intestines
Liver, pancreas & spleen
Kidneys, ureters and urinary bladder
Reproductive organs
Abdominal vessels
what are the 9 regions of the abdomen ?
-Epigastric region
Right/Left hypochondrium
-Umbilical
Right flank, Left Lumbar region
- Hypogastric/Supra pubic region
Right groin and Left iliac region
what are the lines that separate the 9 regions?
Describe another plane
2 midclavicular plane
Subcostal plane—- at L3
Intertubercular plane—-L5
Between the lower edges of the 10th costal cartilages
Transpyloric plane passes through L1
what are the pains from the different regions of the abdomen and what does it consist of ?
Epigastric region
-referred pain from the foregut.
The foregut starts at the point the oesophagus pierces the diaphragm
Ends just after the major duodenal papilla (second part of the duodenum)
Umbilical
-referred pain from the midgut
The midgut begins just inferior to the major duodenal papilla
Ends two-thirds of the way through the transverse colon
Pubic region
-referred pain from the hindgut
The hindgut two-thirds of the way through the transverse colon
Ends mid-way through the anal canal
what are the 4 quadrant of the abdomen, and how is this divided and what organs can you find?
Sagittal plane and transumbilical plane
Right upper quadrant
-Liver and gallbladder
Left upper quadrant
-Spleen and stomach
Right Lower quadrant
-Appendix, ascending colon and caecum
Left lower quadrant
-Descending colon, sigmoid colon
how can you find Mcburney’s point?
Where is the iliac tubercle
It is in the right lower quadrant
McBurney’s point – 1/3 from ASIS to umbilicus is a marking of where an incision for an appendicectomy would be made.
In appendicitis pain can first manifest in the periumbilical area (referred from midgut) and once inflammation invades the subcutaneous tissues it moves to the R inguinal region
Relevant for acute appendicitis
The iliac tubercle is located 5cm posterior to the ASIS on the iliac crest
how is the rectus abdominas positioned?
Rectus abdominas muscle:
On the anterior wall on either side.
Semilunar lines.
A long, flat muscle
Paired muscle
Separated by the linea alba: A linear, fibrous structure which is formed from the aponeurosis of the lateral abdominal muscles.
Intersected three of four times by tendinous intersections (just some fibrous tissue)
easily visible
Origins -Pubic crest -Pubic tubercle -Pubic symphysis (all the pubic stuff)
Insertion :
- Costal cartilages of ribs 5 to 7
- Xiphoid process
Describe the layers of the abdomen
what are the abdominal wall muscles and what is made of those
Skin, Superficial fascia - fatty layer, Superficial fascia- membranous fatty, Parietal peritoneum, Extraperitoneal fascia, Transversalis fascia, Transversus abdominus muscle, Internal olique, external olique
Anterior wall
-Paired vertical rectus abdominis muscles within rectus sheath
Lateral wall - 3 flat sheet muscles
- External oblique
- Internal oblique
- Transversus abdominis
Posterior wall
Post vertebral muscles –erector spinae group
-Psoas, quadratus lumborum and iliacus muscles
what are the 3 flank sheet muscles and how are the muscle fibres orientated and describe where they are?
Obliques – external and internal
Transversus abdominis.
External: inferiormedially
At the midline, the large aponeuroses combine to form the linea alba which extends form the xiphoid process to the pubic symphysis
Origin: The outer surfaces of the lower eight ribs (so from ribs 5 to 12)
Insertion: Later lip of the iliac crest
Internal: superiormedially
Origin: Thoracolumbar fascia
Iliac crest
Lateral 2/3s of the inguinal ligament
Insertion:
Inferior border of the lower three or four ribs
Xiphoid process
Aponeurosis ends at linea alba
Also attached to pubic crest (just medial to the pubic tubercle)
Transverse abdominas: horizontally fibres
Origin:Thoracolumbar fascia
Iliac crest
Lateral 1/3 of inguinal ligament
Costal cartilages of the lower six ribs (so ribs 7 to 12)
Insertion: Aponeurosis ends in linea alba
Pubic crest
The three muscles are separate in the flanks and have fascia in between each layer.
The three flat muscle fibres continue anteriorly as aponeurotic sheets and contribute to the rectus sheath (encloses the rectus abdominas muscle)
what are the function of the flank muscles
- Compress the abdomen and increase the intra-abdominal pressure to aid expiration, and evacuation of urine, faeces, parturition, heavy lifting
- Supports viscera – “guarding” mainly the intestines
- Flex and rotate the trunk
Desscribe how the anterior and posterior link?
Link via the external, internal and transverse abdominas. Each have a layer of fascia in between.
Aponeurosis of three anterolateral muscles form rectus sheath and form around the abdominal muscles.
-Fibrous sheath.
External internal and transverse abdominas doesnt run all along to the rectus abdominus. The muscle stops. This is the semilunar lines.
describe the external oblique attachments and what does it form at the pubic tubercle
Muscle fibres are directed down ward and forward.
Attached to:
External surface of lower 8 ribs
Free posterior border
Fans out to attach to xiphoid process, linea alba, pubic crest and tubercle, anterior half of iliac crest.
The lower border of the aponeurosis of the external oblique forms the inguinal ligament
The inguinal ligament runs from the ASIS to the pubic tubercle
what is apneurosis, ligament and tendon?
Apneurosis: flat tendon of the muscles
Ligament: muscles to bone
Tendon: muscles to tendon to bone (generally stronger muscles e.g. biceps)
what happens to the aponeurosis and what happens to the lower aponeurotic edge?
The aponeurosis fuses medially with the rectus sheath
Lower aponeurotic edge is rolled inwards and forms the inguinal ligament. ASIS to pubic tubercle.
what are the attachments of the internal olique?
Muscle fibres are directed downward and backward
Lateral:
Thoracolumbar fascia
Iliac crest - anterior 2/3rd
Inguinal ligament - lateral half
Medial: Lower 3 ribs and costal cartilages Xiphoid process, Rectus sheath, Conjoint tendon
what is the attachment of the transversus abdominus?
Muscle fibres are directed horizontally
Lateral: Lower 6 costal cartilages Thoracolumbar fascia Iliac crest – anterior 2/3rd Inguinal ligament –lateral 1/3rd
Medial: Xiphoid process Linea alba (rectus sheath) Symphysis pubis Conjoint tendon
The neurovascular plane (blood supply to these muscles and nerve supply to the skin) lies between the internal oblique and transversus abdominis muscle layers
what is the arrangement of the rectus abdominas?
Long strap muscle of the anterior abdominal wall enclosed in rectus sheath
Rectus sheath Two heads
Superior attachment
5-7 costal cartilages
Xiphoid process
Inferior attachment
Symphysis pubis
Pubic crest
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what is the rectus abdominas muscle divided into?
The muscle is divided into segments by tendinous intersections (3/4 on each side) which are attached to the anterior wall of the rectus sheath.