Lecture 10 - Anterior Abdominal wall and inguinal region Flashcards
The muscle layers in the abdo are important for what role?
rewspiration - increasing intra abdominal pressure - urination, defecation and child birth
Once inside the muscles we have a ______ layer which is continuous with pelvic cavity below
Once inside the muscles we have a peritoneum layer which is continuous with pelvic cavity below
So there is skin, _______ fascia and then _layers for abdominal (flat) muscle - very similar to thorax
So there is skin, superifical fascia and then 3 layers for abdominal (flat) muscle - very similar to thorax
Lining the internal surface of rectus abdominus is _______ fascia and then extra peritoneal ___ before the peritoneum.
Lining the internal surface of rectus abdominus is transversalis fascia and then extra peritoneal fat before the peritoneum.
The 3 muscles attach to what superiorly?
Costal margin - but 3 layers wold get too crowded
Superficial -over top
middle - to the border
inferior - innerside
The 3 muscles are fleshy lateral (very clear msucle fibres) but in the midline they are replaced by _______ membrane
The 3 muscles are fleshy lateral (very clear msucle fibres) but in the midline they are replaced by aponeurotic membrane
The relationship of the abdominal wall to the spermatic cord and teses is important, why?
The spermatic cotrd traverses these abdomial wall muscles
External oblique is homologous with whihc other msucle
external intercostals
“Front pocket” msucles - medially and inferiorly orientated
The most superior fiberes of EO overlap what?
the costal margin - touches pec major and serratus anterior
EO attaches to what inferiorly?
anterior half of iliac crest and the ASIS
Then jumps down and attaches to pubic tubercle/crest (free inf. edge between - thickened, called the inguinal ligament)
Internal Oblique (IO) is on what direction
back pockets - posterior and inferior
How does IO insert superiorly?
perfectly ont he costal margin
thoracolumbar fascia posteriorly
linear alba medially
How does IO insert inferiorly?
Anterior half of the iliac crest and the ASIS
Lateral 2/3 of the inguinal ligament
True or False
The fibres of IO arise from the inguinal ligament
True
True or False
the lowest most fibres of IO don’t go to the linear alba
True
they arise from the inguinal ligament, arch over and attach to the pubic tbercle
Transversus Abdominus (TA) goes ____ the costal margin
Transversus Abdominus (TA) goes inside the costal margin
The lowermost fibres of TA arise from ______ of inginal lig.
lateral 1/3
True or False
Superiorly, TA is continuous in origin with the diaphragm
True
Posteriorly, Ta goes as far as …
the thoracolumbar fascia
Anteriorly, TA meets at the ..
linear alba
The Lowermost fibres of TA also arise from the inguinal ligament, but the ________ - fibres then arch over and insert into the _____ _______ (join with __in a conjoined tendon)
The Lowermost fibres of TA also arise from the inguinal ligament, but the lateral 1/3 - fibres then arch over and insert into the pubic tubercle (join with IO in a conjoined tendon)
Rectus Abdominis (RA) is a pair of ______ oriented muscles in the midline
Rectus Abdominis (RA) is a pair of longitudinal oriented muscles in the midline
RA is anchored inferiorly at the ___ ____, as they ascend - they get ___ overlapping the front of the ____
RA is anchored inferiorly at the pubic crest, as they ascend - they get wider overlapping the front of the ribcage
RA inserts on costal cartilages ….
5,6,7
Three tendonous intersections of RA interrupt the vertical fibres - divides the muscle in _ compartments that makes the muscle fibres more ______
Threee tendonous intersections interrupt the vertical fibbres - divides the muscle in 4 compartments that makes the muscle fibres more powerful
Where are the 3 tendonous interuptions of RA?
2 in between sternum and umbilicus
- at the umbilics
Aponeurosis of the 3 lateral muscles creates what…
a sheath for RA
The nerves and vessels also relate to the ____ _____
The nerves and vessels also relate to the rectus sheath
they are within
How do the abdominal wall muscles arrange themselves around RA?
TA goes behind,
Internal splits into 2
external is in front
aponeurosis of EO is synonymous with what?
the Rectus sheath (fibrous envelope)
At a point halfway between the umbilicus and the pubic bone all 3 aponeuroses pass above the __
At a point halfway between the umbilicus and the pubic bone all 3 aponeuroses pass above the RA
Happens all of a sudden - only have an anterior rectus sheath
The posterior rectus sheath is lost at a distinct point - where is this?
halfway between the umbilicus and pubic bone
What is the nerve supply to the anterior abdominal wall?
Lower six intercostal nerves - T7-12
skin and muscles
What is the artery supply to the anterior abdominal wall?
The superior epigastric a. (branch of the internal thoracic) meets the inferior epigastric (from external iliac) to supply the the anterior abdominal wall
The superficial epigastric (from femoral a.) is also in the superficial fascia
Where does the arterial supply run?
in the posterior rectus sheath.
There is dual venous drainage of ant. abdominal wall what are they?
Cava system
and
Portal vein
it is a site overlap for the two systems
Which veins follow the arteries in the ant. abdominal wal?
super and inferior epigastric veins (+superificial and deep) veins follow the arteries
From the medial side of the inguinal ligament there is a slight extension - some fibres reflect onto the pectineal line of the pubic bone, what is this called?
lacunar ligament
What is the pectineal ligament?
small linear attachment that follows along the pectineal line
What is the triangle opening created by the free inferior edge of EO - extending between the ASIS and pubic tubercle
The superficial inguinal ring
Where to the testes develop?
on the posterior abdominal wall in the extraperitoneal fat (quite deep in the abdominal)
WHen do they descend into the scrotum?
28th week
The scrotum has ___and ________ ______ continuous with the anterior wall
The scrotum has skin and superficial fascia continuous with the anterior wall
What do the testes have to traverse through?
the 3 muscles of abdo wall
transversus fascia
traverse through the inguinal canal
From the deep inguinal ring the inguinal canal continues 5 cm and the exit point is where?
The superficial (external) ring which is a triangular deficiency in the external oblique aponeurosis
What creates the roof of the inguinal canal?
the arches of TA and IO
What is the order of strucutres that the testes passes through on its way to the scrotum
Transversalis facia
TA
IO
EO
What is the deep inguinal ring?
a hole in fascia transversalis
a fingerbreadth above the inguinal ligament halfway between the ASIS and pubic tubercle
As the testes descending they bring the vas deferens and associated vessels - can see them clearly before the enter the canal - but not after because…
they bcome encolsed in sheaths:
internal spermatic fascia (through fascia transversalis)
cremaster beneath the arching fibres of EO
External fascia from the ring
What is the superficial ring
medial opening the EO aponeurosis
What is the Deep ring
deficiency “outpouching” of fascia transversalis
What is the floor of the Inguinal canal?
Inguinal ligament
What is the anterior wall of the inguinal canal?
EO aponeurosis
IO muscle (lat)
What is the posterior wall of the inguinal canal?
Transversalis fascia, conjoint tendon (med)
The external spermatic fascia is derived from…
external inguinal ring
The protrusoin of abdomial contents through the abdominal wall is called a..
Hermia - usually at a site of weakness at linea alba, umbilical
Scars may allow it to happen
What wil cause inguinal hernias?
Raised intra abdominal pressure 0 abdominal contents leave through the inguinal.
Indirect hernias mean..
Arise from incompltee closure of the processus vaginalis
Contents are going through the canal - is possible to push contents back up
What are DIRECT hermia’s?
Protrusion through a weakness in its posterior wall
