the abdomen Flashcards
how are the muscle fibers oriented in the EO?
fibers directed anterior and inferior
how are the muscle fibers oriented in the IO?
fibers directed posterior and superior
how are the muscle fibers oriented in the transversus abdominis?
fibers in the horizontal direction
what are aponeurosies
flat broad tendon for muscular attachment
what do the aponeuroses of the obliques at the midline form to create?
linea alba
what do the aponeuroses that surround the rectus abdomenis muscle form?
the anterior and posterior rectal sheaths
what does the start of the aponeuroses on the lateral sides of the recuts abdominis muscle forms
linea semilunaris
what nerve gives innervation (Sensory and motor) to the anterior abdominal wall?
throaco-abdominal N T7-T11
what are the spinal segments associated with the iliohypogastric N?
T12-L1
what are the spinal segments associated with the ilioinguinal N?
L1
how is the abdomen divided into?
9 regions
what lines form the 9 regions of the abdomen?
the midclavicular line on either side
the subcostal (transpyloric) plane at L1
the transtubercular plane at L5
what segments of the abdomen are found in the central column
the epigastric region: upper central (upon the stomach)
The unbilical region: middle central (where the belly bottom)
The suprapubic region: lower central (superior to the pubic bone)
what segements are found of either side of the abdomen?
Right & left hypochondriac region (where coastal cartilage merges onto costal margin) [superior sides]
Right/left lumbar regions [central sides]
Right/left iliac region
how can the abdomen also be divided into?
quadrants
where does the inguinal ligament stretch from?
Stretches from the ASIS to the public tubercle
what are the rings found at either end of the inguinal canal?
deep inguinal ring and superficial inguinal ring
what created the inguinal ligament?
the thickening of the aponeurosis of the external oblique
what passes through the inguinal canal?
spermatic cord and round ligament of the uterus
what forms the walls of the inguinal canal?
- Anterior wall is formed by the external oblique aponeurosis
- Roof: internal oblique and transversus abdominis
- Posterior: tranversalis fascia
- Floor: inguinal ligament
what transitions into the cremaster muscle?
IO
where can the thoracoabdominal N be found?
They travel between the IO and TA wrapping from the back to the front to get to the skin
what nerve is found at T12?
subcostal N
where does the iliohypogastic N sit?
above the ilioinguinal N
where does the ilioingunal N travel?
Travels within the canal, above cremaster muscle
Exits the superficial inguinal ring above the muscle
where do the testes start up in the fetus?
• Testes start up in the abdomen between the peritoneum and the transversalis fascia
what happens to the testes during the descent phase?
• Teste gets pulled from the abdomen all the way to the scrotum
what pulls the testes down to the scrotum?
The gubernaculum
does The gubernaculum change in length as the fetus develops?
no, it stays the same size
what is the gubernaculum composed of?
fibrous tissue
how do the testes reach the scrotum?
the gubernaculum pulls on the testes from the posterior abdominal wall through the processus vaginalis and into the scrotum
what does the gubernaculum transition into once the testes reach the scrotum?
the ligament of scrotum and holds the testes into the scrotum
during gestation, when does the descent of the testes occur?
between the 10th and 15th week
what creates the processus vaginalis?
the deep inguinal ring
when does processsus vaginalis open?
its open during the descent of the testes
when does processus vaginalis close?
during the fusion of the peritoneum
what does the EO aponeurosis transition to become as the testes descend?
the external spermatic fascia
does the Transversus abdominis evaginate?
no, it doesnt contribute to anything
what is the internal spermatic fascia an extension of?
transversalis fascia
what does the peritoneum wrap around?
wraps down around the turcica vaginalis
what is turcica vaginalis
similar to the pericardium of the heart, has a double layer
- parietal layer: lines the interior aspect of the scrotum
- visceral Layer: on top of the testes
what is the most common type of hernia?
indirect hernia
what population group is most susceptible to indirect hernia?
• more common early on in males due to the process of descent of the testes (children or early adolescent)
what is the main cause for indirect hernia?
due to improper closure of Processus vaginalis
what happens to the intestines during indirect hernia?
the intestines come down and make their way into the scrotal sac while the intestines impinge on the testes
what happens during femoral henrias?
bulge in the medial thigh
intestines go through the femoral canal into the thigh
where are direct hernia generally found?
• found within the hesselbach triangle (inguinal triangle)
what borders the hasselbach triangle?
medially: rectus abdominis
inferior: inguinal ligament
lateral: inferior epigastric vessels
what is the hasselbach’s triangle?
its the weakest point of the abdomen
what happens to the intestine in direct hernias?
• intestines will herniate medial to the inferior epigastric vessels
what population group is most susceptible to direct hernias? why?
seen more commonly in men over 40 years old
due to wear and tear and loss of strength of the abdominal wall
what does the parietal peritoneum line?
abdominal cavity
what does the visceral peritoneum line?
lines the surface of the organs
what is the name of the region where the double peritoneum layer is more prominent in the abdomen?
the messenter
where does the parietal pericardium transition into the visceral pericardium?
the messenter
what is the function of the messenter?
Functions to protect the blood vessels due to its location on either side
intraperitonial organs are covered on what sides and by what?
• Intraperitoneal organs are covered on all sides by the visceral peritoneum
what holds the intraperitonial organs in the abdomen?
the messenter
what are retroperitonial organs?
organs which are Not free in the abdomen
they are Attached the posterior abdomen wall
the Organs covered with peritoneum on anterior surface only
what do the omenta create?
cavities within the abdomen
where does the stomach and liver sit within the abdomen?
stomach on the left hand side
liver on the right hand side
what omentum is created by the extension of tissue from the lesser curvature of the stomach to the liver
lesser omentum
what ligaments are associated with the lesser omentum?
- Hepatogastric ligament
* Hepatoduodenal ligament
where does the greater curvature of the stomach extend from?
The greater omentum extends from the greater curvature of the stomach extends down below the transverse colon and fold onto itself and comes back up to attach to the transverse colon
what does the greater omentum create?
spaces refered to as sacs
where does the lesser sac of the abdomen sit?
• Sits behind the stomach behind the lesser omentum, continues down between both layers of the greater omentum
on what side of the body is the lesser sac opened on and what is it closed by?
Open on the R side of the body and closed off on the L side by the ligaments of the spleen
what is the opening of the lesser sac of the abdomen known as?
eoicloic foramen
what does the epiploic foramen give access to?
the liver an pancreas when the greater omentum is cut
what compartments are found in the greater sac of the abdomen?
- Supracolic compartment
* Infracolic compartment
