Abdomen Flashcards
How many regions and quadrants can the abdomen be divided into?
9 regions
4 quadrants
What is the pubic symphysis?
This is formed by the articulation between the left and right pubic bones. It is a joint.
What are a few examples of organs in the peritoneum?
Stomach, Spleen and Liver
What is the peritoneal cavity?
Between the Visceral peritoneum and parietal peritoneum. Contains peritoneal fluid which allows the movement of fluid during digestion.
What does intraperitoneal mean?
This means organs are almost completely covered with the visceral peritoneum (e.g. liver and stomach)
What does extraperitoneal, retroperitoneal and sub peritoneal mean?
Retroperitoneal= the space behind the peritoneum. These organs are partially covered by the peritoneum with just a layer of parietal peritoneum (e.g. where kidneys are)
Sub peritoneal= the space inferior (below) the peritoneum (e.g. bladder)
Extraperitoneal= outside the peritoneal.
How many parts are there to the peritoneal? What are they called?
How can the 2 parts communicate with each other?
2.
Greater and lesser sac.
Via the epiploic foramen.
What is the dorsal and ventral mesogastrium? What structures develop in each?
These are the two channels that open to the Stomach within the peritoneum.
Dorsal = back (spleen is here)
Ventral = front (liver is here)
What are the 3 parts of the gut? What is the blood supply for each?
Foregut (Coeliac trunk- T12), Midgut- from 2nd part of the duodenum to proximal 2/3 of the transverse colon (Superior mesenteric artery- arises from L1) and Hindgut- from the distal 1/3 of the transverse colon to the rectum (Inferior mesenteric artery- arises from L3)
What ligament is the inguinal canal on top of?
Inguinal ligament
What are the roles of the abdominal muscles?
Protect the viscera
Assist in breathing
For Coughing and vomiting
Assist in defecation, urination and giving birth (by increasing the pressure in the thorax)
What is the linear alba?
White line running down the centre of the abdominal muscles. Formed by the aponeuroses of the 3 side abdominal muscles that join together at the midline (the 3 side abdominal muscles enclose the upper 3/4 of the rectus sheath and in the lower 1/4 only the anterior surface of the rectus abdominis muscle). It also separates the two sides of the rectus abdominis muscle.
What are the horizontal lines between rectus abdominis muscles?
They are called tendinous intersections (visible if you have a 6 pack)
What is the pyramidalis?
A small triangular muscle located just below the rectus abdominis and forms part of the rectus sheath
What are the 3 side abdominal muscles? What direction to they go?
External oblique- Downwards and towards the midline (hands in pockets)
Internal oblique- Pass upwards and towards the middle (hands on tits)
Transverse abdominis- Fibres run horizontally
What does it mean saying the internal oblique splits into 2 layers?
For the top 3/4 of the rectus sheath, the internal oblique splits into 2 layers to enclose the rectus abdominis muscles on their anterior and posterior surfaces.
What is an aponeurosis?
A broad flat tendon
What does the inguinal ligament stretch between?
ASIS- Anterior superior iliac spine (Top)
Pubic tubercle
What is meant by the arcuate line?
This line divides the rectus sheath into the upper 3/4 and lower 1/4 of the abdominal muscles. (Upper 3/4 is surrounded entirely by muscle while the lower 1/4 is only surrounded anteriorly)
What canal do the testes travel down to get to the scrotum?
The inguinal canal
What does the cremaster muscle do?
Found only in males and it covers the testes. It raises and lowers the testes in response to changes in temperature.
What is an inguinal hernia?
A protrusion of the parietal peritoneum and viscera through a normal or abnormal opening. Can be direct or indirect.
What is Hesselbach’s triangle?
This is a potential area of weakness in the abdominal wall through which a hernia can protrude
What is the difference between a direct and indirect hernia?
Direct hernia passes through Hesselback’s triangle while indirect does not. Indirect hernia is where there is a protrusion into the inguinal canal (usually happens before it closes once testes have fully descended into the scrotum during puberty)
Direct hernias occur medial to the inferior epigastric artery while indirect hernias occur lateral to the inferior epigastric artery.
What is a Mesentary?
This is a fold in the peritoneum that creates a channel to an intraperitoneal organ
What is meant by secondary retroperitoneal?
It originally had a mesentery and was intraperitoneal but this mesentery has now collapsed and it is secondary retroperiotneal.
What artery supplies the foregut?
Coeliac Trunk
How many main branches does the coeliac trunk divide into? What are they called?
3 main branches- Left Gastric, Splenic and the common hepatic
What is the Camper’s fascia and the Scarpa’s Fascia?
These two layers lie below the skin and above the external oblique muscles. The Camper’s fascia is a large fatty layer that sits directly below the skin and the Scarpa’s fascia is directly below it (thinner layer)
What is the deep and superficial inguinal ring?
The superficial inguinal ring is the entrance to the inguinal canal which is nearest to the pubic tubercle while the deep inguinal ring is the other entrance and is just above the midpoint of the inguinal ligament.
What is the omentum?
Greater and lesser omentum. They are folds in the peritoneal layer of the abdomen which relate to the stomach. The greater omentum is the large fold below it that creates 4 layers (connects greater curvature of the stomach to the transverse colon) while the lesser omentum is the smaller fold above it that is just 2 layers thick (connects lesser curvature of the stomach to the duodenum of the liver)
It prevents the visceral and parietal layers of the peritoneum from sticking to each other
What is the pylorus?
This is the exit tube out of the stomach which leads to the first part of the small intestine (the duodenum)
What is the fundus of the stomach?
The dome shaped part of the stomach at the top.
What is the falciform ligament?
It is the line running down the centre of the liver that connects the liver to the anterior abdomen wall
What is the portal triad?
Made up of the Bile duct (front right), Hepatic artery (front left) and Portal Vein (Posterior)
What are the 3 openings of the diaphragm and at what vertebrae level do they fall at?
Caval Opening (T8), Oesophageal opening (T10), Aorta (T12)
What is the function of the mesocolon?
Connects the transverse mesocolon of the large intestine to the posterior abdominal wall
How is a hepatic portal system different to normal circulation?
A Hepatic portal system has 2 capillary beds while normal circulation has 1 capillary bed
What is the Portal Vein? Does it contain valves?
The Portal Vein is a vein that drains blood from organs in the abdomen into the bottom of the liver.
No valves so blood flow can be in any direction depending on pressure gradient.
What does it mean if an organ has both portal and caval drainage?
What abdominal organs have both portal and caval drainage?
It means its can drain blood via veins through the portal venous system and the caval drainage system.
The portal vein brings 75-80% of the blood to the liver while the hepatic artery accounts for 20-25% of the blood. The portal vein has reduced oxygenation but is rich in nutrients from the intestines. The hepatic artery supplies oxygenated blood
Distal Oesophagus, Rectum and Anterior abdominal wall (Umbillicus)