The peritoneal cavity Flashcards
Endoderm
The innermost germ layer.
Develops into most of the gut including the epithelium and glands of the digestive tract.
Mesoderm
The middle layer in a gastrula.
Develops into the muscle layer in the gut.
Includes muscles of the oesophagus, stomach and intestines.
Ectoderm
The outermost layer of the gastrula.
Develops into the epithelium at the crucial and caudal ends of the digestive tract.
Membrane that closes the cranial end of the primitive gut.
Buccopharyngeal membrane
Occurs at week 4.
Membrane that closes the caudal end of the primitive gut.
Cloacal membrane.
Membrane forms at week 4.
Components of the [5]
Oesophagus
Stomach
Proximal half of the duodenum
Liver
Pancreas
Components of the midgut [6]
Distal half of the duodenum
Jejunum
Ileum
Cecum
Ascending and 3/4 of the transverse colon (first part of the colon)
Components of the hindgut [5]
The last 1/4 of the transverse colon
Descending colon
Sigmoid colon
Rectum
Origin of the mesentery
Mesodermal origin
Mesentery
- structure
- two types
- function
Structure formed from the double layer of the peritoneum.
Can be dorsal or ventral.
Function:
- Suspends gut organs
- Pathway for various structures: blood vessels, nerves, lymphatics.
What mesentery degenerates during development
Ventral mesentery
Only part that remains is the foregut.
Dorsal mesentery ligaments [4]
Gastrosplenic
Lienorenal
Greater omentum
Mesentery of the small and large intestines.
Ligaments of the ventral mesentery
Ligaments of the liver
Falciform
Lesser omentum
Lesser omentum
- What mesentery
- Function
Of the ventral mesentery.
Attaches the lesser curvature of the stomach to the liver.
Contains a free edge that allows one to reach to the back of the stomach.
Other term for abdominal cavity
Abdominopelvic
Inguinal ligament
Ligament that attaches the Anterior, superior iliac spine (ASIS) to the pubic tubercle.
Location of the Inguinal canal.
External oblique
- Origin
- Insertion [3]
- Fibres
Skeletal muscle of the anterior abdominal wall.
Contains fibres going downwards.
Origin:
Outer surface of the lower 8 ribs.
Insertion:
- Linea alba
- Iliac crest
- Pubic tubercle
Internal obliques
- Origin [2]
- Insertion [3]
- Fibres
Muscle of the anterior abdominal wall with upward fibres.
Origin:
- Lateral third of linguinal ligament.
- Anterior 2/3 of the iliac crest.
Insertion:
- Linea alba
- Costal margin
- Crest of pubic bone
Transversus abdominis
- Origin [3]
- Insertion [2]
- Fibres
Muscle of the anterior abdominal wall with horizontal fibres.
Origin:
- Lateral third of the inguinal ligament.
- Interior surface of the lower 6 ribs.
- Iliac crest.
Insertion:
- Linea alba
- Crest of pubic bone
Rectus abdominis
- Origin [2]
- Insertion [2]
- Fibres
Anterior abdominal muscle with vertical fibres.
Origin:
Pubic symphysis
Pubic crest
Insertion:
Xyphoid process
5-7th costal cartilages
Arteries that supply the muscles of the anterior abdominal wall.
Superior and inferior epigastric.
Intercostal
Circumflex iliac
Veins that drain the muscles of the anterior abdominal wall.
Thoracoepigastric vein
Innervation of the muscles on the anterior abdominal wall.
Thoracoabdominal nerves
Thoracic and subcostal nerves- supply rectus abdominis
Function of the external oblique muscle
Torsional movement of the trunk- works with internal oblique.
Function of the internal oblique muscle
Flexes and rotate the trunk.
Compresses viscera.
Function of the transverse abdominis
Compresses viscera
Supports viscera
Function of the rectus abdominis
Flexes the trunk
Compresses viscera
Greater and lesser pelvis
Greater pelvis:
- Also false pelvis, contains abdominal organs.
Lesser pelvis:
- Also true pelvis, contains pelvic organs.
Pelvic inlet
- boundaries
Planar surface of the pelvis that separates the abdominal from the pelvic cavity.
Posteriorly- promontory
Posterio-lateraly- margin of ala
Laterally- Arcuate line.
Anterolateraly- pecten pubic
Anteriorly- pubic crest.
Lesser sac
Formed as a result of organ rotation.
The sac is the region behind the stomach.
Greater sac
Formed as a result of organ rotation.
The majority of the peritoneal cavity that is not behind the stomach.
The greater sac communicates with the epiploic foramen
Inguinal canal
- Structures that limit it
- Comparison in male vs females
- Similarity in males and females
Difference in males and females:
- Canal is larger in males.
- Passageway for the spermatic cord in males.
- Passageway for the round ligament of the uterus in females.
Structures that limit it:
- Superficial inguinal ring: formed by aponeurosis of the external oblique transversalis fascia
- Deep inguinal rings: formed by the transversalis fascia
Similarities in males and females:
- Genital nerve passes through the canal
Genital nerve
- Origin
- Innervation in males and females
Branch of the genitofemoral nerve that passes through the inguinal canal.
Present in both males and females.
- Supplies the cremaster muscle and anterior scrotal skin in males
- Supplies the skin of the mons pubis and labia majora in females.
Spermatic cord
Structure that inguinal canal serves as a passageway for.
Contains:
- Vas deferens: carries sperm to the ejaculatory duct.
- Gonadal vessels
- Cremaster muscle
- Nerves, lymphatics.
Internal spermatic fascia
The innermost covering of the spermatic cord.
Derived from the transversalis fascia of the abdominal wall.
Transversalis fascia
An aponeurotic membrane between the inner surface of the transverse abdominis and the parietal peritoneum.
Contributes to the internal spermatic fascia.
Cremasteric fascia
The middle covering layer of the spermatic cord.
It is a continuation of the aponeurosis of the abdominal internal oblique muscle.
External spermatic fascia
The outer covering of the spermatic cord.
It is a continuation of the aponeurosis of the abdominal external oblique muscle.
