The peritoneal cavity Flashcards
Define gastrula
The stage following the blastula. Embryo develops 3 layers: ecto-, meso- and endoderm
Which organ does the word gastrula refer to?
The stomach
When does the alimentary system begin to develop?
2-3 weeks
State what originates from the endoderm
Majority of gut, including most of epithelium and glands of digestive tract
State what originates from the mesoderm
Muscular layers
State what originates from the ectoderm
Epithelium at extremities of tract (cranial and caudal)
Name the two folds during embryological development which form the primitive gut
cranial-caudal
lateral
Name the membranes closing the ends at week 4
bucco-pharyngeal
cloacal
Describe the contents of the foregut
Oesophagus Stomach Proximal half Duodenum Liver Pancreas
Describe the contents of the midgut
Distal half duodenum, Jejunum, Ileum, Cecum, Asc. + ¾ Transv. Colon
Describe the contents of the hindgut
¼ Transv. + Desc. + Sigmoid Colon & rectum
How is the primitive gut held in position?
By mesenteries
What is the parietal peritoneum?
Layer of fascia
What is a mesentery?
Formed by a double layer of peritoneum
List the functions of mesentery
Suspends gut organs
Pathway for blood, innervation, lymphatics etc to reach the gut
Ventral mesentery degenerates during development, except for…
Foregut
Describe dorsal mesentery
Attaches gut organs to posterior abdominal wall
What does the dorsal mesentery give rise to?
Mesentery of small & large intestine
Greater omentum
Lienorenal ligament
Gastrosplenic ligament
What does the ventral mesentery give rise to?
Ligaments around the liver
Lesser omentum
Falciform ligament
Describe the lesser omentum
Attaches lesser curvature stomach to back of liver
Has a free edge
Where is the ventral mesentery?
Foregut only
What is the inguinal ligament?
From ASIS to pubic tubercle
Describe the external oblique
From: outer surface of lower eight ribs
To: linea alba
iliac crest
pubic tubercle
In which direction do the fibres of the external obliques go?
Hands in pockets
Describe the internal obliques
From: lat 1/3 inguinal ligament ant 2/3 of iliac crest To: linea alba costal margin crest of pubic bone
In which direction do the fibres of the internal obliques go?
Hands on tits
Describe the transversus abdominis
From: lat 1/3 inguinal ligament int surf lower 6 ribs iliac crest To: linea alba crest of pubic bone
Describe the rectus abdominis
From: pubic symphysis + crest
To: xyphoid process
5th-7th costal cartilages
Describe the function of external oblique
work with Int Obl for torsional movement of trunk
Describe the function of internal oblique
flex and rotate trunk; compress viscera
Describe the function of transverse abdominis
compress and support viscera
Describe the function of rectus abdominis
flexes trunk; compress viscera
Name the veins and arteries supplying the abdominal muscles
Arteries: Sup and Inf epigastric, intercostal,
circumflex iliac
Veins: thoracoepigastric
(between lat thoracic and Sup epigastric)
Name the innervation of the abdominal muscles
Thoracoabdominal nerves (also thoracic and subcostal nerves for rectus abdominis)
What is meant by retroperitoneal?
An organ found in more than one cavity.
How are the greater and lesser sacs formed?
Result of organ rotation
How do the greater and lesser sacs communicate?
Epiploic foramen (of Winslow)
Where is the lesser sac found?
Behind the stomach
What goes through the inguinal canal?
Spermatic cord to reach the scrotum in the male
The round ligament of the uterus to reach the labia majora in the female
For both genders the genital nerve (a branch from the genitofemoral) and other blood and lymphatic vessels also travel through this canal
Which gender has a larger inguinal canal?
Men
How many layers form the wall of the spermatic cord?
3
