understanding the peritoneal cavity Flashcards
what are the 3 layers that the peritoneal cavity originates from?
- endoderm
- mesoderm
- ectoderm
what is formed from the endoderm?
- majority of the gut
- most of epithelium and glands of digestive tract
what is formed from the mesoderm?
muscular layers
what is formed from the ectoderm?
epithelium at extremities of tract (cranial and caudal)
what are the key characteristics of the primitive gut?
- formed as a result of 2 folds: cranial-caudal (head to tail) and lateral (side to side)
- at 4 weeks the cranial and caudal ends are still closed by membranes: bucco-pharyngeal and cloacal
what are the 3 divisions of the gut?
- foregut
- midgut
- hindgut
what is contained in the foregut?
- oesophagus
- stomach
- proximal half duodenum
- liver
- pancreas
what is contained in the midgut?
- distal half duodenum
- jejunum
- ileum
- cecum
- ascending and 3/4 transverse colon
what is contained in the hindgut?
- 1/4 transverse colon
- descending & sigmoid colon
- colon
what holds the primitive gut in place?
mesenteries
what forms the mesentery?
double layer of peritoneum
what are the 2 types of mesentery?
- dorsal
- central
what are the functions of the mesentery?
- suspends intensities
- pathway for blood, innervation & lymphatic to reach the gut
- ventral mesentery degenerated during development, except for foregut
what is the cause of the anomaly of gut rotation?
unclear
what is the format of gut rotation?
- duodenum construction
- midgut volvulus, leading to ischaemia, necrosis or possible death
what are the common symptoms of gut rotation?
- vomiting
- pain
- abdominal distention
where does the dorsal mesentery attach?
attaches gut organs to posterior abdominal wall
what does the dorsal mesentery give rise to?
- gastrosplenic ligament
- lienorenal ligament
- greater omentum
- mesentery of small & large intestine
what does the ventral mesentery give rise to?
foregut region only
- ligaments around the liver
- falciform ligament
- lesser omentum
what does the lesser omentum attach together?
attaches lesser curvature stomach to back of liver and has a free edge
where is the abdomen?
below diaphragm
what composes the abdominal wall?
- flat abdominal muscles
- lumbar vertebral column
where does the external oblique muscles go from and to?
- from: outer surface of lower 8 ribs
- to: linea alba, iliac crest, pubic tubercle
where does the internal oblique muscles go from and to?
- from: lateral 1/3 inguinal ligament, anterior 2/3 of iliac crest
- to: linia alba, costal margin, crest of pubic bone
where does the transversus abdominis go from and to?
- from: lateral 1/3 inguinal ligament, interior surface lower 6 ribs, iliac crest
- to: linea alba, crest of pubic bone
where does the rectus abdominis go from and to?
- from: pubic symphysis and crest
- to: xyphoid process, 5-7th costal cartiladges
what are the arteries and veins that supply the abdominal wall?
- arteries: superior and inferior epigastric, intercostal, circumflex iliac
- veins: thoracoepigastric
what is the innervation for the abdominal wall?
thoracoabdominal nerves
what is the function of the external oblique?
work with interior oblique for torsional movement of trunk
what is the function of the internal oblique?
flex and rotate trunk; compress viscera
what is the function of the transversus abdominus?
compress and support viscera
what is the function of the rectus abdominus?
flexes trunk; compress viscera
what are the key characteristics of the lesser/greater sacs
- formed as a result of organ rotation
- lesser sac behind stomach
- rest of peritoneal cavity: greater sac
- communicate via epiploic foramen
what does the inguinal canal do?
serves as a passageway for: spermatic cord to reach the scrotum in the male and the round ligament of the uterus to reach the labia majora in the female
what invites the inguinal canal?
invited by the superficial and deep inguinal rings
what travels through the inguinal canal?
the genitcal nerve and other blood and lymphatic vessels
where is the inguinal canal larger?
larger in males than females
what the spermatic consist of?
- vas deferens
- gonadal vessels
- nerves
- lymphatics
- cremaster muscle
what does the transversalic fascia contribute to?
the innermost covering of the spermatic cord - the internal spermatic fascia
what does the internal oblique contribute to?
the middle covering layer to the cord - the cremasteric fascia
what does the external oblique contribute to?
the outer covering of the cord - the external spermatic fascia
