understanding the peritoneal cavity Flashcards
what is the origin of the gut? 4
- gastrula (stage following the blastula)
- endoderm- majority of gut, including most of the epithelium and glands of the digestive tract
- mesoderm- muscular layers- gives rise to the visceral peritoneum
- ectoderm- epithelium at extremities of tract (cranial and caudal)
describe the primitive gut? 4
- formed as a result of two folds:
- cranial-caudal (head to tail)
- lateral (side to side)
- at 4 weeks, the cranial and caudal ends are still closed by membranes: bucco-pharyngeal and cloacal
describe gut division? 3
- foregut
- midgut
- hindgut
what does the foregut consist of? 5
- oesophagus
- stomach
- proximal half duodenum
- liver
- pancreas
what does the midgut consist of? 5
- distal half duodenum
- jejunum
- ileum
- cecum
- ascending and 3/4 transverse colon
what does the hindgut consist of? 2
- 1/4 transverse, descending and sigmoid colon
- rectum
how is the primitive gut held in place?
by mesenteries (a structure of mesodermal origin)
what is a mesentery? 4
- formed by a double layer of peritoneum, dorsal or ventral according to its position with respect to the gut tube
- suspends intestines
- pathway for blood, innervation and lymphatics to reach the gut
- ventral mesentery degenerates during development, except for the foregut
describe the anomaly of gut rotation? 3
- cause is unclear
- format is duodenum constriction, midgut volvulus leading to ischaemia, necrosis or death
- symptoms include vomiting, pain and abdominal distention
describe the dorsal mesentery?
what does it give rise to? 4
- attaches gut organs to posterior abdominal wall
- give rise to:
- gastrosplenic ligament
- linenorenal ligament
- greater omentum
- mesentery of small and large intestine
describe the ventral mesentery?
what does it give rise to? 3
at the foregut region only
- give rise to:
- ligaments around liver
- falciform ligament
- lesser omentum
what is the lesser omentum? 2
- attaches lesser curvature of the stomach to back of the liver
- has a free edge
where is the abdomen? 3
- below the diaphragm
- abdominal cavity is occasionally called abdominopelvic (abdomen proper and greater pelvis)
- greater pelvis is continuous with lesser pelvis
where is the inguinal ligament?
- runs between the anterior superior iliac spine and the pubic tubercle
what makes up the abdominal wall? 2
- flat abdominal muscles
- lumbar vertebral column
what muscles are in the anterior abdomen wall? 4
- external oblique (from outer surface of lower eight ribs to linea alba, iliac crest and public tubercle)
- internal oblique (from lateral 1/3 of inguinal ligament and anterior 2/3 of iliac crest, to linea alba costal margin and crest of pubic bone)
- transverse abdominis (from lateral 1/3 inguinal ligament , interior surface of lower 6 ribs and iliac crest, to the linea alba and crest of the pubic bone)
- rectus abdominis (from pubic symphysis and crest to xiphoid process and 5th-7th costal cartilages)
what is the blood supply/ drainage to muscles in the anterior abdomen wall? 2
innervation?
- Arteries: superior and inferior epigastric, intercostal, circumflex iliac
- Veins: thoracoepigastric
- thoracoabdominal nerves (also thoracic and subcostal nerves for rectus abdominis)
what are the functions of the muscles in the anterior abdomen wall? 4
- External oblique= work with internal oblique for torsional movement of trunk
- Internal oblique= flew and rotate trunk, compress viscera
- Transversus abdominis= compress and support viscera
- Rectus abdominis= flexes trunk, compress viscera
what are the lesser and greater sacs? 4
- formed as a result of organ rotation
- lesser sac if behind stomach
- rest of peritoneal cavity= greater sac
- communicate via the epiploic foramen (of Winslow)
what is the inguinal canal? 4
- serves as a passageway for the spermatic cord to reach the scrotum in the male and the round ligament of the uterus to reach the labia majora in the female
- limited by superficial and deep inguinal rings
- for both genders the genital nerves (a branch from the genitofemoral) and other blood and lymphatic vessels also travel thoughout this canal
- the inguinal canal is considerably larger in males than females
describe the spermatic cord? 5
- consists of vas deferens, gonadal vessels, nerves, lymphatics and the cremaster muscle
- as the spermatic cord passes through the abdominal wall, it takes a sleeve or covering from each of the 3 layers
- transveralis fascia= contributes the innermost covering of the spermatic cord, the internal spermatic fascia
- internal oblique= contributes the middle covering layer to the cord, the cremasteric fascia
- the external oblique= contributes the outer covering of the cord, the external spermatic fascia
what is the abdomen?
a specifically defined region
what is does the peritoneum cover?
abdomen and abdominal organs
what is the peritoneal cavity divided into?
divided into sacs
