Download Outline22 Coelom - Napa Valley College

Biology 218 – Human Anatomy
Coelom and Peritoneum
Clemens
Ch.1:14-17; Ch.11:350; Ch.24:761-763
A. Coelom – fluid-filled cavities within the ventral body cavity
enclosed by serous membranes
1. Embryology
- forms in early embryo (3rd-5th week)
- during 2nd month, coelom subdivides into 4 cavities:
coelomic cavities
serous membranes
surrounds the
pleural cavities (2)
pleura(e)
lungs
pericardial cavity
pericardium
heart
peritoneal cavity
peritoneum
abdominal organs (most)
B. Thoracic Cavity
- extends from the thoracic inlet to the diaphragm
1. Thoracic inlet
- bounded by first pair of ribs, manubrium of sternum, first thoracic vertebra
what passes through: trachea
esophagus
common carotid and subclavian arteries
brachiocephalic veins
vagus nerves (+ recurrent laryngeal nerves)
phrenic nerves
2. Diaphragm
- separates thoracic and abdominopelvic cavities
- primary muscle for inhalation
features: muscular portion
central tendon
what passes through: esophagus
aorta
inferior vena cava
vagus nerves
phrenic nerves (inferior branches)
thoracic duct
C. Abdominopelvic Cavity
- extends from the diaphragm to the pelvic floor muscles
1. Peritoneum
- largest serous membrane; visceral and parietal layers
- peritoneal folds:
greater omentum - “fatty apron” extends from stomach to transverse colon
lesser omentum - connects liver to stomach
falciform ligament - attaches liver to ventral body wall
mesentary - attaches small intestine to dorsal body wall
mesocolon - attaches transverse colon to dorsal body wall
intraperitoneal organs
retroperitoneal organs
stomach
liver and gallbladder
jejunum and ileum
transverse and sigmoid colon
spleen
duodenum
pancreas
ascending and descending colon
kidneys
aorta
(pelvic organs are inferior to peritoneum)
Biology 218 – Human Anatomy
Clemens
Study Questions
1.
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5.
Name the four serous membranes of the body. Distinguish between the parietal
layer and the visceral layer of each membrane. What is the largest serous
membrane of the body?
List the major organs and structures pass through the thoracic inlet.
List the major organs and structures pass through the diaphragm.
Describe the general arrangement of the peritoneum. Describe the location of the
following folds of the peritoneum and identify the organs they attach to:
● greater omentum ● lesser omentum ● falciform ligament ● mesentary
What is a retroperitoneal organ? Which abdominal organs are intraperitoneal and
which organs are retroperitoneal?