Lecture 9 - Body Cavities Flashcards
2 ventral cavities?
- Thoracic
2. Abdominopelvic
2 dorsal cavities?
- Cranial
2. Vertebral
What are the 2 areas of the thoracic cavity? What does each contain?
- Mediastinum: everything except lung
2. Pleural cavities: lungs in serous membranes
What are the 2 parts of the mediastinum?
- Superior mediastinum
2. Inferior mediastinum
What are the 3 parts of the inferior mediastinum?
- Anterior mediastinum
- Middle mediastinum
- Posterior mediastinum
What divides the superior mediastinum?
Sternal angle = imaginary plane at the joint between two bones of the sternum
What body cavity is the heart found in?
Middle mediastinum
Which is larger: anterior or posterior mediastinum? Why?
Posterior because of vertebrae and diaphragm curvatures
What is in the posterior mediastinum?
- Esophagus
- Thoracic duct
- Aorta
- Azygos system
What is in the anterior mediastinum?
Fat tissue left from thymus
What does the sternal angle plane separate?
- Superior and inferior mediastinum
- Trachia branching out into bronchi
- Boundaries of the aortic arch
- Vertebral level between T4 and T5
- Second rib joins sternum
- Azygos vein drains to IVC
What body cavity is the trachea found in?
Superior mediastinum
How to locate the sternum angle on an X-ray?
Locate the trachial bifurcation
Are most X-rays AP or PA?
PA
What 2 views are usually necessary for chest X-rays?
- PA
2. Lateral
What are the abdominal and pelvic cavities separated by?
Pelvic inlet (rim within pelvic bones)
What are the abdominal and thoracic cavities separated by?
Diaphragm
Is there an actual physical border between the abdominal cavity and the pelvis?
NOPE
What is peritoneum? 2 types?
Very thin film that covers organs in the abdomen:
- Parietal: lines abdominal wall
- Visceral: covers organs suspended in the peritoneal cavity
What are serous membranes?
Tissues that cover organs in 3 areas of the body:
THORAX
- Pericardium around the heart
- Pleura around the lungs
ABDOMEN
1. Peritoneum
What are the 2 types of organ peritoneum encasement in the abdominal cavity? Which organs are in a more fixed position?
- Intraperitoneal organs: completely covered by visceral peritoneum and held in peritoneal cavity by double layer of folded peritoneum = mesentery with slippery fluid between them so they don’t stick
- Retroperitoneal organs: positioned between peritoneum and abdominal wall, behind peritoneum (more fixed position)
Describe the inferior portion of the peritoneum.
Goes down through pelvic inlet in pelvic cavity and drapes over pelvic organs which are infraperitoneal (also forms support structures for pelvic organs)
What are the 9 structures that are retroperitoneal?
- Urinary system (kidneys, ureters)
- Adrenal glands
- Aorta and IVC
- Part of rectum
- Most of the pancreas (except for the tail)
- Most of the duodenum (except for the first segment and distal-most portion)
- Ascending and descending colon
- Lymphatic channels
- Nerves
Do both intraperitoneal and retroperitoneal organs have both visceral and parietal peritoneum?
YUP