Module 1.4: The Organization of the Human Body

Question 1

List the subdivisions of the thoracic and abdominopelvic cavities

Answer 1

Thoracic cavity
- plearal cavity
- pericardial cavity
- mediastinum

Abdominopelvic cavity
- abdominal cavity
- pelvic cavity

Question 2

What are serous membranes, and what are their functions?

Answer 2

thin sheets of tissue from body cavity
single and continuous layer, enclose a single space like a bean bag chair

3 main serous membranes:
1. pleural membranes : around the lungs, forms pleural cavities
- parietal pleura(outer layer, curving along the thoracic wall)
- visceral pleura(inner, running along the surfaces of the lungs)

2. pericardial membranes: around the heart, forms pericardial cavity
   - parietal pericardium(encircling the heart in the mediastinum)
   - visceral pericardium(attacehd to the heart muscle)
3. peritoneal membranes: around some abdominal organs, forms the peritoneal cavity(much larger than the others)
   - parietal peritoneum
   - visceral peritoneum
   intraperitoneal organs are surrounded by visceral peritoneum
   cf. retroperitoneal organs(kidneys, …) lie behind the parietal peritoneum, not located within the peritoneal cavity

Within the cavity between the visceral layer and the parietal layer ->serous fluid’s primay functions
: Lubricate organs
: Prevent frictions as they move against adjacent structures

Question 3

Explain how serous membranes form certain anterior body cavities.

Answer 3

Between the two parts of serous membranes, which are visceral layer being attached to the organ and patrietal layer, surrounding the structure

i.e. Pleural cavity is the space enclosed by parietal pleura(the outer layers, curving along the thoracis wall) and visceral pleura(the inner layers, contacts the organ)

Question 4

In an industrial accident, a piece of shattered equipment enters a man’s body near the right anterior pelvis and travels through the organs until it rests inside the left lung. List all of the body cavities and serous membranes through which the fragment passed on its way through this man’s body.

Answer 4

The fragment entered the pelvic cavity, then passed into the abdominal cavity, where it likely encountered the peritoneal cavity (and the parietal and visceral peritoneal membranes). The fragment then pierced the diaphragm to enter the thoracic cavity and finally the pleural cavity (passing through the parietal and visceral pleural membranes).

parietal pleura&visceral pleara
parietal peritoneum&visceral peritoneum

Question 5

Certain conditions lead to inadequate serous fluid in the pleural cavities. Predict the effects of these conditions.

Answer 5

impairs the lung’s ability to move within the cavity without friction. This could lead to pain as the two layers of the serous membrane rub together

Question 6

Inflammation of serous membranes may cause the cavities to fill with excess serous fluid. Predict ​how this will affect the function of the organs they surround.​

Answer 6

This condition will impair an organ’s ability to expand, as the excess serous fluid will compress the organ.

Question 7

Describe the location of the body cavities. Identify the major organs found in each cavity.

Answer 7

Posterior body cavity
- Cranial cavity(within skull) - brain
- Vertebral/spinal cavity(within vertebral column) - spinal cord
the two cavities are continuous with each other

Anterior body cavity
Thoracic cavity
- Pleu_r_ar cavities(spelling!) - the lungs
- Mediastinum: the heart, great blood vessels, trachea and esophagus
- Pericardial cavity(within the mediastinum) - the heart

Abdominopelvic cavity

• Abdominal cavity
  contains the organs of the digestive, lymphatic and urinary systems.
  Peritoneal cavity - the liver, the stomach, large and small intestines
• Pelvic cavity
  contains the organs of the reproductive, digestive, and urinary systems