Serous Membranes & Body Cavities

Question 1

Serous Membranes

Answer 1

Thin tissue layers that line certain body cavities and cover internal organs.

They have 2 layers:
* Parietal layer & Visceral layer

It produces serous fluid

Question 2

Parietal layer

Answer 2

Outermost layer of serous membrane, attached to the body wall and surrounding structures.

Example: parietal pericardium (around the heart), parietal pleura (around the lungs).

Question 3

Visceral layer

Answer 3

Inner layer of serous membrane, attached to the organs (called viscera).

Example: visceral pericardium (on the heart), visceral pleura (on the lungs).

Question 4

Serous Fluid

Answer 4

• watery substance that the serous membranes produces
• Found between the parietal and visceral layers.
• Serves as a lubricant for the organs allowing them to move freely without friction within the cavity

Ex. pleural fluid (around lungs), pericardial fluid (around the heart).

Question 5

Body Cavities

Answer 5

Body cavities hold organs, and they’re fluid-filled and lined by thin tissue layers called serous membranes.

• 2 major cavities: anterior & posterior cavities

Question 6

Major Cavity 1 - Anterior/Ventral Cavity

Answer 6

• Made of 2 parts: Thoracic Cavity and Abdominopelvic Cavity, which contains organs/structures found in the anterior side of the body.
• The cavities are separated by a thin muscle called the diaphragm.

Question 7

Minor Cavity 1: Thoracic Cavity

Answer 7

located above the diaphragm and contains chest organs.
* minor cavity within the major ventral cavity

Divided into 3 smaller cavities: mediastinum, pleural, & pericardial cavities.

Question 8

Mediastinum

Answer 8

• Small cavity within the minor thoracic cavity
• A space between the lungs, from neck to diaphragm.
• Contains the heart, esophagus, trachea, blood vessels, lymph nodes, and nerves

Question 9

Pleural Cavity

Answer 9

• Small cavity within the minor thoracic cavity
• Surrounds each lung
• Contains serous membranes (parietal & visceral pleura) and pleural fluid (lubricates the lungs).

Question 10

Pericardial Cavity

Answer 10

• Small cavity within the minor thoracic cavity
• A space between the lungs that contain the heart & other cardiac structures only
• Contains serous membranes (parietal & visceral pericardium) and pericardial fluid (lubricates the heart).

“Peri-“ means around
The heart is found both in the mediastinum & pericardial cavity. Pay attention to the inclusion of the word “only” in the question.

Question 11

Minor Cavity 2: Abdominopelvic Cavity

Answer 11

The space found below the diaphragm and contains most of the digestive, urinary, lymphatic, endocrine, and reproductive organs.
* minor cavity within the major ventral cavity
* can be divided into 4 quadrants: right upper, right lower, left upper & left lower

Divided into 3 smaller cavities: abdominal, peritoneal, & pelvic cavities.

Question 12

Abdominal Cavity

Answer 12

• small cavity within the minor abdominopelvic cavity
• Above the pelvic cavity.
• spans from the diaphragm to the the pelvic brim
• Contains digestive organs (like the stomach, liver, intestines) and some urinary and endocrine organs.

Question 13

Peritoneal Cavity

Answer 13

• small cavity within the minor abdominopelvic cavity
• Contains the serous fluid called peritoneal fluid (lubricates organs).
• A space found between the 2-layered serous membrane called the peritoneum.
• Intraperitoneal: Organs inside the peritoneal cavity (the liver, most of the small intestine, much of the colon, the stomach, the spleen, & part of the pancreas).
• Retroperitoneal: Organs behind the peritoneal cavity ( kidneys, adrenal glands, the sex organs, the urinary bladder, part of the colon, & part of the pancreas)

The 2 layers of the peritoneum are called the:
* outter parietal peritoneum: Lines the cavity wall.

• inner visceral peritoneum: Covers and holds organs in place (like the liver, small intestine, spleen, stomach).

Question 14

Pelvic Cavity

Answer 14

• small cavity within the minor abdominopelvic cavity
• Below the pelvic brim
• Contains organs like the urinary bladder, reproductive organs, rectum, and prostate gland.

Question 15

Major Cavity 2 - Posterior/Dorsal Cavity

Answer 15

• Made up of 2 minor cavities: cranial & vertebral cavities, which pretty much contains the major organs of the nervous system.

Question 16

Minor Cavity 1: Cranial Cavity

Answer 16

• minor cavity within the major dorsal cavity
• Contains the brain and is enclosed by the skull

Both cavities, cranial & vertebral, are lined with membranes called meninges (singular: meninx), instead of serous membranes.

Question 17

Minor Cavity 2: Vertebral Cavity

Answer 17

• minor cavity within the major dorsal cavity
• Contains the spinal cord and is enclosed by the vertebrae (spine).

Both cavities, cranial & vertebral, are lined with membranes called meninges (singular: meninx), instead of serous membranes.