lect 3 membranes

What is a membrane?

A membrane is an organ made of two or more tissue types working together for a common function.

What two tissue types make up membranes?

Epithelial tissue and connective tissue.

What type of epithelium is usually found in a membrane?

Simple squamous epithelium.

What type of connective tissue is usually found in a membrane?

Loose areolar connective tissue.

What is a general function of membranes?

They generally line and cover structures.

What are the four main types of membranes?

Serous, mucous, synovial, and cutaneous membranes.

What is another name for a serous membrane?

Serosa.

Where are serous membranes located?

They line body cavities and cover organs within those cavities.

What are the two layers of a serous membrane?

The parietal layer and the visceral layer.

What does the parietal layer of a serous membrane line?

The body wall.

What does the visceral layer of a serous membrane cover?

The organs within the body cavity.

What fluid do serous membranes secrete?

Serous fluid.

What are the characteristics of serous fluid?

It is thin, watery, slippery, and fluid-like.

What is the main function of serous fluid?

It prevents friction between the parietal and visceral layers.

Why are the visceral and parietal layers usually very close together?

They normally sit very close to or almost touching each other, with a small amount of serous fluid between them that allows them to glide.

What would happen without serous fluid between the layers?

Movement would create friction, heat, and potential tissue damage.

What serous membrane is associated with the abdominal cavity?

The peritoneum.

What is the visceral peritoneum?

The portion of the serous membrane that covers the abdominal organs.

What is the parietal peritoneum?

The portion of the serous membrane that lines the abdominal body wall.

What happens between the visceral and parietal peritoneum when the body moves?

They slide across one another, helped by serous fluid, which prevents friction.

What serous membrane is associated with the lungs?

The pleura.

What is the visceral pleura?

The serous membrane layer associated with and covering the lungs.

What is the parietal pleura?

The serous membrane layer that lines the body wall of the thoracic cavity.

Why is serous fluid important around the lungs?

It allows the pleural layers to slide against each other as the lungs inflate and deflate, preventing friction.

What serous membrane surrounds the heart?

The pericardium.

What are the two layers associated with the pericardium?

The visceral pericardium and parietal pericardium.

Why is serous fluid important around the heart?

The heart beats continuously, so serous fluid allows the layers to slide against one another and prevent friction.

What is a mesentery?

A structure formed by two serous membranes positioned back-to-back with connective tissue between them.

What structures are found within the connective tissue of a mesentery?

Arteries, veins, and nerves.

What is the function of a mesentery?

It provides a pathway for blood vessels and nerves to travel between an inner tube/organ and the outer body wall.