Membranes

Membranes…

are organs because they are made of 2 or more tissues working together to achieve a common function.

What are membranes made of?

They are made of epithelial tissue and connective tissue (usually simple squamous epithelium and loose areolar connective tissue

How many types of membranes are there?

There are 4

Name the 4 types of membranes

Serous (Serosa) Membrane

Mucus (Mucosa) Membrane

Synovial Membrane

Cutaneous (Skin) Membrane

Describe the Serous membrane

A membrane that is made of 2 parts, a parietal layer (lines body wall) and visceral layer (lines organs).

They line body cavities and cover organs in the cavity.

Secretes serous fluid

Made of epithelial tissue and connective tissue

What are the characteristics and function of serous fluid?

A thin, slippery, watery fluid that prevents friction.

What is a mesentery?

A mesentery is 2 serous membranes backed up against eachother and is a pathway for vessels and nerves.

Describe the Mucus membrane

Lines all openings to the outside world (e.g. respiratory system, inner tube)

Secretes mucus

All about protection

What are the characteristics and function of mucus fluid?

Thicker and sticker than serous fluid made from the mucin secreted from goblet cells and water

Helps maintain moisture and and acts as a debris and pathogen trap

Describe the Synovial membrane

Lines capsules of most mobile joints (e.g. knee)

Secretes synovial fluid

What are the characteristics and function of Synovial fluid?

Reduce friction in the joint cavity

Distribute nutrients to the cartilage of the joint surfaces of the bone

Describe the Cutaneous membrane

It is the outer body covering

Protects organs and prevents the loss and gain of water

Classified as keratinized stratified squamous ET (Epidermis)

Also contains loose areolar and dense irregular CT (Dermis)

Dry compared to other membranes

Keratinized

Cells filled with keratin protein to the point of dying

Keratin protein - impermeable to water