1. Types of Membranes in Human
Body
There are five types of membranes found within the body. Membranes are flat sheets
of tissue that cover or line parts of the body and are typically composed of epithelial
cells and connective tissue. Epithelial cells cover the inner and outer layers of surfaces
and form glands that secrete fluids. Connective tissue is the most abundant type of
tissue in the body; it binds and supports the structures of the body.
MUCOUS MEMBRANE
Mucous membranes, also called mucosa, line the inside of cavities that open directly to
the exterior environment. Mucous membranes line the gastrointestinal tract,
respiratory tract, reproductive tracts and the urinary tract. This type of membrane is
composed of an epithelial cell layer and an underlying connective tissue layer. The
epithelial layer is an important defense mechanism that prevents the entry of
pathogens and microbes into the body. The cells are tightly packed together, so fluid
cannot leak through the epithelial layer. Specialized cells secrete mucous to keep the
membrane moist. Mucous also traps dust particles in the respiratory, or lung passage
ways and lubricates food as it travels through the intestinal tract. The connective tissue
component of a mucous membrane stabilizes the membrane against the structure it is
protecting; it also holds blood vessels that supply blood and nutrients to the epithelial
layer in place.

2. f. Mucous membrane, with vessels and part of a
lymphoid.
Section of the human esophagus.Moderately magnified. The section is transverse and
from near the middle of the gullet.
SEROUS MEMBRANE
Serous membranes, or serosa, line cavities of the body that do not open directly to the
external environment; it also covers the organs within the cavities. For example, this
type of membrane lines the chest and abdominal cavities, in addition to covering the
liver, spleen, kidneys, heart etc. Serous membranes are made of two layers: a layer to
line a cavity, called the parietal membrane, and a layer to cover an organ, called the
visceral layer. Serous membranes secrete a lubricant called serous fluid that allows the
organs to glide against other structures without causing friction, according to
"Principles of Human Anatomy".

3. CUTANEOUS MEMBRANE
The cutaneous membrane, also known as the skin, covers the entire body. It is
composed of many layers of epithelial cells to protect the body from invading microbes
or pathogens, in addition to light, heat and injury. The skin is the largest organ of the
body that also stores fat, vitamin D and water and houses the sensory receptors for
touch and pain. It regulates body temperature by secreting sweat to dissipate heat.
SYNOVIAL MEMBRANE
The junction where two bones meet is called a joint. Surrounding freely movable joints
like the shoulder, elbow, or knee is a synovial membrane. The synovial membrane
secretes synovial fluid to lubricate the joint space, making motion much easier. The
synovial fluid also nourishes the cartilage attached to the ends of bones and contains
immune cells called macrophages that rid the joint space of invading microbes and
debris, according to "Principles of Human Anatomy".

4. MENINGES
Covering the brain is a dense connective tissue membrane, composed of three layers,
called the meninges. The outer most layer is called the dura mater; it is a thick
connective tissue that prevents the brain from moving too much in the skull. The
second layer is the arachnoid layer; it is a loose connective tissue layer that resembles
the web of a spider. The inner most layer is the pia mater; it is a thin layer that adheres
directly onto the brain, according to California State University.