P2: Outline the structure of the main tissues of the body
Tissues are made from specialist cells and are the material that humans are made from. The
main tissues of the body which I will be looking at are:
Skin
The purpose of skin is to protect our bodies, regulate the temperature around us, allow us to
sense and feel things, and excretion of water, urea, ammonia, and uric acid. Skin has three
layers: the epidermis, dermis, and hypodermis. The colour of the skin is determined by cells
in the epidermis called melanocytes which produce melanin.
There are several types of skin made from different cell structures these are -
Epithelial
Epithelial tissues line the surfaces of blood vessels and organs throughout the body.
Functions of epithelial cells include secretion, selective absorption, protection, transcellular
transport, and sensing. The epithelial layers do not contain blood vessels meaning that they
have to recieve nourishment from diffusion of substances from surrounding connective
tissue.
Squamous cells
Squamous cells are flat cells that look like fish scales. They make up most of the cells in the
outer layer of our skin. One side of the cells opens to the environment while the other cells
provide a thin membrane that allows small molecules to enter into the body.
Ciliated cells
Cilia are hair-like structures that sit on top of tissue. They wave back and forth to help move
things like mucus. They are often found in the upper respiratory tract and fallopian tubes.
Goblet cells
Goblet cells are found in the epithelia of most organisms. The main role of goblet cells is to
secrete mucus to protect the mucous membranes. Goblet cells accomplish this by secreting
mucins, large glycoproteins formed mostly by carbohydrates. The term goblet refers to the
cell’s goblet shape.
Blood: (red blood cells, white blood cells, platelets)
Red blood cells
Red blood cells transport oxygen and minerals for aerobic respiration. They help absorb
oxygen in the lungs by going through narrow blood vessels, and release oxygen to respiring
cells. Red blood cells have a biconvave shape which allows it to maneuver through blood
vessels.
White blood cells
White blood cells ingest pathogens and destroy them, they produce antibodies to destroy