Types of Cells in our Body

Keywords

Cells, red blood cells, white blood cells, platelets, endothelial cells, stem cells, reproductive cells, sperm, ova, bone cells, muscle cells, myocytes, fat cells, adipocytes, skin cells, nerve cells, pancreatic cells, haploid, diploid.

Introduction

We have a lot of cells in our body. Some go through our body supplying us with oxygen, some connect together to make tissues or organs, and othes fight off infection. Here, we take a closer look at them.

Interesting fact: there are more than 20 different types of cells in our bodies, ranging from ones that make up our muscles and bones, to ones that fight infection, and ones we can reproduce from.

Blood Cells

We have several cells that travel through our circulatory system. They include:

Red Blood Cells: they travel through our circulatory system gathering oxygen from the lungs, and redistributing it to the rest of the body where it is needed.

White Blood Cell: they travel with the red blood cells, and fight off infection. Some of them fight any pathogen that enters our body, and some of them are specific to a type of disease or infection.

Platelets: these are small plate-shaped cells that just flow with the plasma and blood cells, but when needed, they change to spiky shaped cells that help with regeneration of a cut or graze.

Endothelial cells: a thin layer of cells that provide a wall between the blood vessels (veins, capillaries and arteries) and the rest of the body. They are there to help maintain a protective layer between these two so that the blood doesn't get infected, or go off somewhere it shouldn't.

You can read more about what they do in the Circulatory System section.

Stem Cells

A stem cell is a cell with no assigned function. These cells are handy, as they can be given a purpose when they are matured, and at a moment's notice. If you're fighting off an infection, more white blood cells can be made through maturation of a stem cell.

You can read more about these in the Bone Marrow section.

Reproductive Cells

Sperm: one of the two types of gamete in our body, a male will produce a sperm cell. These are tiny cells that when released into a woman's vagina, fight their way up to an ova, or egg.

Ova (Egg): the egg cell is situated in the woman's reproductive system, and once joined with a sperm cell, allows for the creation of a baby. A woman will have all the eggs she needs to reproduce before she is even born, as during the foetal stage of pregnancy, all the eggs are created then.

You can read more in the Reproductive System section.

Other Types of Cells

There are a plethora of other types of cells in our body. Here are some more:

Bone Cells

These are cells that make up the bones in our body. They need to be strong, and able to support the rest of the body. Once created, they are difficult to break (please, don't try!), and are very dense.

Bone cells are made for the skeleton, and grow inside our body as we continue to develop from a small child to an adult.

Muscle Cells

Muscles are made up of cells (myoctyes). Some are made up of a lengthy and fibrous material (skeletal), others are barred (cardiac and skeletal), and others are smooth. They are able to contract and expand using a series of motor proteins within them, which specifically arrange depending on what is required for them.

Some organs like the heart are actually a giant muscle, and are made up of muscle cells. Because the heart contracts with each beat, muscle cells are needed for this rhythm.

Fat Cells

Now, don't go around telling people that they're fat, that's not nice. We all have fat cells (adipocytes) in our body. They are regulated by our organs and systems to maintain a healthy amount.

We need them to remain warm, as if we didn't have them, we would simply freeze. Animals also have similar fat deposits in their bodies. If you were to look at animals like the walrus or seals, for example, you would see they rely on it to keep them warm, especially in places like the Arctic Circle.

Skin Cells

We need our skin, as it keeps everything inside our body. Without it, it would make us look very different. A fun fact about our skin: when we eat, it takes up to 7 days for the nutrients to come to the surface (so to speak).

Our skin regenerates on a 7 day cycle, so if you eat an unhealthy meal (McDonald's or KFC for instance), about a week later, you would notice differences in your skin - it would be a little more greasy, etc.

Nerve Cells

Our nervous system is literally littered with nerve cells. They react to electrical impulses from the brain, and enable us to move our fingers, toes, arms, legs - basically everything. They also react to senses - touch, sight, smell, etc.

There are three types of nerve cell - sensory, motor and relay, and they work together to allow us movement and also gives us sight. Yes, nerve cells allow our eyes to move and picture what we are looking at.

Pancreatic Cells

As the pancreas is both an endocrine and an exocrine gland, it helps with many functions, including the digestion of food, and the maintenance of blood glucose levels. For this purpose, it has three different types of cells to enable its functions.

The three types of cells include: acinar cells, which have an exocrine function; Islets of Langerhans, which are split between four sub-types and have different functions; and pancreatic stellate cells, or PSC, which help repair injured parts of the pancreas.

Haploid vs Diploid

So, most of the cells in our body are known as diploid. This is because they have both sets of chromsomes in each cell. There are also other differences, including the fact that they divide by mitosis to create new cells.

The other type of cell is called haploid. This is singularly the reproductive cells in each of the male and female body, the sperm and egg (ova). They are haploid as they only contain one set of chromosomes each. This is because in order to carry all the chromosomes, we need the cells from the father and mother present in order to do so. They are provided by each of the reproductive cells as mentioned before.

Haploid cells also reproduce, but by meiosis, instead of mitosis.