TYPES OF CELLS IN HUMAN BODY

WHAT ARE STEM CELLS ?

Stem cells are special human cells that are able to develop into many different cell types. This can range from muscle cells to brain cells. In some cases, they can also fix damaged tissues.

STEM CELL

WHAT ARE RED BLOOD CELLS?

Red blood cell, also called erythrocyte, cellular component of blood, millions of which in the circulation of vertebrates give the blood its characteristic color and carry oxygen from the lungs to the tissues. The mature human red blood cell is small, round, and biconcave; it appears dumbbell-shaped in profile. The cell is flexible and assumes a bell shape as it passes through extremely small blood vessels. It is covered with a membrane composed of lipids and proteins, lacks a nucleus, and contains hemoglobin—a red iron-rich protein that binds oxygen.

RED BLOOD CELL

WHAT ARE WHITE BLOOD CELLS ?

White blood cell, also called leukocyte or white corpuscle, a cellular component of the blood that lacks hemoglobin, has a nucleus, is capable of motility, and defends the body against infection and disease by ingesting foreign materials and cellular debris, by destroying infectious agents and cancer cells, or by producing antibodies.

WHITE BLOOD CELL

WHAT ARE NERVE CELLS?

Nerve cells, commonly known as neurons, transmit information throughout the body in the form of electrical signals or nerve impulses. Structurally, neurons have four specific regions; the cell body, dendrites, the axon and axon terminals. The cell body contains a nucleus and is responsible for synthesising neural proteins. The axon is long and thin, and protrudes from the cell body like a tail and can be myelinated or unmyelinated. Axons are responsible for conducting electrical impulses in the form of action potentials, away from the cell body.

NERVE CELL

WHAT ARE NEUROGLICAL CELLS ?

Neuroglial cells, more commonly known as glial cells or glia, are cells of the nervous system that are not involved in the conduction of nervous impulses. Glia are very common in the brain, outnumbering neurons at a ratio of 3 to 1. Glia are smaller than neurons, and do not have axons or dendrites. They have a variety of roles in the nervous system, they modulate synaptic action and rate of impulse propagation, they provide a scaffold for neural development, and aid recovery from neural injuries.

NEUROGLICAL CELL

WHAT ARE MUSCLE CELLS ?

There are 3 types of muscle cells, known as myocytes, in the human body. These types are skeletal, cardiac and smooth muscle. Skeletal and cardiac muscle cells are known as striated, due to the aligned arrangement of myosin and actin proteins within them. Actin and myosin allow muscle contraction by sliding past one another, as described by sliding filament theory. Actin and myosin are arranged more randomly in smooth muscle cells, creating a smooth rather than striated appearance.

MUSCLE CELL

WHAT ARE CARTILLAGE CELLS?

Cartillage cells, also known as chondrocytes, make up cartilage, a firm tissue that is vital to the body’s structure. Cartilage is found in joints between bones, in the ears and nose, in the airways as well as other locations. For example, cartilage can be found between the vertebrae in the spinal column.

CARTILLAGE CELL

WHAT ARE BONE CELLS ?

There are four types of bone cells in the body; osteoblasts, osteoclasts, osteocytes and lining cells.

BONE CELL

WHAT ARE SKIN CELLS ?

There are many different types of cells in the epidermis (top layer) of the skin. The epidermis contains the following cell types:

-keratinocytes

-melanocytes

-langerhans cells

-merkel cells

SKIN CELL

WHAT ARE ENDOTHELIAL CELLS ?

Endothelial cells are the cells that form the lining of blood vessels. They are flat in structure, and are between 1 and 2 µm thick. They have a central nucleus, and are connected to one another via intercellular junctions. Endothelial cells are highly adaptable, being able to migrate and adjust their numbers and arrangements to accommodate the body’s needs. This allows growth and repair of body tissues, as new blood vessel networks can easily form.

ENDOTHELIAL CELL

WHAT ARE EPITHELIAL CELLS ?

Epithelial cells make up the linings of cavities in the body such as the lungs, small intestine and stomach. They are joined to one another forming sheets called epithelia, and are connected by tight junctions, adherens, desmosomes and gap junctions. Tight junctions are unique to epithelial cells and form the closest type of junction between any cell type in the body. They are supported by a basement membrane known as a basal lamina, which covers a capillary bed. The nucleus of an epithelial cell is found close to the basal lamina, towards the bottom of the cell.

EPITHELIAL CELL

WHAT ARE FAT CELLS ?

Fat cells, also referred to as adipocytes and lipocytes are the cells of the body that are specialised to store energy in the form of adipose tissue, or fat. There are two types of fat cell, white fat cells and brown fat cells. White fat cells, or unilocular cells, are vacuolar cells that contain a lipid droplet and cytoplasm. They have a nucleus which is flat and at the edge of the cell, rather than the centre. White fat cells vary in size, but on average they are around 0.1 mm in diameter. The fat inside white fat cells is mainly made up of triglycerides and cholesteryl ester, and is stored in semi-liquid form.

FAT CELL

WHAT ARE SEX CELLS ?

Sexual reproduction is the result of the fusion of two different types of sex cells called gametes. Male sex cells are commonly known as sperm cells, or spermatozoa, and female gametes are known as eggs or ova. When they fuse together, fertilization occurs and a zygote is formed.

SEX CELL