Human Cell Types

All cells in the human body contain the DNA necessary for life. Cells that comprise certain tissue have different active genes than other tissue. For instance, liver tissue cells produce different proteins than kidney cells. The human body has several tissues and cell types that maintain homeostasis and essential components for life. Some of the main cell types generate organ proteins that make up the major systems in the body.

Red Blood Cells

Red blood cells are responsible for bringing oxygen to all tissue in the body. Red blood cells circulate from lungs where they bind to four oxygen atoms. The heart pumps red blood cells through the arteries to the body. As they pass through the body, oxygen elements are exchanged with cell tissue and the deoxygenated blood cells travel back to the heart through the veins. The heart sends the red blood cells back to the lungs where the process is repeated. Old blood cells are recycled in the liver and excreted in the form of bilirubin.

Liver Cells

Liver cells are the location for many of the metabolism processes like glucose breakdown and protein and carbohydrate synthesis. The liver is an essential organ for life, and these cells have developed high rates of regeneration. Even through years of abuse, the liver heals by rapid cell division. The liver also metabolizes drugs and waste to lower toxicity as the molecules travels to the kidneys for excretion.

Brain and Nerve Tissue

Brain cells are the electric impulse creators for control of all functions of the body. The brain is comprised of complex neural networks that spread down the spinal cord and to innervated cells like muscle. Nerve cells are covered with an added layer of cells called a myelin sheath. This sheath gives nerves greater conductivity for electric impulse messages back and forth to the brain.

Chief Cells

Chief cells are found in the stomach. They produce the gastric acid that breaks down food for delivery to the small intestines. The three main enzymes excreted by gastric chief cells are pepsinogen, gastric lipase and rennin. These compounds cleave the links from larger molecules into smaller parts. For instance, pepsinogen breaks protein's bonds into smaller peptides, which are sent to the intestines for further breakdown and absorption.

Kidneys

Kidney cells are the filtration system of the body. Kidneys remove toxins and waste in the blood and send it to the ureter for excretion. Nephrons are the main component of the kidneys responsible for absorbing beneficial ions and water and removing toxins. These cells have high sodium concentration to absorb water through osmosis. One sign of kidney damage is excess fluids in the body from the destruction of these cells.

References

• Merck Manual