A spermatozoon is the male sex cell or gamete that fertilizes the female egg or ovum in organisms that reproduce sexually, including all animals and some plants. Unlike most of the cells that make up multicellular organisms, spermatozoa consist of a head and at least one flagellum or tail, which allows them to move independently. … Read more
The urothelium is the bladder’s lining that also coats other parts of the urinary system, including the ureters. In most cases, people have two ureters—one tube that links the left kidney to the bladder and another that links the right kidney to the bladder. Urothelial cancer is a medical condition that can strike the urothelium. … Read more
Also known as the pubocapsular ligament, the pubofemoral ligament attaches the pubis, a bone on the underside of the pelvis, to the femur bone of the thigh. It crosses the inferior or bottom aspect of the acetabulofemoral or hip joint. In doing so, this ligament functions along with the other joint ligaments to hold the … Read more
The central nervous system uses the process of neuromodulation to transmit nerve signals to large groups of nerve cells or neurons. Neurotransmitters such as serotonin, dopamine and acetylcholine are brain chemicals that often use a neuromodulation process to transmit brain signals to large groups of neurons. They affect the perception of pain as well as … Read more
A granzyme, or granule enzyme, is a group of serine proteases that are released the body’s natural killer cells and cytotoxic T-cells. When cells become infected viruses, the immune system is triggered. Granzymes are released in order to trigger apoptosis, or programmed cell death, which leads to the destruction of the infected cells. … Read more
A hepatic vein is any of the veins that carry oxygen depleted blood out of the liver and into the inferior vena cava. The term vein refers to a blood vessel that transports blood back to the heart, in contrast to an artery, which carries blood away from the heart. The term hepatic relates to … Read more
The lacrimal bone is one of 22 bones of the skull and is, in fact, the tiniest of these bones. Situated within the orbit or eye socket, it is a flat, quadrilateral bone found on the side of the socket nearest the nose. Its borders make contact with four other bones of the skull: the … Read more
VEGF, or vascular endothelial growth factor, is a cell protein produced the body. The protein binds to cells and encourages certain cell activity. Creation and repair of blood vessel networks is perhaps the protein’s most important function. It also serves a major role in keeping the body’s tissues supplied with adequate amounts of oxygen. … Read more
A vertebrae model is a medical model that provides a representation of the vertebrae, the bones on the spine. Medical catalogs and stores usually stock vertebrae models of various styles and designs for a wide range of purposes from patient education to artist’s references. It is also sometimes possible to acquire used models from doctor’s … Read more
Pus often results from an infection and is usually made up of dead white blood cells, debris from other damaged cells and tissue, and bacteria. Cells called neutrophils can kill the invaders, but are often killed in the process; bacteria in pus are therefore sometimes called pyogenic. These are often cocci, which are spherical organisms … Read more