Tag: anatomy
- The Structure of the Nervous System ()
Although terminology seems to indicate otherwise, there is really only one nervous system in the body. Although each subdivision of the system is also called a “nervous system,” all of these smaller systems belong to the single, highly integrated nervous system. Each subdivision has structural and functional characteristics that distinguish it from the others. The […]
- Nerve Tissue ()
Although the nervous system is very complex, there are only two main types of cells in nerve tissue. The actual nerve cell is the neuron. It is the “conducting” cell that transmits impulses and the structural unit of the nervous system. The other type of cell is neuroglia, or glial, cell. The word “neuroglia” means […]
- The Life & Death of a Neuron ()
Until recently, most neuroscientists thought we were born with all the neurons we were ever going to have. As children we might produce some new neurons to help build the pathways – called neural circuits – that act as information highways between different areas of the brain. But scientists believed that once a neural circuit […]
- More Tissue & Cell Exchange ()
Blood Reservoir More than 60 per cent of all the blood in the circulatory system is usually in the veins. For this reason and also because the veins are so compliant, it is said that the venous system serves as a blood reservoir for the circulation. When blood is lost from the body and the […]
- Pediatric vs Adult Anatomy ()
A child’s physiology and anatomy is different in many ways from an adult. When a baby is born there are still gaps in the bones of the skull. The shape of the head can therefore be altered by constant pressure on it especially if the baby is always lying the same way in a bed. […]
- Respiratory System – More Structures ()
The phrenic nerve originates from the spinal cord at C3 through C5 and traverses the neck, heart, and lungs to reach the diaphragm and terminate into right and left branches at the subclavian artery. The left phrenic nerve innervates the left diaphragmatic dome, and the right phrenic nerve innervates the right diaphragmatic dome, with the […]
- Anatomical Terms ()
Directional terms Directional terms describe the positions of structures relative to other structures or locations in the body. Directional terms are used solely for comparison. Superior or cranial – toward the head end of the body; upper (example, the hand is part of the superior extremity). Inferior or caudal – away from the head; lower […]
- Threats To Perfusion ()
Perfusion is the passage of fluid through the circulatory system (blood stream) or lymphatic system to an organ or a tissue, usually referring to the delivery of blood to an area. Obviously, since the circulatory system transports oxygen and vital nutrients to the body’s cells, any interruption would result in certain death for millions of […]
- Skin ()
The skin is a vital organ that covers the entire outside of the body, forming a protective barrier against pathogens and injuries from the environment. The skin is the body’s largest organ; covering the entire outside of the body, it is about 2 mm thick and weighs approximately six pounds. It shields the body against […]
- Tissue and Cell Exchange ()
Air enters the body through the mouth or nose and quickly moves to the pharynx, or throat. From there, it passes through the larynx, or voice box, and enters the trachea. The trachea is a strong tube that contains rings of cartilage that prevent it from collapsing. Within the lungs, the trachea branches into a […]