A nematode (roundworm) also called the human whipworm. The third most common round worm of humans. Occurs worldwide, with infections more frequent in areas with tropical weather and poor sanitation practices, and among children. It is estimated that 800 million people are infected worldwide. Trichuriasis (infection with Trichuris trichiura) occurs in the southern United States.
The adult worms (approximately 4 cm in length) live in the cecum and ascending colon (the first part of the large intestine). Female worms in the cecum shed between 3,000 and 20,000 eggs per day. The unembryonated eggs are passed with the stool. In the soil they embryonate and become infective in 15 to 30 days. After ingestion (soil-contaminated hands or food), the eggs hatch in the small intestine, and release larvae that mature and establish themselves as adults in the colon. The adult worms are fixed in that location, with the anterior portions threaded into the mucosa (the lining) of the intestine. The females begin to oviposit (lay eggs) 60 to 70 days after infection. The life span of the adults is about 1 year.
Having three flaps or cusps. For example, the aortic valve and the tricuspid valve in the heart each have three cusps.
- Tricuspid valve
One of the four heart valves, the first one that blood encounters as it enters the heart. The tricuspid valve stands between the right atrium and the right ventricle, and it allows blood to flow only from the atrium into the ventricle.
- Trigeminal nerve
The chief nerve of sensation for the face, which is also the motor nerve that controls the muscles used for chewing. Problems with the sensory part of the trigeminal nerve result in pain or loss of sensation in the face. Problems with the motor root of the trigeminal nerve result in deviation of the jaw […]
- Tricyclic antidepressants
One of a class of medications used to treat depression. The tricyclic antidepressants (TCAs) are also used for some forms of anxiety, fibromyalgia, and the control of chronic pain. “Tricyclic” refers to the presence of three rings in the chemical structure of these drugs.
Something that either sets off a disease in people who are genetically predisposed to developing the disease, or that causes a certain symptom to occur in a person who has a disease. For example, sunlight can trigger rashes in people with lupus.A predisposing event.