Category: Hg-Hx

Also known as Cutis anserina, a temporary local change in the?skin when it becomes rougher due to erection of little muscles, as from?cold, fear, or excitement. The chain of events leading to this skin change starts with a stimulus such as cold or fear. That stimulus causes a nerve discharge from the sympathetic nervous system, a portion of the…

A chemical substance produced in the body that controls and regulates the activity of certain cells or organs. Many hormones are secreted by special glands, such as thyroid hormone produced by the thyroid gland. Hormones are essential for every activity of life, including the processes of digestion, metabolism, growth, reproduction, and mood control. Many hormones, such as neurotransmitters, are active in…

An intestinal parasite that usually causes diarrhea or cramps. Heavy infestation with hookworm can be serious for newborns, children, pregnant women, and persons who are malnourished. Hookworm infections occur mainly in tropical and subtropical climates and affect about 1 billion people — about one-fifth of the world’s population. One of the most common species of hookworm, Ancylostoma duodenale, is…

A person sexually attracted to persons of the same sex. Homosexuals include males (gays) and females (lesbians). The term “homosexual” can also be an adjective.

An amino acid that is produced by the human body, usually as a byproduct of consuming meat. Homocysteine is normally converted into other amino acids. An abnormal accumulation of homocysteine, which can be measured in the blood, can be a marker for the development of heart disease. Elevated levels of homocysteine in the blood appear to increase the risk of heart attack, stroke, peripheral…

Prefix meaning same, as in homology (similarity in DNA or protein sequences between individuals or between species) and homosexual (a person who is sexually attracted to persons of the same sex). The opposite of homo- is hetero-.

The primate species of mammal to which modern humans belong. Homo sapiens is Latin for knowing man or wise man.

A homeotherm is a warm-blooded animal (such as homo sapiens). Another term for us warm-blooded creatures is endotherm. Those of us who are homeotherms or endotherms are as opposed to a poikilotherm (an organism such as a frog that is cold-blooded) and a stenotherm (a creature that can only survive only within a very narrow temperature range). Homeotherm…

A property of cells, tissues, and organisms that allows the maintenance and regulation of the stability and constancy needed to function properly. Homeostasis is a healthy state that is maintained by the constant adjustment of biochemical and physiological pathways. An example of homeostasis is the maintenance of a constant blood pressure in the human body through a series of…

This relatively common birth defect of the brain, often also affects facial features, causing closely spaced eyes, small head size, and sometimes clefts of the lip and roof of the mouth. Not all individuals with holoprosencephaly (HPE) are affected to the same degree, even in families where more than one individual has this predisposition. The risk of reoccurrence is…