DEFINITIONS - LETTER H

HALF-LIFE, CIRCULATING - the time required for elimination of 50% of a drug, hormone, or other factor from circulation.

HETEROGAMETIC - having 2 types of sex chromosomes; the human male is heterogametic as he has both X and Y chromosomes

HOMOGAMETIC - having a single type of sex chromosome; the human female is homogametic as she has only X chromosomes

HYDROLYSIS - splitting a molecule by addition of water

HYDROPHILIC/LIPOPHOBIC - generally water soluble; liking water but not liking fats

HYDROPHOBIC/LIPOPHILIC - generally lipid soluble; not liking water but liking fats

HYDROSTATIC - physical pressure exerted by water trying to move downward with gravity or out of a confined pressurized space such as a blood vessel; blood pressure is principally a form of hydrostatic pressure

HYPERCALCEMIA - elevated plasma calcium

HYPERCHALEMIA - elevated plasma potassium

HYPERCHLORIDEMIA - elevated plasma chloride

HYPERNATREMIA - elevated plasma sodium

HYPERPLASIA - an increase in tissue size due to an increase in the number of cells

HYPERPROTEINEMIA - elevated plasma protein

HYPERTENSION - elevated blood pressure

HYPERTROPHY - an increase in tissue size due to an increase in the size of cells

HYPERVOLEMIA - elevated plasma volume

HYPOCALCEMIA - low plasma calcium

HYPOCHALEMIA - low plasma potassium

HYPOCHLORIDEMIA - low plasma chloride

HYPOGLYCEMIA - this is an insufficiency of plasma glucose; an insufficiency of energy to muscles causes fatigue-like symptoms in these tissues; much more serious is the lack of available glucose for the CNS (neuroglucopenia); glucose is the only suitable energy substrate for the nervous system

HYPONATREMIA - low plasma sodium

HYPOPHYSEOTROPIC - meaning something released from the pituitary, which is also known as the "hypophysis."

HYPOPHYSIS - another name for the pituitary

HYPOPROTEINEMIA - low plasma protein

HYPOTENSION - low blood pressure

HYPOVOLEMIA - low plasma volume

HYPOXIA - insufficient oxygen deliver to the tissues