| HOME Other Health Articles A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | Y | Z random selection: Selection of experimental and control subjects for a research project in an entirely random manner, such as drawing names or numbers from a paper bag. rape: A sexual assault with penile penetration of the vagina under the use or threat of force that overcomes the earnest resistance of the victim. receptor site: A point on a target cell that binds a chemical molecule to exert its biological effect. rectovaginal: Concerning the rectum and vagina. reflexogenic: Caused by a reflex action. refractory period: The period in the male immediately following ejaculation during which further orgasm is physiologically impossible; there is no such period in the female response cycle. replication: Repetition of an experiment. resolution phase: The fourth phase of the sexual response cycle in which the sexual systems return to their nonexcited state. retarded ejaculation: The delay or absence of ejaculation following an adequate period of sexual excitement; also known as ejaculatory incompetence and inhibited male orgasm. retrograde ejaculation: A condition in the male in which orgasm is not accompanied by an external ejaculation of semen; instead, the ejaculate goes into the urinary bladder. Rh factor: An antigen (chemical) that may be present on the surface of the red blood cells. Rh negative: Lacking the Rh blood group or antigen on the surface of one’s red blood cells. Rh positive: Possessing the Rh blood group or antigen on the surface of one’s red blood cells. rhythm methods: Methods of conception control based on the abstinence from coitus during the calendar days of highest female fertility. |