Sexual Dictionary - letter R

Radiology
a branch of medicine dealing with the diagnostics and therapeutics using x-rays.
Rash
any change in the skin which affects its appearance or texture. Rashes may cause the skin to change colour, itch, become warm, bumpy, dry, cracked or blistered, swell and may be painful.
Rh factor
one of the antigens present on red blood cells of about 85% of people. Persons with the factor are designated Rh-positive, those lacking the factor are designated Rh-negative. A Rh-negative mother carrying a Rh-positive fetus may initiate an immune response against her baby's blood leading to miscarriage. Blood for transfusions must be compatible for this factor as well as for the ABO blood group.
Rubella
an acute contagious viral infection that causes a mild illness in children (rash and fever) and slightly more severe illness in adults. The disease is spread person-to-person through airborne particles. It's dangerous to pregnant women during the early stages of pregnancy because it can cause birth defects.
Also called German measles.
Rubeola
an acute and highly contagious viral disease marked by distinct red spots followed by a rash which occurs primarily in children. Sometimes can lead to serious complications and death.
RNA
abbreviation from Ribonucleic acid; a nucleic acid found in all living cells. Plays a role in transferring information from DNA to the protein-forming system of the cell.
Reproduction
the process of generating offspring.
Rape
a crime wherein the victim is forced into sexual activity against his or her will, including oral, vaginal or anal sex, or penetration with an object by a person using physical force, threat, or coercion. If the act occurs while the victim is unconscious, asleep or otherwise unable to communicate unwillingness, it is still considered rape. Statutory rape - sexual intercourse with a person who is under the statutory age of consent even if done with the minor's consent. Rape it is considered to be among the most severe crimes.
Refractory period
the time period in the male's sexual response cycle immediately following ejaculation during which man cannot achieve an erection or cannot achieve orgasm although partial or full erection may sometimes be maintained. The duration of the refractory period can vary from just a few minutes to several days and there is great variability in the length of the refractory period both within and between men. This time period it is not present in the female's sexual response cycle.
Reproductive system
major body organ systems responsible for reproduction and thus the survival of the species.
Reproductive system in male : testes which produce spermatozoa, are located in scrotal sac. It consists of approximately 1000 highly coiled seminiferous tubes with total length of 250 meter. Vas efferentia, fine tubes, connects from seminiferous tubes to the epididymis, where spermatozoa are stored. From there, vas deferens joins to the urethra, a tube connecting from urinary bladder to the exterior that goes through penis. Erectile tissue, also located in penis, causes erection during periods of sexual excitement. Seminal vesicles, prostate glands, and Cowper's glands produce seminal fluid lubricate the passenger through which semen travel, and the semen is transferred to the female during copulation.
Reproductive system in female : the eggs are produced by ovaries, which is about 3 cm long, and they are passed into uterus, through one of the two fallopian tubes. Uterus, which is about the size of clenched fist, is where embryo develops. It is covered with thick walls of smooth muscles, and mucous lining. The vagina, serves as a birth canal, and a receptacle for sperm and it connects vagina to the exterior. Vulva, the external female organs include, l abia majora, labia minora, and clitoris. Labia majora and Labia minora enclose the opening of urethra and vagina. Clitoris is a sensitive erectile organ, which responds to erotic stimulation.
Retrograde ejaculation
the flow of semen backward into the bladder rather than forward through the penis. May be caused by prostate or urethral surgery, diabetes or some medications.
Also called reverse ejaculation.
Rectum
lower end of the large intestine, leading to the anus.
Red blood cells
the blood cells that carry oxygen from the lungs throughout the body to all the tissues and take carbon dioxide back to the lungs from the tissue. Red blood cells have a high concentration of hemoglobin witch is carrying agent and gives blood its red color.
Red blood cells are also called erythrocytes.
Retroverted uterus
uterus that is bended backward. The uterus is normally bended slightly forward toward the belly, on top of the bladder. Retroverted position of the uterus within the pelvis can be caused by laxness of the supporting pelvic ligaments, a tumor, scar tissue that forms in the pelvis as a result of salpingitis, pelvic inflammatory disease, or endometriosis, or as the result of a pregnancy.
Rhythm method
a form of natural birth control method which can work by timing intercourse according to the consistency of the woman's cervical mucus.