Semen and Stains PDF

**SEMEN and STAINS** *The examination of semen and seminal stains is an important part in the routine investigation of sexual offenses like cases of rape, adultery, sodomy, bestiality and sexual homicide.* ***Semen*** - Also known as seminal fluid, is a bodily fluid that contains spermatozo...

**SEMEN and STAINS** *The examination of semen and seminal stains is an important part in the routine investigation of sexual offenses like cases of rape, adultery, sodomy, bestiality and sexual homicide.* ***Semen*** - Also known as seminal fluid, is a bodily fluid that contains spermatozoa. - Semen is a greyish white bodily fluid that is secreted by the gonads of male animals. It carries sperm or the spermatozoa and fructose and other enzymes that help the sperm to survive to facilitate successful fertilization. - The whitish opalescence is due to the large amount of protein that it contains and its slightly turbid appearance is due to the spermatozoa contained within it. **Process of Ejaculation** - Semen is released during the process of ejaculation and is processed in the seminal vesicle in the pelvis, which is where it is produced. **How does ejaculation occur?** Ejaculation is controlled by the central nervous system and occurs when there is friction on the genitalia and other forms of sexual stimulation. The stimuli lead to impulses that are sent up the spinal cord and into the brain. **Semen composition** The semen travel travels through the ejaculatory ducts and mixes with fluids from the seminal vesicles, the prostate, and the bulbourethral glands. - The seminal vesicles produce a viscous, fructose-rich fluid forming around 65-70% of the semen base. - The white color of the semen is due to secretion from the prostate glands containing enzymes, citric acid, lipids, and acid phosphatase. This forms around 25-30 % of the semen base. - At each ejaculation around 200-500 million sperms are released by the testes. This forms about 2-5 % of the semen composition. - Apart from these, the bulbourethral glands produce a clear secretion. This helps in the mobility of the sperm cells in the vagina and cervix. The glands secretion contributes less than 1% to the overall semen composition. - The semen comprises of: The semen comprises of: - fructose - ascorbic acid - zinc - cholesterol - protein - calcium - chlorine - blood group [[antigens]](https://www.news-medical.net/health/What-is-an-Antigen.aspx) - citric acid - DNA - Magnesium - vitamin B12 - phosphorus - sodium - potassium - uric acid - lactic acid - nitrogen - other nutrients What is sperm morphology? Sperm morphology refer to the shape of the sperm, which includes head size and head DNA content (revealed by a nuclear color stain), the midpiece appearance and the structure of the tail. The head shape is important because it can affect the sperm's ability to penetrate the outer surface of a woman's egg to fertilize it. Sperm morphology is assessed during routine semen analysis that examines the sperm cells under a microscope. The semen analysis will also examine the motility (movement ability) and concentration of sperm present. Every male, fertile or infertile, has varying percentages of abnormally-shaped sperm. There are many factors that can lead to abnormally shaped sperm including increased testicular temperature, exposure to toxic chemicals, infection and genetic traits. The medical term for when a man has a large number of abnormally shaped sperm is tetratozoospermia or tetratospermia. **Types of Sperm Morphology**    **CASES WHEREIN EJACULATION HAS NO SPERMATOZOA** 1\. **Aspermia** -- A condition wherein males have no spermatozoa at all in their seminal fluid. 2\. **Oligospermia** -- a condition whereby males have abnormally low sperm counts or with few spermatozoa These two diseases can be taken from excessive sexual intercourse. Those suffering from chronic epididymitis and other testicular diseases. Also taken from chronic venereal diseases **LOCATION OF SEMEN AND SEMEN STAIN AS EVIDENCE** 1. As Fresh a. Vaginal contents of the victim b. Rectal contents of the victim c. Oral part of the victim 2. As Wet or Dried condition a. Hair b. Skin around genitals 3. As Dry stains a. Underclothing b. Bed clothing **COLLECTION, PRESERVATION, PACKING AND TRANSIT OF SPECIMEN:** 1. Seizure of apparel must be done as soon as possible. 2. In packaging of wearing apparel there should be no friction between the apparel and the stain. 3. Specimen should not be rolled for transit. 4. Smaller objects like hair should be placed in a test tube and corked. 5. Specimen should be thoroughly dried before packing. 6. Fluid semen should be placed in a test tube. It may be preserved by a few drops of 10% solution of formalin during hot weather. 1. Transfers a drop of specimen to a glass slide. 2. Add a drop of water or saline solution and cover with cover slip. 3. Examine under the microscope. 4. Observe for the presence of spermatozoa. **OTHER STAINS OF MEDICO LEGAL INTERESTS** 1. Obstetrical and gynecological stains. 2. Excrements 3. Paint Stains 4. Rust Stains - Rust - reddish - brown in color, insoluble in water and soluble in dilute acid. Resembles blood stains. 5. Synthetic Dyes -- resembles old bloodstains but can be recognized by treating with strong acids and alkalis. 6. Mineral Stains these are due to red paints containing oxides of iron. 7. Stains of vegetable Origin stains resembling blood -- may be produces by fruit juices like mulberry, mangosteen.