Download
1 / 28
280 likes | 294 Vues
Male Sexual Act. Overview. Origin of sexual sensation Stages. Male Sexual Act. Sensory nerve endings presence Glans penis-Main Adjacent areas of the penis Anal epithelium Scrotum Perineal structures Internal structures
E N D
Male Sexual Act Male Reproductive System
Overview • Origin of sexual sensation • Stages Male Reproductive System
Male Sexual Act • Sensory nerve endings presence • Glans penis-Main • Adjacent areas of the penis • Anal epithelium • Scrotum • Perineal structures • Internal structures • Areas in the Urethral ;Bladder; Prostate; seminal vesicles; testes & vas deferens Male Reproductive System
Male Sexual Actneural transmission • Neuronal Transmission of signals • Sexual signals pass through • Pudendal nerve • sacral plexus • sacral portion of the spinal cord • up the cord to the brain (central nervous system) Male Reproductive System
Male Sexual Actneural transmission • Psychic element of stimulation • Initiates the male act/ejaculation • Thinking sexual thoughts • Dreaming the act • Nocturnal emission /wet dreams • Common in teens Male Reproductive System
Integration of male sexual act in the cord • Male sexual act results from • Inherent reflex mechanism integrated in the sacral and lumbar spinal cord • Mechanisms are initiated by • Psychic stimulation from the brain • Actual stimulation from the sex organs • Combination of both Male Reproductive System
Stages of male sexual act • Penile erection • Lubrication • Emission and ejaculation • Resolution Male Reproductive System
Stages of male sexual act 1. Penile erection • Role of parasympathetic nerve on stimulation • Psychic or physical • Releases nitric oxide +/- vasoactive intestinal peptide and acetylcholine • N.O is a vasodilator (arterioles) • Dilates arteries in the penis • Relaxes smooth muscle fibers in the erectile tissue in the shaft of penis • corpora carvenosa • corpus spongiosum Male Reproductive System
Stages of male sexual act • large cavernous sinuses in the erectile tissue are filled with blood • Tremendously dilated • Venous outflow is partially occluded • Erectile tissues balloons • Penis becomes hard and elongated Male Reproductive System
Stages of male sexual act 2. Lubrication • A parasympathetic function • Cause urethral glands and bulbourethral glands to secret mucus • Aids in lubrication during coitus • NB: Most lubrication function provided by female Male Reproductive System
Stages of male sexual act 3.Emission & ejaculation • Function of sympathetic • Final stage • Extremely intense sexual stimulation • Reflex centres of spinal cord to emit sympathetic impulses • Impulses leave the cord at T12 to L2 • Pass to the genital organ through the hypogastric and pelvic sympathetic nerve plexus to initiate emission (forerunner of ejaculation) Male Reproductive System
Stages of male sexual act • Contraction of vas deferens & ampular • Sperm expulsed into internal urethra • Semen formation Ejaculation • Internal urethra filling & distension • Creates a stretch reflex • Contraction of • internal genital organs • Ischiocarvenous & ulbocarvenous muscles Male Reproductive System
Stages of male sexual act • Base of erectile tissue compressed • Pelvic abdominal muscles contracts • The entire period of emission and ejaculation is called orgasm 4. Resolution • After ejaculation • Male sexual excitement disappears • Erection ceases • Lasts 1-2 minutes Male Reproductive System
Stages of male sexual act • Contraction of vas deferens & ampular • Sperm expulsed into internal urethra • Semen formation 4. Ejaculation • Internal urethra filling • Creates a stretch reflex • Caused by distension • Contraction of internal genital organs Male Reproductive System
Stages of male sexual act • Contraction of vas deferens & ampular • Sperm expulsed into internal urethra • Semen formation 4. Ejaculation • Internal urethra filling • Creates a stretch reflex • Caused by distension • Contraction of internal genital organs Male Reproductive System
FEMALE SEXUAL ACT • Transmission of signals • From sexual organs • to the sacral segments of the spinal cord • Thru pudendal nerve & sacral plexus to spinal cord • Finally to cerebrum Male Reproductive System
FEMALE SEXUAL ACT • Female erection & ejaculation • Erectile tissue located in introitus & clitoris • Controlled by parasympathetic nervous system • Sexual stimulation causes PSN to release • Nitric Oxide (NO) • Vasoactive intestinal peptide(VIP) • Acetylcholine (Ach) • Dilates arterioles of the erectile tissue • Introitus tightens around penis Male Reproductive System
FEMALE SEXUAL ACT • PSN signals also pass thru • the bilateral Bartholins gland located beneath the labia minora • Vaginal epithelium • Secrete mucus into the introitus for lubrication • Establishes a satisfactory messaging sensations rather than irritative sensation Male Reproductive System
Female orgasm • Maximum intensity during local sexual stimulation • Initiates local reflexes from cerebrum (cerebral reflexes) • cause female orgasm (female climax) • Analogous to emission & ejaculation in the male • Helps in promoting the fertilization of ovum • Rhythmical contraction of female perineal muscles resulting from spinal cord reflexes • Increase uterine and fallopian tube motility during orgasm • Helps to transport sperm upward through the uterus towards the ovum Male Reproductive System
Female orgasm • 2. studies in lower animals • Copulation leads to increased release of oxytocin from posterior pituitary gland • Which increase rhythmical contraction of the uterus • Increased transport of sperm Male Reproductive System
Female orgasm • Resolution • Intense sexual sensation during orgasm pass to cerebrum • Cause intense muscle tension through out the body • This gives way during succeeding minutes to a sense of satisfaction • Characterized by relaxed peacefulness • An effect called resolution Male Reproductive System
MALE CLIMACTERIC • Male adult sexual life • After puberty • Gonadotropic hormones • produced by a male pituitary gland for the remainder of life • At least some spermatogenesis usually continues until death Male Reproductive System
MALE CLIMACTERIC • Most males however exhibit slowly decreasing sexual functions in their late 40s 0r 50s • Average age for termination of intersexual relations is 68years • Decline in sexual function (male climacteric) is related to decrease in testosterone secretion • Occasionally associated with • Hot flushes • Suffocation • Psychic disorders Male Reproductive System
MALE CLIMACTERIC • Management • Administration of • testosterone • Synthetic androgens • Estrogens Male Reproductive System
MENOPAUSE • Sexual cycles becomes irregular • Ovulation fails to occur at age 40s-50s • Cycles ceases after few months to years • Menopause • Period during which the cycle ceases and female sex hormones diminishes to almost none • Cause • Burning out of estrogen Male Reproductive System
MENOPAUSE • About 400-500 of primordial follicles into mature follicles through out a woman's reproductive life • Hundreds of thousands of ova degenerates • At about 45 yrs only a few primordial follicles remain to be stimulated by FSH & LH • Production of the estrogen by the ovaries is almost zero • Increase production of GnRH (FSH & LH) Male Reproductive System
MENOPAUSE • Physiological changes due to loss of oestrogen • Hot flushes-characterised by extreme flushing of skin • Psychic sensation of dysponea • Irritability • Fatique • Anxiety • Occasionally various psychotic states • Decreased strength and calcification of bones thru out the body Male Reproductive System
MENOPAUSE • 15 % need treatment • Counseling • Daily administration of estrogen in small quantities Male Reproductive System
