Male Reproductive System Male Sexual Act 17-Apr-17 Male Reproductive System
Male Reproductive System Overview Origin of sexual sensation Stages 17-Apr-17 Male Reproductive System
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 17-Apr-17 Male Reproductive System
Male Sexual Act neural 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) 17-Apr-17 Male Reproductive System
Male Sexual Act neural transmission Psychic element of stimulation Initiates the male act/ejaculation Thinking sexual thoughts Dreaming the act Nocturnal emission /wet dreams Common in teens 17-Apr-17 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 17-Apr-17 Male Reproductive System
Stages of male sexual act Penile erection Lubrication Emission and ejaculation Resolution 17-Apr-17 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 17-Apr-17 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 17-Apr-17 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 17-Apr-17 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) 17-Apr-17 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 17-Apr-17 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 17-Apr-17 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 17-Apr-17 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 17-Apr-17 Male Reproductive System
Male Reproductive System FEMALE SEXUAL ACT Stimulation Psychic Local sexual organs Sex hormone levels Message from other types of stimulation Vulva, vagina & other perineal regions can create sexual sensation Glans of the clitoris 17-Apr-17 Male Reproductive System
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 17-Apr-17 Male Reproductive System
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 17-Apr-17 Male Reproductive System
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 17-Apr-17 Male Reproductive System
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 17-Apr-17 Male Reproductive System
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 17-Apr-17 Male Reproductive System
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 17-Apr-17 Male Reproductive System
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 17-Apr-17 Male Reproductive System
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 17-Apr-17 Male Reproductive System
Male Reproductive System MALE CLIMACTERIC Management Administration of testosterone Synthetic androgens Estrogens 17-Apr-17 Male Reproductive System
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 17-Apr-17 Male Reproductive System
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) 17-Apr-17 Male Reproductive System
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 17-Apr-17 Male Reproductive System
Male Reproductive System MENOPAUSE 15 % need treatment Counseling Daily administration of estrogen in small quantities 17-Apr-17 Male Reproductive System