Male Sexual Anatomy PDF
Document Details
Uploaded by AmpleOnyx7380
MedadTeam
Tags
Summary
The document provides detailed information about male sexual anatomy and functions, including the structure of the penis, its arterial supply, and venous drainage. It covers the nerve supply and various aspects related to erection. This document is comprehensive and aimed at a professional audience in the field.
Full Transcript
Wondershare PDFelement ANDROLOGY NMT13 MALE SEXUAL ANATOMY S...
Wondershare PDFelement ANDROLOGY NMT13 MALE SEXUAL ANATOMY Structure of the penis: The penis is formed of 2 dorsally placed corpora cavernosa and a ventral corpus spongiosum containing the urethra. The glans penis is the expanded distal end of the corpus spongiosum. Erection is the function of the corpora cavernosa, which are covered by a tough tunica albuginea. The cavernous spaces of the corpora cavernosa are interconnected blood sinusoids lined by endothelial cells and surrounded by smooth muscle fibres. Arterial supply: The penis is supplied by the internal pudendal artery, which has the following terminal branches: Dorsal artery: supplying the glans penis and skin Spongiosal/ urethral artery: supplying the corpus spongiosum and urethra. Cavernosal artery: supplying the corpora cavernosa. Bulbar artery: supplying the bulb. Venous drainage: The penis is drained at 3 venous levels: Superficial system, which is formed by the superficial dorsal vein draining the skin and subcutaneous tissue and terminating into the saphenous vein. Intermediate system: Deep dorsal vein draining the distal corpora cavernosa into the peri-prostatic venous plexus. It receives emissary veins and circumflex veins. Deep system: Cavernosal and bulbo-urethral veins drain proximal corpora cavernosa and the corpus spongiosum into the internal pudendal vein. Nerve supply: 1. Somatic: Pudendal nerve (S2, 3,4) Sensory: skin of the penis. Motor: Bulbocavernosus and ischiocavernosus muscles. 2. Autonomic Sympathetic (T12 – L2) Parasympathetic (S2,3,4) 1 MedadTeam More Than You Dream Wondershare PDFelement ANDROLOGY NMT13 SEXUAL RESPONSE CYCLE Sexual arousal can be initiated by a variety of sexual stimuli including visual, auditory, olfactory, imaginative, memorizing and tactile. If such stimuli are perceived as being sexual, they lead to the following changes: In males In female 1- Genital Penile erection Vaginal transudation Excitation changes: Bartholin gland secretion phase Retraction of labia minora Erection of clitoris Extragenital increase in heart rate, blood pressure, respiratory rate changes and depth and skeletal muscle tone. Additionally females may also develop sexual flush and nipple erection. 2- Plateau phase: sexual excitation changes are maintained at their maximum during intercourse. This phase lasts for about 2 - 5 minutes Shorter Longer 3- Orgasmic phase the pleasure felt at the climax of sexual connection. only one orgasm can be multi-orgasmic per one sexual response cycle Ejaculation Rhythmic involuntary contraction of pelvic floor, perineal and perivaginal muscles (occasionally the uterus) 4- Resolution phase subsidence of all the changes that occurred during sexual excitation. Rapid Gradual 5- Refractory period In which whatever intense the sexual stimulus there can never be similar response present and its Absent duration depends on the age, psychological state and general health. 2 MedadTeam More Than You Dream Wondershare PDFelement ANDROLOGY NMT13 PHYSIOLOGY OF ERECTION AND EJACULATION A-Erection From the neurological point, there are 2 type of erection: a. Psychogenic erection: If visual, auditory, olfactory, memorizing or imaginative stimuli are integrated in the limbic system as being sexual, descending tracts pass through the sympathetic outflow of T12-L2. b. Reflexogenic erection: Tactile stimulation of the genital area sends afferent impulses along the pudendal nerve, which reach the sacral segments S2-4 the efferent impulses of which are parasympathetic. The neurological impulses lead to erection by mediating the following vascular response: a. Maximum dilatation cavernosal artery. b. Relaxation of smooth muscle fibres around the cavernous spaces of the corpora cavernosa. c. Passive venous occlusion results from compression of small venules between the expanding cavernous spaces as well as the emissary and sub-tunical veins under the tunica albuginea. Phases of penile erection a. Flaccid phase b. Initial filling phase c. Tumescence phase d. Full erection phase e. Rigid erection phase f. Detumescence phase Sequence of events during erection Under resting conditions (flaccid): Sympathetic tone Tonic contraction of smooth muscles of the penis The diameter of the cavernosal artery = 0.5 mm The blood flow velocity = not more than 15 cm/seconds During sexual stimulation: Release of endothelial factors & neurotransmitters relaxation of the smooth muscles of the cavernous tissue & arteries The diameter of the cavernosal artery = 1 mm The blood flow velocity = above 30 cm/seconds. This is the initial filling phase which will then lead to the tumescence and the full erection phase afterwards Dilatation of the cavernous spaces compression of the subtunical venous plexus and the emissary veins being trapped between the 3 MedadTeam More Than You Dream Wondershare PDFelement ANDROLOGY NMT13 two layers of the tunica albuginea additional decrease in the venous flow. These changes a steady increase of the intracorporeal blood pressure to reach above the diastolic blood pressure (Tumescence phase) then to 90% of the systolic pressure (Full erection phase). Dorsal nerve stimulation during coitus contraction of the ischiocavernosus muscle more venous compression and consequently more rise of the intracavernosal pressure to above the systolic blood pressure. This is the phase of rigid erection. During this phase there is no blood inflow and the penis becomes a completely closed space. Its short duration due to muscle fatigue prevents ischemia and tissue damage. B-Ejaculation Ejaculation is sympathetically mediated and involves 2 phases: 1. Emission phase: Contractions of the wall of the prostate, seminal vesicles, cauda epididymis and vas deferens expel their contents into the prostatic urethra (sympathetic T12, L 1,2,3). 2. Contraction of internal sphincter: Antegrade ejaculation phase: Semen is expelled from the prostatic urethra to the outside after bladder neck closure (sympathetic and somatic). It depends on the contraction of the pelvic floor muscles in addition to the ischiocavernosus & the bulbocavernosus muscles (each contraction is about 0.8s) ERECTILE DYSFUNCTION Definition: The persistent inability of the male to obtain and/or maintain a quality of erection sufficient to permit coitus to be initiated and/or completed. Etiology ED is either due to psychogenic or organic disorders. Psychogenic factors were previously thought to dominate (95%). Following the recent progress in diagnostic techniques, more than 60% of ED cases have ED-related organic problems Psychogenic ED 1. Developmental factors 2. Interpersonal factors Gender identity conflict Divergent sexual preferences Traumatic childhood experience Excessive hatred Negative family attitude towards Dislike female figure sex (religious or social) Distrust of the partner Paternal & maternal dominance Marital relationship conflicts Homosexuality Oedipal complex 4 MedadTeam More Than You Dream Wondershare PDFelement ANDROLOGY NMT13 3. Affective factors 4. Cognitive factors Anxiety Sex ignorance Depression Misinterpretation about articles, books Guilt or talks about sex Phobia e.g.pregnancy, STDs and Acceptance of cultural and religious failure. orders Organic ED Vascular causes Neurogenic causes Arterial disorder Atherosclerosis, Central:cerebro-vascular Embolism, Trauma, Leriche Syndrome accident,multiplesclerosis, spinal cord Venous disorder: venous leakage injury, etc (failure of corporal veno-occlusive Peripheral:peripheral neuropathy mechanism) Cavernous space disorder: fibrosis (post-priapism) & Peyronie’s disease Endocrinal causes Drug-induced 1- Diabetes mellitus (due to Antihypertensives non selectiv BB neuropathy, atherosclerosis,micro- Psychoactive drugs: high dose of angiopathyor psychogenic) major tranquilizers and 2- Hypogonadism e.g. Klinefelter antidepressants. syndrome Addictive agents: alcohol, marijuana, 3- Hyperprolactinemia and heroin. 4- Myxedema Estrogen & antiandrogens Systemic disorders Liver, renal and heart failure Diagnosis of ED 1- History Taking :to differentiate organic from psychogenic ED and to determine the etiology and of organic ED. PSYCHOGENIC ED ORGANIC ED Onset Usually sudden Usually gradual Course Usually intermittent Usually progressive Duration Usually short Usually long Morning erections Present & good quality Absent or weak Erection at non-coital Present Absent occasions History of HTN, DM, etc Less frequent Usually positive 5 MedadTeam More Than You Dream Wondershare PDFelement ANDROLOGY NMT13 2- Examination GENERAL LOCAL Endocrinal: Penis: Secondary sex characters and Peyronie’s disease, penile size, pulse and gynecomastia urethral orifice fibrosis in corpus cavernosum Vascular: Scrotum: BP and pulse Testis size and consistency Neurological: PR: Sensations and reflexes Prostate and seminal vesicles Others: e.g. surgical scars Cremasteric reflex Scrotal reflex Bulbocavernosus reflex 3- Diagnostic Procedures For ED: A) Laboratory Investigations All ED patients must be subjected to: Fasting and post-prandial blood sugar, Serum testosterone and prolactin level. According to clinical suspicion, some patients may need: Liver function tests Renal function tests T3 - T4 - TSH level B) Nocturnal Penile Tumescence (NPT) Monitoring Normally, during rapid eye movement (REM) stage of sleep, penile erections occur. In adolescents, this happens 4-5 times per night (duration of 15-20 min each). It tends to decrease in duration and frequency with age. Eliciting the occurrence of these erections during sleep helps to differentiate organic from psychogenic ED. This can be done using: Regiscan: This is the most precise method that detects the frequency, degree of rigidity and the duration of nocturnal penile erections. C) Penile Vascular Studies Intracavernous Injection (ICI) Test: This is a screening test for vasogenic ED Normally, injection of certain vasodilator agents (e.g. Prostaglandin E1, papaverine or phentolamine) into the corpora cavernosa leads to full rigid erection this erection starts within 10 min. and lasts for more than 30 min. The occurrence of this response is a good positive test that penile haemodynamics are normal. In arterial problems: Delay in the onset of erection occurs In venous leak: Unsustained erection (< 30 min.) occurs. 6 MedadTeam More Than You Dream Wondershare PDFelement ANDROLOGY NMT13 In neurogenic ED: prolonged erection and priapism occur even with the smallest doses of vasoactive agents due to denervation hypersensitivity. Confirmatory Tests For Penile Arteriogenic ED: Evaluation of penile arteries is indicated if no or delayed erection occurs in the ICI test. A. Duplex ultrasonography: This is the method of choice for evaluation of the penile arteries. It allows measurement of diameter and blood velocity in the cavernosal artery before and after injection of the vasoactive drugs. Normal cavernosal arteries show: a. Peak systolic velocity more than 25 cm/sec. b. Diameter increase after ICI by more than 75% B. Selective internal pudendal angiography: This is an invasive procedure performed only before arterial surgery. Confirmatory Tests For Venogenic ED: These are indicated if a venous leak is suspected by: No or unsustained erection in the ICI test. Duplex shows normal cavernosal arteries with elevated end diastolic velocity more than 5 cm/sec. Cavernosometry: Saline is injected intracavernously (after ICI) at a rate that induces and maintains a rigid erection (I.C. pressure = 150 mm Hg). Normally: Induction rate is less than 40 ml/min. Maintenance rate is less than 15 ml/min. The rate of drop in I.C. pressure after stopping infusion is less than 40 mm Hg in the first half minute. In venous leak, there are higher figures especially the drop of I.C. pressure. Cavernosography: If cavernosometry shows venous leak, intracorporal radio-opaque dye is injected and X-ray is done to demonstrate the leaking veins. Neurological evaluation Biothesiometry A biothesiometer is a vibration sense-measuring apparatus that can be used for screening of sensory deficit. Dorsal nerve somato-sensory evoked potential Electrical stimulation of the dorsal nerve of the penis followed by recording the evoked EEG waveforms over the sacral cord and cerebral cortex helps to diagnose sacral and suprasacral sensory lesions. 7 MedadTeam More Than You Dream Wondershare PDFelement ANDROLOGY NMT13 Treatment of ED Choice Of Treatment Depends Upon Etiology Age of the patient / Spouse Associating disease Availability Cost Choice of the patient Management of the cause e.g. Specialized psychiatric treatment for deep psychic ED Quit smoking, alcohol and addiction Control DM, hypertension, etc Testosterone or gonadotropins for hypogonadism Bromocriptine for hyperprolactinemia Switching to safe medications in drug-induced ED Sex Therapy Indications: Treatment of performance anxiety in psychogenic ED Principles of sex therapy: Sex education. Mutual responsibility about any sexual disorders. Establishment of proper physical and psychological stimulation. Elimination of marital relationship difficulties. Systemic desensitization “Master and Johnson's technique” “Sensate focus” - stages Medical Treatment Empirical treatment o Aphrodisiac o Herbals and other forms of primitive medicine o Androgens: Testosterone 50-100mg Phosphodiesterase inhibitors hypotension/ syncope 1 hr before intercourse on o selective cavernous tissue dilator longer duration than sildenafil empty o contraindicated in cardiac patients receiving nitrates. stomach o Sildenafil (Viagra), Vardinafil (Levitra), Tadalafil (Cialis) Alpha adrenergic blockers o Yohmbine :presynaptic α2 blocker o Phentolamine: α 1&2 blocker K channel openers:Minoxidil Opioid receptor antagonist: Naltrexone Dopamine receptor agonists o Trazodone o Apomorphine 8 MedadTeam More Than You Dream Wondershare PDFelement ANDROLOGY NMT13 Beta-adrenergic stimulant: Isoxupine Intracavernous Injections (ICI) Therapy The patient is trained at ICI self-injection that can be used before a desired intercourse. Prostaglandin E1, papaverine and phentolamine can be used separately or in combination.safest Indications: Psychogenic ED Mild vascular ED Complications: Prolonged erection(2-6 h) Priapism(>6h) treated by repeated aspiration of blood from the corpora± ICI of sympathomimetic (ephidrine). If erection persists shunt operation may be done Penile pain commonest Corporal fibrosis Transurethral Alprostadil Using a special applicator, PGE pellet can be introduced trans-urethrally to induce penile erection. Although results are inferior to the intracavernous injection therapy patients who are not happy with self-injection may prefer this line of treatment. External Vacuum & Constriction Devices The idea of this type of treatment is to: Induce erection using a vacuum device Maintain erection using a rubber band applied to the base of the penis Surgical Management 1- Penile Vascular surgery In Arteriogenic ED: Proximal arterial disease: internal iliac reconstruction Distal arterial disease: anastomosing inferior epigastric artery to penile arteries In Venogenic ED: Ligation of deep dorsal vein with its tributaries in addition to the cavernosal and crural veins Arterialization of the deep dorsal vein using the inferior epigastric artery 2- Penile prosthesis Artificial cylinders or rods are placed in the corpora cavernosa to induce an erection-like state. Indications: All intractable causes of ED in which other lines of treatment failed or simply unavailable: Advanced diabetic ED 9 MedadTeam More Than You Dream Wondershare PDFelement ANDROLOGY NMT13 Venogenic ED Neurogenic ED Post-priapism ED Peyronie’s disease Longstanding resistant psychogenic ED Types: Rigid prosthesis (obsolete) Malleable rods (popular) Inflatable prosthesis EJACULATORY DYSFUNCTION PREMATURE EJACULATION RETARDED EJACULATION Definition Inability of the male to Definition Inability of the male to control his ejaculatory reflex so that reach orgasm intravaginally despite an he can satisfy his wife in at least 50% adequate erection quality. of their coital connections. Incidence A very common condition Incidence Uncommon problem affecting around 40% of patients Etiology Etiology Psychogenic causes (>90%) Psychogenic causes 1- Conditioned prematurity: This 1- Obsessive compulsive personality occurs when the early sexual 2- Repressed hostility experiences have been with 3- Phobias e.g. prostitutes, through petting or chronic Fear of pregnancy heavy masturbation. Religious guilt feelings 2- Subconscious hatred towards Fear of soiling the partner with females. semen 3- Anxiety and over concern about Oedipal fears of retaliation partner satisfaction. 4- Unresolved marital problems. Organic causes Organic causes (