Pathophysiology of ED - عبدالرحمن PDF

- ‫ادعوا لنا‬ ‫غفرة‬,‫خي بالرحمة وا‬4‫و‬ Definition of Erectile dysfunction Erectile dysfunction is defined as the persistent...

- ‫ادعوا لنا‬ ‫غفرة‬,‫خي بالرحمة وا‬4‫و‬ Definition of Erectile dysfunction Erectile dysfunction is defined as the persistent (for a minimum of 3 months) or& => ⑧ recurrent failure to achieve or maintain a penile erection to allow for- satisfactory sexual intercourse. Erectile dysfunction must be distinguished from disorders of libido w or ejaculation and of infertility. A ~ L couth o person 6 S  · C C g - & · x E I - - do Physiology of a normal penile erection A normal penile erection requires full functioning of:- Vascular system. Nervous system - Hormonal systems The patient also must be psychologically receptive to sexual stimuli. Vascular System v The penis is composed of two corpora cavernosa on the dorsal side and => one corpus spongiosum on the ventral side. The corpus spongiosum surrounds the urethra and forms the glans penis. The corpora are composed of multiple interconnected sinuses, which can sin fill with blood to produce an erection. - The corpora cavernosa are encased by the tunica albuginea.  a ephas Y 8 - 3 Vascular System ① so s 556 -⑮ In the flaccid state, arterial flow into and venous outflow from the - > Dodd shase · corpora are balanced. Atrial flow = venous equall- During the erectile phase, arterial blood flow increases and blood fills - D the sinusoids within the corpora causing penile swelling and elongation. - Fo The erection is prolonged by a decrease in venous outflow from the - corpora, which is caused by compression of subtunical venules by the swollen corpora. -  Acetylcholine-mediated · ⑳ vasodilation by: Enhances the production of nitric & enhances the activity of adenyl cyclase * oxide Nitric oxide increases the conversion Adenyl cyclase increases the of c GTP to cGMP W conversion of c ATP to cAMP cGMP decreases intracellular ↑ calcium cAMP is a potent muscle relaxant in smooth muscle cells Smooth muscle relaxation and so vasodilatation Nervous System and Psychogenic Stimuli Some erections are mediated by a sacral nerve reflex arc (e.g, erections occurring during sleep) - In the conscious patient, sensory sexual stimulation mediatesc erections via the CNS. The patient’s brain (hypothalamus) processes sensed sex stimulation & and the impulse is carried down to peripheral cholinergic nerves that supply the vascular supply to the corpora, resulting in an erection. Nervous System and Psychogenic Stimuli -- Dopamine exerts a proerectogenic effect α2 -adrenergic stimulation causes the penis to become and/or remain flaccid. The progression of an erect penis to a flaccid state, results from the actions of norepinephrine, which contracts vascular smooth muscle to decrease arterial inflow and increases venous outflow from the corpora. Hormonal System Testosterone is produced by the testes in a circadian pattern at a daily rate of 4 to 8 mg and a normal physiologic serum concentration is 300 to 1,100 ng/dL. Testosterone stimulates libido (sexual drive) and increases muscle mass in males. pecidapat Androgen receptors are present in the penile arterial endothelium and - I w prouse are enhancing vascular processes essential for a penile erection.  S Hormonal System At age 40 years, men experience a gradual decrease in testosterone, with a decrease in muscle mass and sexual function. The cardinal symptoms of low serum testosterone levels are decreased libido, erectile dysfunction and loss of spontaneous morning erections. To confirm hypogonadism two serum total testosterone should be obtained on different days Causes of erectile dysfunction Vascular, neurologic, or hormonal etiologies of erectile dysfunction are referred to as organic erectile dysfunction. Patients who do not respond to psychogenic stimuli have psychogenic ↳ erectile dysfunction.  Vogue A way Causes of erectile dysfunction Conditions affecting vascular flow (peripheral vascular disease, arteriosclerosis, essential hypertension and cigarette smoking) Diseases that impair nerve conduction to brain (spinal cord injury · or stroke) ↓ Conditions that impair peripheral nerve conduction (diabetes mellitus) Causes of erectile dysfunction Conditions that affect the hormone Primary hypogonadism occurs with surgical removal of the testes for treatment of prostate or testicular cancer, or with testicular injury or disease. Secondary hypogonadism may result from hypothalamic or pituitary disorders of LH-releasing hormone or LH or elevated prolactin levels. Excessive alcohol lead to androgen deficiency and peripheral neuropathy. Causes of erectile dysfunction Patients who suffer from malaise, have reactive depression or performance anxiety, are sedated, or have Alzheimer’s disease, hypothyroidism, or mental disorders commonly complain of erectile dysfunction. Medication that can cause erectile dysfunction Q Q Medication that can cause erectile dysfunction Q Medication that can cause erectile dysfunction v Clinical presentation of erectile dysfunction - Symptoms: Erectile dysfunction or inability to have sexual intercourse, which may or may not be associated with decreased libido and ejaculatory disorders. Signs:- IIEF (International Index of Erectile Function) survey results are consistent with low satisfaction with the quality of erectile function. Clinical presentation of erectile dysfunction Signs:- Medication history may reveal prescription or nonprescription medications that could cause or contribute to erectile dysfunction. In hypogonadism signs of (gynecomastia, small testicles, decreased body hair or beard, and decreased muscle mass). Abnormalities of the penis (curved penis when erect) Decreased anal sphincter tone (suggesting impaired nerve function to the corpora). Laboratory Tests A serum testosterone concentration may be below the normal range, which would be consistent with a hormonal cause of erectile dysfunction. Prostate specific antigen is done for patient with enlarged prostate.