Andrology

Ejaculation is the discharge of semen (the ejaculate; normally containing sperm) from the penis through the urethra. It is the final stage and natural objective of male sexual stimulation, and an essential component of natural conception. After forming an erection, many men emit pre-ejaculatory fluid during stimulation prior to ejaculating. Ejaculation involves involuntary contractions of the pelvic floor and is normally linked with orgasm. It is a normal part of male human sexual development.

An erection (clinically: penile erection or penile tumescence) is a physiological phenomenon in which the penis becomes firm, engorged, and enlarged. Penile erection is the result of a complex interaction of psychological, neural, vascular, and endocrine factors, and is often associated with sexual arousal, sexual attraction or libido, although erections can also be spontaneous. The shape, angle, and direction of an erection vary considerably between humans.

thumb|270px|A 15th century Ottoman Empire|Ottoman medical illustration by [[Sabuncuoğlu Şerafeddin depicting an operation for castration]]

sex chromosome in the XY sex-determination system

Andrology (from , anēr, genitive , andros 'man' and , -logia) is a name for the medical specialty that deals with male health, particularly relating to the problems of the male reproductive system and urological problems that are unique to men. It is the parallel to gynecology, which deals with medical issues which are specific to female health, especially reproductive and urologic health.

ejaculation and climax soon after initiating sexual activity

noncancerous increase in size of the prostate

measurement of the human penis

A varicocele is an abnormal enlargement of the pampiniform venous plexus in the scrotum. In males, this plexus of veins drains blood from the testicles back to the heart. The vessels originate in the abdomen and course down through the inguinal canal as part of the spermatic cord on their way to the testis.

museum in Reykjavík, Iceland

thumb|320px|Baculum of a dog's penis; the arrow shows the urethral sulcus, which is the groove in which the urethra lies. thumb|Fossil baculum of a Indarctos|bear (Indarctos) from the [[Miocene]]

Human disease

thumb|400x400px|Diagram of a human spermatozoa showing the acrosome

male anatomical structures

small protuberances that may form on the ridge of the glans of the human penis

mammalian protein found in Homo sapiens

rare condition in older men, characterized by measurably low testosterone levels

spontaneous erection during or after sleep

priapism observed in the corpses of men who have been executed, particularly by hanging

proposed medical condition

genital-related neurosis, in which an individual has an overpowering belief that one’s genitalia are retracting and will disappear, despite the lack of any true longstanding changes to the genitals

The spermatid is the haploid male gametid that results from division of secondary spermatocytes. As a result of meiosis, each spermatid contains only half of the genetic material present in the original primary spermatocyte.

medicine dealing with prevention, diagnosis and management of reproductive problems

medical device, implanted for the surgical treatment of organic erectile dysfunction

physical, mental, and social well-being, as experienced by boys and men

incubation of embrya in the male of a species

The discharge, by sperm, of a single, anterior secretory granule following the sperm's attachment to the zona pellucida surrounding the oocyte. The process begins with the fusion of the outer acrosomal membrane with the sperm plasma membrane and ends

Electroejaculation is a procedure used to obtain semen samples from sexually mature male mammals. The procedure is used for breeding programs and research purposes in various species, as well as in the treatment of ejaculatory dysfunction in human males. This procedure is used frequently with large mammals, particularly bulls and some domestic animals, as well as humans who have certain types of anejaculation. Electroejaculation has also been used for the cryoconservation of animal genetic resources, where semen is stored in low temperatures with the intent of conserving genetic material and f

human reflex affecting the testicles

Capacitation is a process sperm must undergo to prepare to fertilize an egg. This is a process that mature spermatozoa undergo after entering the oviduct and uterus of the female reproductive tract. Sperm must undergo capacitation and the acrosome reaction to be able to penetrate through the outer layers of an oocyte, namely the cumulus ooporus and the zona pellucida. Capacitation results in hyperactivation of sperm motility, with the acrosome and cortical reaction following this. Compounds such as heparin and progesterone can be used to induce capacitation.

offensive odour or taste from pork from non-castrated male pigs once they reach puberty

method of preventing pregnancy that solely involves the male physiology

production of milk in male mammals

Human disease

Tumescence is the quality or state of being tumescent or swollen. Tumescence usually refers to the normal engorgement with blood (vascular congestion) of the erectile tissues, marking sexual excitation, and possible readiness for sexual activity. The tumescent sexual organ in males is the penis and in females is the clitoris and other parts of the genitalia like the vestibular bulbs. Arteries in the penis dilate to increase blood volume.

eight-question written screening tool for prostatic hyperplasia

cellular structure seen by microscope in endodermal sinus tumors (yolk sac tumors)

surgical subspecialty of obstetrics and gynecology

medical condition

mechanisms that form the reproductive system

study of infertility in men