Regulation of Reproduction by Dopamine
Nira Ben-Jonathan in Dopamine, 2020
The vas deferens carries sperm from the epididymis to the ejaculatory ducts by peristalsis. During ejaculation, the sperm mixes with fluids from the seminal vesicles, prostate gland, and bulbourethral glands, which form the semen and provide an environment that promotes sperm survival and fertility. Semen contains only 10% sperm by volume, with the remainder consisting of the combined secretion of the accessory glands; seminal vesicles contribute about 60% of this fluid. The secretion of the seminal vesicles contains fructose (the main substrate for sperm glycolysis), ascorbic acid, and prostaglandins. Prostaglandins were first discovered in seminal fluid and were mistakenly considered the product of the prostate gland, and hence their name. The prostate produces polyamines, citric acid, cholesterol, fibrinolysis, and acid phosphatase, which are necessary for the coagulation and subsequent liquefaction of semen.
Pelvis and perineum
David Heylings, Stephen Carmichael, Samuel Leinster, Janak Saada, Bari M. Logan, Ralph T. Hutchings in McMinn’s Concise Human Anatomy, 2017
to the symphysis pubis and inferior to the bladder, and the ureter passes through it.The seminal vesicles and the ductus deferens are located laterally to the prostate and the ejaculatory ducts they form enter the urethra from a lateral position.The prostate has a groove on its posterior surface, inferior to the seminal vesicles, which is palpable on rectal examination.The membranous urethra passes through the prostate gland and has openings for the ejaculatory ducts and the 12 ducts from the gland itself.Sitting on the pelvic diaphragm, the prostate is located inferior to the body of the pubis.
Physical Aspects of the Sex Response
Philipa A Brough, Margaret Denman in Introduction to Psychosexual Medicine, 2019
Emission is the forerunner of ejaculation and is primarily mediated by the sympathetic nervous system, with outflow from twelfth thoracic to second lumbar spinal cord segments via the hypogastric and pelvic parasympathetic plexi. Contraction of the vas deferens and ampulla expels sperm into the urethra via the ejaculatory ducts. This accounts for 10% of ejaculate volume. Seminal vesical contraction expels a further 60% via these shared ejaculatory ducts, while the prostate contributes 30% via prostatic sinuses on either side of the posterior urethral lumen ducts into the urethra. In the urethral lumen, further mixing occurs with previous secretions from bulbourethral and small periurethral glands. Closure of the internal urethral sphincter, with simultaneous relaxation and opening of the external sphincter, facilitates direction of semen into the bulbar urethra.
Aluminum reproductive toxicity: a summary and interpretation of scientific reports
Published in Critical Reviews in Toxicology, 2020
Spermatozoa travel from the seminiferous tubule lumen through efferent ductules to enter the head of the epididymis, a long, coiled tube (duct) on the backside of each testis that transports and stores the spermatozoa. The epididymis is composed of its initial segment and head (caput) which is characterized by its thick epithelium, body (corpus), and tail (cauda), where spermatozoa are stored. Within the epididymis, sperm mature while gaining mobility. During sexual arousal, contractions force the sperm into the vas deferens. The vas deferens is a long, muscular tube that travels from the epididymis into the pelvic cavity to transport mature sperm to the urethra in preparation for ejaculation. Seminal vesicles are sac-like pouches attached to the vas deferens. They produce fructose that provides sperm with an energy source and assists the sperms’ motility. Seminal vesicle fluid provides most of the ejaculate volume.
Extracellular vesicle cargo of the male reproductive tract and the paternal preconception environment
Published in Systems Biology in Reproductive Medicine, 2021
Ahmet Ayaz, Emily Houle, J. Richard Pilsner
In addition to the presence of prostasomes, EVs originating from the epididymis (referred to as epididymosomes) have been identified in human seminal fluid. Sperm are initially non-motile when they exit the seminiferous tubules of the testes and undergo maturation process during their passage in the epididymis (which can last up to 14 days). The epididymis is a coiled structure (4–6 m in length), which is positioned posterior to the surface of the testes and bridges the efferent ductus and vas deferens. It is divided into three main regions: proximal caput (head), elongated corpus (body), and distal cauda (tail), where sperm are ultimately stored until ejaculation. The epididymis provides an alkaline intraluminal environment to stimulate sperm motility. The complexity of epididymal intraluminal secretions arises from absorptive activity, secretory activity, and more importantly, bi-directional vesicle trafficking (Hermo et al. 2019).
Protein markers of spermatogenesis and their potential use in the management of azoospermia
Published in Expert Review of Proteomics, 2021
Sophia Costa Araujo, Ricardo Pimenta Bertolla
Azoospermia is classified as obstructive azoospermia (OA) and non-obstructive azoospermia (NOA) [4,6]. In obstructive azoospermia, sperm are produced in the testis, but due to physical obstruction in the male reproductive tract, they are not released in the ejaculate. This obstruction, in most cases, is due to congenital anomalies, such as congenital bilateral absence of the vas deferens (CBAVD) or obstruction of the epididymal duct of unknown origin [6]. The physiological results of OA are similar to those of a vasectomy. Patients with OA, when they resort to assisted reproduction techniques to retrieve sperm directly from the testis or the epididymides, usually present high success rates [7] because the issue is not sperm production. NOA, on the other hand, is defined as the absence of sperm in the ejaculate due to a testicular dysfunction that affects production of male gametes [4,6–8].
Related Knowledge Centers
- Inguinal Canal
- Seminal Vesicles
- Sperm
- Epididymis
- Spermatic Cord
- Ejaculation
- Ejaculatory Duct
- Male Reproductive System
- Ampulla of Vas Deferens
- Artery to The Ductus Deferens