University:
Texas A&M University
Course:
BIOL 319 | Integrated Human Anatomy and Physiology I
Academic year:

2023
Views:

419

Pages:

56
Author:

omiliar74be

Male reproductive system: Part 2 Excurrent ducts Part 2 Excurrent ducts Objectives • Identify the endocrine and exocrine subdivisions of the testes? • Distinguish the cells of the spermatogenic cell lineage. • Identify and distinguish among epididymis, vas deferens, urethra, seminal vesicles and the prostate gland. • Describe the structure of the penis and indicate how it becomes tumescent. Outline secretions into the excurrent ducts, pathway of the ducts, epididymal maturation of spermatozoa and follow with characteristics of a fertile ejaculate, erection mechanisms, and clinical correlations. 165 Interstitium (monkey) 1. Leydig cell 2. Endothelial cell of lymph vessel 3. Blood vessel 4. Fibroblast 291 intact Hormonal control of height of epithelium seminal vesicles Replacement testosterone castrate ACCESSORY GLANDS - COMPOSITION AND SECRETION ACCESSORY GLANDS SECRETION SEMINAL VESICLES FRUCTOSE FIBRINOGEN CITRATE FIBRINOLYSIN MUCUS-LIKE LUBRICANT MUCUS PROSTATE BULBOURETHRAL GLAND GLANDS OF LITTRE Accessory glands duct glands ducts Urethea EM 23; prostate; 31 000x 1. Secretory granule 2. RER 3. Nucleus 4. Tight junction Prostate gland Tubulo-alveolar secretory units with prostatic secretions Large nerves and ganglia are in surrounding CT Stroma Ejaculatory ducts Utricle Urethra Prostatic gland duct Prostate gland (with concretions) - Prostatic concretions Male reproductive system Seminal vesicles ureter Ductus deferens Seminal vesicle Seminal vesicle Nerve in adventitia Adventitia Muscularis externa Seminal vesicle Columnar epithelium Lamina propria Seminal vesicle, monkey Seminal vesicles FUNCTIONAL PROPERTIES OF THE ACCESSORY GLANDS SPECIFIC CONTRIBUTIONS OF SEMINAL PLASMA AS MEASURED BY THE SPLIT EJACULATE METHOD FRACTION of EJACULATE CONTAINS FIRST 90% OF ALL CITRATE 90% OF ALL SPERM LAST 90% OF ALL FRUCTOSE SOURCE PROSTATE DUCTUS DEFERENS SEMINAL VESICLES DEVELOPMENTAL RESPONSE TO ANDROGENS Testes and seminiferous tubules Copyright McGraw-Hill Companies human testis junction of seminiferous tubule and rete testis for sperm to exit (toluidine blue) Epididymis – head; efferent ductules True cilliated cells (efferent duct, top) and Stereocilliated cells (epididymis, with sperm in lumen) of psudostratified columnar epithelium (toluidine blue) slide Veins nerve Epididymis nerve Efferent ducts Human head of epididymis Smooth muscle EPIDIDYMAL SPERM MATURATION -FERTILITY -MOTILITY -NATURE OF PLASMA MEMBRANE -MITOCHONDRIAL STRUCTURAL STABILITY -CHROMATIN -STABILITY 93 Epididymis Smooth muscle Pseudostratified columnar epithelium Non-motile sterocilia EM 21: ductus deferens; 11 000x 1. Golgi 2. Stereocilia 3. Mitochondria 4. Swirl of SER EM 2: Epididymis Centriole pair In summary Human Muscle layer of the epididymal duct increases in thickness in its more distal regions further away from the efferent ducts Smooth muscle and psudostratified columnar epithelium in tail of epididymis slide 19716 19716 EPIDIDYMAL SPERM MATURATION (FERTILITY) MODIFY DNA-PROTEIN COMPLEX ENABLE ENERGY TRANSLATION FOR MOTILITY DEVELOP SURFACE MASK FOR PROLONGED SURVIVAL IN FEMALES DEVELOP MULTIPLE BINDING PROTEINS FOR EGG CHARACTERISTICS OF FERTILE HUMAN EJACULATES GOOD VISCOSITY (CLOT THEN DISPERSE) about 3 ml in volume Spermatogenesis and edididymal maturation of sperm continues regardless of ejaculation frequency. Where do nonejaculated sperm go? Spermatozoa appears in urine after several days (7-8 days) of sexual rest in humans. Ductus (vas) deferens Thick longitudinal Thick circular Thin longitudinal outer layer middle layer inner layer Thick muscularis externa Mucosa Non-motile sterocilia Pseudostratified columnar cells There are several nerves in this connective tissue (adventitia of the ductus) to control coordinated smooth muscle contractions. Ductus (vas) deferens Under sympatric control, the thick muscularis externa of the vas deferens produces strong peristaltic contractions during ejaculation, which rapidly move spermatozoa along this duct from the epididymis to the ejaculatory ducts of the prostate just in time. Skeletal muscle in spermatic cord UT 196 Copyright McGraw-Hill Companies Spermatic cord ut 196 Ductus (vas) deferens Spermatic cord Ductus (vas) deferens Smooth muscle and psudostratified columnar epithelium in ductus deferens (toluidine blue) slide Human penis – transitional or stratified columnar epithelium and surrounding spongy cavernous of penal urethra Corpora cavernosa Corpus spongiosum Tunica albuginea Penis – corpus cavernous Corpora cavernosa Corpus spongiosum Penis - transitional or stratified columnar epithelium of penal urethra Penis (monkey) Urethra Corpus spongiosum Blood vessels and nerve of penis Vasodilation of this corpus tissue occurs in response to parasympathetic stimulation? Tunica albuginea Corpora cavernosa Small deep artery Fig. Mechanism of erection “Erection occurs as a complex process, constituted by psychological, neurological, hormonal, and vascular factors. The penis is composed of three basic anatomical structures – two longitudinal cavernous bodies (a kind of chambers) and one spongy body, including the urethra. These are the cavernous bodies that (supplied by respective arteries) increase their volume during erection, owing to the inflowing blood. …Arteries (as opposed to veins)… – by dilation or contraction – regulate the blood flow”. http://www.vediclinic.com/the-mechanismof-erection.html “..With sexual arousal the increasing activity autonomic nervous system stimulates the release of neurotransmitters at nerve endings in the cavernous bodies or in the endothelium of the arteries. This leads to secretion of NO – nitric oxide, which is one of the strongest smooth muscle relaxants. With dilated cavernous arteries, the amount of blood flowing into the penis increases, and its outflow is hindered by a physiological compression of some specific veins. Moreover, contraction of the ischiocavernous muscle stabilises the penis in erectile position. A key factor of effective erection is the condition of the vascular system, ensuring a proper perfusion of the reproductive organs. Any pathologies of this system (e.g., atherosclerosis, coronary disease, hypertension) lead to problems with erection”. Clinical Correlation A male patient suffers from infertility, immotile spermatozoa and repeated respiratory infections. You suspect Kartagener syndrome. Images from Primäre ciliäre Dyskinesie und Kartagener-Syndrom at Lungenliga.de Normal cilia with proper dynein arms Abnormal cilia lacking dynein arms of Kartagener patient Clinical Correlation A male patient suffers from infertility, immotile spermatozoa and repeated respiratory infections. You suspect Kartagener syndrome. • • Both sperm flagellum and respiratory epithelium cilia contain axonemes, which require proper dynein arms for mobility. In Kartagener syndrome, the patients’ dynein arms are defective; and therefore, the patient lacks proper motility of sperm flagellum and respiratory epithelium cilia. This often results in male infertility (the sperm cannot swim to reach or penetrate the egg) and recurrent respiratory infections (cilia cannot move mucous). Images from Primäre ciliäre Dyskinesie und Kartagener-Syndrom at Lungenliga.de Normal cilia with proper dynein arms Abnormal cilia lacking dynein arms of Kartagener patient

Male Reproductive System Part 2 Excurrent Ducts

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