The Male Reproductive System Flashcards
Es un organo glandular tubular ovoide alojada dentro del saco escrotal
Testiculo
Capsula que Se encuentra en la superficie interna del saco escrotal formanda de tejido conectivo denso dandole forma de capsula
Tunica albuginea
Capa externa de la tunica albuginea hecha de mesotelio
Tunica vaginalis
De la tunica albuginea se invagina hacia dentro del testiculo formando septos definiendo Los
250 lobulillos
Compartimientos piramidales en los cuales se encuentran de uno a cuatro tubulos seminiferos
Lobulillos testiculares
Medidas de los tubulos seminiferos que se encuentran muy plegados
Diametro 150 a 250 micrometros y de 30 a 70cm de largo
Porcion exocrina del testiculo
Tubulos seminiferos
Entre los tubulos seminiferos se encuentran células epiteliales especializadas llamadas
Celulas intersticiales o celulas de Leydig
Los tubulos seminiferos se encuentran revestidos por epitelio de tipo
Germinal estratificado
Epitelio germinal del tubulo seminifero cuenta con dos tipos de celulas
Celulas de sostén o Sertoli y celulas espermatogenicas
Se encuentran adheridas a la lamina basal del tubulo seminifero son altas con forma columnar irregular que en ocaciones llega a parecer una cruz, con nucleo pálido con nucleolo prominente ,las cuales captan testosterona controlando la espermatogenesis
Celulas de Sertoli o de sostén
Tipos de celulas encargadas de la espermatogenesis
Espermatogonia Espermatocito primario Espermatocito secundario Espermatides Espermatozoides
Celula movil, capaz de nadar, que consta de una cabeza la cual contiene un nucleo con la carga genética que tiene el padre, y una cola o flagelo
Espermatozoide
La cabeza del espermatozoide mide
4 a 5 micrómetros de longitud y de 2.5 a 3.5 micrómetros de anchura
Lisosoma especial, que se encuentra en los dos tercios anteriores del nucleo, con enzimas para la penetracion de las cubiertas del ovulo
Acrosoma
La cola del espermatozoide mide
55 micrómetros de largo y en grosor varia desde 1.0 micrómetros de la base a 0.1 micrómetros de su extremo terminal
La cola del espermatozoide presenta cuatro segmentos
El cuello
La pieza intermedia
La pieza principal
La pieza terminal
Zona del acrosoma donde hay una condensación de su contenido y es donde ocurre la fecundación
Segmento ecuatorial
Es el sitio en donde la cola se une a la cabeza del espermatozoide
Zona de implantación
Inmediatamente después de la cabeza se halla …. Que tiene un capitulum denso que se adapta a la forma de la fosa de implantación
Pieza conectora
Por debajo del capitulum hay
Nueve columnas segmentadas de 1.0 a 1.5 micrómetros continuas con nueve fibras externas del flagelo espermatico
Debajo de la superficie articular del capitulum hay
Un centriolo proximal orientado transversalmente, existe otro centriolo distal orientado en el eje del flagelo ausente en espermatozoide maduro
En el centro del flagelo espermatico esta el
Axonema que consta de dos microtubulos centrales rodeados por 9 dobletes
El axonema esta rodeado por
Nueve fibras densas externas
La pieza intermedia del espermatozoide se caracteriza por
La presencia de mitocondrias orientadas circunferencialmente
Cuantas vueltas dan las mitocondrias en el espermatozoide
15 vueltas
Debajo de las mitocondrias se encuentra un anillo de material electrodenso al cual esta adherida firmemente la membrana flagelar
Annulus
La pieza principal del espermatozoide mide …, formada por una serie de bandas electrodensas que figuran una parrilla costal
45 micrómetros de largo
La pieza terminal es
Solo el axonema cubierto por la membrana flagelar
La espermatogenesis en epitelio germinal se inicia por
La FSH
Celula esférica ubicada en la capa basal del tubulo seminifero y que va dividirse por mitosis
Espermatogonio
De mayor tamaño que el espermatogonio y realiza la primera división meiotica con el propósito de producir una célula haploide (23 cromosomas) e introducir una variante genética
Espermatocito primario
Es pequeño y es la celula que lleva la segunda división meiotica pero mantiene su numero de cromosomas de 23
Espermatocito secundario
Durante la espermatogenesis solo están incompletamente separadas
Espermatide
Es el producto de la espermatogenesis, siendo el gameto masculino y se libera de las células de Sertoli hacia la luz del tubulo seminifero
Espermatozoide
Celulas eosinofilas que contiene una gran cantidad de REL, lípidos y cristales de Reinke, producen testosterona
Celulas de Leydig
La testosterona es responsable de
Espermatogenesis
Desarrollo y mantenimiento de los conductos y glandulas accesorias a la reproducción
Características sexuales secundarias
El comportamiento masculino del apareamiento
El metabolismo en general
Una vez terminada espermatogenesis y liberado el espermatozoide en el tubulo seminifero, este debe de pasar por
Los tubulos rectos o vasa recta La rete testis Conductos eferentes Epididimo Conducto deferente Conducto eyaculadores Uretra
Es el primer segmento segmento del sistema de conductos excretores
Los tubulos rectos o vasa recta
Es un sistema plexiforme de espacios revestidos por epitelio cúbico y encuentran en el mediastino testicular, estructura adherida al órgano testiculo
La red testis
En un número de seis a 12 tubos revestidos por un epitelio columnar simple en grupos de celulas altas y bajas, la pared del conducto tiene musculo liso distribuido en forma circular, su función son la reabsorber el liquido que se emplea para mover el esperma fuera el testiculo y maduración del mismo
Conducto eferente
Conducto tubular plegado sobre sí mismo que está revestido por epitelio columnar simple con estereocilio no móviles que cuentan con celulas basales redondas y mas pequeñas dando aspect de pseoudoestratificado, con musculo liso escaso rodeado por TC denso y capilares
Epididimo
Es un tubulo largo y muscular que termina como una ampolla o ampula con pliegues de epitelio, su pared es gruesa capa de musculo liso distribuido de forma longitudinal en su porción interna, circular en su porción media, y longitudinal en la externa
Conducto deferente
Forman el cordón espermatico
Nervios, vasos sanguineos y linfáticos al igual que el musculo cremaster y epididimo
La eyaculacion se encuentra bajo control
Parasimpatico
Posterior a la dilatación ampular del conducto deferente y se encuentra revestido por epitelio pseoudoestratificado a columnar simple sobre capa de TC el cual no presenta musculo liso, este conducto va a llegar a la uretra prostatica a través del verumontanum
Conductos eyaculadores
Conductos eyaculadores va a llegar a la uretra prostatica a través de
Verumontanum
Es el conducto final del aparato urogenital masculino
Uretra
La uretra masculina está formada por tres porciones
Prostatica , membranosa, y cavernosa
Órgano glandular lobulado ubicado debajo de la vejiga
Prostata
La próstata se divide en tres zonas
Zona periférica
Zona periuretral
Zona anterior
Zona de la próstata que es la más propensa a desarrollar cáncer
La zona periférica
Zona de la próstata más propensa a sufrir hipertrofia y obstruir la vía urinaria causando retención urinaria en adultos mayores
Zona periuretral
La próstata se encuentra formada por
TC irregular denso y musculo liso entremezclados con la presencia de adenomeros que son de 30 a 50 glandulas tubuloalveolares simples
Tipo de epitelio de los adenomeros de la próstata
Epitelio cúbico simple
Acinos glandulares de glycoproteinas que sufrieron calcificación presentes en la próstata
Corpora amylcea
Órgano tubular retorcido varias veces sobre sí mismo con pliegues de su mucosa característicos con epitelio columnar simple, su secreción es licor seminal
Vesícula seminal
El licor seminal producido por la vesícula seminal esta compuesta por
Seminogelina y fructosa, prostaglandinas
Aporta energía a los espermatozoides
Fructosa
Pueden llegar a producir contracción del tracto genital femenino
Prostaglandinas
Is important for spermatogenesis, sexual differentiation during embryonic and fetal development and control of gonadotropin secretion in pituitary
Testosterone
Spermatozoa and the secretions of the accessory glands make up the
Semen
Tunica albuginea thick on the posterior side to form the
Mediastinum testis
During migration from the abdominal cavity each testis carries with a serous sac call
Tunica vaginalis
Tunica vaginalis consist of two layers
Outer parietal layers line the scrotum
Inner visceral layer covering the tunica albuginea on the anterior and lateral sides of testis
Temperature maintain in the scrotal sac by a pampiniform venous plexus that surrounded each testicular artery
34 degrees.
Move the testes away from or closer to the body allowing control on testicular temperature
Cremaster muscle and thin dartos muscle
An excessive accumulation of serous fluid in one or both sides of the scrotal sac
Hydrocele
The failure of one or both testes to descend from the abdomen, occurs about 4% of male neonates
Cryptorchidism
Bilateral cryptorchism causes infertility if not surgically corrected by
2 or 3 years of age
Testosterone secretion by Leydig cells is triggered by pituitary gonadotropin called
Luteinizing hormone which is also called interstitial cell stimulating hormone ICSH
In the late embryonic testes gonadotropin from…… stimulates interstitial cells to synthesize the testosterone needed from development of the ducts and glands of the male reproductive system
Placenta
Interstitial or Leydig cells are very active in pregnancy in months…
Third and fourth
Percentage of testicular cancer that involves germ cell tutors
95%
Sperms are produce at a rate of about
2x10^8 per day in young adult
Each testis has from….. such tubules in its lobules and each tubule measures 150 to 250 micrometers in diameter and 30 to 70 cm in length
250 to 1000
The total length of the tubules of one testis about
250 m
Each seminiferous tubule linked by …. To the rete testis
Straight tubule
Number of efferent ductules that connect the rete testis to the head of the epididymis
10 to 20
The basement membrane of the germinal epithelium contain smooth muscle like
Myoid cells
The primary spermatocyte has
46 (44+ XY) content 4N
The first meiotic prophase last about
3 weeks
Secondary spermatocyte has
Only 23 chromosomes (22+X,22+ Y) and amount of DNA is 2N
Very short living cells
Secondary spermatocyte
All subsequent divisions of the daughter cells have incomplete cytokinesis remain attached to one another by
Intercellular bridges
The cellular events and changes between the final mitoses of spermatogenia and formation of spermatids take about
2 months
Four phases of spermiogenesis
Golgi phase
Cap phase
Across me phase
Maturation phase
phases of spermiogenesis in which Golgi apparatus is prominent and have proacrosomal vesicles coalesce as a single membrane limited acrosomal cap
Golgi phase
Specialized type of lysosome containing hydrolytic enzymes, mainly achyaluronidase and a trypsin like protease called
Acrosin
The acrosomal cap spreads over about half of the condensing nucleus
Cap phase
phases of spermiogenesis in which nuclei become more enlongated and very highly condensed with his tones replace by protamines
Acrosome phase
phases of spermiogenesis with uneeded cytoplasm is shed as a residual body
Maturation phase
Poor semen quality, with sperm cell density less than 10 - 20 million/mL
Oligospermia
Each Sertoli cells support …… germ cells
30 to 50 germ cells
Tight occluding junctions between their basolateral membranes that form…, that prevents autoimmune attacks against the unique spermatogenic cells
Blood testis barrier
Three general function of Sertoli cells
Support, protection,and nutrition of spermatogenic cells
Exocrine and endocrine secretion
Phagocytosis
Sertoli secretion which concentrates testosterone to a level required for spermiogenesis promote by follicle stimulating hormone FSH
Androgen binding protein ABP
Sertoli secretion a glycoprotein which feeds back on the anterior pituitary gland to suppress FSH synthesis and release
Inhibin
Sertoli cells secretion that cause regression of the embryonic mülllerian (paramesonephric) ducts
Mülllerian inhibiting substance MIS
Acute or chronic inflammation of the testis, produced by infective agents occurs secondarily to a urinary tract, infection or a sexually transmitted pathogen
Orchitis
A result of sexually transmitted infections such as gonorrhea or chlamydia
Epididymitis
Epithelium of efferent ductules
Alternating patches of simple cuboidal nonciliated and simple columnar ciliated support by thin layer of smooth muscle
Pseudostratified columnar epithelium with small basal cells and tall principal cells bearing long stereocilia support by circle smooth muscle initially with inner and outer longitudinal layer
Epididymal ducts
Pseudostratified columnar with few stereocilia with three thick layers of smooth muscle
Ductus vas defferent
Length of the three part of epididymis (head, body and tail)
4 or 5 m
Secrete glycolipids and glycoproteins and absorb water and remove residual bodies with long stereocilia, line epididymal ducts
Principal cells
Each vas deferens passes over the urinary bladder where it enlarges as an
Ampulla where the epithelium is thicker and more extensively folded
Within the prostate gland the end of the two ampulla merge with the ducts of the two seminal vesicles to form the
Ejaculatory duct which open in the prostatic urethra
Small incision is made through the scrotal skin near the ducts and each vas is exposed, cut, and cauterized, the most common surgical method of male contracepton
Vasectomy
Highly torturous tubes each about 15 cm long, unusual mucosa with folds that fill much of the lumen with simple or pseudostratified columnar epithelial cells rich in secretory granules, lamina propia with elastic fibers surround by smooth muscle making the 70% of the ejaculate
Seminal vesicles
Major energy source for sperm as well as inositol, citrate, and other metabolites
Fructose
Stimulate activity in the female reproductive tract part of secretion of seminal vesicles
Prostaglandins
Allows semen to coagulate after ejaculation
Fibrinogen
Percentage of seminal vesicles fluid in ejaculate
70%
Dense organ that surround the urethra below the bladder weigh about 20 grams, collection of 30 to 50 tubuloacinar glands embedded in a dense fibromuscular stroma in which smooth muscle contracts ejaculation
Prostate gland
Major zones around the prostatic urethra
Transition zone 5%
Central zone 25%
Peripheral zone 70%
Occupies about 5% of the prostate volume, surround the superior portion of urethra and contains the periurethral mucosal glands
Transition zone
Comprise 25% of the glands tissue and contains the periurethral submucosal glands with longer ducts
Central zone
With about 70% of the organs tissue contains the prostate main glands with still longer duct
Peripheral zone
A clinically important product of the prostate is…, that helps liquefy coagulated semen for the slow release of sperm after ejaculation
Prostate specific antigen PSA
Small spherical concretions, 0.2 to 2 mm in diameter often partially calcified are normally present in the lumen of many prostatic tubuloacinar glands, containing primarily deposited glycoproteins and keratan sulfate
Corpora amylacea
Three common problems of prostate gland
Chronic prostatitis involve bacteria or infectious agent
Nodular hyperplasia or benign prostatic hypertrophy occurring in periurethral mucosal glands with often leads to compression of urethra
Prostate cancer
Prostate cancer occurs mainly in glands of the
Peripheral zone
3-5mm in diameter, located in urogenital diaphragm and empty into the proximal part of the penile urethra, each gland have lobules with tubuloacinar secretory units surrounded by smooth muscle cells and line by a mucus secreting simple columnar epithelium that is also testosterone dependent
Bulbourethral glands or Cowper glands
During erection Cowper glands release
Mucus-like secretion that coat and lubricates the urethra in preparation for the imminent passage sperm
Erectile masses
Corpora cavernosa, are dorsal
Corpus spongiosum, surround the urethra
Glans
Penile Urethra is lined with
Pseudostratified columnar epithelium in the glans becomes stratified squamous epithelium
Small mucus-secreting are found along the length of penile urethra
Urethral glands
The corpora cavernosa are each surrounded by a dense fibroelastic layer the
Tunica albuginea
All three erectile tissues consist of many venous
Cavernous spaces line with endothelium and separated by trabeculae with smooth muscle and connective tissue continuous with the surrounding tunic
Central arteries in the corpora cavernosa branch to form nutritive arterioles and small coiling
Helicine arteries which lead to the cavernous vascular spaces of erectile tissue
Involves blood filling the cavernous spaces in the three masses of erectile tissue
Erection
Erection is controlled by
Autonomic nerves in vascular walls, parasympathetic stimulation relaxes the trabecular smooth muscle and dilates the helicine arteries, this enlarges the corpora cavernosa and causes to compress the dorsal vein against the dense tunica albuginea which blocks the venous outflow and produce rigidity
At ejaculation sympathetic stimulation.
Constrict the helicine arteries and trabecular muscle decrease blood flow into the space lowering the pressure
At erection sympathetic nerves produce acetylcholine that causes the vascular endothelial cells of helicine arteries and cavernous tissue torealease
Nitric oxide NO diffuse into the surrounding smooth muscle cells and activates gaunylate cyclist to produce cGMP, which cause these cells to relax and promotes blood flow for erection
