Term
| What portions of the male reproductive system are located within the scrotal sac? |
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Definition
| The testes, epididymis, and initial portion of the ductus (vas) deferens |
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Term
| What structures contribute secretory products to produce semen? |
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Definition
| The prostate gland, seminal vesicles, and bulbourethral glands |
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Term
| What is the mediastinum of the testis? |
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Definition
| It is the thicker continuation of the tunica albuginea in the region where the rete testis are located |
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Term
| How do the seminiferous tubules end? |
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Definition
| They end at the mediastinum testis by straightening out, forming tubuli recti |
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Term
| What are the layers of the testis? |
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Definition
Tunica albuginea (mediastinum testis, tunica vasculosa)
Tunica Vaginalis
Lobuli testis |
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Term
| What is the tunica vasculosa? |
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Definition
| The inner layer of the tunica albuginea; loose connective tissue with abundent blood vessels; its vessels penetrate septa to reach and supply the lobular tissue |
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Term
| What is the lobuli testis? |
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Definition
| Pyramidal shaped compartments; form the structural unit of the testis; bounded by connective tissue septae; each lobule is composed of 1-4 seminiferous tubules positioned within a loose connective tissue stroma |
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Term
| What are the two primary cell types of the seminiferous tubules' epithelium? |
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Definition
| Sertoli cells and germinal spermatogenic cells (spermatogonia, spermatocytes, and spermatids) |
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Term
| What does the wall of the seminiferous tubule contain? |
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Definition
| Collagen fibers, fibroblasts, and myoid cells (contractile cells) |
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Term
| What is the function of myoid cells in the seminiferous tubules? |
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Definition
| To move non-motile sperm from the lumen of the seminiferous tubules to the rete testis |
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Term
| What is contained in space between the loops of the seminiferous tubules? |
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Definition
Blood vessels
Lymphatic channels
Macrophages
Leydig cells |
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Term
| What are some of the characteristics of Leydig cells? |
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Definition
They are steroid producing cells, so they contain lipid droplets; well developed ER; mitochondria with tubular cristae
They respond to LH by producing testosterone |
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Term
| Where is the testosterone in the blood produce? |
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Definition
| Most of it is produced in leydig cells; 5% is derived from the adrenal cortex |
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Term
| What is the purpose of Adrogen Binding Protein (ABP) in the lumen of the seminiferous tubules? What produces ABP there? |
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Definition
ABP maintains high testosterone in proximity to the seminiferous tubules
ABP is produced and secreted by Sertoli cells into the lumen of seminiferous tubules |
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Term
| Prior to puberty, what is the principal cell type within the seminiferous epithelium? |
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Definition
Sertoli cells
They also become the predominant cell type again when the patient becomes elderly |
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Term
| What does the plasma membrane of Sertoli cells have an irregular outline? |
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Definition
| They provide crypts in which developing spermatogenic cells, in various stages of differentiation, are housed |
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Term
| Describe the blood-testis barrier |
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Definition
Adjacent sertoli cells are united near their basal aspect by occluding junctions (tight junctions) and thus seperate the seminiferous tubule into basal and adluminal compartments
This spares spermatogenic cells from auto-immunologic destruction by compartmentalizing the seminiferous epithelium |
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Term
| What are the histological and biological features of Sertoli cells? |
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Definition
| Non-dividing (post-mitotic) cells; columnar cell, rests on basal lamina; large, dense nucleolus; nutritive cell which supports developing spermatogenic cells; phagocytoses extruded residual body cytoplasm during spermiogenesis |
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Term
| Inhibin and activin subunits are synthesized and secreted by which cell type? |
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Definition
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Term
| What is mullerian-inhibiting substance and what produces it? |
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Definition
It inhibits development of paired paramesonephric ducts (formation of fallopian tubes and uterus)
Produced by fetal and neonatal Sertoli cells |
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Term
| Do spermatogonia lie within or outside of the blood-testis barrier? |
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Definition
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Term
| What is the most prevalent cell type within the seminiferous epithelium? |
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Definition
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Term
| What is the purpose of the intracellular bridges that connect spermatocytes and spermatids? |
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Definition
They allow free passage of mRNA and protein between differentiating cells
These bridges are lost from spermatozoa prior to their release |
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Term
| What are the three major events of spermiogenesis? |
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Definition
| Development of a flagellum, development of an acrosome, and nuclear condensation |
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Term
| What characterizes the middle piece of the sperm tail? |
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Definition
Microtubular axoneme
Outer dense fibers surrounded by helically arranged mitochondria |
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Term
| What is the longest portion of the sperm's tail? |
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Definition
| The principal piece; it consists of the centrally located |
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Term
| What characterizes the principal piece of the sperm tail? |
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Definition
It is the longest portion of the tail
Contains a centrally located axoneme surrounded by seven outer dense fibers and a fibrous sheath |
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Term
| What type of epithelium lines the tubuli recti and the rete testis? |
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Definition
| Simple cuboidal epithelium |
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Term
| What are the characteristics of the ductuli efferentes? |
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Definition
Simple cuboidal epithelium which functions to absorb fluid from the lumen; ciliated cells are present to help transport sperm; epithelium has a scalloped-appearance; some smooth muscle cells surround the epithelium and its basal lamina
Located in the head of the epididymis |
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Term
| Where do spermatozoa mature? |
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Definition
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Term
| What type of epithelium lines the epididymis? |
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Definition
Pseudostratified columnar epithelium with stereocilia
There are also short basal cells with round nuclei present |
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Term
| What is the epithelium of the ductus deferens? |
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Definition
| Pseudostratified columnar |
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Term
| How is the smooth muscle of the ductus deferens wall arranged? |
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Definition
| An inner and outer longitudinal layer with a middle circularly-arranged layer between them |
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Term
| Where is the ampulla of the ductus deferens located? |
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Definition
Where the ductus deferens approaches the prostate gland
On each side of the ampulla, the ductus deferens unites with the seminal vesicle to form the ejaculatory duct that passes through the substance of the prostate gland to enter the prostatic urethra |
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Term
| Where is the ductus deferens located? |
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Definition
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Term
| What do the seminal vesicles produce? |
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Definition
| A fluid rich in fructose that accounts for 50% to 70% of the volume of the ejaculate |
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Term
| What are the three regions of the prostate gland? |
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Definition
Central zone - periurethral glands
Transition zone - submucosal glands
Peripheral zone - main glands |
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Term
| What is produced by the prostate gland? |
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Definition
| Cells of the prostatic glands secrete prostate-specific acid phosphatase, prostate-specific antigen, amylase, and fibrinolysis |
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Term
| What are corpora amylacea? |
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Definition
Prostatic concretions that are rich in glycoproteins and may become calcified
They are found in the lumen of postatic glands of elderly individuals |
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Term
| What is the epithelium of the prostate gland? |
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Definition
| simple or pseudostratified columnar |
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Term
| What are bulbourethral (Cowper's) glands? What are their characteristics? |
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Definition
Small, paired glands that empty their secretions into the penile urethra; they are lined by a mucous-secreting glandular epithelium; the secretion serves as lubrication during sexual intercourse
They have simple cubiodal or columnar epithelium and a thin fibroelastic capsule with gives rise to septa |
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Term
| What is the epithelial lining of the penile and membranous urethra? |
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Definition
| Pseudostratified columnar epithelium |
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