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29 Cards in this Set
- Front
- Back
What comprises the male reproductive system?
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Testes
Paired Genital ducts -efferent ductules -epididymus -vas deferens -ejaculatory duct Glands (exocrine) -seminal vesicles -prostate -bulbourethral glands of Cowper Penile Urethra |
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What are some macroscopic structures of the testes?
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Tunica albuginea
Mediastinum testis -Rete testis Epididymis Septa: lobules (250 lobules) Seminiferous tubules (1-4 tubules per lobule) |
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Describe the cells of the seminiferous epithelium
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Spermatogenic cells (germ cells)
-spermatogonia -spermatocytes -spermatids -spermatozoa -residual bodies Sertoli cells (somatic) |
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Describe the process of spermatogenesis
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I - Spermatocytogenesis (2N -> 2N)
spermatogonia -> primary spermatocyte II - Meiosis (2N -> N) primary -> secondary spermatocytes -> spermatids III - Spermiogenesis (N -> N) spermatids -> spermatozoa |
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What are the different types of Spermatogonia?
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1. Dark type A spermatogonia = reserve stem cells -> multiply via mitosis. Can become...
2. Pale type A spermatogonia - no light staining vacuole. Can become... 3. Type B spermatogonia - Can become primary spermatocytes |
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How many days do primary spermatocytes spend in meiosis I?
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22 days
lots of time, therefore most likely spermatocyte to be found |
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How much time do secondary spermatocytes exist?
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8 Hours
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How long does a spermatogonia take to become a spermatozoa?
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~64 days
not an instant process! |
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Describe some major features of Spermiogenesis
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Golgi condense to form acrosomal granule -> acrosomal vesicle -> acrosomal cap -> acrosome
Centrioles -> Flagellum = modified cilium Mitochondria organize around flagellum |
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Describe the structure of a sperm tail?
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Early tail: Surrounded by mitochondria, contains dense fibers.
Midtail: Fibrous sheath End tail: cilium/axoneme |
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What is capacitation?
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Biochemical process by which sperm gain the capacity to fertilize an ovum. Before this, they are immotile.
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What proteins to the zona pellucida express?
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3 glycoproteins: ZP1, ZP2, ZP3. Binding to ZP3 facilitates sperm entry into the ovum.
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What are sertoli cells? What do they do?
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Sertoli cells are somatic cells. They are supportive: provide structural support for spermatogenic cells, provide nutrients, transport waste to blood/lymph.
They phagocytize residual bodies and degenerative spermatogenic cells. They secrete Androgen-binding protein (Binds Testosterone), Inhibin (suppresses FSH secretion), Testicular fluid Make up the Blood-Testis barrier |
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Describe the blood-testis barrier
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Adjacent sertoli cells are connected by tight junctions to form the blood-testis barrier; creating the adluminal compartment and the basal compartment. The barrier prevents the electron dense material (lanthanum nitrate) from entering the adluminal compartment. This barrier prevents toxins from affecting the sperm, as well as prevents the body from producing antibodies against sperm.
Barrier forms at puberty, and appears to OPEN and CLOSE |
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What are Leydig cells?
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Testosterone producing cells of the testicular interstitial tissue. Structures include lipids, SER, and mitochondria typical of steroid-producing cells.
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What factors affect spermatogenesis?
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Temperature, Alcoholism, Malnutrition, Cadmium, X-ray irradiation, hormones. Temperature and X-rays do not affect the activity and the number of Leydig cells or Sertoli cells (b/c they are somatic, non-dividing).
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Describe hormonal control of the MRS
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HT ---> FSH/LH-RH
-LH acts on Leydig cells to cause testosterone production -FSH acts on Sertoli cells to synthesize Androgen Binding Protein Negative feedback of Inhibin, Testosterone on the HT to turn off GnRH |
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Describe the path of sperm in the testes
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SN Tubules -> Tubuli Recti -> Rete testeis in mediastinum testes ->efferent ductules -> epididymis (head, body, tail) -> vas deferens -> etc
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How to tell between efferent ductule and ductus epididymus?
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Lumen of efferent ductule is more irregular in outline.
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Describe the cells of the efferent ductule
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Tall ciliated columnar cells: move sperm to the epididymis. Short non-ciliated cells reabsorb some of the testicular fluid.
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Describe the epithelium of epididymus, and its functions.
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Pseudostratified columnar epithelium with stereocilia. Sperm are kept here for 1-12 days. Sperm undergo progressive maturation. Sperm acquire their motility. Absorption and secretion. Phagocytosing of generating sperm. NO CAPACITATION.
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Describe the tissue of the vas deferens?
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Pseudostratified columnar epithelium, 3 smooth muscle layers
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Describe the seminal vesicle
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15cm long duct coiled into a 5-6m long body. The mucosa is surrounded by 2 layers of smooth muscle. The mucosa is highly folded, giving it a honeycombed appearance. Contains pseudostratified columnar or simple cuboidal-columnar epithelium depending on age and hormonal influence. Produces 70% of seminal fluid.
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Describe secretions of the seminal vesicle.
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The 2 seminal vesicles secrete about 70% of the seminal fluid. Thick, creamy, yellowish fluid containing substances that modify sperm activity.
-Fructose - energy source -Prostaglandins -Citrate and seminal vesicle - specific proteins Yellowish flavinoid pigments |
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Describe the structures of the prostate
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Transitional zone surrounds the urethra: 5% of the gland
Central zone: encircles the ejaculatory ducts' 20% of the gland Peripheral zone: 70% of the gland |
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Describe the stroma of the prostate
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Collagenous tissue, smooth muscle, and stromal cells. These stromal cells have a significant role in benign prostatic hyperplasia (BPH). Contain α-reductase to convert testosterone -> dihydrotestosterone
-DHT acts on both stromal and epithelial glandular cells to induce the formation of prostatic nodules |
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What are the secretions of the prostate?
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Thin, milky colored fluid containing: Fibrinolysin - liquefy solidified semen, prostate-specific acid phosphatase, prostate-specific antigen (PSA) tumor marker, citrate, glucose, zinc, lipids, and electrolytes
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What diseases are associated with different parts of the prostate?
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Transition zone: Benign prostatic hyperplasia
Peripheral zone: Prostate cancer |
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Describe the secretions of the bulbourethral gland
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Mucus-like substance rich in galactose and sialic acid. The secretion precedes the emission of semen and has lubrication function for the passage of semen along the urethra.
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