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28 Cards in this Set
- Front
- Back
Leydig cells produce what hormone? This hormone has what effect on germ cels?
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LH binds LH receptors on Leydig cells that convert cAMP to testosterone (via cholesterol and pregnenolone)
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In the seminiferous tubules, what is testosterone bound to?
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Bound to ABG.
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What can happen to testosterone in periphery?
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Can be converted to DHT via 5a-reductase.
Can be converted to estradiol via aromatase (c19 --> c18) |
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What do Sertoli cells do?
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1) Form tight junctions that are called blood-testes barrier.
2) Sertoli cells respond to FSH and are support cells for maturation of spermatogonia. 3) Also secretes inhibin, a feedback regulator 4) FSH --> ABP and aromatase (to estradiol) synthesis. |
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At what level of the HPA axis does inhibin work?
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Inhibin acts by negative feedback on anterior pituitary and hypothalamus.
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Hormones from Leydig cells inhibit where?
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Estradiol from testosterone negatively feedbacks on A.P.
Testosterone itself negatively feedbacks on Hypothalamus. |
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What are the layers of testes from skin to testes?
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Skin --> Dartos --> Tunica vaginalis --> Tunica albuginea --> Tunica vascularis --> Seminiferous tubules.
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What is the relevance of the blood-testes barrier?
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Keeps spermatogonia from being exposed to immune system. Pass barrier as primary spermatocytes...then they can be exposed.
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Will you see more primary spermatocytes or secondary spermatocytes in histological stains?
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You will RARELY see secondary spermatocytes. MAJORITY will be primary because MOST TIME DURING SPERMIOGENESIS is spent in PRIMARY phase.
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How long is spermiogenesis
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64 days.
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What is the energy source added to sperm in the seminal vesicle?
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FRUCTOSE
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What are two things mentioned about cystic fibrosis patients in terms of infertility?
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No fructose added to sperm and ABSENCE of seminiferous tubules.
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What is the minimum requirements for a normal semen analysis?
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10-20 million/mL.
40% motility (must have FORWARD motility) 40-60% show normal morphology. Semen must coagulate first, then liquefy. Approximately 2-5 mL. |
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What is Kallman's syndrome?
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Migration problems of GnRH neurons from olfactory placode.
Patients have difficulty smelling. Patients will have not have GnRH release. |
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What effect does hyperprolactemia have on GnRH secretions?
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Prolaction DOWNREGULATES GnRH secretions.
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Do ANDROGEN or ESTROGEN excess cause problems with testicular development?
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YES!
Estrogen negatively feedbacks at Anterior Pituitary Androgen feedbacks at hypothalamus. BOTH BAD! Increases in testosterone can also lead to precocious puberty and premature secondary sex characteristics (increase in DHT too) |
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How many twists do you need to cause hemorrhagic infarct in torsion of testes?
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2.5 twists for 12 hours.
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Cryptorchidism can lead to what two abnormalities?
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Infertility (germ cells not at ideal temperature) AND neoplasms
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What are some causes of testicular damage?
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Toxins, drugs, alcohol use. Diabetes.
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What are causes of post-testicular infertility?
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Ductal obstruction secondary to STD (gonorrhea/chlam). Epididimytis.
Ejaculatory dysfunction (neuropathy, prostatectomy with nerve damage) |
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What are the TWO TYPES of testicular cancer?
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Seminomas and NON-seminomas
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What is the morphology of a seminoma?
Hallmark histological feature? |
Homogenous, tan colored mass.
NO NECROSIS/HEMORRHAGE Fried eggs. Retraction of cell. |
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What is the morphology of a NON-seminoma?
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Necrosis and hemorrhage.
Combination of solid and cystic. |
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What are the TWO tumor markers you test for in a NON-seminona.
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AFP (produced by yolk sac tumors) and hCG produced by CHORIOcarcinoma.
NON-seminiferous tumors included yolk sac (AFP) and CHORIOcarcinoma (hCG) and embryonal carcinoma, and IMMATURE and MATURE carcinomas |
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What is the difference between a mature and immature carcinoma?
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Mature teratoma shows cells that have differentiated into other tissue types.
Immature teratomas have immature cell types, no differentiation. |
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Metastases above/below the diaphragm make up the cutoff between what two stages of germ cell tumors?
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II and III.
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Do testes atrophy? Do Leydig cells decrease in number with age?
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Yes! yes!
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What is cortical adrenal hyperplasia?
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1) ACTH drives production of cortisol.
2) There is a key enzyme that has been MUTATED (21-hydroxylase). 17a-OH-progesterone build-up can be converted INSTEAD to Androstenedione --> Testosterone. Leads to precocious puberty, premature development of male characteristics. SIMILAR SYMPTOMS with thyroid dysfunction. |