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116 Cards in this Set
- Front
- Back
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spermatogonium
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primitive sperm cell descended from primordial germ cells of embryo
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Type A spermatogonium
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spermatogenic stem cell of the testis niche
located on most basal edge of seminiferous tubule |
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Type B spermatogonium
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derived from Type A spermatogonium
type of Transit Amplifying Cells - can readily differentiate & develop into spermatocytes |
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TYpe B spermatogonia undergo mitosis to produce _____ ______
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primary spermatocytes
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primary spermatocytes remain bound by _______
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cytoplasmic bridges
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cytoplasmic bridges permit...
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intercellular signaling
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spermatocytes
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Type B spermatogonia that have replicated their DNA
connected by cytoplasmic bridges |
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two types of spermatocytes
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Primary
Secondary |
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Primary spermatocytes
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formed from Type B spermatogonium
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process of primary developing into secondary spermatocytes
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primary spermatocytes undergo Meiosis I (REductional Division) to form Secondary Spearmatocytes
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process undergone by secondary spermatocytes develpoping into spermatids
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Meiosis II (Equatorial Division)
produces 1n haploid spermatids |
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Spermatids
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haploid
connected by cytoplasmic bridges |
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where are spermatids located?
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in clusters near lumen of seminiferous tubule
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spermatozoa, aka:
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sperm
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are spermatozoa connected by cytoplasmic bridges?
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no
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when do spermatozoa become mobile?
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after they pass through epididymis
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When does spermatogonial phase occur?
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2 - 2.5 weeks
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when does spermatocyte phase occur?
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3 weeks
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whend does spermatid phase occur?
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4.5-5 weeks
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spermatogonial phase
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stem cells divide:
(1) replace themselves (2) provide pool of committed spermatogonia spermatogonia divide into primary spermatocytes |
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spermatogonia requires...
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high levels testosterone, DHT, estrogesn
requires FSH and LH |
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spermatocyte phase
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1* spermatocytes gives rise to 2* spermatocytes
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spermatid phase
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spermatids differentiate and structurally transform from spherical to pre-mobile cells
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which testes cells synthesize testosterone?
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Leydig cells
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True or False: Sertoli cells can only support a limited number of developing germ cells
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True - a decrease in the number of functional Sertoli cells directly leads to a decrease in the rate of spermatozoa function
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true epithelium of seminiferous tubule =
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Sertoli cells
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Sertoli cells form __ ______ with germ cells at ____ stages of spermatogenic development
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Sertoli cells form GAP JUNCTIONS with germ cells at ALL stages of spematogenic development
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SSJC
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Sertoli Cell-to-Sertoli Cell Junctional Complex
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describe SSJC
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adjacent Sertoli cells form tight junction that divides seminiferous spithelium into basal and luminal compartments
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SSJC restricts spermatogonia and early 1* spermatocytes to the _____ compartment
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basal
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Regulatory function of SSJC
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creates regulated microenvironment
controls mb transporet of nutients, ions, signaling molecules btw developing germ cells and seminiferous tubules on one side & circulatory system on other side |
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what type of proteins are excluded from the seminiferous tubule lumen?
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plasma proteins (including circulating antibodies)
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Blood-Testis Barrier isolates ____ from ______
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antigenic genetically distinct haploid germ cells from recognition and attack by adult males immune system
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embryonic function of Sertoli cells?
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secrete AMH
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3 post-natal functions of Sertoli cells
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Blood-Testis Barrier
phagocytosis of discarded spermatid cytoplasm secretion |
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4 proteins synthesized by Sertoli cells upon stimulation by FSH
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androgen-binding protein
P-450 aromatase enzyme growth factors inhibin |
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where is [testosterone] greater, the male genital tract or the plasma and why?
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male genital tract - because ABP is directly secreted into it
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ABP is secreted by what type of secretion into where?
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exocrine secretion - into seminiferous tubules
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function of P-450 aromatase
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converts testosterone into estradiol within Sertoli cell
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function of estradiol converted from testosterone in the Sertoli cells
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diffuse to Leydig cells (paracrine) and
DECREASES testosterone synthesis |
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Male estrogens found in the plasma are produced primarily by _____ and _____
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liver
adipose tissue |
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growth factors synthesized by Sertoli cells regulate ____ and ______
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Leydig cell activity
spermatogenesis |
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testicular fluid is formed from the secretions of the ____
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Sertoli cells
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testicular fluid contains what, used by tubular cells of the down stream genital ducts?
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growth factors
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Leydig cells are responsible for > ___% circulating testosterone in the male
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> 90%
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what protein concentrates testosterone locally in/around the seminiferous tubules?
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ABP
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under what circumstances is it possible to have both male and female types of reproductive ducts
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if female genital ducts have not been suppressed by the secretion of AMH from the Sertoli cells
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fetal Leydig cell activity is upregulated by ______
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hCG (human chorionic gonadotropin)
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what structure secretes hCG for the fetus?
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placenta
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after the fetal period, Leydig cells are quiescent until _____
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puberty
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At puberty, Leydig cell express ___ receptors
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LH
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3 targets of testosterone during puberty
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Sertoli cells
normal growth and secretions of epididymis and accessory glands enlargement of testis |
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how do exogenous anabolic steroids cause hypogonadism
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inhibition of HPG axis at level of hypothalamus and anterior pituitary
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In addition to testosterone, secondary-sex hair growth requires ____
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DHT
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4 places testosterone is aromatized to estrogens
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fat
liver skin parts of CNS |
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only testosterone-dependent organ/tissue that does not decrease in mass with age
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prostate
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5 structural changes in sperm during spermatid phase
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nucleus size decreases; chromatin condenses
cell shape polarizes acrosome vesicle develops cytosplasm forms a residual body phagocytosed by Sertoli cells flagellum forms and mitochondrial congregate at its proximal end |
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3 main regions of spermatozoa
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head & neck (nucleus & acrosome vesicle)
mid-piece (mitochondrial region) tail |
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acrosome vesicle
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membrane bound vesicle with hydrolytic enzymes at apical end of nucleus
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3 parameters of infertility
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abnormalities in...
number, morphology, motility |
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how many sperm produced per day?
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200 million
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# sperm/ejaculate
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20-50 million sperm/mL
2-6mL/ejaculate |
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azoospermia
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lack of sperm
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oligospermia
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abnormally low number of sperm
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asthenozoospermia
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deficits in motility
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3 functions of excurrent duct system
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reabsorb testicular fluid
condition sperm receive secretions from accessory glands |
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excurrent duct system requires...
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testosterone (& sometimes estrogen)
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excurrent ducts develop from...
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mesonephric ducts
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4 basic structures of excurrent duct system
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efferent ductules --> epididymis --> ductus deferens --> ejaculatory duct
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short tubules conducting spermatozoa from rete testis to epididymis
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efferent ductules
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what moves tubular fluid down efferent ductules?
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smooth muscle contraction
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where are estrogen receptors most concentrated in male reproductive tract?
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efferent ductules
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estrogen is required for which efferent ductule function?
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fluid resorption
normal cytoarchitecture |
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how do efferent ductules concentrate spermatozoa
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reabsorb 50-90% testicular fluid's water
via Na+/K+ ATPase pumps & osmosis |
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2 types of epithelium lining efferent ductule
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ciliated columnar - controls LOCAL flow
non-ciliated cuboidal with microvilli - resorptive cells |
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obstruction of the efferent tubules -->
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extensive degeneration of seminiferous tubules
can lead to irreversible infertility |
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"sperm nursery"
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epididymis
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epididymis secretions inhibit...
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premature motility
preventing capacitation and acrosome reaction until sperm are in female tract |
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normal transit time through epididymis
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10-15 days
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where is sperm stored until ejaculation
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in tail of epididymis and in ductus deferens
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common cause of male infertility is inflammation of the _____ due to ____ from _____
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common cause of male infertility is inflammation of the EPIDIDYMIS due to UTI from STD
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primary function of vas deferens
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propel sperm up to ejaculatory duct during ejaculation
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is vas deferens palpable?
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yes - part of palpable part of spermatic cord
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most muscular part of male body (By weight)
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vas deferens
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gland producing 70% of seminal plasma
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seminal vesicles
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primary energy source for spermatozoa
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fructose
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secondary energy sources for sperm
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other simple sugars
amino acids ascorbic acid PGs |
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secretory activity of seminal vesicle epithelium regulated by ____
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testosterone
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gland contributes about 30% of seminal plasma
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prostate
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gland composed of 30-50 separate compound tubulo-alveolar glands
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prostate
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6 characteristics of prostatic secretions
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alkaline
induce sperm motility prevent premature capacitation/acrosome rxn impart opalescent character to ejaculate (as opposed to clear) fribrinolysin enzume eventually liquifies ejaculate Prostate Specific Antigen |
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location of main gland layer in prostate
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peripheral outer layer
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4 clinical zones of prostate
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peripheral zone
periurethral zone transitional zone central zone |
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outermost zone of prostate, includes main glands
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peripheral zone
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clinical zone of prostate most susceptible to inflammation
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peripheral zone
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narrow region immediately surrounding the urethra
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periurethral zone
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zone outside of periurethral zone
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transitional zone
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site of most prostatic adenocarcinomas
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peripheral zone of prostate
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prostatic zone containing mucosal and submucosal glands
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periurethral zone
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zone palpable during digital rectal exam
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peripheral zone
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prostatic zone containing mucosal glands only (no submucosal)
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transitional zone
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in late state Benign Prostatic Hyperplasia, the stroma of this zone may enlarge
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periurethral zone
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enlargement of this zone is the main cause of Benign Prostatic Hyperplasia
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transitional zone
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enlargement of the transitional zone will result in what?
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extramural compression of the urethra inhibiting urine outflow
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3 characteristics of central zone of prostate
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more posterior region
contains about 25% of glandular region resistant to both carcinomas and inflammation |
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PSA is a marker for...
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prostate epithelial activity
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abnormal increase in PSA suggests...
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CA
prostatic hyperplasia |
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prostatic concretions, aka:
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corpora amylacea
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calcified glycoproteins
may represent cell fragment and debris aggregation |
prostatic concretions
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testosterone acts on both _____ & _____ cells of the prostate to [function]
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testosterone acts on both STROMAL and PARENCHYMAL cells of the prostate to MAINTAIN STRUCTURE AND FUNCTION
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what type of prostatic cell is 5-alpha reductase present in?
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stromal cells
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stomal cells synthesize and secrete which hormone?
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DHT
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cell height and secretory activity of epithelial cells in prostate gland directly related to...
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DHT levels produced locally by stromal cells
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control of erection accomplished by...
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diverting blood flow into sinuses of corpora cavernosa
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distal portion of corpus spongiosum =
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glans penis
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3 segments of male urethra
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prostatic
membranous penile |
