Gametes Flashcards
Gametogenesis meiosis or mitosis
Meiosis
Haploid cells w/ new gene combo.,
Basic gametes for male/female
Male -sperm -w/in testes -ongoing meiosis recombo. Female -oocyte/ova -ovary -arrest @ b4 birth
testes housed in
Scrotum
Testicular layers
Tunica Albuginea
Tunica vasculosa
Tunica propria
Interstial
Tunica Albuginea
Dense CT
Surround seminiferous lobules
Tunica Vasculosa
b/w T. albuginea and Serm. tubules
@ times hard to see
Tunica Propria
Surround each sem. Tubules Collagen layers and Myoid cells -NOT fibroblast Contraction -peristaltic waves=moving spermatozoe/testicular fluid out of seminferous tubules
Myoid cells
peritubular contractile cells
Sm. muscle
Incre. RER for collagen prod.
Leiydig cells
Hormo. production inerstitial cell
+ in early fetal develop
Inhib. until puberty
Respond to pit. hormon. Gonade Tropin horm.
Hist.
-light stain b/c incre. SER of cholester. horm. product.
:IE testosteron
Spermatogensis Overview
W/in=seminiferous tubules -w/in sertoli cells Occurs in waves -not every section of tubule is the same :dif. stg. of meoisis/tubule section are difi. Mice=segmental not patches Basal=mitosis w/ additional gametes Meosis=haploid gamete
Actual spermatogenesis/cell type
Mitosis=spermatogonia -mitosis -cnt tell diff. parts Meiosis I=Primary spermatocytes -@ end=haploid cells -condense chromo. -occur w/in dys Meiosis II=secondary spermatocytes -Haploid -cnt see histologically Spermiogensis/spermatids -Early=immature haploid gametes :w/in sertoli cytop. -late=see arrow head :@ sertoli apical cytop. Resid. body/spermatozoa Spermatid are release into sem. tubule lumen
Sertoli cells
REg.
True Epith. of sem. tubules b/c other cells are spermatogonia
Histolog=nucleus w/ dark nucleoli
Overview
-function=supporting cell w/in sem. tub.
:reg. spermatogonia
-Allow spe. of BSM and tunica propia=protection from immune system
:sperm not created during gamete formation
@ Basal Near basal lamina
Facilitate relase of speratid
Respond tp FSH=express androgen
Spermatid remod.
Early=reg. cells w/ nucleoli -Golgi form acrosome=determine ant. pole :centriole=flagellum Acrosome fap form=flagellum extend Cell flips -flagellum @ lumen -ant. near sertoli Cytoplasm=post to nucleus/acrosome Incre. mitocho. around flagella -mitochonidal sheath form Remove excess cytop.=residual body
Spermatid released from Sertoli cell
Exit serminf. tubules @ the median/rete testes junction Travel through -tubuli recti (short straight tubule.) :line w/ sertoli cells only (smp. cub./columnar epith.) :mainly columnar -Rete testes w/in medianstinum :line w/ simp. cub. epith -Ductile efferent=efferent ductule
Mediastinum
all sem. tubule drain @ this pt.
has dense CT w/ BV (~ to hilum of organ)
Mediastinum
all sem. tubule drain @ this pt.
has dense CT w/ BV (~ to hilum of organ)
Female gametogensis overview
Gametes produced in ovaries
Fertilization=oviduct
Iimplantation=uterus
Oogenesis mitotic division
1st meiotic division=in ovary -begin @ embryonic develop :not @ birth unitl puberty -After each ovulation :oocyte-->fallopiantube 2nd meiotic division -metaphase arrest (prior to oviduct) -if fertilized =completed in oviduct
Ovaries
Layers -Tunic albuginea -Germinal epith. (smp. cub.) Function -produce femal gamete -secrete estrogen/progest. -reg. postnatal growth/reproduced organd -develop 2ndry sex organs
Fallopian tube
AKA oviduct
Fembri=cilia that bind to outer cilular layer of oocyte(corna radiata)
oogonia
Cells that develop during fetal development -mitosis incre. number of future oocyte Dnt need BB(unlike male) b/c was developing during immune syst. develop Most not fully develop=atresia -apoptosis of surrounding cells -80% of cells are destroyed b4 birth Brith -ovaries contain 600,00 to 800,000 -arrest in prophase I
Basic follicle structure
Oocyte Zona peluccida -glylcoprot. -very eosin Granulosa cell=supporting cells
Follicle structure-oocyte
Developing female gamete
-mature=ovum/oval
Vry lrg cell w/ incre number of sub organell
-male=nuclei, mitoch, flagella
Proj. irreg. microvilli–>perivitelline space
Granulosa cell extend in perivitelline space
-allow for communication w/ oocyte a part of communication
Perivitelline space
b/w oocyte/granulosa cell
Zona pellucida forms
Follicle structuer-2ndry follice structures
Cumulus oophorus w/ granuloa cells
Corona radiata
-cell layer surround oocyte after release
Microvilli penetrate zona pellucida/contact oocyte microvilli
No cytoplasmic continuity
-but communicate through gap junction
Follicular develop
Stg1. =primordial oocyte Stg2=primary follicle Stg. 3=secondary follicle Stg. 4=graafian Stg5=relase
Follicular develop-stg. 1/primordial
Housing primary oocyte w/ sq. cells(granulosa cells)
B4 birth/puberty
Follicular develop-stg. 2/primary follicle
AKA developed primordial cell No layers Arrest after crossing over and wait until pubert @ prophase I Early=sum. cub. Lat.=st. cub. -theca follicle begins to develop -beginning of zona pellucida
Follicular develop-stg. 3/secondary follicle
AKA prenatal follicle Atria forms -space surrounding most of oocyte -fluid=oocyte maturation inhibin(OMI) 2 cells start to form -zona pellucida (encase primary oocyte) -mural granulosa cells (premature theca cels) Cumulus oophoras Layers -Granulosa (st. cub.) -BsM -theca=inner and outer
Cumulus oophorus
stop oocyte from mooving by attaching to granulosa cells
Theca cells
Inner=horm. producing cells
-vascular layer
-respond to LH to produce estrogen’s precursor
Outer=sm. muscle/CT
Follicular develop-stg 4/graafrian
AKA pre-ovulatory follicle Very lrg cell Follicle move close to outer aspect of ovary cells -cumulus oophorus -cornoa radia=granulosa cells cell attache to zona pellucida Polar body created -oocyte daughter cell from meiosis -b/w oocyte and zona pellucida -chromo. w/ mini cytop. -undergo apoptosis
Follicle develop-release
Incre. vol./incre. of follicular fluid Plasmin proteolysis of follicular wall Glycoamino glycogen deposit in comulums oophurs Exit=theca ext. sm. contraction -goes into oviduct
Released oocyte layers
corona radiat(granulosa cells) oocyte/nucleus
Hormone reg. in gen.
beginn @ hypoth.=GnRH to pituitary (FSH/LH)
Endocrine for males
FSH=sertoli cells LH=lydig cell Testosteron -2ndry sec charct. -reprod. -metaoblic=growth/kid. -behavi.=libido
endocrine for females
FSH=follicle develop. LH=ovulatin/progesteron/estrogen ovarian cycle -hormo level changes eery 28 dys ovaries release oocyte by uterine wall changes Estrogen/progest=inhib. LHRH/GnRH Progesterone's percursor for estrogen/testorone -secdry sex charact. -reporduciton -lactation
