Male Reproductive System Flashcards
TESTIS - produce sperm, secrete androgens (t_______)
OVARIES - produce eggs, secrete estrogens (e_____/p________)
*Spermatazoa are generated in S______ T________
Spermatazoa mature in the E______ prior ro ejaculation*
TESTIS - produce sperm, secrete androgens (testosterone)
OVARIES - produce eggs, secrete estrogens (estradial/progesterone)
*Spermatazoa are generated in Seminiferous Tubules
Spermatazoa mature in the Epididymus prior ro ejaculation*
Sertoli Cells - epithelial cells that line the s_______ t______\_
- joined together by ______________ [limits diffusion between cells]
Blood _____ ______connects sertoli cells at tight junctions and isolates _______ ____from fluid bathing cells on other side (b____ c_________). Also protects sperm from ______ _____
- Primary function - nuture sperm and control ________
- secrete _______ _____ - transport for sperm and nutrients to developing cells.
- secrete androgen binding protein - binding androgens revesibly acts as an androgen buffer → maintains equilibrium of [androgen]
- secrete inhibin - suppresses release of FSH by the _______ ______
- ____________ and FSH control development
Sertoli Cells - epithelial cells that line the seminiferous tubules
- joined together by TIGHT JUNCTIONS [limits diffusion between cells]
Blood testis barrier connects sertoli cells at tight junctions and isolates lumenal fluid from fluid bathing cells on other side (basal compartment). Also protects sperm from immune attack
- Primary function - nuture sperm and control development
- secrete lumenal fluid - transport for sperm and nutrients to developing cells.
- secrete androgen binding protein - binding androgens revesibly acts as an androgen buffer > maintains equilibrium of [androgen]
- secrete inhibin - suppresses release of FSH by the anterior pituitary
- Testosterone and FSH control development
Sertoli - Germ Cell Interaction
-
__Glycoprotein Secretion
- transport/bioprotective proteins [t________+ c_________)
- proteases + protease inhibitors [tissue __________ during spermination and _______ during spermatogenesis]
- basement membrane glycoproteins
- regulatory glycoproteins [low abundance]
- Function as ______ _______
Sertoli - Germ Cell Interaction
-
__Glycoprotein Secretion
- transport/bioprotective proteins [transferrin+ ceruloplasmin)
- proteases + protease inhibitors [tissue remodelling during spermination and movement during spermatogenesis]
- basement membrane glycoproteins
- regulatory glycoproteins [low abundance]
- Function as growth factors
Transferrin and Ceruloplasmin
Tranferrin
- __ in blood binds to protein
- picks up Fe from GI _____ and ______
Ceruloplasmin
- carries __ in blood
- plays role in iron metabolism
Transferrin and Ceruloplasmin
Tranferrin
- __ in blood binds to protein
- picks up Fe from GI tract and spleen
Ceruloplasmin
- carries Cu in blood
- plays role in iron metabolism
Sertoli - Germ Cell Interaction
-
Sertoli cells make ________ - transports Fe around tight junction complexes to developing germ cells
- transferrin receptors on _______ cells
- secretes ferric ions + synthesises ________ transferrins
- Fe incorporated into ferritin in developing germ cells
- no. of germ cells directly related to no. of sertoli cells
Sertoli - Germ Cell Interaction
-
Sertoli cells make transferrin - transports Fe around tight junction complexes to developing germ cells
- transferrin receptors on sertoli cells
- secretes ferric ions + synthesises testicular transferrins
- Fe incorporated into ferritin in developing germ cells
- no. of germ cells directly related to no. of sertoli cells
- Efficiency is ___ in humans
- duration of spermatogenesis is __ days
- longer cycle length - __ days
- _____ _______ of germ cells in human testis
- _____________ takes __ days to get to spermatozoa
- ___ ______ sperm cells are produced daily
- Spermiogenesis
- formation of the acrosome
- condensation of the nucleus
- formation of the neck piece and tail
- shielding of most of the cytoplasm
- Efficiency is low in humans
- duration of spermatogenesis is 74 days
- longer cycle length - 16 days
- lower density of germ cells in human testis
- spermatogonium takes 74 days to get to spermatozoa
- 300 million sperm cells are produced daily
- Spermiogenesis
- formation of the acrosome
- condensation of the nucleus
- formation of the neck piece and tail
- shielding of most of the cytoplasm
- isolates ___________ & __________ from immune system → their antigens do not simulate auto-immunitiy
- spermatocytes and spermatids apper after _______ → this is why they are seen as ______
- because of this barrier, sertoli cells are responsible for providing factors such as substrates for glycolysis (lactate perferred)
- sperm cant use glucose so they get it from GLUT1 transporter → metabolise to lactate → transfer to developing sperm
- isolates spermatocytes and spermatids from immune system → their antigens do not simulate auto-immunitiy
- spermatocytes and spermatids apper after puberty → this is why they are seen as foreign
- because of this barrier, sertoli cells are responsible for providing factors such as substrates for glycolysis (lactate perferred)
- sperm cant use glucose so they get it from GLUT1 transporter → metabolise to lactate → transfer to developing sperm
starts with Gonadotropin-Releasing Hormone (GnRH) in the hypothalamus….
Aromatase (____): converts Leydig cells derived from testosterone to estradiol 17B
Androgen Binding Protein: specifically expressed intratesticularly , maintains _ androgen level in _______ _________
Müllerain Inhibiting Substance (MIS): induces regression of _________ _______ ______
Inhibin: keeps ___ _____ within a specific range ‘sperm count modulating hormone’
Aromatase (YP19): converts Leydig cells derived from testosterone to estradiol 17B
Androgen Binding Protein: specifically expressed intratesticularly , maintains ^ androgen level in adlumenal compartment
Müllerain Inhibiting Substance (MIS): induces regression of embryonic müllerain duct
Inhibin: keeps FSH levels within a specific range ‘sperm count modulating hormone’
- enzymes involved in ______ metabolism
- isoforms 1+2
- Type _ - expression in urogenital tract, genital skin and hair follicles.
- makes ____________ (DHT) from testosterone
- required for:
- Growth and activity in prostate
- ______ of Penis
- Darkening and ______ of scrotum
- Growth of _____ ____
- Facial and Body Hair
- ^ _______ ____
- enzymes involved in steroid metabolism
- isoforms 1+2
- Type 2 - expression in urogenital tract, genital skin and hair follicles.
- makes dihydrotestosterone (DHT) from testosterone
- required for:
- Growth and activity in prostate
- Growth of Penis
- Darkening and Folding of scrotum
- Growth of Pubic Hair
- Facial and Body Hair
- ^ Muscle Mass
- born with ________ genitalia
- need to convert testosterone to ___ for an effect on some ______ ________ tissue
-
Testosterone:
- ______ sertoli cell function
- induces development of male reproductive tract from ________ ____ in absence of 5α-Reductase
-
Metabolic efforts:
- ^____ + ___ while decrease in HDL
- promotes deposition of abdominal ______ tissue
- ^ ___ production
- promotes ___ growth + health
- protein anabolic effect on muscle
*testosterone is sufficient to maintain erectile function + libido*
- born with feminised genitalia
- need to convert testosterone to DHT for an effect on some androgen responsive tissue
-
Testosterone:
- regulates sertoli cell function
- induces development of male reproductive tract from mesonephric duct in absence of 5α-Reductase
-
Metabolic efforts:
- ^VLDL + LDL while decrease in HDL
- promotes deposition of abdominal adipose tissue
- ^ RBC production
- promotes bone growth + health
- protein anabolic effect on muscle
*testosterone is sufficient to maintain erectile function + libido*
- _________ differentiation, converted to ___ ⇒ penis/scrotum/urethra/______
- epididymis, ________ seminal vesicles
- DHT + ________ ⇒ feedback suppression of gonadotropin secretion, sex drive
- ______ - male voice
- ^ RBC, ^ ______ mass
- liver ⇒ ^ VLDL & LDL, decrease HDL
- ___ + Estradiol ⇒ sperm production
- DHT ⇒ penis ⇒seminal vesicles
- DHT ⇒ prostate, beard growth, ______ formation
- intrauterine differentiation, converted to DHT ⇒ penis/scrotum/urethra/prostate
- epididymis, vans deferens, seminal vesicles
- DHT + Estradiol ⇒ feedback suppression of gonadotropin secretion, sex drive
- larynx - male voice
- ^ RBC, ^ muscle mass
- liver ⇒ ^ VLDL & LDL, decrease HDL
- DHT + Estradiol ⇒ sperm production
- DHT ⇒ penis ⇒seminal vesicles
- DHT ⇒ prostate, beard growth, sebrum formation
- Leydig cells express __ _______, coupled to a cyclic ___ - ___ signaling pathway
Quick Effects: hydrolysis of _________ _____, new expression of steroidogenic acute regulatory proteins
Less Acute Effects: ^ __________ enzyme gene expression, ^ expression of LDL receptor
Long Term: LH promotes Leydig cell ______ + ____________
- Leydig cells express LH receptor, coupled to a cyclic AMP - PKA signaling pathway
Quick Effects: hydrolysis of cholesterol esters, new expression of steroidogenic acute regulatory proteins
Less Acute Effects: ^ steroidogenic enzyme gene expression, ^ expression of LDL receptor
Long Term: LH promotes Leydig cell growth + proliferation
