L2: Male Reproduction Flashcards
the breeding soundness exam evaluates what aspects
- bull fitness
- semen quality
- libido
- ability to copulate
site of spermatogenesis
seminiferous tubules (lumen)
what are the cell types found in the seiminiferous tubules
- germ cells (spermatogonia)
- sertoli cells
cell type found in the CT (interstitial) of testes
- leydig cells (testosterone)
testes produce what 2 essential products
- sperm
- testosterone
sperm move from the seminiferous tubules through the rete testes and into the ______for storage and maturation
Epididymis
process by which spermatogonia (germ cells) are converted to spermatozoa (sperms)
spermatogenesis
packaging and maturation of spermatozoa is called
spermiogenesis
release of spermatozoa from Sertoli cells into lumen of seminiferous tubules
spermination
during this, 2 divisions create 4 diploid primary spermatocytes
proliferation of diploid germ cells
mitosis
characterized by 2 divisions:
- diploid germ cells get converted into haploid spermatocytes
- two divisions create 16 spermatids
- * single strand of one chromosome
meiosis
sperm cells don’t complete cyotkinesis during meiosis so the 4 daughter cells remain connected, forming a _____?
syncytium
* ensures haploid cells contain either X or Y chromosome
the rate of spermatogenesis is constant, and set by _______ within sertoli cells
retinoic acid
tight junctions between sertoli cells form a …..
blood testes barrier
prevents immune cells from accessing spermatozoa
early spermatids remain joined by _______ bridges
cytoplasmic bridges
what cells produce androgen binding protein
sertoli cells
sertoli cells are stimulated by ______ and ________
testosterone and FSH
release inhibin
what is hypogonadism
smaller than normal testicular size, results in below normal sperm counts
the # of ______ cells that ocur in development determines the spermatogenic potential of the testes
sertoli cells
what is the importance of gap junctions between spermatocytes and sertoli cells
permit the transfer of nutrients
2 points during male development when sertoli cells develop
- at birth and puberty
what do seminal (vesicular) vesicles produce
3 things
- prostaglandins
- fructose
- clotting factor
prostate secretions
bicarbonates makes an alkaline fluid
what hormone stimulates cholesterol desmolase within Leydig cells to produce testosterone
Lutenizing hormone (LH)
FSH promotes secretion of _____ and ______ from sertoli cells
inhibin and androgen binding protein (ABP)
where in the testes is testosterone produced
Leydig ccells
what concentrates testosterone in the seminiferous tubules
androgen binding protein (ABP)
testosterone circulates in peripheral blood bound to….?
sex hormone binding globulins (SHBG)
what enzyme converts testosterone into estradiol
aromatase
what enzyme converts testosterone into dihydrotestosterone (DHT)
5α-reductase
what is the rate limiting step in the male steroid biosynthetic pathway
Lutenizing hormone (LH)
it increases the affinity of cholesterol desmolase to cholesterol
cryptorchid testes can produce normal _______ but few ______
normal - testosterone
fewer - spermatozoa
T/F fibroelastic penises are firm when not erect
T
what are the steps in the neuroendocrine activation of sexual stimulation
- sensory stimulus
- stimulus of nerves in supraoptic + paraventricular nuclei
- release of oxytocin from posterior pituitary
- transport of spermatozoa into ejaculatory positon
- contractions of SM in distal tail of epididymis and ductus deferens
corpus cavernosa and corpus spongiosum are in what component of the penis
shaft
erection is achieved by what 3 things
- higher brain activity (env stimulus)
- mechanical stimulation of glans
- parasympathetic impulses from sacral erection generation center (S2-S4)
what is the role of parasympathetics in erection
- release of NO in penis causes sm to relax and increases blood flow
when penis is flaccid, the helicine arteries are ….
contracted
when the penis is erect, the helicine arteries are ….
relaxed (Caused by NO)
