Testicles: Testosterone

where does spermatogenesis take place?

seminiferous tubules

where do sperm cells mature?

epididymis

what is the ductus deferens?

The ductus deferens is a muscular tube that transports sperm from the epididymis to the ejaculatory duct during ejaculation.

what is the pampiniform plexus?

the testicular veins forms an elaborate convoluted network that creates many initmate finger-like wrappings surrounding the highly testicular artery. Allows for temperature regulation and counter-current exchange of testosterone. spermatogenesis requires a temp that is 4-6 degrees cooler than body temp

how is the internal organization of the testes?

the testicular parenchyma is divided by connective tissue septae that divide the testicles into lobules. In each lobule the seminiferous tubules are located, where spermatogenesis occurs.

what is the rete testis?

The rete testis is a network of tubules located within the testis that collects sperm from the seminiferous tubules and transports it to the ductus deferens.

what is the epididymis the site of?

fluid absorption and sperm maturation

what is the ductus deferens?

a long straight, tubular organ that originates at the scrotum and ends as the beginning of the urethra in the pelvic cavity. It transports the ejaculate out of the epididymis and into the pelvic urethra

what are the accessory glands and what do they do?

ampulla of the ductus deferens, seminal vesicles, prostate, bulbourethral glands. They produce the liquid portion of the ejaculate that provides optimal environment and nourishment for the spermatozoa

what structure is responsible for sperm production?

seminiferous tubules

what is the function of the pampiniform plexus?

temperature regulation and testosterone exchange

what is the male reproductive axis?

Hypothalamic (GnRH)- Pituitary (FSH and LH)- Gonadal (testosterone)

what is the nuclei in the male hypothalamus?

tonic center

what does the tonic center produce?

GnRH

After male pubuerty, how is GnRH released?

in a pulsatile fashion, every GnRH pulse induces a corresponding pulse of LH and FSH release from the AP

What are the two compartment?

• tubular compartment (site of spermatogenesis) -

• interstitial compartment (site of testosterone production)

What type of receptors do Leydig cells have?

LH receptors that produce testosterone

what type of receptors do Sertoli cells have?

FSH receptors and produce spermatogenic substances and inhibin

What is an LH pulse?

LH binds to receptors on leydog cells, which then produce/release testosterone. It then diffuses into sertoli cells; it is converted to DHT and then to estrogen. Also released into the bloodstream to regulate various physiological functions.

What is FSH pulse?

FISH binds to receptors on sertoli cells, which then produce spermatogenic substances and inhibin

what is androgen binding protein?

spermatogenic substances that maintains a high tubular testosterone concentration despite pulsatile release.

what does inhibin inhibit?

FSH release

what are some effects of testosterone on male behavior?

search for partner, courtship, sexual arousal, mounting, memory

what are some effects of testosterone on the body?

increased metabolic rate, muscle growth, bone thickness, skin thickness, hair growth, hair darkening

what are the major hormones produced by the anterior pituiatary?

FH and LH

what is spermatogenesis?

a process involving sequential mitotic and meiotic divisions and concludes after differentiation of spherical spermatids into highly specialized spermatozoa

where does spermatogenesis take place?

seminiferous tubules

how long does spermatogenesis take?

40-60 days

where is the most immature germ cell located in the male?

at the periphery of a seminiferous tubule near the basement membrane

what are the 3 major phases of spermatogenesis?

mitosis, meiosis, differentiation

what happens in the mitosis phase of spermatogenesis?

During the mitosis phase of spermatogenesis, spermatogonia divide to produce primary spermatocytes, increasing the number of germ cells for subsequent phases. After the mitotic divisions a primary spematocyte is produced

what is sperm cell renewal in spermatogenesis?

loss of intercellular bridges allows some spermatogonia to revert to stem cells providing continual renewal of these stem cells from which spermatogonia can develop

what happens in the meiosis phase of spermatogenesis?

In meiosis 1, cross over of DNA occurs during the production of secondary spermatocytes. In meiosis 2, secondary spermatocytes divide to produce four haploid spermatids, which later mature into sperm cells.

what happens in the differentiation phase of spermiogenesis?

During the differentiation phase of spermiogenesis, spermatids undergo a series of changes, including the development of a flagellum, condensation of the nucleus, and formation of the acrosome, ultimately transforming into mature sperm cells.

what is capacitation?

the final maturation of the spermatozoa that takes place in the female reproductive tract. It includes enhancement of flagellar activity and acrosome reaction.