TestisBy: Kyle Nagel, Amada Stewart, Matthew Whyte

Location Of The Gland

In abdomen while embryoMove to Scrotum month before birthScrotum located between penis and anus

Hormones Produced

pituitary gland releases luteinizing hormone and follicle stimulating hormone which is sent to the leydig cells distributed throughout the testis

The leydig cells also called interstitial tissue produces the hormone testosterone

Leydig cells commonly have more than one nucleus

Testosterone is mainly produced in males since they contain the testes, but females also produce a small amount by the ovaries

Target Cells

Sertoli cells-assist in the production of sperm

Leydig cells (interstitual)-secrete testosterone

Gametes-sex cells

Effects of Hormone

Testosterone controls reproductive system growth, sex drive, and stimulates sexual characteristics in men.Example: Deepening of voice, chest hair, male body shape.

Also promotes high metabolism, nitrogen retention and protein synthesis for muscle growth, and calcium retention and bone matrix development for male skeletal structure development.

Testosterone levels decrease with age, as well as erectile functions

Triggers/Controls

The hypothalamus releases GnRHCauses Pituitary to create LH and FSHLH triggers Testosterone production FSH controls sperm productionTestosterone levels suppress

Hypothalmus’ GnRH production

Cont.

Testosterone bound to sex hormone binding globulin (SHBG) in blood stream

As SHBG decreases, usable testosterone increases

60% bound to SHGB38% bound to protein (albumin)2% floating in blood freely

Complications

Factors causing Low testosterone levels:

Trauma to the testesType 2 diabetes which may cause

a malfunction of the pituitary gland or hypothalamus

CastrationDeficiency of LH or FSHAlcoholAnd other factors such as

Klinefelder’s disease and Turner’s syndrome

Malfunctions

Malfunction of the testes is called gonadism and there are two types:

hypergonadotropic hypogonadism(primary gonadism) or

Hypogonadotropic hypogonadism (secondary gonadism)

Cont.

Primary gonadismdamage to leydig cellsincreases levels of LH and FSH to try to

balance the low testosterone levelsSecondary gonadismfailure to secrete hormones normal levels

of gonadotropics(LH and FSH)

Low testosterone

Complications due to low testosterone levels:

low sex drivefatigueloss of muscleweigh gain from fatincreased risk of osteoporosisincreased risk of cardiovascular diseaseinfertility