Testis By: Kyle Nagel, Amada Stewart, Matthew Whyte

Location Of The Gland In abdomen while embryo Move to Scrotum month before birth Scrotum 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 GnRH Causes Pituitary to create LH and FSH LH triggers Testosterone production FSH controls sperm production Testosterone 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 SHGB 38% bound to protein (albumin) 2% floating in blood freely

Complications Factors causing Low testosterone levels: Trauma to the testes Type 2 diabetes which may cause a malfunction of the pituitary gland or hypothalamus Castration Deficiency of LH or FSH Alcohol And 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 gonadism damage to leydig cells increases levels of LH and FSH to try to balance the low testosterone levels Secondary gonadism failure to secrete hormones normal levels of gonadotropics(LH and FSH)

Low testosterone Complications due to low testosterone levels: low sex drive fatigue loss of muscle weigh gain from fat increased risk of osteoporosis increased risk of cardiovascular disease infertility