Dysfunction of the Male System Flashcards
Identify the main stages of pubertal maturation of male genitalia.
Stage 1: No pubic hair, no enlargement of penis or testes
Stage 2: Testicular enlargement to >2.5 cm, start of pubic hair
Stage 3: Penal enlargement, enlarging testicles, more pubic hair
Stage 4: Further enlargement of scrotum, and testes, darkening of pubic hair
Stage 5: Adult genital appearance
What is the average age of males in puberty ? of females ? What are the main events of this in males ?
Boys- 14 years
Girls- 13 years
Height spurt, penis and testes increase in size, pubic hair appears.
Distinguish between fast and slow matureres. Does this impact final height ?
Fast maturers begin their growth spurt earlier, but generally all reach around the same size.
At what age without puberty do we begin to worry ?
15, certainly 16
Identify the main endocrine changes of puberty.
1) Pre-pubertal stage
- low testosterone
- low gonadal steroids
- Hypothalamus is extremely sensitive to that low testosterone production so still switches off LH and FSH
- If at this stage around 14, delayed puberty
2) Initiation of puberty
- At start, still low testosterone
- Higher centers has decreasing sensitivity to testosterone, so FSH and LH (simulates testosterone formation) rise
3) Adult
- Adult levels of testosterone
- Feedback has decreased to adult level
- FSH and LH higher than pre pubertal stage (at adult level) (but respond to this through feedback mechanism)
Define hypogonadism, and state its main types.
Circulating testosterone is low, or undetectable (not enough testosterone to give secondary male characteristics and to see over genital maturation).
1) Primary gonadal failure: If abnormality is in the testes then feedback system so anterior pituitary and hypothalamus (with GnRH) sense lack of testosterone, so start producing LH. Soon, seminiferous tubules are not developing, so pours out FSH as well.
2) Secondary gonadal failure: (abnormality in hypothalamus or pituitary) still low testosterone, but also low or no FSH and LH.
Identify the main causes of hypogonadism in the phenotypic male.
1) Temporary Delay of Puberty
2) Hypogonadotrophic Hypogonadism (secondary hypogonadism)
3) Hypergonadotrophic Hypogonadism (primary hypogonadism)
Identify the main causes of temporary delay of puberty.
- Constitutional delay of puberty (familial, sporadic)
- Chronic illness (e.g. malabsorption (e.g. due to esophagus achalasia, due to anorexia nervosa), malignancy (If pituitary tumor is pressing on cells making GnRH, then do not have enough to stimulate LH and FSH OR the tumor is in hypothalamus/pituitary area itself then get low testosterone with high FSH and LH), malnutrition)
- Hormonal disturbance (e.g. GH deficiency, hypothyroidism (may decrease efficacy of FSH and LH))
Identify the main causes of Hypogonadotrophic Hypogonadism.
i.e. stimulation from LH/FSH is lacking
- Kallman’s syndrome (one of its distinctive characteristics is anosmia, lack of functioning olfaction) (cause of failure of development of GnRH cells in hypothalamus, which control release of FSH and LH)
- Hypopituitarism (e.g. trauma, tumor (e.g. pituitary tumor pressing on FSH and LH producing cells such as craniopharynioma))
Identify the main causes of Hypergonadotrophic Hypogonadism.
- Klinefelter’s Syndrome (XXY) (e.g. shown by osteoporosis)
- Anorchia
- Orchitis (i.e. inflammation of testes) (e.g. due to mumps)
- Radiation treatment and/or cytotoxic chemotherapy (e.g. in leukemia)
- Surgical or traumatic castration
Describe treatment for delayed puberty. Does delayed puberty affect future fertility ?
Short term low dose monthly testosterone (but puberty will likely be reached at some point without the testosterone)
No, as long as he reaches puberty, able to become a father
What are the levels of the main hormones in delayed puberty ? Describe any other features of delayed puberty.
- Low LH, FSH, testosterone (basically pre-pubert endocrine stage)
- No testicular development
What are the risks of giving high dose testosterone for hypogonadism ? Are there any dangers to testosterone other than this ?
Causes fusion of epiphysis, so halts growth.
No
Under which BMI does a delay in puberty occur ?
Under 16-17, gonadotrophins fall so no stimulation to ovaries from FSH
State the procedure performed for oesophagus achalasia.
Oesophagomyotomy (Heller’s procedure)
What does the presence of absence of pubic hair, size of penis and testes signifiy with respect to hormones ?
Presence of pubic hair, larger penis size means testosterone presence
Absence of those means testosterone absent
Growth of testicles means FSH present, otherwise FSH absent.
Identify the main tests performed to investigate hypogonadism.
1) FSH, LH, testosterone
2) Chromosome analysis
Describe treatment for hypogonadotrophic hypogonadism. How does hypogonadotrophic hypogonadism affect future fertility ?
Monthly testosterone injections (higher than for delayed puberty)
Patients cannot produce FSH or LH, so no way we can return fertility to them unless we can give them FSH. Following this treatment, patient will recover normal penile size and pubic hair, but testicles will still be small, as there is no FSH to drive testicular growth.
Exogenous GnRH may then be administered to stimulate production of FSH (and LH), allowing for testicular growth and spermatogenesis.
HOWEVER, GnRH is not needed for normal sexual relations so only given when attempting to get pregnant.
Craniopharyngioma is a cause of hypogonadotrophic hypogonadism. Identify possible signs and symptoms of it.
Headache Visual disturbance Short Stature Diabetes Insipidus Arrested growth/sexual development
Explain how Klinefelter’s Syndrome can lead to hypergonadotrophic hypogonadism.
Failure of development of seminiferous tubules so feedback mechanism so hypothalamus and pituitary keeps sending more LH and FSH so high FSH and LH. There is some Leydig cell activity but not full, so scanty pubic hair may be present, some puberty there
Describe treatment for hypergonadotrophic hypogonadism. How does hypergonadotrophic hypogonadism affect future fertility ?
-Testosterone injections
Identify some of the main signs and symptoms of Klinefelter’s.
Gynecomastia
Poor sexual development with hypogonadism
Small penis
Scanty pubic hair
Osteoporosis with collapse vertebrae (due to testosterone deficiency)
Describe treatment for hypergonadotrophic hypogonadism due to Klinefelter’s.
-Testosterone replacement
- Biphosphonates and Calcium supplements (for osteoporosis)
- Reduction mammoplasty (for gynecomastia)
Identify the main symptoms of male hypogonadism.
- Sexual dysfunction
- Fatigue
- Depressed mood
- Osteoporosis
- Decreased in muscle mass and strength
- Loss of facial and body hair
How is testosterone replacement administered ?
-IM injections (every 2-3 weeks) OR -Oral (3-4 times daily) OR -SC pellets (every 4-6 months) BUT ALSO -Transdermal -Buccal
