Please enable JavaScript.
Coggle requires JavaScript to display documents.
22 year old male with testicle shrinkage (Effects over time of steroid…
22 year old male with testicle shrinkage
Background
Endocrine System functions
Made up of glands that secrete hormones
hormones control and regulate the body's complex activities
Regulate metabolic functions
regulate chemical reactions in various cells
influence the ability of substances to transport themselves through cell membranes
hormones are secreted into the blood stream
Kinds of hormones
Amino Acids
molecular size variety
simple biogenic amines
peptides (short chains)
proteins (long polymers)
Water soluble ... cannot cross plasma membrane
Binds to receptors on the outside of the cell
Steroids
Synthesized from cholesterol
gonadal and adrenal cortical hormones
lipid soluble (can cross plasma membrane)
Activates receptors on the inside of the cell
Endocrine glands
Hypothalalmus
GHRH
stimulate GH production in pituitary
GHIH
inhibits GH production in pituitary
TRH
Stimulates TSH production in pituitary
CRH
stimulates ACTH production in pituitary
GnRH
stimulates gonadotropin (LH,FSH) production in pituitary
PRH
stimulates prolactin production in pituitary
PIH
inhibits prolactin production in pituitary
Pituitary
Anterior
TSH
stimulates thyroid glad to release TH
ACTH
promotes release of glucocorticoids and androgens
FSH
LH
triggers ovulation, production of estrogen, progesterone, testosterone
PRL
promotes lactation
GH
stimulates somatic growth
Posterior
Oxytocin
stimulate contractions, labor
ADH
stimulates kidney cells to reabsorb water
Thyroid
thyriod
regulates metabolism, blood pressure, tissue growth
Calcitonin
regulates levels of calcium and phosphate in the blood
Parathyroid
PTH
calcium and vitamin D regulation
Pancreas
Insulin
allows glucose to enter cells
glucagon
controls blood sugar
somatostatin
regulates hormone secreation
Gonads
testes
testosterone
male characteristics, sperm production
ovaries
estrogen
female characteristics
progesterone
ovaries, ovulation
Pineal
melatonin
sleep cycle regualtion
Thymus
thymosin
immune system deveopment, T cells
Adrenals
Cortex
Aldosterone
increases levels of sodium and lowers potassium
Cortisol
controls blood pressure, glucose, metabolism, stress
androgens
development of pubic and axillary hair in females
produces estrogen after menopause
Medulla
Epinephrine
adrenaline
norepinephrine
increases muscle and heart contraction
Hormonal pathway
Hypothalamus sends GnRH to the pituitary
Pituitary releases FSH or LH depending on testosterone levels
LH stimulates testosterone production
So if testosterone levels are high the pituitary makes less LH
Feedback loops
Feedback loops control the start and maintenance of most hormone secretion in response to various stimuli.
Positive feedback loops release more hormone in response to an original hormone release. ex... The release of oxytocin during childbirth
Negative feedback inhibits of further secretion of a hormone in response to adequate levels of that hormone
UP- DOWN regulation
Down regulation
A significant amount of hormone in the blood stream causes target cells to become less sensitive to that hormone
Up regulation
When the level of a hormone is chronically reduced, cells increase their receptors to increase sensitivity to that hormone
Testicular atrophy
testicles shrink because of loss of some germ and leydig cells
Germ cells produce sperm while Leydig cells produce testosterone.
a person could have a lower sperm count, lower testosterone levels, or both, due to the loss of these cells.
When someone takes steroids down regulation occurs causing the target cells to become less sensitive to testosterone
Also tell the hypothalamus to stop producing GnRH
Steroid abuse
Side effects
shrinking testicles
decreased sperm count
baldness
development of breasts
increased risk for prostate cancer
People abuse steroids to look fitter, build muscle faster and enhance athletic performance
Effects over time of steroid abuse for this male (may experience)
decreased sperm production
enlarged breasts
more shrinking of the testicles
male-pattern baldness
testicular cancer
high blood pressure
blood clots
heart attacks
stroke
artery damage
liver damage
skin complications
If he stops
receptors for testosterone will become more sensitive (up regulation)
Body slowly starts to produce testosterone and sperm
although may not reach levels of production prior to when he started taking steroids