Physiology: Male Sex Hormones: Dragatsis Flashcards
Testes are fed by what artery? What is unique about its journey to the testes?
Testicular artery goes through the pampiniform plexus to cool off blood to the 37* primo temperature for spermatogenesis
What moves the testes and why?
Cremaster muscle, to maintain temperature.
Elephants testes are where?
Inside!
Sperm is stored where?
Epidydimus
Semen is stored where?
Seminal vesicles
How many sperm in 5ml of ejaculate
400 million viable sperm!
What is the food of the spern?
Fructose in semen
How does semen neutralize the acidic vagina?
Alkali bicarbonate and enzymes
Why does sperm become coagulated outside body? When does it re liquidize?
To stick to vagina, re-liquidizes when acid is neutralized and vagina is wet again.
What are irreversible changes of puberty?
Beard growth, voice, muscle mass
What are the two major function of testes?
Spermatogenesis and androgenesis.
What occupies the most space in the testes?
Seminiferous tubules: make sperm
What makes T in testes?
Leydig cells
What is required for spermatogenesis?
Seminiferous: FSH and high T (T requires LH in leydig)
How many days to a mature sperm?
62 days
What are sertoli cell functions?
Stimulate spermatogenesis
make, neourish, and protect sperm
Make inhibin hormone to feedback to decrease FSH
Phagocytosis of dead or defective sperm
What is the site of action of FSH and T?
Sertoli cells in tubules
What happens if sperm enter blood stream?
Antibody attack
What prevents immune reaction to sperm?
Testicular-blood barrier made by sertoli cells
What is the release [attern of LH and T?
Pulsatile
What is the receptor affinity of DHT vs. T?
Higher affinity, but different organ targets
What converts T to DHT?
5 alpha reductase
What does DHT cause?
Enlarged prostate
Hair changes
Acne
What tissues do not need T transformation to DHT?
Skeletal muscle
Penis
Scrotum
Libido
Where is T degraded?
Liver
Where is T excreted?
Urine
What can T be converted to?
DHT
Estradiol
Where is estradiol converted?
Adipose
Pituitary
Hypothalamus
What transport T?
GBG SHBG TeBG TEBG Albumin
What percent of T is free?
2-3%
How do epidydimus cells get T, since they are isolated from blood?
Androgen binding protein in luminal fluid from leydig cells
Is there a link between T and homosexuality?
No
What does T do in Hypothalamus? Pit?
Hypo: less GnRH, wider pulses
Pit: Less LH, FSH
When do bodybuilders know they are taking too much T?
Testes shrink due to FSH decrease, no more Seminiferous tubule stimulation
At what age does T begin to drop?
35 yo
What happens in old male?
Reduced free T, more SHBG made due to liver
Liver does what with T?
Makes estradiol
