Steroid Hormone Biosynthesis Part 2 Flashcards
Describe the layers of the adrenal gland cortex and the steroids secreted in each layer
- outermost layer is glomerulosa: aldosterone
- middle layer is zona fasciculata, innermost is zona reticularis: cortisol and sex steroids
What cells are in the adrenal medulla and what hormones are secreted
- chromaffin cells that secrete epinephrine and small amount of norepinephrine
What are the cell types found in male testis?
- Leydig cells
- Sertoli cells
Describe the role of Leydig cells
- LH binds to receptor on Leydig cells leads to increase in cAMP
- activates protein kinase A causes synthesis of enzymes involved in synthesis of testosterone from cholesterol
- increases production of testosterone, which diffuses out of Leydig cell
Describe the role of Sertoli cells
- responds to FSH through cAMP pathway which increases protein synthesis
- responsible for maturing sperm
- also produces small amount of aromatase which converts some testosterone to oestradiol
- important for maintaining protein synthesis in Leydig cells
What are the cells found in the female uterus?
- granulosa cells
- thecal cells
Describe the function of the granulosa cells in the folllicular phase of the menstrual cycle
- cells that surround ovum
- make aromatase by stimulation from FSH
- testosterone moves in from thecal cells to be converted to estradiol
Describe the function of the thecal cells in the follicular phase of the menstrual cycle
- LH acting by cAMP mediated mechanism
- stimulates conversion of cholesterol to testosterone
What is the function of granulosa cells and thecal cells in luteal phase of menstrual cycle?
- vascularisation of corpus luteum makes LDL available to granulosa-lutein and theca-lutein cells
- leads to production of progesterone, HSD (hydroxysteroid dehydrogenase), LDL and LH
