Anterior Pituitary Hormone Flashcards
(49 cards)
Where is growth hormone (GH) produced?
GH is produced in the anterior pituitary gland by specialized cells called somatotrophs
What is the primary function of growth hormone?
GH plays a crucial role in bone and muscle growth, metabolism, and increasing serum glucose levels
What is the role of IGF-1 in GH function? (Insulin like growth factor)
IGF-1 mediates the effects of GH, stimulating bone and muscle growth and maintaining stable GH-related functions
Why is IGF-1 measured instead of GH in clinical evaluations?
IGF-1 levels are more stable than GH, which is secreted in a pulsatile manner throughout the day
How does GH promote bone growth?
GH and IGF-1 stimulate growth at the epiphyseal plates in children, leading to increased height
Why does bone growth stop after puberty?
By age 18 (females) and 20 (males), the epiphyseal plates close, preventing further linear bone growth
How does GH affect muscle growth?
GH and IGF-1 promote myocyte hypertrophy, increasing muscle mass and protein synthesis
Why is GH treatment in kids a big deal?
It is used in children with growth deficiencies but has restrictions due to potential misuse(سوء استخدام) in sports
How does GH affect blood sugar levels?
GH increases serum glucose via hepatic gluconeogenesis, lipolysis, and insulin antagonism (making liver produce more glucose)
What hormone stimulates GH secretion during starvation?
Ghrelin, secreted from the stomach, induces GH secretion to maintain blood sugar levels
What causes dwarfism?
GH deficiency leads to short stature, delayed puberty, and developmental issues
What is gigantism, and what causes it?
Gigantism is excessive height due to excess GH secretion before puberty, often caused by pituitary tumors
What is acromegaly?
A where excess GH after puberty causes enlargement of hands, feet, and facial bones
Where is prolactin produced?
Prolactin is produced in the anterior pituitary by lactotroph cells
What are the primary functions of prolactin?
Prolactin promotes milk production, maternal behaviors (motherly behaviors) , and influences reproductive hormones
How does prolactin inhibit reproductive function?
Prolactin inhibits GnRH, leading to decreased FSH and LH, reducing estrogen/testosterone levels
What are the positive regulators of prolactin secretion? ( makes prolactin go up)
increase prolactin secretion:Nipple stimulationestrogenthyrotropin-releasing hormone (TRH)
What inhibits prolactin secretion? ( stops prolactin from being made)
Dopamine is the main inhibitor, reducing prolactin release from the anterior pituitary.
How does prolactin contribute to autoimmunity?
It suppresses B-cell negative selection, increasing the likelihood of autoimmune diseases
It makes the immune system more likely to attack the body, which can lead to autoimmune disease
Why does prolactin remain high during pregnancy?
Estrogen and TRH increase it, but dopamine keeps it from getting too high
What happens to prolactin levels after childbirth?
Prolactin levels peak during nursing, stimulating continuous milk production
Which hormone directly increases GH secretion?
Ghrelin
Which hormone increases prolactin levels during pregnancy?
Estrogen
Which hormone inhibits prolactin secretion?
Dopamine
