Lecture 22 Flashcards
What is CRH?
corticotropin-releasing horomone
What is aldosterone?
related to minerals (ie: Na and K) | minimize waste as much as possible
What induces the hypothalamus to release CRH?
stress and circadian rhythm
What is POMC?
precursor of ACTH in the anterior pituitary
What is hypercortisolism?
excess cortisol | Cushing’s syndrome
What are the 3 causes of hypercortisolism?
adrenal tumor (high cortisol) | pituitary tumor (high ACTH) | over-prescribed by doctor
What is Moon Face caused by?
pituitary tumor = high ACTH = high cortisol = red cheeks
How are stretch marks caused?
high cortisol = deposit fats in trunk , protein breakdown under skin causes stretch marks
What is the cause of gigantism?
excess growth hormone
What is a sign of excess growth hormone?
growth of jaw
What are the 2 effects of growth hormones?
hypertrophy and hyperplasia
What is hypertrophy?
increase in cell SIZE
What is hyperplasia?
increase in cell NUMBERS
What are the 4 things bone and soft tissue growth need?
growth hormone | insulin-like growth factor (insulin) | calcium | thyroid hormone
What type of hormone is the growth hormone, tropic or trophic?
trophic
What is the epiphyseal plate within bones?
site of bone growth | area in long bone | gives height
What is the function of chondrocytes?
forms cartilage
What adds length to the bones?
dividing chondrocytes
What cells does the growth hormone act on?
osteoblasts
What are osteoblasts? What are its 2 functions?
bone-building cells | lays down bone on top of cartilage | makes Ca++ phosphate crystals to replace cartilage
How do the hormones calcitonin and parathyroid hormone work opposite to one another?
PTH = take Ca++ out of bone to increase plasma Ca++ levels | calcitonin = takes Ca++ from plasma and puts into bones
Which cells are responsible for bone resorption? What is bone resorption?
osteoclasts | breakdown of bone and release minerals into plasma/blood
What is osteoporosis?
too much Ca++ pulled out of bone | can be due to increase in parathyroid hormone levels and overactivity of osteoclasts | calcitonin is not being effective
What do osteoclasts secrete?
acid and enzymes that dissolve calcium phosphate in bone
Is growth hormone catabolic or anabolic?
anabolic
What is GHRH?
growth-hormone releasing hormone
What 4 factors affect the release of GHRH or somatostatin from the hypothalamus?
circadian rhythm | cortisol | fasting | stress
Which hormone affects cartilage growth?
insulin-like growth factor