Endocrinology 5 Flashcards
What is the most abundant of all the anterior pituitary hormones?
Growth Hormone
What hormone is in the same family as Growth Hormone?
Prolactin
What does it mean by Growth Hormone shows species selectivity?
It cannot be used from one species to another
When is growth hormone secreted?
Throughout life
When is growth hormone not important for growth?
Before birth
How is growth hormone secreted?
In pulses
When is most growth hormone secreted?
During the nighttime
What kind of receptors does Growth Hormone act on?
Cell-surface receptors
What are the receptors associated with Growth Hormone associated with?
Protein Kinases (not G-proteins)
How does Growth hormone affect bones?
It causes them to grow longer
What is the shaft of a bone called?
The Diaphysis
What is the rounded portion of the bone called?
The epiphysis
What is between the Epiphysis and the Diaphysis?
The Epiphyseal plate (cartilage)
Who is the cartilage in bones present in?
Children
What does the presence of the epiphyseal plate allow?
The bone to grow longer
What does the Epiphyseal plate contain?
Precursor Progenitor cells (fibroblasts)
What do the Fibroblasts differentiate into?
Cartilage cells (chondrocytes)
What happens to the Chondrocytes?
They undergo ossification and turn to bone
Why is there no bone growth in vitro (outside the body) with Growth Hormone?
Because the body also requires insulin-like growth factor (IGF) required for bone growth as well as growth hormone
What is the primary source of IGF?
The liver
