PSL201Y1 Lecture Notes - Lecture 7: Thyroid, Growth Hormone, Ghrelin
Document Summary
Too much & too little gh: acromegaly, courser features (muscle growth but no lengthening of bones) too much gh in. How do bones form : 2-steps bone growth: chondrocytes form cartilage model of bone, osteoblasts differentiate to start ossification during fetal development, epiphyseal growth plate able to growth bone here, stays til puberty. Gf-1 = insulin-like growth factor 1gh, directly & indirectly via igf-i, stimulates bone remodeling: epiphyseal cartilage in child, epiphyseal lines in an adult fusion of plates, no more bone growth, no more cartilage, solid bone. Growth, a complex process, depends on: diet, genetics, hormones & growth factors promote growth. Gh & insulin-like growth factor 1 . Sex steroids peak during puberty, promote growth, gh from birth-20 birth-20 increase growth, eventually end up causing fusion of epiphyseal plates. Local tissues can make idf but main source = liver.
