growth lectures Flashcards
PHCR / red book
Used to record data on family and birth related info, growth, immunisations
Puberty in girls
Earlier than boys
Types of cell changes
Hypertropy = larger cell Hyperplasia = double cell Differentiation = new type Apoptosis = death Migration - move
Factors that influence growth
Nutrition
Genetics
Environment
Genetics influencing growth
Insulin like growth factor 1 , growth hormone
How do we grow
Increase in cell size/ number
Growth requires building blocks, fuel and hormones
Growth hormone
Anterior pituartry peptide hormone
Causes growth in most tissues that can grow
Promotes differentiation in some cell types
Binds to GH receptor in target tissues
Works with IGF-1
GH SECRETION
SLEEP - often secreted the most at night
GHRH - growth hormone releasing hormone
Negative feedback of GH secretion
GH stimulates SS ( somatostatin)
SS inhibits GH release = negative feedback
Actions of GH
ACute = metabolic change
Long term= growth promotion
Acute GH release
Protein = increase in AA uptake and utilisation
Increase in protein synthesis
Decrease in protein catabolism
Lipid - lipogenesis decreases
Carbs = decreased glucose uptake, increased blood glucose
PROTECTION OF PROTEIN
GH actions - longterm
GH induces IGF-1 in the blood that mediates the actions of GH
Direct effects of GH
On GH receptor Anti insulin Diabetogenic effects - increase in blood glucose and protein synthesis effect on adipose tissue
Indirect effects of GH
Multiple tissues
Liver
depend on inulin like growth factor
Bone growth
How does insulin effect adipose tissue formation ( DIRECT)
Simtulates lipogenesis
Stimulates proliferation, differentiation, and maintenance of differentiated adipocytes
GH effecting adipose tissue formation( direct )
Inhibits lipogenesis( reduces fat mass) and promotes lipolysis ( available energy)
Adrenal glands 0 adipose tissue ( direct)
Cortex- glucocorticoids, visceral fat increased
Medulla - adrenaline - lipolysis
regulation of bone growth ( indirect) - GH and insulin lie growth factor
Growth hormone - stimulates expression on IGF 1
IGF-1
Promitogenic ( chondorblasts increased)
Recruitment of precursor cells
Maintenance of differentiated state
Glycorticoids and androgens - regulation of bone growth ( indirect)
Glucocorticoids - permissive, but in chronic high does leads to bone loss
Androgens - testeosterone surge during puberty accelerates growth plate closure
GH deficiency
RARE
causes: GH recepto defect, IGf 1 deficiency/ carrier protein defect
Excess GH
Causes by pitarary tutors
- BEFORE epiphyseal growth plate has closed = giantism
AFTER closure = acromegaly
Effect of GH on blood glucose
GH release increases blood glucose
THEN raising blood glucose inhibits GH secretion
does gh make u slimmer
yes
