endocrine Flashcards
(71 cards)
Feedback regulation
Negative
Sensors detect a decrease in hormone levels, they increase hormone production. When hormone levels rise above the set point of system, sensors decrease hormone production.
Feedback regulation
Positive
Rising levels of a hormone cause another gland to release a hormone that is stimulating the first.
Ex: estradiol production causes increased gonadotropin (FSH) production. this stimulates further increases in estradiol levels until demise of follicle.
Hypofunction
Altered endocrine function.
Can occur due to absence or impaired development of a gland or a deficiency of an enzyme needed for hormone synthesis. Gland could be destroyed .
Hyperfunction
Altered endocrine function.
Excessive hormone production. Can result from excessive stimulation and hyperplasia of the endocrine gland of from a hormone-producing tumor.
Hormone Resistance
Altered endocrine function.
May be associated with receptor defects at the target cells. Hormone receptors may be absent or the receptor binding of hormones may be defective.
Hypopituitarism
Altered endocrine function.
Characterized by a decreased secretion of pituitary hormones and is associated with increased morbidity and mortality. May be congenital or acquired.
Growth hormone
(also called somatotropin)
ANTERIOR PITUITARY
necessary for growth and contributes to the regulation of metabolic functions.
GHRH- increases GH release-
somatostatin- inhibits GH
Short stature in children (GH)
condition in which height is less than the third percentile on the app. growth curve.
causes of short stature in children (GH)
endocrine causes- GH deficiency, hypothyroidism, and panhypopituitarism (deficiency of all pituitary-derived hormones)
genetic or chromosomal- Turner syndrome, Noonan syndrome, achondroplasia, & skeletal dysplasias.
Familial and constitutional short stature (GH)
not a disease. but variation from population norms. requires monitoring but not treatment.
Psychosocial dwarfism (psychosocial short stature) (GH)
Involves functional hypopituitarism and is seen in some emotionally deprived children.
Present with poor growth, potbelly, and poor eating and drinking habits.
Severely neglected or disciplined.
GH returns to normal when removed from environment.
Growth hormone deficiency in adults (GH)
2 categories:
- present in childhood.
- developed during adulthood.
Diagnosis of GH deficiency in adults
Low IGF-1 level in the presence of low levels of 3 or more pituitary hormones indicated GH deficiency
Treatment of GH deficiency in adults
recombinant GH replacement
Growth hormone deficiency in children (GH)
present with short stature (pituitary dwarfism). increased fat in abdomen, immature facial features with frontal bossing, delayed dentition, and an underdeveloped nasal bridge.
GH deficiency in children (GH) causes
genetic mutations. some are idiopathic. can occur as pituitary tumors
Tall stature (GH)
height is greater than the 97th percentile.
Tall stature (GH) causes
genetic or chromosomal (Marfan syndrome, Klinefelter syndrome, fragile X sydrome, and Beckwith-Wiedemann syndrome). other causes is normal familial stature and advancement of growth
GH excess in children
occurring before puberty and the fusion of the epiphyses of the long bones result in pituitary gigantism. All tissues and bones grow rapidly.
GH excess in children causes
Excessive secretion of GH by somatotrope adenomas causes gigantism in the prepubertal child. Epiphyses are not fused and high levels of IGF-1 stimulate excessive skeletal growth.
Acromegaly (GH excess in adults)
occurs in adulthood or after the epiphyses of the long bones have been fused.
Acromegaly causes
excess circulating blood levels of GH and IGF-1. most common cause is a GH-secreting somatotrope adenoma in the pituitary gland.
Acromegaly manifestations
Soft tissue growth (person does NOT get taller).
- enlarged small bones of the hands and feet, broad bulbous nose, protruding lower jaw, and a slanting forehead, deepened voice, kyphosis (hunchback), cardiomegaly (hypertension), barrel chest, glucose tolerance/insulin resistance, male sexual dysfunction/menstrual in women, degenerative arthritis, thickened skin (sweaty and smelly)
Precocious puberty
early activation of the hypothalamic-pituitary-gonadal axis, resulting in the early development of sexual characteristics and fertility.
pubertal changes noted before 8 for girls and 9 for boys.