Ch 15 Endocrine Flashcards
Study of hormones and endocrine organs
endocrinoogy
Produce hormones
Lack ducts
endocrine
Nonhormonal substances (sweat, saliva) Have ducts to carry secretion to membrane surface
exocrine
endocrine glands
pituitary, thyroid, parathyroid, adrenal, and pineal glands
Some have exocrine and endocrine functions
pancreas, gonads, placenta
long-distance chemical signals; travel in blood or lymph
hormones
chemicals that exert effects on same cells that secrete them
autocrines
locally acting chemicals that affect cells other than those that secrete them
paracrines
two main classes of hormones
amino acid and steroids
posterior pituitary
neural tissue
anterior pituitary
glandular
stores ADH and oxytocin
posterior pituitary
Strong stimulant of uterine contraction
Released during childbirth
Hormonal trigger for milk ejection
Acts as neurotransmitter in brain
oxytocin
Inhibits or prevents urine formation
Regulates water balance
Targets kidney tubules reabsorb more water
Release also triggered by pain, low blood pressure, and drugs
Inhibited by alcohol, diuretics
High concentrations vasoconstriction
ADH
ADH deficiency due to hypothalamus or posterior pituitary damage
Must keep well-hydrated
diabetes insipidus
Retention of fluid, headache, disorientation
Fluid restriction; blood sodium level monitoring
SIADH
anterior pituitary hormones
Growth hormone (GH) Thyroid-stimulating hormone (TSH) or thyrotropin Adrenocorticotropic hormone (ACTH) Follicle-stimulating hormone (FSH) Luteinizing hormone (LH) Prolactin (PRL)
In children results in gigantism
In adults results in acromegaly
hypersecretion
In children results in pituitary dwarfism
hyposecretion
Mediates growth via growth-promoting proteins
stimulate:
Uptake of nutrients DNA and proteins
Formation of collagen and deposition of bone matrix
IGFs
Produced by somatotropic cells
Direct actions on metabolism
growth hormone
Secreted by corticotropic cells of anterior pituitary
Stimulates adrenal cortex to release corticosteroids
ACTH
Follicle-stimulating hormone (FSH) and luteinizing hormone (LH)
gonadotropins
stimulates gamete (egg or sperm) production
FSH
promotes production of gonadal hormones
LH
Secreted by prolactin cells of anterior pituitary
Stimulates milk production
Role in males not well understood
prolactin
Two lateral lobes connected by median mass called
isthmus
produce the hormone calcitonin
parafollicular cells
Major metabolic hormone
Increases metabolic rate and heat production (calorigenic effect)
Regulation of tissue growth and development
Maintenence of blood pressure
thyroid hormone
hyposecretion of TH in adults
myxedema and goiter
hyposecretion of TH in infants
cretinism
hypersecretion of TH
graves disease
Produced by parafollicular (C) cells
Antagonist to parathyroid hormone (PTH)
calcitonin
nervous tissue; part of sympathetic nervous system
adrenal medulla
three layers of glandular tissue that synthesize and secrete corticosteroids
adrenal cortex
layers of adrenal cortex and what they each produce
Zona glomerulosa—mineralocorticoids
Zona fasciculata—glucocorticoids
Zona reticularis—gonadocorticoids
synthesize epinephrine (80%) and norepinephrine (20%)
Medullary chromaffin cells
hypersecretion of adrenal medulla
Hyperglycemia, increased metabolic rate, rapid heartbeat and palpitations, hypertension, intense nervousness, sweating
hyposecretion of adrenal medulla
Not problematic
Adrenal catecholamines not essential to life
