Endocrine Week 1 Flashcards
Are group I hormones lipophilic or hydrophilic?
Do they have transport proteins?
What is their half life like?
Lipophilic
Yes
Long
What hormones are in Group I?
Steroids, iodothyronines (thyroid)
List the following in order of longest to shortest half life: Steroids, thyroids, peptides/proteins
Thyroid>Steroids>Peptides/proteins
What is the rate limiting step for all steroidogenic pathways?
StAR protein mediation of cholesterol uptake from cytosol to inner mitochondrial membrane
What determines the major steroid product of each gland?
enzyme expression
What determines which circulating secretagogue the gland will respond to?
G-coupled protein receptor
Quick summary of the following types of signaling: A) Endocrine B) Paracrine C) Autocrine D) Neurotransmitter E)Neuroendocrine
A) cell to distant cell B) cell to adjacent cell C) cell to itself D) neuron to adjacent neurons E) neuroendocrine cell to distant organ
Where can thyroid hormone receptors be found?
Glucocorticoid receptors?
Peptides, etc?
Nuclear receptors
Cytoplasmic or Nuclear receptors
Cytoplasmic receptors
What differentiates polypeptide receptors from proteins?
Proteins have a tertiary structure
What enzyme is targeted in breast cancer? What are its actions?
Aromatase
Converts androstenedione to estrone (E1 which is then converted to E2/estradiol which promotes growth in estrogen related tumors)
Hypothalamus releases what hormone to the anterior pituitary? What hormone does the anterior pituitary release to the adrenal cortex? What does the adrenal cortex release that inhibits the previous two hormones?
CRH
ACTH
Cortisol
Example of positive feedback
Ovulation during menstrual cycle (estradiol leads to more hormone)
Childbirth (cervix stretch->post pit->uterine contraction->stretch)
Lactations (suckling->post pit->oxytocin->milk)
How do you recognize secondary hyperfunction?
Secondary hypofunction?
Cushing’s example: ACTH is inappropriately elevated when it should be suppressed by cortisol
Secondary adrenal insufficiency: ACTH is inappropriately unelevated in relation to the low levels of cortisol
Which portion of the pituitary is more cellular? Which is more fibrous and resembles nerve tissue?
Anterior pituitary (distal, intermediate, tuberal lobe) Posterior pituitary (neural lobe, pituitary stalk, median eminence)
What will damage to long portal vessels cause?
atrophy of anterior pituitary
Effects of pituitary adenoma?
Excess hormone secretion–endocrine syndromes
Can compress optic chiasm
Most thyroid tumors are derived from what type of cells?
follicle epithelial cells
Adipocytes are a constant feature of what gland?
Parathyroid
What disease do you think of when serum calcium levels are persistently low?
Primary hyperparathyroidism
What are the key characteristics of steroid secreting cells?
abundant smooth ER
tubulovesicular cristae in mitochondria
membrane bound lipid droplets
What germ layer are the endocrine and exocrine layers derived from?
epithelium
What is the pituitary gland derived from?
Oral ectoderm/hypophyseal diverticulum/Rathke’s Pouch
(forms anterior lobe, pars distalis & tuberalis & intermedia)
Neural ectoderm/Infundibulum
(forms stalk and posterior lobe)
Craniopharyngioma symptoms?
Originating tissue?
Optic chiasm impingement, hyrodephalus, pituitary dysfunction
Rathke’s pouch remnants-pharyngeal hypophysis
Aberrant thyroid tissue is found where most often?
What are midline structures that can rupture or form fistula?
Base of tongue
Thryoglossal Duct cysts
What do the parathyroid glands originate from?
Pharyngeal pouches 3 & 4