ENDOCRINE Flashcards
what makes up endocrine system
- glands
2. endocrine tissue
FUNCTIONS what are functions of endocrine system
- secrete hormones / chemical messengers into blood
- integrate activities of organs / organ system
- maintain homeostasis (w nervous system)
FUNCTIONS what is glandular epithelium composed of
specialized cells / endocrine cells
FUNCTIONS what is the function of specialized cells / endocrine cells
- synthesize hormones
- store hormones
- secrete hormones
FUNCTIONS what are 2 types of glands
- endocrine glands
2. exocrine glands
FUNCTIONS where do exocrine glands release secretions
ducts that lead to epithelial surface
FUNCTIONS where do endocrine glands release secretions
blood
HORMONES what is a hormone
- chemical messenger tat - produced by endocrine cell
- secreted by endocrine cell
- travels through circulation to target tissue
- acts of target cells within target tissue
HORMONES what is required for hormone to have effect on target tissue
ligand-receptor interaction
HORMONES what hormones are derived from proteins
- amino acid derivatives
2. peptide hormones
HORMONES what do peptide hormones contain
multiple aa
HORMONES what hormones are derived from lipids
- steroid hormones
2. eicosanoid hormones
HORMONES what are steroid hormones derived from
cholesterol
HORMONES what are eicosanoid hormones derived from
fatty acids
HORMONES why might eicosanoid not be considered hormone
acts locally
THYROID where is thyroid gland located
anterior to trachea
THYROID what joins R and L thyroid gland
isthmus
THYROID FOLLICLES what are follicular cells
T thyrocytes
THYROID FOLLICLES where are follicular cells located
outside of follicle
THYROID FOLLICLES what is function of follicular cell
- produce thyroglobulin
- store thyroglobulin in lumen of follicle
- pump iodine into lumen of follicle
THYROID FOLLICLES what happens to iodine that is pumped into lumen of follicle
added to thyroglobulin
THYROID FOLLICLES what is thyroglobulin
hormone precursor
THYROID FOLLICLES what is colloid
protein-reich fluid in lumen
THYROID FOLLICLES what is the function of colloid
store thyroglobulin
TSH what is the function of TSH
stimulate thyrocytes to remove Tg from lumen
TSH what happens when Tg removed from lumen
cleaved by lysosome
TSH what happens after Tg cleared by lysosome
T3 and T4 fragments go into blood
THYROID HORMONES what hormone class do thyroid hormones belong to
amino acid derivative hormones
THYROID HORMONES what are thyroid hormones
derivatives of tyrosine w added iodine
THYROID HORMONES what are 2 thyroid hormones
T3 and T4
THYROID HORMONES which thyroid hormone secreted more
T4
THYROID HORMONES which is more active thyroid hormone
T3
THYROID HORMONES what is the function of thyroid hormones
regulate metabolism
THYROID HORMONE REG how are T3 and T4 released
- hypothalamus releases TRH
- TRH stimulates anterior pituitary to release TSH
- TSH stimulates thyroid glands to release Tg
THYROID HORMONE REG what happens when T3 and T4 levels become too high
feed back to inhibit hypothalamus from releasing TRH
feedback to inhibit pituitary to from releasing TSH
PITUITARY where does pituitary gland sit
sella tutica
PITUITARY what is anterior lobe
adenohypophysis
PITUITARY what does adenohypophysis contain
epithelial cells
PITUITARY what is posterior lobe
neurohypohysis
PITUITARY what does neurohypophysis contain
nerve terminals
PITUITARY what is portal system
vein that connects capillary be in hypothalamus to capillary bed in anterior pituitary
PITUITARY what are neuro secretory cells
neurons in hypothalamus
PITUITARY where do axon terminals of neuro secretory cells terminate
primary capillary plexus