Endocrine System Flashcards
Hormone
- Travels through the bloodstream to reach target tissues
Peptide Hormone
- Produced in Cell
- Charged, cannot pass through lipid bilayer
- link to extracellular receptors, trigger second messengers
- ex: insulin
Dîmerization
Pairing of two receptor-hormone complexes
What do Kinases do?
- Phosphorylate
MSteroid Hormones
- Derived from cholesterol
- produced by gonads/adrenal cortex
- nonpolar
- intracellular receptors can bind directly to DNA
- ex: testosterone/estrogen
Peptide vs Steroid
- Steroid hormones are slower than peptides but longer lasting
Amino Acid- derivative Hormone
- Derived from one or two AA
- Ex: epinephrine, norepinephrine, triiodothyronine, thyroxine
Catecholamine
- Epinephrine and norepinephrine
- bind to G protein receptors
- fast onset, short lived like peptide hormone
Thyroid hormones
Direct vs Tropic Hormones
- Secreted and act directly on target tissue vs stimulate production of another hormone to work on target tissue
Hypothalamus
Negative feedback
- Production of a certain amount of hormone inhibits further production of it
Hypophysis
Pituitary
Anterior Pituitary - FLATPEG
- Tropic Hormones
- Follicle Stimulating (FSH)
- lutenizing Hormone (LSH)
- adrenocorticotropic hormone (ACTH)
- Thyroid-stimulating hormone (TSH)
- Prolactin (direct)
- Endorphins
- Growth hormone (GH)
Posterior pituitary
- Oxytocin and Antidiuretic hormone/vasopressin (réabsorbs water in kidneys)
What does the Thyroid produce?
- Triodothyronine (T3)
- Thyroxine (T4)
- through iodination
What is the role of T3 and T4?
- Increased cellular respiration leads to increased protein and fatty acid production and degradation (turnover)
What do C-cells produce, and what does the product do for the body?
- Calcitonin
- decreases calcium levels in blood by storing calcium in bone, excreting through kidneys and decrease absorption of calcium through gut
Parathyroid Hormone
- Opp calcitonin, raises calcium in blood, decreases kidney release, increase absorption in gut
- Activates Vitamin D
Where is the Adrenal Cortex and what does it secrete?
- Located on top of the kidneys in the adrenal glands, release corticosteroids
Glucocorticoids
Steroid hormone regulates glucose levels
Mineralcorticoids
Salt and water homeostasis (ex: aldosterone for sodium réabsorption)
Cortical Sex hormones
Androgens and estrogens
What does the adrenal medulla release?
Epinephrine and norepinephrine for the sympathetic nervous system
Pancreas
Islet of langerhans secrete alpha beta and delta cells which secrete glucagon insulin and somatostatin
Glucagon vs Insulin
Encourages Glucose productions vs encourages uptake of clubhouse into muscle and liver cells for storage
