Exam 2 - Endocrine System Flashcards
What is Autocrine Signaling?
Made by the cell, but stimulate the same cell, “talking to yourself”
Where is Autocrine Signaling important?
Inflammatory cells
What is Paracrine Signaling?
When cells signal to nearby cells “playing telephone”
What is Endocrine Signaling?
Hormones produced by endocrine glands enter the circulation
What are two important functions of the endocrine system?
Communication and regulation
What is endocrinology?
The study of endocrine glands and hormones
Exocrine glands
Have ducts that allow secretions to empty into a lumen (like the intestine) or onto a surface like the skin
Endocrine glands
Ductless glands that secretes directly into blood vessels
Hormones
Chemical messengers produced by specialized cells
______ __________ of hormones needed to have a large effect on organs and tissues
Low concentration
Properties of the endocrine system (6)
Wireless, chemical signal in the blood, slower acting, long duration, specific receptors, hormone
What stimulates humoral release
Hormones release caused by altered levels of certain critical ions or nutrients
What stimulates neural release
Hormone release caused by neural input
What causes hormonal release
Hormone release caused. By another hormone (a tropic hormone)
An example of humoral stimulus
Stimulus: Low concentrations of Ca2+ in capillary blood
Response: Parathyroid glands secrete parathyroid hormone (PTH), which increases blood Ca2+
An example of neural stimulus
Stimulus: action potentials in preganglionic sympathetic fibers to adrenal medulla
Response: Adrenal medulla cells secrete epinephrine and norepinephrine
An example of hormonal stimulus
Stimulus: hormones from hypothalamus
Response: anterior pituitary gland secretes hormones that stimulate other endocrine glands to secrete hormones
Properties of peptide hormones:
Synthesized as ___________, can travel ________ in the blood, utilize _______ _______, have ________ ________
Preprohormones; freely; second messengers; rapid onset
Properties of steroid hormones
Synthesized from ________, require _______ ________ to travel in the blood, change _________ ________ _______, have _______ onset but have a ________ duration
Cholesterol; carrier proteins; gene expression directly; slower; longer
Amine hormones are ________ from _______
Synthesized; tyrosine
Adrenaline amine hormone properties
Adrenaline - like _______, ________ and ________ ________
Adrenaline- peptides; polar; second messengers
Thyroid amine hormone properties
Thyroid hormones - like ________, ______-______, direct action on _______ _______
Thyroid- steroids; protein-bound, nuclear receptors
Examples of peptide hormones
Insulin, glucagon, prolactin, ACTH, gastric PTH
Examples of steroid hormones
Cortisol, aldosterone, estrogen, progesterone, testosterone
