Niyogi Lectures 13-14 Flashcards
The central nervous system and endocrine system cooperate to regulation homeostasis through extensive feedback loops.
The CNS works over a _____ term and the ES work over a _____ term.
The CNS works over a short term and the ES works over a long term
Compare the endocrine and nervous systems.
Define gland.
organ/tissue responsible for synthesis and secretion of cellular products
Define edocrine
secretion of material into extracellular space or blood vessels; includes autocrine, paracrine and neuro-endocrine
Explain local regulation using the terms autocrine and paracrine
What is distance regulation in the endocrine system?
Key terms: endocrine regulation, neuroendocrine regulation
Define hormone and list it’s functions.
Hormone: signalling molecule secreted by endocrine cells
Hormones regulate physiology, behaviour, and development
Define exocrine
Secretion of material onto a body surface or into a duct
Summarize the general chemistry of hormones using the terms amines, peptides, and steroids
This is not an exhaustive list; there are some hormones that do not fit into these categories
What are the signalling mechanisms of non-steroid hormones (derived from amino acids)? Give two examples.
Bind to plasma membrane receptors
e.g. epinephrine, insulin
What are the signalling mechanisms of steroid hormones (lipids derived from cholesterol). Give two examples.
Bind to intracellular receptors
e.g. insect developmental hormones, human sex hormones
Several hormones can be produced in a synthesis pathway. The molecule produced depends on enzyme gene expression in secretory cell.
These molecules can act as a hormone or a neurotransmitter.
Describe this synthesis pathway and the products at each step.
Hydrophilic hormones are stored in ________ ________ before secretion from the cell.
secretory vesicles
List the 6 steriods that are made from cholesterol.
Cortisol
Aldosterone
Androgens
Estrogens
Progesterone
Ecdysons
Are hydrophobic hormones (steroids) stored in the cell?
Hydrophobic hormones diffuse out of the cell after synthesis
How are hormone levels in the blood regulated?
- altering the rate of synthesis
- altering the rate of secretion
- removal mechanisms in the liver and kidney of vertebrates
- conversion of inactive form to active form of target tissue (T4 to T3 by deiodinase in the liver)
- homeostatic feedback loops
True or false? Virtually all tissues produce an endocrine messenger.
true
True or false? Cells will respond to most hormones.
False. Only cells with a specific receptor protein will respond to a hormone.
Summarize the role of the hypothalamus, pineal gland, pituitary, thyroid and parathyroid, adrenal cortex and medulla, pancreas, and ovaries/testes in the endocrine system.
What is the main centre of control for the endocrine system?
the hypothalamus
Note this explains the close relationship between the endocrine system and the nervous system
What tissues exclusively produce steroid hormones?
Only the adrenal gland and sex organs produce steroid hormones
Explain the brain-pituitary connection in the endocrine systems of vertebrates.
The anterior lobe produces and releases hormones. The posterior lobe does not produce hormones per se—this is done by nerve cells in the hypothalamus—but it does release them into the circulation.
What hormones are released by the posterior vs anterior pituitary?
What is the function of growth hormone?
Promotes protein synthesis and use of body fat for energy, and thus has a very broad effect. It also promotes development and enlargement of all body parts so it is essential for normal growth and development.
