Endocrine System - Lecture Twenty Five : Homeostasis and Hormones
7 important questions on Endocrine System - Lecture Twenty Five : Homeostasis and Hormones
What are the differences between the endocrine system and the nervous system ?
- Hormones released into the bloodstream
- Targeting by the presence of specific receptors on target cells
- Relatively slow but long lasting action
- Good for widespread and sustained responses
- Major endocrine organ is the hypothalamus which links the nervous system to endocrine
- Action potentials in axons and neurotransmitters are released at the synapse
- Targeting achieved by specific "wiring"
- Fast transmission speed results in minimal response delay. This is good for rapidly changing conditions, where delay can lead to damage
- Good for brief responses
What are the mechanisms of Water-soluble hormones?
- Chemicals : Mostly peptides (75% of hormones) and some catecholamine
- Storage : Made and stored until required. Released by exocytosis
- Polarity : Hydrophilic
- Transport : Dissolved in the blood
- Receptors : on cell surface
- Mechanism of action : Through second messenger molecules
- Speed of response : milliseconds to minutes
What are the mechanisms of lipid-soluble hormones?
- Chemicals : Steroids and thyroid hormones
- Storage : Steroids are made from cholesterol.Thyroid hormones are produced in the thyroid cells. They are both stored and released when required
- Polarity : Hydrophobic
- Transport : Travel in the blood and must bound to a carrier protein
- Receptors : Intracellular receptors in the cytoplasm or nucleus
- Mechanism of action : Alter gene transcription
- Speed of response : hours to days
- Higher grades + faster learning
- Never study anything twice
- 100% sure, 100% understanding
For my 1st exam I got a C. Then, I started looking for ways to learn better and I came across Study Smart. Since then I have scored a A+, A, A- and another A. I highly recommend it to everyone who wants to hear it. I am so happy with it!!
I was struggling to finish all my first-year subjects for 3 years. Then I discovered Study Smart, which helped me to finish all of them within 3 months.
Because of StudySmart, things are going well in many ways. Before, I always had study stress and no time for anything. Now I feel calm and confident (because of the program). I used to score a B, now I usually score an A or A+.
Hey Chris, I really want to thank you very much for developing the platform, I usually got around C for my exams, now I scored an A+, an A and a A- !!
Since using Study Smart, my average has increased significantly. I even completed a statistics course with a A+ while I'm bad at statistics. I took on extra courses this year, because of Study Smart. Thanks so much!
Ever since I started studying with StudySmart I passed all my exams !!! No more re-sits!! At first, I was happy with a pass and now I only get good grades. Many thanks!
I aced all the courses I studied with Study Smart. For law, I first scored a D, and now an A! I’m 100% sure that I’ll pass all the courses I study with Study Smart.
I always thought I studied well. My grades were fine. I could never have imagined that applying these study skills would have such a huge and direct impact on my grades, my speed and the pleasure I have in learning.
For the first time, I finally feel totally confident about the way I learn. I have the perfect overview and make great progress in terms of speed and the grades I get. Thanks, Chris!
I immediately started to enjoy learning again, and my grades soared. All of a sudden, everything went better. I highly recommend Study Smart to all students..
Being able to create my materials online made the process of studying so much smoother and quicker. I no longer have to spend a huge amount of my time on creating my summaries.
At first, my notes were a mess. Now I use Study Smart to take my notes in a perfectly structured way. It helps me to save a lot of time and do other things I enjoy.
Students that study with Study Smart get better grades. The system applies all the learning methods in such a way that both well-performing students and students who struggle perform much better.
Hi Chris, I would like to thank you very much. Last year I scored C on a course, and this year I got an A+ thanks to your method! Thank you very much!
The largest effect is that my child is more enthusiastic about school! Every parent wants their children to be happy at school, Study Smart made it happen.
In high school, I failed several exams, and that has really changed now. I actually needed this tool very much back then. Since I started studying with StudySmart, I haven't had any D's. My average score is now an A and those are results I would have never had in the past
With my old method, I passed only 3 out of 8 courses. Since I started taking my notes digitally in Study Smart, I have passed all my courses on the first try. For me, StudySmart takes away the stress of wondering if I will pass or not.
Thanks to StudySmart, I passed all my exams, and with better grades than before! On top of that, I have mastered a very good study method now, which I am confident will help me earn my degree.
Explain the cellular response to receptor activation of water-soluble hormones ?
- Water-soluble hormones binds to the cell surface receptors
- Hormone binding allows activation of associated G-proteins
- G-proteins activates/inhibits adenylate cyclase or increases intracellular Ca2+
- Second messengers production or reproduction (eg cyclic AMP or Ca2+)
- Downstream proteins/pathways are activated or deactivated
Explain the cellular response to receptor activation of lipid-soluble hormones ?
- Lipid soluble hormones dissociates from the carrier proteins
- Hormones diffuse across the cell membrane and binds to the intracellular receptors which is either in the cytoplasm or nucleus
- Hormone-receptor complex acts as a specific transcription factor
- Target gene is activated and new mRNA is generated
- New proteins are generated by translation of mRNA and mediates the cell specific response (slow process)
What is the function and location of a pancreas ?
Function : It is both an endocrine and exocrine gland
- EXO : secretes products into ducts that lead to target tissues
- ENDO : secretes products directly into the bloodstream (eg hormones)
- Pancreatic alpha cells = glycogen
- Pancreatic beta cells = insulin
What disease do people have when they have problems with insulin secretion ?
- Hyposecretion of insulin
- Autoimmune disease, loss of pancreatic beta cells which results in low levels of insulin
- Symptoms include glucosuria (glucose in urine), polyuria (large urine volume), polydipsia (thirst) and polyphagia (hunger)
- Treatments are insulin injections or infusion
- Hyposensitive receptors to insulin
- Associated with obesity
- Symptoms are the same as Type 1 Diabetes
- Treatments are insulin injections and lifestyle changes (exercising and dieting)
The question on the page originate from the summary of the following study material:
- A unique study and practice tool
- Never study anything twice again
- Get the grades you hope for
- 100% sure, 100% understanding
