Doesn't 55°F feel the same for everybody?! Nope, it doesn't! As long as their vacation is just for a week or two, they would totally feel like this LA weather, even at night, is pretty warm! When your body temperature is dropping because it's been consistently cold over several days or weeks, your body ramps up production of your thyroid hormone. Your thyroid hormone is what regulates your metabolism. And your metabolism is only about 40% efficient, meaning that when sugars/fats/proteins … [Read more...] about How come people from very cold climates can visit LA in the winter and walk around in shirts and shorts?
Physiology
Examples of Neurotransmitters that are usually inhibitory
Glycine and GABA: Glycine is one of the 20 amino acids. Some neurons absorb this and it slows down electrical activity in the nervous system. Another one is gamma-aminobutyric acid (GABA). But the two we really want to focus on are serotonin and endorphins. Serotonin is actually made from the amino acid tryptophan. While most amino acids have the ending of -ine, tryptophan doesn't. It's converted by some of our neurons to become 5-hydroxy tryptamine (serotonin). So serotonin is chemically … [Read more...] about Examples of Neurotransmitters that are usually inhibitory
Summary of Neurotransmitters
The excitatory NT's create a local depolarization (EPSP) and they activate it by opening ligand gated sodium ion channels. In the nervous system, however, there are other neurons that are inhibitory NT's (IPSP) and when they activate a receptor site, instead of opening up a ligand gated sodium ion channel, it opens either a potassium ion channel or calcium ion channel and the inside of the cell becomes more negative (hyperpolarization). We just went over ACh, glutamic acid and the … [Read more...] about Summary of Neurotransmitters
Examples of Neurotransmitters that are usually excitatory
There's literally hundreds of neurotransmitters they've discovered and we're only going to mention a few of them here. The following are usually excitatory (usually, meaning, there are exceptions!): Acetylcholine (ACh) certainly excites the nervous system. If you inject someone with ACh, when it reaches their brain it will open up sodium ion channels and depolarize them but it wont last long because there's acetylcholinesterase. That's why they would use a mimetic (a synthetic drug that's … [Read more...] about Examples of Neurotransmitters that are usually excitatory
Actions of Excitatory and Inhibitory Neurotransmitters
Some neurons in the CNS release neurotransmitters that excite other neurons (meaning to fire off APs) and some inhibit (prevent) the generation of action potentials. Action of Excitatory Neurotransmitters Presynaptic neurons are the neurons that conduct the AP to release a neurotransmitter and they affect the postsynaptic neurons. What ALWAYS causes a neuron to release any neurotransmitter (whether it is excitatory or inhibitory) is an action potential. Question and reminder: Where are … [Read more...] about Actions of Excitatory and Inhibitory Neurotransmitters
The Renin Angiotensin Aldosterone Reflex
We are going to talk about the homeostatic reflex mentioned as the following things in a textbook: renin-angiotensin system (RAS) renin-angiotensin-aldosterone system (RAAS) renin-angiotensin-aldosterone pathway (RAA pathway) Don't let these words scare you! We're going to follow a pattern here. Renin leads to Angiotensin being released which eventually leads to Aldosterone being released. We're going to explain all that in detail. We begin with the kidney. The kidney is an … [Read more...] about The Renin Angiotensin Aldosterone Reflex
Types of Hypertension
Since we mentioned renal hypertension as a cause of hyperaldosteronism, let's go over hypertension. What is the normal blood pressure? A typical normal blood pressure is like 120/75 or 120/80 and the units are mm of Mercury, known as TORR. We'll learn about the two numbers further later. What's the definition of high blood pressure? As a definition, it's 140/90... some say 135/85 is borderline high blood pressure. What is the cause of high blood pressure? Well, there's two MAJOR types of … [Read more...] about Types of Hypertension
The Four Hormones Essential for Living
While there are hundreds, there are only 4 that are essential to life and if you don't have them, you die. We've only talked about two of them in detail, which is insulin and the glucocorticosteroids, such as cortisol. We can't explain cortisol really well, and it's weird because it breaks down protein, reduces immune system and reduces inflammatory response. Don't think for a moment we understand how everything works but we do know that someone will die within a week without this … [Read more...] about The Four Hormones Essential for Living
Birth Control
Primers to help you better help understand how birth control works: The Menstrual Cycle and FSH and LH (Gonadotropic Hormones) If a woman took a pill containing estrogen everyday and raised the estrogen level in the blood, that would inhibit her pituitary from releasing Follicle Stimulating Hormone (FSH), which means the ovarian follicles will NOT develop in her ovaries. FSH is what causes ovarian follicles to grow, so you can't get pregnant if there's no egg growing in the ovary. What if … [Read more...] about Birth Control
FSH and LH (Gonadotropic Hormones)
The hypothalamus releases the following Releasing Hormones that stimulate the release of different hormones from the adenohypophysis: Corticotropin Releasing Hormone (C.R.H. causes the release of ACTH) Thyrotropin Releasing Hormone (T.R.H. causes the release of Thyroid Stimulating Hormone aka Thyrotropin) Gonadotropin Releasing Hormone (GnRH releases LH and FSH.) Growth Hormone R.H. & Growth Hormone I.H. Prolactin R.H. & Prolactin I.H. In this … [Read more...] about FSH and LH (Gonadotropic Hormones)