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This IBDP Blog post will include different types of hormones that is crucial for the Biology component when learning about hormones and homeostasis in more detail, let's get started!
Homeostasis
Homeostasis is the physiological variables that stay within a certain limit
- IE: blood pH, blood carbon dioxide concentration, blood glucose concentration, body temperature (37), water balance within tissue
- Negative feedback
- the physiological process that brings a value back towards to a set point
- Nervous system and Endocrine system work to keep homeostasis
- Hormones are transported by the bloodstream from the gland, where it is produced, to the specific
target cell
Thyroxin:
Gland is located in your neck
- Thyroxin created from an amino acid and iodine; signals from the hypothalamus
- used for basal metabolic rate; achieve by stimulating carbohydrate and lipid metabolism via the oxidation of glucose and fatty acid; helps to regulate body temp
- Thyroxin exists in two forms: T3 and T4 which indicate the number of iodine atoms within the structure; insufficient iodine in diet is bad
- T4 is typically converted to T3 in the target cell
- T3 enters the nucleus of cell and acts as a transcription regulator; leads to increase in messenger (m)RNA; increase in proteins; increase in the metabolism of the cell
- cells under the influence need greater volume of oxygen
Leptin:
produced by adipose (fat) tissues
- more fat stored; more leptin produced and secreted into the bloodstream
- target cells in hypothalamus of brainstem; binds to receptors on the
- hypothalamus
- leptin lowers appetite and reduces food intake
- obese people should have an increased leptin circulating but cells have been desensitized so don't recognize leptin
Melatonin
- Pineal gland regulates their daily 24 hour cycle activity
- (Circadian rhythm)
- Melatonin is secreted from here
- little melatonin in daytime; high melatonin at night
- highest production is 2am and 4am
- exposure to light can change circadian rhythm
- Person who is jet lag can take melatonin pills to alter circadian rhythm
That's all for part 1 of introducing different hormones!
References:
- https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.drsiddharthachakravarthy.com%2Fthyroid-disorders%2F&psig=AOvVaw2Nn-8DNCgWaJEAJoPh8DMX&ust=1626322022023000&source=images&cd=vfe&ved=0CAoQjRxqFwoTCLCq3-XX4fECFQAAAAAdAAAAABAO
- https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.researchgate.net%2Ffigure%2FLeptin-and-regulation-of-Body-Weight-Leptin-is-synthesized-and-released-by-fat-adipose_fig1_50937183&psig=AOvVaw0th1VA-voZrh3rxz6pXWT0&ust=1626322075032000&source=images&cd=vfe&ved=0CAoQjRxqFwoTCLCzi4DY4fECFQAAAAAdAAAAABAP
- https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.vitabasix.com%2Fen%2Fmelatonin-supplementation-how-long-does-melatonin-last-in-the-body%2F&psig=AOvVaw3IwScQvPfD45EMukTTKCpl&ust=1626322154858000&source=images&cd=vfe&ved=0CAoQjRxqFwoTCNCp-qXY4fECFQAAAAAdAAAAABAJ
Drafted by Venetia (Biology)