Lesson 24.2 - The Roles of Hormones Flashcards
(23 cards)
are organic substances released by the glands of the endocrine system. They can change the physiological and metabolic behavior of their target cells to maintain homeostasis.
Hormones
Hormonal functions may be categorized into four:
Regulation
Response
Reproduction
Growth and Development
Regulation
Hormones help maintain balance within the body.
__________ refers to the mechanism of the body to maintain a stable internal environment.
Homeostasis
Factors that affect the production and release of hormones:
Metabolite
Feedback mechanisms
regulate the stimulus-response pathway of the body.
Feedback mechanisms
__________ refers to a substance that is formed in or necessary for metabolism.
Metabolite
Example of homeostasis: (Regulation)
The pancreas regulates the blood sugar by secreting insulin, which lowers blood sugar level, or glucagon, which increases blood sugar level.
Hormones are highly specific in targeting cells or organs to help the body respond to internal and external changes. This allow the body to cope with physical, physiological, and psychological stresses.
Response
Example of hormonal response: (Response)
During hot days, pituitary gland releases more antidiuretic hormone (ADH) to increase kidney’s reabsorption of water to prevent water loss from sweating. Then the other way around if you drank a lot of water.
Hormones help prepare the body for the development of sex cells, secondary sex characteristics, and even conception and birth in females.
Reproduction
Example of reproductive function of hormones:
During menstrual cycle, estrogen signals the ovaries to start maturing a follicle that will develop into an egg at ovulation.
Hormones involved in reproductive function:
Follicle stimulating hormone (FSH)
Luteinising hormone (LH)
causes the maturation of an egg in the ovary.
Follicle stimulating hormone (FSH)
stimulates the release of the egg.
Luteinising hormone (LH)
Hormones promote growth and development of the body starting from conception until adulthood.
Growth and Development
Example of hormonal function for growth: (Hormones)
Growth hormone or somatotropin that stimulates growth and cell regeneration in humans and other animals.
This stimulates the decrease in production of adipose tissues and increase the production insulin-like growth factor (IGF) from the liver that acts on muscle and bone cells to grow and increase in mass.
Each hormone has a _______ organ that contains the specific ________ where the hormone molecule can bind.
target, receptor
Hormones bind to their specific target receptor on the cell membrane instead of entering the cell. The receptor is fixed and embedded in the cell membrane.
Fixed Membrane Receptor Mechanism
Fixed Membrane Receptor Mechanism Steps (3)
- Adenycyclase enzyme is activated once the hormone binds to the receptor and produces cyclic AMP (cAMP).
- The cAMP act as a secondary messenger that triggers various enzymatic reaction to cause biochemical changes.
- Phosphodiesterase deactivates cAMP once the target cell creates a response to the hormone.
Hormones that follow this mechanism: (Fixed Membrane Receptor Mechanism)
proteins or peptides like the growth hormone, ADH, insulin, and FSH
The hormone binds to the specific receptor and activates enzymatic activity of the cell. The receptors are within the cell where it freely floats in the cytoplasm.
Mobile Receptor Mechanism
Mobile Receptor Mechanism Steps (3)
- The hormone-receptor complex starts transcription of the DNA and forms specific mRNA.
- The production of mRNA triggers protein synthesis in the cytoplasm.
- It is the synthesized proteins that cause biochemical changes in the cell.
