L8-L9 Flashcards
(47 cards)
What is Endocrinology?
This is the study of Hormones
What are hormones and their responsibility?
Hormones are chemical messengers within the body that are responsible for long term, on going functions of the body
What are the 5 example functions of hormones?
- Metabolism
- Reproduction
- Regulation of Internal environment
- Development
- Growth
What kind of effects can hormones produce? (Hint: enzyme)
Hormones can speed up chemical reactions (act as enzymes). You can have short or long term effects with hormones that will impact tissues in the long term.
What do hormones have to be in order to not cause issues within the body?
Specific
( for example, a target tissue yields—> rate of enzyme reaction, transportation of ions across membrane, and gene expressions/proteins synthesis.
What are the classic steps to identifying endocrine glands and hormones they produce?
- Remove suspected gland
- Replace hormone
- Create hormone excess
What are ectohormones? Give an example.
Ectohormones are hormones that we put into the environment. An example is pheromones.
Five steps that make a chemical a hormone
- hormone is a chemical signal that is secreted by a cell or cell groups.
- hormones are secreted into the bloodstream either by cell—>ECF or cell—>environment (exocytosis vs endocytosis)
- hormones are transported at a distance through the bloodstream
- hormones are transported short distances through growth factors
- Hormones exert their effect at [low]
How do hormones bind to receptors?
- depends on binding to target cell receptor
- initiates biochemical responses
How are hormones terminated?
- by limiting hormone secretion (smaller amounts= smaller effect)
- removing or inactivating the hormone (half life determines length of activity)
- terminating the hormone activity in target cell
Explain ‘Active Hormones’
These are able to be released when a signal is given. Hormones are stored in a vesicle unit signal is transmitted. From here, hormone is released.
Explain ‘preprohormones’
These are large inactive precursors that need to be processed to be hormones
Explain ‘prohormones’
These ARE hormones but not ready to be used. They must be specialized in order to be functional.
Explain how peptide hormones undergo signal transduction
- peptide hormones must combine with membrane receptors that initiate signal transduction process
- these bind to surface of membrane receptors
- cellular response occurs through signal transduction system
What are steroids? Explain their lipid-solubility.
Steroids are derived from cholesterol and are another type of hormone which are lipophilic—only a select tissue is capable of making them. Lipophilic means dissolved or combines with lipids.
What happens if steroids are lipophobic?
They bind to a carrier protein that can carry them through the water.
Characteristics of steroids
- steroids are derived from cholesterol
- made only in a few organs: adrenal cortex of adrenal gland and gonads
- steroids were made when needed, never stored due to lipophilic nature
Binds to carrier proteins in blood and have longer half lives
Explain the relationship between steroids and genetics
- steroids increase or decrease expressions of genes
- majority of steroids have a response to a genome
- cytoplasm or nucleus receptors stimulate genomic effects
- cell membrane receptors stimulate non-genomics responses
Hormones are derived— wha derives from tryptophan? Tyrosine?
Tryptophan= melatonin from pineal gland Tyrosine= a single tyrosine gives rise to catechloamines. A double tyrosine gives rise to thyroid hormones that behave like steroids
For peptide hormones, list:
- Synthesis and storage location
- How its released from parent cell
- Its transportation in blood
- Half life
- Location of receptor
- Receptor response
- General target response
- Made in advance, stored in secondary vesicles
- Released via Exocytosis
- Dissolved in plasma within blood
- Short half life
- Location of receptor is within cell membrane
- Activation of a second messenger signal
- Modifying old proteins and synthesizing new ones
For steroid hormones, list:
- Synthesis and storage location
- How its released from parent cell
- Its transportation in blood
- Half life
- Location of receptor
- Receptor response
- General target response
- Synthesis on demand
- Simple diffusion
- Bound to carrier protein
- Long
- Cytoplasm or nucleus
- Activation of genes, nongenomic/genomic
- Introduction of new protein synthesis
For catechloamines, list:
- Synthesis and storage location
- How its released from parent cell
- Its transportation in blood
- Half life
- Location of receptor
- Receptor response
- General target response
- Made in advance, stored in second vesicle
- Exocytosis
- Dissolved in plasma
- Short
- cell membrane
- Activation for second messenger system
- Modification of existing hormones
For thyroid hormones, list:
- Synthesis and storage location
- How its released from parent cell
- Its transportation in blood
- Half life
- Location of receptor
- Receptor response
- General target response
- Made in advance, stored in second vesicle
- Transport protein
- Protein carrier bonded
- Long
- nucleus
- Activation for genes to transcribe/translate
- Introduction of new protein synthesis
Explain hormones and their reflexes.
- Reflex pathways have similar components
- endocrine cell is the sensor in simple endocrine reflexes (insulin or PTH)
- many endocrine reflexes involve nervous system, neurohormones are secreted to blood
