Endocrinology Flashcards
What type of cellular message is sent to other cells via the bloodstream?
Endocrine
What type of cellular message is sent to other cells via the gastrointestinal tract?
Exocrine
What type of cellular message is sent to other cells neurologically?
Neurocrine
What type of cellular message is sent to other cells via the interstitial fluid?
Paracrine
What are some characteristics of an amine?
- Very short half life
- Includes things like tryptophan, epinephrine, and melatonin
What are some characteristics of a peptide?
- Generally an unbroken chain of AA of 50 or less
- HYDROPHILIC (H2O soluble) = doesn’t cross cell membranes easily
- Must first bind to membrane bound receptors
What are some characteristics of a protein?
- Made of chains of AA (>50)
- Primary, secondary, and tertiary structures
What are some characteristics of a glycoprotein?
- Conjugated proteins bound to carbs
- Solubility and half life are similar to protein hormones
What are some characteristics of a steroid?
- Derived from a lipid (typically cholesterol)
- HYDROPHOBIC = must be transported into the blood bound to carrier proteins and can cross the cell
What are some characteristics of a fatty acid?
- Small fatty acid derivatives of an arachidonic acid
- Rapidly degraded
- Effective only seconds
Define metabolism
The sum of chemical processes that occur within a living organism to maintain life and includes both catabolism and anabolism
What determines the extent to which hormones are capable of binding to receptors and eliciting their intended effects?
The rate of catabolism or anabolism
How does alcohol consumption affect hormones metabolism?
- It appears to INC the degradation of testosterone
- Extended consumption may cause cirrhosis, which in turn causes less albumin and other binding proteins
Many hormones are produced in the ___ ___ by a cascade of ___ reactions
Adrenal gland; enzymatic
What are the two predominant organs for eliminating hormones?
Kidney and Liver
What is the role of the liver in hormone elimination?
Tagging certain hormones for destruction or creation of different molecules
How are steroid hormones eliminated?
By inactivating metabolic pathways and excretion in the urine or bile
How are thyroid hormones eliminated?
They are inactivated by intracellular deiodinases
How are catecholamines eliminated?
They are rapidly degraded within the blood circulation
How are fatty acid derivatives eliminated?
They are rapidly inactivated by metabolism and typically active for a short period of time (seconds)
What are the two forms in which hormones will circulate the bloodstream after they are released from the endocrine gland?
Free (unbound)
Protein bound
T/F:
Free floating hormones are susceptible to degradation and metabolism
TRUE
Hydrophilic = ____ soluble
Water
Lipophilic = ___ soluble
Fat
T/F:
Water-soluble hormones are transported bound to a carrier protein
FALSE
FAT-soluble are transported bound to a carrier protein
What are Micelles?
Enclosed packages containing lipid-rich substances with hydrophilic outer layer and hydrophobic inner layer
What is the most common feedback mechanism in the body?
Negative feedback
What occurs during negative feedback?
The stimulus will feedback upstream to decrease the production of itself
What occurs during positive feedback?
Increases stimulus received until a distinct endpoint is achieved. Because this causes an increased production of stimuli, this pathway can go out of control
A disorder affecting a regulating endocrine gland is a ___ disorder
Secondary or tertiary
Disorders that affects the final endocrine gland that is regulated is a ___ disorder
Primary
List factors that can affect hormone levels
- Emotional stress
- Time of day
- Menstrual cycle
- Menopase
- Food intake/diet
- Drugs
What are the three distinct parts of the pituitary?
- Anterior pituitary
- Intermediate lobe
- Posterior pituitary
What is the function of the posterior pituitary?
Storage and release of oxytocin and AVP (formerly known as ADH)