Chapter 45 Assessment & Management of Patients w/ Endocrine Disorders Flashcards
Endocrine System
Plays a vital role in orchestrating:
- Transportation of chemicals across cell membranes
- Growth & Metabolism
- Fluid & Electrolyte balance
- Acid-base balance
- Adaptation
- Reproduction
What is the endocrine system composed of?
Pituitary gland, thyroid gland, parathyroid glands, adrenal glands, pancreatic islets, ovaries, & testes
Pituitary Gland
AKA “Master Gland”
Regulates endocrine hormones
Primary role: Secrete hormones into bloodstream-> affects endocrine glands
Anterior Pituitary Gland
Posterior Pituitary Gland
Hormones
Chemical transmitter substances prod in 1 organ/part of the body & carried to bloodstream to other cells/organs on which they have a specific regulatory effect
Generally produced by endocrine glands
- Some may be produced by specialized cells
Ex) GI, kidneys, WBCs
Hormones Produced by the GI System
Gastrin, enterogastrone, secretin, & cholecystokinin
Hormones Produced by the Kidneys
Erythropoietin: Stimulates bone marrow for RBC production
Hormones Produced by the WBCs
Cytokines (hormone-like proteins)
Function & Regulation of Hormones
Rapid action of the nervous system is balanced by slower action of hormones
- Permits precise control of organ functions in response to changes w/in & outside the body
Endocrine glands are composed of acini
- Rich blood supply allows for hormones produced by endocrine glands to quickly enter the bloodstream quickly
-> Amount depends on unique function & body’s needs
Negative feedback system prevents overaccumulation of hormones
Acini
Secretory cells arranged in minute clusters
Negative Feedback
Regulating mechanism where an increase or decrease in hormone levels decreases or increases organ function producing the substance
When hormone concentration increases-> further production decreases
When hormone concentration decreases-> production increases
What are the 4 classifications of hormones?
1) Amines & amino acids: epinephrine, norepinephrine, & thyroid hormones
2) Peptides, polypeptides, proteins, & glycoproteins: Thyrotropin-releasing hormone {TRH}, FSH, GH
3) Steroids: Corticosteroids (hormones prod by adrenal cortex)
4) Fatty acid derivatives: Eicosanoid, retinoids
Paracrine Action
Hormones that NEVER enter the bloodstream & act locally in area where they are released
Ex) Sex hormones secreted via ovaries
Autocrine Action
Hormones may act on actual cells from where they are released
Ex) Effect on insulin from pancreatic beta cells on those cells
Action of Peptide & Protein Hormones
Hormones can alter the function of the target tissue via interacting w/ chemical receptors located on either side of the cell membrane/ interior
Ex) Cyclic AMP
1) Peptide & protein hormones interact w/ receptor sites on cell surface
2) Stimulation of the intracellular enzyme adenyl cyclase
3) Increased production of cyclic AMP (3’, 5’-adenosine monophosphate) inside the cell
- Alters enzyme activity
- 2nd messenger that bonds the peptide hormone at cell surface to change in intracellular environment
Can also act by changing membrane permeability & act w/in secs or mins
Amine Hormones Mechanism of Action
Similar to peptide hormones
Steroid Hormones Mechanism of Action
Penetrate cell membranes & interact w/intracellular receptors
- Due to smaller size & high lipid solubility
Steroid-receptor complex modifies cell metabolism & formation of mRNA & DNA
- mRNA stims protein synthesis w/in the cell
Req several hrs to exert their effects
Why? They exert their action via modification of protein synthesis
Endocrine Assessment: Health History
Ask about duration, severity, how these changes affect ADLs and self perception, and family history
Ask if they have experienced following changes:
Energy level
Tolerance to heat or cold
Weight
Thirst
Urination frequency
Bowel function
Body proportions
Muscle mass
Fat & fluid distribution
2ndary sexual characteristics (hair loss)
Menstrual cycle
Memory
Concentration
Sleep patterns
Mood
Vision
Joint pain
Sexual dysfunction
Endocrine Assessment: Physical
Should include: VS, head-to-toe exam, palpation of skin, hair, & thyroid
Compare findings w/ previous finding, if applicable
Note physical, psychological, & behavioral alterations
Changes in Physical Characteristics:
- Growth of facial hair in women
- “Moon face”
- “Buffalo hump”
- Exophthalmos, vision changes
- Edema
- Thinning of the skin
- Obesity of the trunk
- Extremity thinness
- Increased size of hands & feet
- Edema
- Hyper/or hyporeflexia
Exophthalmos
Abnormal protrusion of one or both eyeballs
Mood & Behavior Changes
Nervousness, lethargy, & fatigue
Diagnostic Evaluation: Blood Tests
Determine the levels of circulating hormones, presence of autoantibodies, and effect of specific hormones on other substances
Ex) Effect of insulin of blood glucose levels
Serum levels of hormones help determine presence of hypo-/hyperfunction of endocrine system & site of dysfunction
Radioimmunoassay tests: Detect antigen levels
Diagnostic Evaluation: Urine Tests
Used to measure the amount of hormones/ end products of hormones excreted by the kidneys
1-time/ 24-hr specimens are collected to measure hormones or metabolites
Ex) Urinary levels free of catecholamines (norepinephrine, epinephrine, & dopamine) for pts w/suspected pheochromocytoma
Disadvantages: Pts may be unable to urinate at scheduled intervals
- Some meds/diseases may affect the test results
Pheochromocytoma
Tumor of the adrenal medulla
Diagnostic Evaluation: Stimulation Tests
Used to determine hypofunction of an endocrine organ
Diagnostic Evaluation: Suppression Tests
Diagnostic Evaluation: Imaging
Diagnostic Evaluation: Genetic Screening
