MOD 10 Flashcards
Endocrine system overview
The use of chemical messengers (hormones) to control the flow of information between different tissues and organs of the body, interacts with the nervous system
Nervous system
Fast response but short-acting
function using neurotransmitter molecules transported by neurons over a short distance to muscles and glands that respond within milliseconds. but is short-lived
Endocrine system response
Slow response but long-acting
hormones released from glands directly into the bloodstream
tend to take much longer than the response to neurotransmitters but once initiated they tend to be much more prolonged than those induced by the nervous system
Tropic hormones
hormones that have other endocrine glands as their target
non-tropic hormones
directly stimulate target cells
Regulation abilities
negative feedback (most common)
-deficiency of factors stimulates release hormones to increase factor until it is in normal range then the stimulus is ended and hormone release stops
positive feedback (rare)
-hormone secreation stimulates additional hormone secretion (feedback loops)
Hormone transport for water-soluble hormones
-Hormones are not bound to protein = water soluble
-hormones decompose quickly and require frequent or continuous synthesis
-Examples of water-soluble hormones are insulin, pituitary hormones, and parathyroid hormones
Hormone transport for water-soluble hormones
lipid soluble hormones ARE bound to protein molecules
they have longer half-life and are produced in a more cyclic pattern
availability is dependent on having enough protein to bind to target tissues
steroid and thyroid hormones are lipid-soluble
take longer to effect the body but last longer.
Exocrine glands
use ducts to transport hormones/ enzymes
(salivary glands, sweat glands, gastrointestinal tract glands and exocrine pancreas)
Endocrine glands
ductless
excrete hormones into surrounding tissue or through the bloodstream
(thyroid gland, pituitary gland, adrenals, endocrine pancreas)
The duration of endocrine transmission is prolonged because kidneys have to filter blood
Pancrease is exocrine or endocrine
It is both! exocrine because enzymes are excreted through ducts, and endocrine because hormones are excreted into blood stream
Effects of aging on hormones
- Decreased hormone secretion leads to increase risk for hormone deficiencies
2.
Glands to know
BRAIN: hypothalamus and pituitary
THROAT: thyroid and parathyroid
ABDOMEN: pancreas and adrenal
Pituitary gland ADH
Antidiuretic hormone
Function: controls amount of urine produced in kidneys
Too much adh = fluid retention (SIADH)
Too little adh = profuse urine (D.I.)
Pituitary gland TSH
thyroid-stimulating hormone
function: triggers the thyroid gland to grow and release thyroid hormones T4 & T3
Pituitary Gland ACTH
adrenocorticotropic hormone
function: causes adrenal gland to release several hormones. the major one is cortisol (DEFICIENCY IS LIFE THREATENING)
Pituitary gland GH
growth hormones
function: main hormone for body growth
Reproductive hormones (pituitary gland)
oxytocin: stims uterine contractions
follicle stim hormone: ovulation and sperm production
luteinizing hormone: ovulation and testosterone product
prolactin: breast milk
SIADH
too much adh fluid retention
s/s fluid overload especially in lungs and brain
-high b/p, bounding pulse, low hct/hgb)
concentrated urine (high urine osmolarity)
high specific gravity
at risk for seizures and dyspnea
TX: hypertonic solution
DI
kidneys excrete h2O
s/s polyuria >200ml/hr , concentrated blood, dehydrated, High Na, low B/P, thirst, weak pulse, high hct/hgb
High serum osmolarity and hypernatremia (high na)
low specific gravity
at risk for hypovolemic shock
TX: Isotonic
Hyperthyroidism and graves disease
etiology: autoimmune abnormalities (IgG) called graves diseae
common cause: benign tumors, thyroiditis
incidence: less common, 20-40 yr olds, women
patho: excess excretion of t4 and t3
s/s: weight loss, tachycardia, heat intolerance, diarrhea, hypermetabolism, exophthalmos (Permanent eye bulging), insomniaT
Thyroid storm
aka thyroid crisis
life threatening
marked by elevation of body temp (105-106F) and tachycardia or heart palpitations, high b/p
s/s: chest pain, dyspnea, potential heart failure, and cardiac arrest
TX: Drugs to lower temp, heart rate, and b/p
usually occurs in the first 12 hours after a thyroidectomy
hyperthyroidism
most common cause: autoimmune thyroiditis (hashimotos disease)
myxedema
Hashimoto’s diseae (hyperthyroidism)
antithyroid antibodies destroy thyroid, can be inherited
Patho: decreased met, autoimmune disease, decreased T3 and T4, usually after thyroidectomy.
hypothyroidism
BMR: decreased
Weight: gain
Temp: cold Intolerance decreased sweating
GI: constipation decreased appetite
CV: decreased CO2, bradycardia
General appearance: brittle hair/nails, impaired menstruation
behaviors: mental and physical sluggishness, joint paint
Hyperthyroidism
BMR: increased
Weight: loss
Temp: heat intolerance, increased sweating
GI: diarrhea, increased appetite
CV: increased CO2, tachycardia and palpitations
Resp: dyspnea
Appearance: lid lag, decreased blink, Exophthalmos (fish eye)
behavior: restless, irritable, anxious, wakeful, sore
hyperparathyroidism
High calcium means “muscles are TOO calm”
pathophys: elevated calcium in serum, reduces calcium stores in bone, causing bone demineralization, leading to pathologic fractures and risk of injury
common in older women
characterized: bone pain weakness
s/s: Same as hypercalcemia, lethargy, drowsiness, Nausea/ vomiting, decreased DTR, and is greater risk for fractures
Rx: medications to decrease resorption of Ca++ from bone surgical removal of glands
Parathyroid gland controls
calcium
Hypoparathyroidism
Muscles cannot calm down!
etiology: atrophy, trauma, surgical removal along with thyroid
pathophys: decreased PTH, leads to decreased Vit D activation, leads to decreased Ca++ reabsorption
S/S: same as hypocalcemia, tetany, paresthesia (tingling in hands), irritability, and arrhythmias
Rx: vitamin D and Ca++ replacement
Adrenal glands medulla functions
Medulla (middle) exretes catecholamines (epinephrine and norepinephrine) that are responsible for fight or flight response
Adrenal glands cortex functions
Cortex (covering) excretes cortisol, aldosterone, and androgens (sex hormones), these steroids help regulate the body’s response to chronic stress
Is medullary function essential for life?
No the sympathetic nervous system also secretes neurotransmitters epinephrine and norepinephrine,
however adrenal cortical function is needed
Adrenal cortex Cortisol
Cortisol = stress hormone
1. helps regulate stress response
2. diverts metabolism from building tissues to supplying energy for dealing with the stress
3. causes s/s of chronic stress
(high blood levels of cortisol, affects reproduction, fat distribution, and macrophage functioning of the immune system)
End result of chronic stress: infertility, med section obesity, decreased immune functioning, risk of disease