Endocrine Flashcards
What are the five general functions of the endocrine system?
- A role in reproductive and CNS development
- Stimulating growth and development
- Sexual reproduction
- Maintaining homeostasis
- Responding to emergency demands
What is the difference between an endocrine and exocrine gland? Provide an example of each
Exocrine – secretes into ducts that empty into body cavity or onto a surface (Example – salivary glands)
Endocrine – secrete directly into the blood (Example – adrenal glands (epinephrine))
What is the difference between paracrine and autocrine action?
Paracrine action – act locally on nearby cells
Autocrine action – act on same cell that made it
What are the three common characteristics of hormones?
- Secreted in small amounts at variable but predictable rates
- Regulated by feedback systems
- Ability to bind to a specific target cell receptor
What is the difference between an endogenous and exogenous hormone?
Endogenous - produced within the body
Exogenous - from outside the body – need to supplement or assist the body
What is an example of a hormone that is both endogenous and exogenous?
Insulin
How do lipid soluble hormones act versus water soluble?
Lipid soluble – bound to plasma proteins as they travel, cross cell membranes by diffusion
Water soluble – circulate freely in the blood and act directly on target tissues
What is the difference between the circadian and diurnal rhythm?
Circadian – hormones fluctuate over 24-hour period
Diurnal – sleep wake cycle
What is the region that links the nervous and endocrine system?
The hypothalamus
What is the role of the pineal gland?
Controls the circadian rhythm and produces melatonin
What hormones does the thyroid release?
TSH, Thyroxine (T4) and triiodothyronine (T3), Calcitonin
What types of hormones does the thymus secrete?
Immune and lymphatic
Does the pancreas have endocrine, exocrine, or both actions?
Both
What do TSH, T3, and T4 blood studies indicate?
- TSH - Most sensitive method of evaluating thyroid disease
- T3 - Measures serum levels of the more active thyroid hormone
- T4 - Measures serum levels of the thyroid hormone that accounts for 90%
What does calcium, PTH, and phosphate blood studies indicate?
- Calcium - Measures serum levels of the electrolyte for skeletal mineralization
- PTH - Use to evaluate hyper/hypocalcemia
- Phosphate - Measures serum levels of the electrolyte necessary for bones and teeth
When assessing someone for hypo or hypercalcemia, what blood study would you order?
Parathyroid hormone (PTH)
What is the function of the parathyroid?
Creates PTH. This chemical regulates the amounts of calcium, phosphorus and magnesium in the bones and blood.
What does cortisol, aldosterone, and blood glucose blood studies indicate?
- Cortisol - Measures the most abundant and potent glucocorticoid
- Aldosterone - Measures a potent mineralocorticoid
- Blood glucose - Measures circulating levels of your body’s primary source of energy
What does HgBA1C, amylase, and lipase blood studies indicate?
- HgBA1C - Measures glucose control for the last three months
- Amylase - Measures amount of an enzyme used to digest proteins
- Lipase - Measures amount of an enzyme that helps the body absorb fat
What would the presentation of glucose, ketones, and WBCs show in a urinalysis (normal/abnormal)?
- Glucose - Normal result would be little or none
- Ketones - Present in urine when body needs to break down fats and fatty acids to use as fuel
- WBCs - May indicate infection or inflammation in the urinary tract
What time of day is peak metabolic function?
Morning to early/mid-afternoon is peak metabolism function
What do thyroid hormones T3/T4 stimulate?
They exert effects on almost every organ system and stimulate cell metabolism/activity
What seven general things do thyroid hormones effect?
- Metabolic rate
- caloric requirements
- oxygen consumption
- carbohydrate and lipid metabolism
- growth and development
- brain function
- nervous system activity
What is necessary in the diet for thyroid hormone synthesis?
Iodine
Define thyrotoxicosis and what condition it is synonymous for
Clinical state of high tissue levels of T3 and T4 and actions in the tissue
- Has potential to be life-threatening (ABCs may be compromised)
Synonymous with hyperthyroidism
Define Grave’s disease
Autoimmune disease, thyroid enlargement, and excessive hormone secretion
Does Grave’s disease have a known etiology?
No
How would we palpate for an enlargement of the thyroid?
sweeping motion along the neck to palpate for enlargement
What are the four precipitating factors for hyperthyroidism?
- Insufficient iodine supply
- Infections
- Stressful life events
- Interaction w/ genetics
What is a goiter?
An enlarged thyroid gland that is visibly noticeable
What are the 6 clinical manifestations of hyperthyroidism?
- Palpation or visualization of the thyroid gland
- bruit
- ophthalmopathy (abnormal eye appearance or function)
- exophthalmos (bilateral, unilateral, or asymmetrical protrusion of the eyeballs)
- weight loss
- nervousness
What is ophthalmopathy?
abnormal eye appearance or function due to hyperthyroidism
What is exophthalmos?
bilateral, unilateral, or asymmetrical protrusion of the eyeballs due to hyperthyroidism
What is thyrotoxic crisis (thyroid storm)?
A complication of hyperthyroidism that is rare, acute, and life-threatening
What is the cause of a thyrotoxic crisis? Does it happen in controlled or uncontrolled hyperthyroidism?
stressors in a patient with hyperthyroidism; may occur due to a stressful event (i.e., someone with hyperthyroidism is in a car accident)
May occur in anyone with hyperthyroidism, whether controlled or uncontrolled
What are the manifestations of thyrotoxic crisis?
severe tachycardia, heart failure, shock, hyperthermia (>39), restlessness, agitation, seizures, abdominal pain, nausea, vomiting, diarrhea, delirium, and coma
What type of diet should someone with hyperthyroidism be on?
high calorie, high protein, high carbohydrates, minerals, vitamins, substitutes for caffeine containing beverages
What is hypothyroidism?
High levels of TSH, low T4
Define the difference between primary and secondary hypothyroidism
primary - destruction of thyroid tissue/defective hormone synthesis
secondary - pituitary disease or hypothalamic dysfunction
What is the precipitating factor for hypothyroidism?
iodine deficiency
What are the clinical manifestations of hypothyroidism?
No symptoms to classic symptoms and physical changes, severity depends on deficiency
fatigue and lethargy
myxedema (characteristics facies – puffiness in the face)
What is myxoedema?
Puffiness in the face due to hypothyroidism
What is the most intense complication of hypothyroidism?
Myxedema coma – medical emergency, hypothermia, notable impairment of consciousness/coma, may not be LAO x3
What is euthyroid?
Homeostasis of the thyroid
What medication would be administered to someone with hypothyroidism?
Levothyroxine