endocrine system
DESCRIPTION
Endocrine System. I’m hot, I’m cold, I’m fast, I’m slow. EMT-Paramedic Program. The System Itself. The other regulating system of the body Closely linked to nervous system Uses glands and tissues Via hormones, the system regulates: growth the use of foods for energy - PowerPoint PPT PresentationTRANSCRIPT
Endocrine System
I’m hot, I’m cold, I’m fast, I’m slow.
EMT-Paramedic Program
The System Itself
• The other regulating system of the body– Closely linked to nervous
system
• Uses glands and tissues• Via hormones, the
system regulates:– growth– the use of foods for energy– pH of body fluids– fluid balance– reproduction– provides resistance to stress
Hormones
• Chemical messengers to either:– Body organs– Tissues– Or Both
• Binding depends on:– Quantity – Quality of receptor
sites
• They may be divided into three groups:– Amines
• Tyrosine, epi, norepi
– Proteins• amino acids; insulin, GH,
calcitonin, ADH, oxytocin
– Steroids• cholesterol; cortisol,
aldosterone, estrogen, progesterone, and testosterone
Hormone Secretion
• Negative feedback mechanism
• Endocrine glands respond to blood level changes or other hormones present
• Secretion of hormone until stimulus is negated or changed
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Exocrine Glands – Ducted Gland
• Release chemicals nearby tissues through a duct
• Salivary glands
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Endocrine Glands – Ductless Glands
• Release chemicals directly into blood
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Gland Effects
• Exocrine glands – tend to be localized
• Endocrine glands – tend to be widespread
Pituitary “Master Gland”
• Posterior holds hypothalamus hormones ADH and oxytocin
• Anterior produces GH, TSH, ACTH, prolactin, FSH, LH
Specific Hormones
• ADH – maintains BP by
reabsorption of water by kidney tubules and vasoconstriction
• Oxytocin– stimulates
contraction of uterus and release of milk
Specific HormonesThyroid Stimulating Hormone
Growth Hormone
Adrenocorticotropic Hormone
Anterior Pituitary
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Anterior Pituitary
• These hormones primarily regulate other endocrine glands; rarely a factor in endocrine emergencies.
• TSH – (Thyroid-stimulating hormone) - stimulates thyroid to release hormones, = increased metabolic rate. (Critical for survival).
• GH – (Growth hormone) - adults; decrease glucose use, increase consumption of fats for energy
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Anterior Pituitary
• ACTH – (Adrenocorticotropic hormone) - stimulates growth of the adrenal cortex & release of corticosteroids
• FSH – (Follicle stimulating hormone) - ovarian release
• LH – (Luteinzing hormone) - ovarian release– Estrogen and progesterone
Thyroid Gland
• Produces:– T4 - Thyroxine– T3 – Triiodothyronine
• Contain Iodine• Regulate energy
production & growth– Calcitonin –
• Regulates calcium• Maintains strong
bones…– Also feeds back
through pituitary
Parathyroid Glands
• “Pair-a-thyroids?” • Produces parathyroid
hormone– Also involved in
calcium & blood phosphate levels
Disorders Associated with Thyroid Gland• Issues directly associated with gland
– Tumor• Pituitary malfunction indirectly affecting• Hypothyroidism (Myxedema)• Hyperthyroidism
(Grave’s Disease)– Thyrotoxicosis– Thyrotoxic Crisis
(Thyroid Storm)
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Hypothyroidism
• Inadequate levels of thyroid hormones
• Most common cause for primary
hypothyroidism is chronic lymphocytic
thyroiditis (Hashimoto’s); more
common in women. Can also be
caused by iodine deficiency, surgery.
Usually have a small goiter.
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Hypothyroidism (Myxedema)
• Sx: decreased metabolic rate, facial bloat, weakness, cold intolerance, lethargy, altered mental status, slowed speech, oily skin and hair, hair loss, weight gain.
• Levothyroxine is drug of choice.• Patients may be difficult to wean from
a ventilator after anesthesia.
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Myxedema Coma
• Trauma, emergency surgery, severe infection may be poorly tolerated and lead to myxedema coma.
• Rare disorder, characterized by hypo-ventilation, hypotension, hypothermia, hyponatremia, hypoglycemia.
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Hyperthyroidism
• A toxic condition characterized by tachycardia, nervous symptoms, increased metabolism secondary to hyperactivity of the thyroid.
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Hyperthyroidism (Thyrotoxicosis)• Excessive circulating thyroid hormone.
• Graves disease; Most common cause (95%)
• Familial, 6X more common in females and relatively often in elders. Best clinical marker; ophthalmopathy.
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Hyperthyroidism (Thyrotoxicosis)
• Sx: nervousness, diarrhea, insomnia, fatigue, dyspnea, A-fib w/o cardiac hx., tachycardia, HTN, heat intolerance, weight loss, exophthalmos, hair loss, palpitations, amenorrhea, edema of hands and face.
• Elders; wasting with none of classic S/S, serious cardiac symptoms.
• Younger adults; nervous system symptoms
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Hyperthyroidism (Thyrotoxicosis)• Tx: Propranolol decreases many sx
rapidly.
• Diltiazem (calcium channel antagonist) if propranolol is contraindicated.
• Iodide is effective for thyroid storm or prep. for thyroid surgery - short term tx.
Disorders of the Thyroid Gland
• Thyroid Storm– Severe Tachycardia, Dysrhythmias– Heart Failure– Shock– Hyperthermia– Restlessness, Agitation & Paranoia– Abdominal pain– Delirium, Coma
• What else does this look like?• What could help you distinguish?• Danger in becoming a cynic?
Adrenal Glands
Each adrenal has:
Cortex -Aldosterone-Cortisol
Medulla -Epinephrine-Norepinephrine
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Adrenal cortex
• Secretes 3 classes of hormones - all steroid hormones
• Glucocorticoids (95%) (Cortisol)– Release = increased glucose blood levels and
other functions i.e., Anti-inflammatory and immune suppression - released in response to stress, trauma, serious infection.
• Mineralocorticoids– Play an important role in regulating concentration
of potassium and sodium
• Androgenic hormones– Cause masculinization
Trouble Associated with Adrenal Gland
Cushing’s Syndrome– ACTH Levels too
high• Enlarges adrenal
gland– May be associated
with pituitary tumor
Disorders Associated with Adrenal Glands
Addison’s Disease– Deficiency of cortisol & aldosterone– Slow, gradual onset– Progressive
• Fluid volume deficit• Hyperpigmentation (bronze)• Anorexia• Hypotension
Adrenal Gland Disorders
Addisonian Crisis– Acute episode preceded by:
• Physical or emotional stress– Surgery– Alcohol intoxication– Trauma– Infection– Hypoglycemia
– Adrenal cortex cannot comply with body’s increased demand
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Gonads
• Endocrine glands associated with reproduction
• Ovaries produce eggs - controlled by FSH & LH from anterior pituitary, also manufactures estrogen and progesterone - several functions; sexual development, preparation of uterus for implantation
• Testes - produce sperm, manufacture testosterone - promote male growth and masculinization. Controlled by anterior pituitary hormones FSH and LH.
Ovaries
Secrete
– Estrogen
– Progesterone
progesterone
Testes
Secrete
– Testosterone
– Inhibin
Pancreas
• U R&L Q• Islets of
Langerhans– Produce Glucagon
& Insulin
Pancreatic Hormones
• Glucagon – Alpha Cells– stimulates liver to change
glycogen to glucose– raises blood glucose
levels• Insulin – Beta Cells
– lowers blood glucose levels by increasing transport of glucose into the cells
Glucose/Dextrose (D-glucose)
• An intermediate in metabolism of carbohydrates
• The most important carbohydrate, and is formed during digestion; absorbed from intestines into blood of portal vein; in passage through liver, is converted into glycogen
Glucose
• May be:– Used immediately – Stored in muscles– Stored in fat
• Brain cannot store it’s food– Requires continuous circulating volume– Reason neuro s/s develop quickly
Disorders Associated with Pancreatic Dysfunction
Diabetes Mellitus
– Hyperglycemia
– Hypoglycemia
– DKA
– HHNK
Diabetes Mellitus
• 16 million in U.S. & rising• 3 diagnostic types:
– IDDM Type I– NIDDM Type II– Other (Secondary) DM
Diabetes Mellitus
• IDDM type 1• Most commonly occurs in children and
young adults– Genetic predisposition; Immune mediated
destruction of insulin-producing cells
Diabetes Mellitus
• NIDDM type II– Usually occurs after age 30. – A strong genetic
predisposition is evident but pathogenesis is different.
– Most individuals obese– Resistance to insulin action is
present. – Exogenous insulin not
required.
Promotion of Hyperglycemia
• Increased dietary intake (esp. carbohydrates)
• Limitation of physical activity
• Reduction of hypoglycemic therapy
• Limitation of endogenous insulin production– Pancreatic diseases– Drug treatment– Electrolyte disorders
Diabetes Mellitus
• Other (secondary) DM– Associates hyperglycemia to another
cause including:• Pancreatic disease/Pancreatectomy• Drugs or chemical agents• Others too
• Gestational diabetes– Develops during pregnancy and resolves
with birth but increased risk of DM later.
Development of Insulin Resistance
• Infection• Inflammation• Myocardial ischemia or infarction• Trauma• Surgery• Emotional stress• Pregnancy• Drug treatment
S/S of Hyperglycemia/Insulin Insufficiency or Resistance
• Polyuria
• Polydipsia
• Nocturia
• Weight Loss
• Fatigue
• Blurred vision
Control
• Oral
• Transplant– Islet cells– Pancreas
Oral Hypoglycemic Drugs
Metformin 500-1000 mg PO tid
Avandia 4 mg PO qd
Insulin
Insulin Route Onset Peak Duration
Novolog
Aspart
SQ 15 min 1-3 hr 3-5 hr
Humalog
Lispro
SQ 15 min 30-90 min 3-5 hr
Regular IV 10-30 min 15-30 min 30-60 min
Humulin Regular
SQ 30-60 min 2-4 hr 5-7 hr
NPH SQ 3-4 hr 6-12 hr 18-24 hr
Lantus Glargine
SQ 1.1 hr None 24 hr
70/30 NPH/regular
SQ 30 min 4-8 hr 24 hr
Diabetic Ketoacidosis
• A result of severe insulin insufficiency
and an excess of glucagon. Type I
• Common causes:
– Interruption of insulin therapy
– Stress, infection
– Non-compliance frequently a factor
• Onset slow, from 12-24 hours.
Diabetic Ketoacidosis
• Transition from glucose to lipid metabolism– Forms ketones & increase to toxic levels
(diuresed)– Metabolic Acidosis
• Symptoms • Causes severe osmotic diuresis and
severe dehydration• Tx: Requires close monitoring
– Draw red-top– Give IV fluids (Typically 3-5 L Low)– Consider thiamine
• All vitamins & Electrolytes grossly deranged
Non-Ketotic Hyperglycemic Hyperosmolar Coma (HHNK)
• Complication of Type II – Typically preceded by infection &/or
diuretics– Hyperglycemic state causes
hyperosmolar diuresis– Pronounced volume loss (Towards 10L)
• CBG (PG) levels 1000 & higher• Only mild metabolic acidosis
– Non-Ketotic– Many electrolytes within normal levels
Hypoglycemia
• Common causes– Excessive insulin– Stress– Overexertion– Infection– Under eating
• Symptoms• Treatment
– O2, IV, CBG (Red Top), 50% dextrose IV
Endocrine Summary
• A VERY complicated system
• A specialty of it’s own
• Much of EMS treatment is symptom oriented
• Much of care is cause oriented– Important distinction