Transcript Endocrine Disorders

Chapter 25
Endocrine Disorders
Endocrine System
 Endocrine system deals with
transmission of “messages” via
hormones
 Compared to nervous system
which uses electrical conduction
of neurons.
 Hormones are transmitted by
two methods:
 Endocrine: hormone released
directly into the blood stream
 Exocrine: hormone released via a
duct or tube into the blood stream.
Hormones
 Most hormones work on a
negative feedback mechanism
 e.g. when glucose gets too high,
the pancreas releases insulin to
raise the blood glucose level
 When glucose gets too low, the
pancreas releases glucagon to
increase the blood glucose
level.
Important Glands and Hormones
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Pituitary gland
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The master gland of the body
Controlled by the hypothalamus of the diencephalon of the
brain.
Located beneath the hypothalamus, protected by the sella
turcica “turkish saddle” of the Sphenoid bone.
Pituitary Gland is divided into two parts.
 Adeno-hypophysis
 Secretes “sex” hormones
 Growth Hormone (GH)-stimulates growth
plates
 Follicle-Stimulating Hormone (FSH)stimulates sperm and ovary production at
puberty. Regulates secretion of estrogen by
ovaries.
 Luteinizing Hormone (LH)-stimulates
testosterone and maturation of eggs
 Prolactin-stimulates breast milk production
 Adenocorticotropic (ACTH)-stimulates
adrenal gland to secrete Cortisol.
 Thyroid-stimulating (TSH)-stimulates thyroid
gland.
 Neuro-hypophysis
 Oxytocin
 Stimulates contraction during labor and
expulsion of placenta.
 Stimulates “love” sensation
Important Glands and Hormones
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Adrenal gland- sits atop the kidneys
 Two sections
 Adrenal cortex (outer layer)
 Cortisol- hormone released to lower stress and
inflammation
 Also releases stored glucose when energy levels run low
 Excessive use of Prednisone leads to adrenal shutdown.
 Adrenal medulla (inner layer)
 Epinephrine (adrenaline) and Norepinephrine
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Stimulates increased heart rate, breathing rate, and
vasodilation to skeletal muscles. “Fight or Flight” response.
Signal sent from pituitary to release these hormones
Thyroid gland and parathyroid glands
 Thyroid gland is wrapped around your trachea just
beneath your larynx
 Secretes thyroxine hormone (T4)which stimulates cell
metabolism.
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Too much-hyperthyroidism
Too little- hypothyroidism
 The parathyroid glands are 4 tiny dots enmeshed in your
thryroid gland
 Releases Parathyroid hormone- used to regulate the
amount of calcium in your blood and bones.
Important Glands and Hormones (cont)
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Pancreas
 Largest gland in the body located beneath liver
 Its exocrine function is to release trypsin and other
digestive juices.
 Its cells secrete into the long Pancreatic duct when
funnels into the Sphincter of Odi of the duodenum.
 Its endocrine function is primarily the release of two
important hormones by special “nodes” in the
pancreas called the Islets of Langerhans.
 Insulin
 Produced by Beta Cells in the Islets of
Langerhans
 Secreted when blood sugar level is too high.
 Insulin helps cells accept glucose.
 If insulin is low/non-existent, too much
glucose runs amok in the body.
 Glucagon
 Produced by Alpha Cells in the Islets of
Langerhans
 Secreted when blood sugar level is too low
 Causes liver to release glycogen (stored
glucose) into the blood stream.
 Cortisol and Glucagon serve similar
purposes.
Other glands and hormones
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Gonadal Hormones
Follicle Stimulating hormone (FSH) of pituitary gland
regulates gonadal hormones.
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Testosterone
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Estrogen and Progesterone
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Produced by gonads
Makes women “women” and regulates cycle.
Human Chorionic Gonadotropin Hormone (hCG)
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Produced by gonads (ovaries and testicles)
Makes men “men” and women horny
Produced by placenta once zygote attaches to uterine wall
Pregnancy tests detect hCG
Pineal gland
 Located in brain posterior to pituitary gland
 Releases melatonin hormone, which regulates sleep
Diagnostic Tests/Treatment
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Diagnostic
Blood tests
Urine analysis (UA) tests
Scans, ultrasounds, magnetic resonance imaging
(MRI)
 Biopsy
 Treatment
 Hormone replacement medications
 Radiation
 Surgery
 Medications
Insulin and Diabetes Mellitus
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Diabetes Mellitus (DM) manifests in 2 predominant ways.
 Insufficient amount of insulin secretion by pancreas, or
 Production of insulin antagonists that disallow insulin being absorbed by cells.
Either way, insulin is required for glucose to pass through cell membranes to be
metabolized by cells for energy.
In DM, blood glucose levels rise too high leading to complications.
Type 1 DM
 Autoimmune destruction of beta cells in pancreas
 Insulin replacement required
 Acute onset in children and adolescents
 Not linked to obesity
 Genetic factors may play a role.
Type 2 DM
 Non–insulin-dependent
 Oral hypoglycemic medications may be used.
 Caused by decreased production of insulin and/or increased resistance by
body cells to insulin
 Onset is slow and insidious and usually in 50+ age
 Associated with obesity
 Caused largely by lifestyle choices (poor diet, lack of exercise)
Symptoms of DM
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The high level of glucose circulating in the body leads to the following symptoms.
Polyuria
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The kidneys produce more glucose-filled urine to rid the body of the excess glucose.
Glucosuria in a urine analysis is an easy indicator of DM.
Polydipsia (Excess thirst)
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The release of higher than normal urine dehydrates the body, thus leading to perpetual
thirst.
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Polyphagia
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 Since the organs are not receiving glucose, the brain overcompensates by
increasing hunger pangs.
Fatigue
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Cells cannot be metabolize glucose for energy so energy levels drop.
Weight Loss
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Organs are “starving” for lack of energy; kidneys expelling sugar so quickly weight loss
ensures.
Diabetes – Treatment
Principles
 1. Diet and exercise
 Exercise reduces blood glucose as skeletal muscle uses
glucose.
 Reduce simple carbohydrates
 2.Oral medication
 Increase insulin secretion
 Reduce blood glucose levels
Chronic Complications of Diabetes
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Macroangiopathy: -plaque accumulation of greater arteries.
 Result of abnormal lipid levels
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 High incidence of heart attacks, strokes, peripheral vascular disease
 May result in ulcers on feet and legs – slow healing
 Frequent infections and gangrenous ulcers
 Amputation may be necessary.
Peripheral neuropathy
 Common complication due to ischemia in microcirculation to peripheral
nerves
 Impaired sensation, numbness, tingling, weakness, muscle wasting
Neuropathic Diabetic Foot
Ulcer
Chronic Complications of Diabetes
(Cont’d)
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Infections
 Common and often more severe in diabetics
 Infections in feet and legs due to vascular and neurologic impairment
 Fungal infections common
 Candida
 Vagina and/or oral cavity
 Urinary tract infections
 Dental caries
 Gingivitis and perodontitis
Retinopathy in Eye
 Causes blindness
Pregnancy
 Complications to both mother and fetus may occur.
 Increased incidence of spontaneous abortions
 Increased birth size; predisposition to obesity for child.
Periodontal Disease in
Diabetics
Potential Complications of
Diabetes Mellitus
Pituitary Problems.
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Adenomas are the most common
cause of pituitary disorders.
 May cause pressure in the skull
 Headaches, seizures,
drowsiness, visual deficits
Its Effect on hormone secretion is
dependent on cells and location
involved
 May cause excessive or
decreased release of hormones
Pituitary Problems.
 Dwarfism
 Deficit in growth hormone
production/release
 Gigantism
 Excess GH prior to puberty and
fusion of growth plates
 Agromegaly
 Excess GH secretion in adults
 Often associated with pituitary
adenoma
 Bones become broader and
heavier
 Soft tissue grows
 Enlarged hands and feet;
change in facial features
Effects of Growth
Hormone
Parathyroid Abnormalities
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Hypoparathyroidism
 Too little secretion of parathyroid pTH hormone
 Leads to Hypocalcemia
 Causes
 Tumor
 Congenital lack of parathyroid
 Surgery or radiation in neck region
 Eating Disorders; too little Vitamin D
 Results in:
 Seizures
 Arrhythmia and Numbness/Tingling
Hyperparathyroidism
 Too much secretion of pTH hormone
 Results in hypercalcemia, results in:
 Arrthymia
 Osteoporosis
 Predisposition to kidney stones and peptic ulcers
 Causes
 Tumor
 Renal Failure
 Too much Vitamin D
Common Effects of
Parathyroid Hormone
Imbalance
Quiz-ito
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Cortisol and Epinephrine are created by this endocrine organ?
In what intercostal space is V4 placed?
Name one of the classic symptoms of diabetes.
What is the condition in which too little growth hormone is produced during
puberty?
Hypothalamus-PituitaryThyroid Gland Feedback
Thyroid Disorders
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Goiter
 Enlargement of thyroid gland
 It is a symptom not a disease, similar
to jaundice.
 Normally due to deficiency in Iodine in
diet.
 Hyper or hypothyroidism is indicator
 Treatment: based on cause:
 Iodine given
 If hypo, then oral supplements of
thyroxin given
 If hyper, radiation to suppress the
overproduction of thyroxin.
Hyperthyroidism
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Hyperthyroidism (Graves disease)
 Autoimmune disease that causes goiter
 Hypermetabolism and increased stimulation of SNS
 Increased body temperature
 Sweating
 Soft silky hair and skin
 Reduced BMI
 Insomnia
 Hyperactivity
 Exophthalmos is most pronounced symptom.
 Presence of protruding, staring eyes, decreased blink
and eye movement
 Result of increased tissue mass in the orbit
 May result in visual impairment
Hypothyroidism
 Hypothyroidism
 Normally an Iodine deficiency
 2 Other causes
 Hashimoto Thyroiditis
 Autoimmune disorder; body attacks the thyroid
 Causes mania, depression, weight gain,
parasthesia
 Cretinism
 Untreated congenital hypothyroidism
 Results in short stature and severe
cognitive deficits
 May be related to iodine deficiency
during pregnancy
Comparison of
Hypothyroidism and
Hyperthyroidism
Adrenal Glands Abnormalities
 Adrenal Cortex
 Cushing syndrome
 Caused by an excessive
level of cortisol – possible
result of
 Adrenal adenoma
 Pituitary adenoma
 Substance abuse
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Changes associated with Cushing
syndrome
 Change in person’s appearance
 Round face with ruddy color
 Truncal obesity with fat pad
between scapulae
 Thin limbs
 Thin hair
 Fragile skin
Addison Disease
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Caused by the deficiency of cortisol hormone
Opposite of Cushings
Autoimmune reaction is a common cause.
Gland may be destroyed by hemorrhage or infection.
Symptoms
 Decreased blood glucose levels
 Inadequate stress response
 Fatigue
 Weight loss; frequent infections
Comparison of Addison
Disease with Cushing
Syndrome
Antidiuretic Hormone (ADH)
 Diabetes insipidus: deficit of ADH
 Adenoma
 May originate in the neurohypophysis
 Head injury or surgery
 Possible genetic problem
 Replacement treatment required
 Inappropriate ADH syndrome
 Excess ADH
 May be temporary, triggered by stress, may be secreted by an
ectopic source such as a tumor
 Treatment: diuretics and sodium supplements