Endocrine System
Jane Bordner, RN BSN
Nursing Instructor
HACC, Central Pennsylvania’s Community College
N100
Spring 2015
Endocrine System
• Works with nervous system to maintain
homeostasis
• Consists of organs that secrete chemical
messengers called hormones and
neurohormones
Endocrine System
• Regulates
– growth
– reproduction
– use of nutrients by cells
– electrolyte and fluid balance
– metabolic rate
• Helps us cope with stress
Feedback Control Mechanism
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Glands are controlled by feedback system
Circulating hormone is monitored by gland
Has affect on secretion of hormone
Gland responds in homeostatic manner
Usually a negative feedback system
Negative Feedback System
Positive Feedback System
Endocrine Glands
Pituitary Gland
• Hypophoysis = Master gland
• Secretes 9 distinct hormones
• Hormones control activities of several
other endocrine glands
– Thyroid
– Parathyroid
– Adrenal
– Pancreas
– Ovaries and testicles
Pituitary Gland
• Consists of three lobes
– Posterior = 2 hormones
– Anterior = 6 hormones
– Middle = 1 hormone
Pituitary Gland: Posterior Lobe
• Oxytocin
• Uterine contractions
• Ejection of milk from breasts
Pituitary Gland: Posterior Lobe
• Antidiuretic Hormone (ADH)
– Regulates fluid balance
– Indirectly controls BP
– Body conserves H2O by increasing H2O
reabsorption from kidneys
– Results in decreased urine output
Pituitary Gland: Anterior Lobe
• Prolactin
– Initiates and maintains breast milk
Pituitary Gland: Anterior Lobe
• Growth Hormone (somatotrophin)
– Stimulates growth
– Stimulates repair of tissues and cells
– Deficiency = pituitary dwarfism
– Over production = gigantism in children and
acromegaly in adults
Anterior Lobe
• 4 Tropic hormones
–Stimulate activity of other endocrine
glands
Tropic Hormones
• Thyroid Stimulating Hormone (TSH)
– Controls activity of thyroid gland
• Adrenocorticotropic Hormone (ACTH)
– Controls growth and secretory activity of
adrenal cortex
Tropic Hormones
• Follicle Stimulating Hormone (FSH)
– Stimulates egg development in ovaries,
secretion of estrogen, and sperm development
• Luteinizing Hormone (LH)
– Caused ovulation in females and secretion of
testosterone in males
Pituitary Gland: Middle Lobe
• Melanocyte stimulating hormone
– Responsible for skin pigment
– Albinism
– Vitiligo
– Patches of melanin form freckles
Thyroid Gland
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Regulates and controls metabolism
Stimulated by TSH
Produces T3, T4, & calcitonin
Must have iodine
Thyroid Hormone (T3 & T4)
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Regulate rate cellular metabolism
hormone =
metabolism
Must have iodine
levothyroxine/Synthroid
liothyronine/Cytomel
Iodine
• Basic component of thyroid hormone
• Deficiency
– Hypothyroidism
– Goiter
• Sources
– Iodine enriched salt
– Seafood
Parathyroid Glands
Calcitonin
• Regulates calcium and phosphate
• Blocks resorption of calcium and phosphate
by bones
• Release stimulated by hypercalcemia
Parathyroid Glands
• Secrete parathyroid hormone (PTH)
• Regulates calcium and phosphorus
• Appropriate amounts required for:
normal nerve and muscle function - blood
clotting
• Ca+ and phosphorus
have inverse relationship
Parathyroid Hormone
• Increases resorption of Ca+ and phosphate
from bones
• Increases absorption of Ca+ and
phosphorus from food
• Activates Vit D
• Increases reabsorption of Ca+ by kidneys
• Increases excretion of phosphate by
kidneys
Adrenal Glands
Adrenal Glands
• 2 portions
– Medulla (middle portion)
– Cortex (outer portion)
Adrenal Cortex
• Stimulated by ACTH
• Produces steroids
– Glucocorticosteroids
– Mineralocorticosteroids
– Androgens
Adrenal Cortex
• Glucocorticosteroids
– Cortisol
• Reduce inflammation
– Blocks histamine
– Kills T- cells
• Promote glucose production
– Increases blood glucose
– Increased secretion in times of stress
Adrenal Cortex
Mineralocorticosteroids
– Aldosterone
• Target organ is kidney
• Regulate water and salt balance
• Involved in acid/base balance
Adrenal Cortex
• Androgens
– Sex hormones
• Small amounts of testosterone and estrogen
Adrenal Medulla
• Emergency gland
• Part of sympathetic nervous system
• Produces 2 neurohormones
– Epinephrine
– Norepinephrine
Ovaries and Testicles
• Sex glands
• Important in development of secondary sex
characteristics
• Testicles produce testosterone
• Ovaries produce estrogen and progesterone.
Pancreas
Pancreas
•Secretes
•Glucagon
•Insulin
Glucagon
• Stimulates
breakdown of
glycogen and
release of glucose
from liver
• Causes increased
serum glucose
Insulin
• Metabolism of blood
glucose
• Maintenance of
proper serum glucose
levels
• serum glucose =
insulin production
• serum glucose =
insulin production
Functions of Insulin
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Allows glucose into cells
Allows glucose to enter liver
Stores excess calories/glucose as fat
Prevents fat breakdown
Normal serum glucose: 70 to 110 mg/dl
After meals may reach 140 to 150mg/dl
• http://www.youtube.com/watch?v=NazZCu1l
wOE&feature=related
Factors Affecting Serum Glucose
• Raises
– Food
– Stress
– Illness
– Growth
– Medications
– Menstrual cycle
• Lowers
– Insulin
– Oral Diabetic Drugs
– Exercise
Assessment of Endocrine System
• Health History
• Inspection
• Palpation
Diagnostic Testing
• Serum hormone levels
– Stimulation tests
– Suppression tests
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Urine tests
Nuclear scanning
Radiographic testing
Ultrasound
Biopsy
Endocrine Disorders
• Disorders of Pituitary Gland
– Diabetes Insipidus
– Syndrome of Inappropriate Antidiuretic Hormone
• Disorders of Thyroid Gland
– Goiter
– Hyperthyroidism
– Hypothyroidism
• Disorders of Parathyroid Gland
– Hyperparathyroidism
– Hypoparathyroidism
Endocrine Disorders
• Disorders of Adrenal Gland
– Addison’s Disease
– Cushing’s Disease
– Cushing’s Syndrome
• Disorders of Pancreas
– Diabetes Mellitus
Diabetes Mellitus
• Chronic illness in which body lacks insulin, is
unable to use insulin, or a combination of
both
• Body may also have difficulty using fats and
proteins
• Causes build up of glucose in blood
Classifications of Diabetes Mellitus
• Prediabetes
• Gestational Diabetes (GDM)
• Type I = absolute insulin deficiency
– Insulin Dependent DM (IDDM)
• Type II = insulin resistance
– Non-Insulin Dependent DM (NIDDM)
Type I Diabetes
http://www.youtube.com/watch?v=OYvav8aDGCc
Type II Diabetes
http://www.youtube.com/watch?v=V
LiTbb6MaEU&feature=related
Causes of Diabetes
• Type I = body kills beta cells
• Type II = body cannot use insulin = INSULIN
RESISTANCE
Who Will Get Which Type?
• Type I
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Seen in children and young adults
Family history (Genetic element)
Autoimmune disease
Triggered by exposure to virus
• Type II
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Seen in people over 40
Strong family history
Often over-weight
Race/Ethnic group is a factor
Diagnostic Studies for Diabetes
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Fasting Blood Sugar (FBS)
Random glucose
Urine analysis
Glucose Tolerance Test
Glycohemoglobin (HbA1c)
eAG
HbA1c
Red Blood Cells
hemoglobin
Glucose
Glycohemoglobin
HbA1c % Compared with eAG
mg/dL
A1C %
eAG mg/dL
6
126
6.5
140
7
154
7.5
159
8
183
8.5
197
9
212
9.5
226
10
240
Criteria for Diagnosis
• FBS – after 4 hours of fasting, BG > 126 mg/dl
on 2 separate occasions
• Random glucose > 200 mg/dl with symptoms
• Elevated HbA1c
Scope of Problem
• Affects millions of Americans
• Affects multiple body systems
• Causes both acute and chronic health
problems
• Older individual gets greater their risk of
developing Type II
Type I: Symptoms
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Polyuria
Polydipsia
Polyphagia
Weight loss
Fatigue
Glucosuria
Blurred vision
Type I: Treatment
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Insulin
Diet
Activity/Exercise
Glucose Monitoring
Insulin
• Cannot be taken orally
• Must be taken daily or more often
• Sources:
– Pure pork
– Human*
– Beef/pork mixed
*Most often prescribed (less allergic reactions)*
Insulin
Types of Insulin
 Rapid-acting
Novolog (aspart)
Humalog (lispro
Apidra (glulisine)
 Short-acting
Humulin R (Regular)
Novolin R (Regular)
 Intermediate-acting
Humulin N (NPH)
Novolin N (NPH)
 Long-acting
Levemir (determir)
Lantus (glargine)
Insulin
• Brand names (Humulin and Novolin) specify
this is a human insulin
• Brand names like Iletin Pork specify this is
pork insulin
• Humulin R = regular human insulin
• Combining types allows better control
DRUG EFFECT
Insulin: NPH and Regular
TIME
DRUG EFFECT
Insulin: Lantis and Novolog
TIME
Insulin Sliding Scales
Blood Glucose
Units to be Administered
< 120
0 units
121 – 150
1 unit
151 – 180
2 units
181 – 200
3 units
201 - 230
4 units
Why So Many Different Types?
• Allows care provider to chose insulin
program that works best for client R/T
– Eating habits
– Willingness to monitor BG levels
– Willingness to take multiple injections
– Work and activity schedule