ENDOCRINE
DISORDERS
Chapter 62-63
Endocrine glands
Secrete hormones
Thyroxine
Cortisol
Epinephrine
Growth hormone (GH)
Parathyroid hormone (PTH)
Antidiuretic hormone
Basic concepts
Hypothalamic-pituitary-hormone axis:
Hypothalamus – coordinating center of
endocrine system
Hypothalamus delivers signal to pituitary
gland
Pituitary gland releases specific tropic
hormone that stimulates endocrine target
organ
Autoimmunity
Genetics
Body’s immune system attacks the target organ
Creates hormone resistance
Type 1 DM
Type 2 DM
Neoplasm
Radiation
Tumor growth
Common causes of Endocrine dysfunction
Endocrine Dysfunction
Hypofunction or Hyperfunction
Primary Disorder
– Due to endocrine gland itself
Secondary Disorder
– Problem with the pituitary gland
Tertiary Disorder
– Problem with the hypothalamus
Pituitary gland
Pea-sized organ
“Master gland”
Anterior pituitary
Follicle-stimulating hormone
(FSH)
Luteinizing hormone (LH)
Growth hormone (GH)
Prolactin (PRL)
Adrenocorticotropic hormone
(ACTH)
Thyroid-stimulating hormone
(TSH)
Posterior pituitary
Stores & releases ADH & oxytocin
(OCT) (hypothalamus synthesizes)
Insufficiency of ADH
Posterior Pituitary
Polyuria and polydipsia
Disorders
Partial or total inability to concentrate the urine
Diabetes Insipidus
Manifestations are related to enhanced water excretion,
hypernatremia, and hyper-osmolality
Neurogenic (Central DI)
Insufficient amounts of ADH
Posterior Pituitary
Nephrogenic
Disorders
Inadequate response to ADH by kidney
Diabetes Insipidus
Psychogenic (Polyuria DI)
Partial resistance to ADH, Chronic ingestion
of large amounts of water
How do you think we might treat DI?
Anterior Pituitary Disorders
Hypersecretion of growth hormone (GH)
Acromegaly
– Hypersecretion of GH during adulthood
– Gradual growth of jaw, hands, and feet
Gigantism
– Hypersecretion of GH in children and adolescents
– Stimulates growth plates of long bones
– 7 ft or taller
SIADH
Posterior Pituitary
Disorders
SIADH
High levels of ADH (vasopressin)
– Ectopic production: small cell lung ca, carcinoma of duodenum
& pancreas, leukemia, lymphoma, Hodgkin disease, sarcoma,
squamous cell cancer of tongue
– Brain injury or infection
– Stroke, trauma, bleed, meningitis
WHAT DOES ADH
DO?
ADH released continuously
Water retained – fluid overload - - - decreased serum osmolality (dilute)
Sodium diluted (hyponatremia)
Urine concentrated (increased specific gravity) & excess urine sodium
Symptoms
Secondary mainly to hyponatremia
–
T hirst , impaired taste , anorexia, dyspne a with e xe rtion, fatigue, c onfusion, v omiting, abdominal cramping
SIADH = Too much Water Retention
Thyroid and Parathyroid
T hyroi d s ecretes
Th yr ox i ne ( T 4 )
Tr i i od ot h yronine ( T 3 )
C al citonin i s a n ta gonist to p a r a t hyroi d
h or mon e
P a rat hyroid h o rmone ( PTH)
P TH r e g u lates se r u m ca l ci u m
O p p os e d b y c a l c i t on in f r om t h yr oi d
Goiter
Large goiters are prevalent in
areas of iodine deficiency.
Hypothyroidism
Deficient production of thyroid hormone by the thyroid gland
Most common causes: Hashimoto’s thyroiditis and post Graves’ disease treatment
hypothyroidism
Hashimoto’s disease is an autoimmune disorder that affects the thyroid
Hypothyroidism Symptoms
Manifestations: fatigue, cold intolerance, weight gain,
constipation, hair loss, Bradycardia, coarse hair, Myxedema, and
delayed relaxation of deep tendon reflexes
Myxedema – edema around hands, eyes and feet
Women may have menstrual irregularities. Labs may show high
prolactin levels
Treatment involves hormone replacement
Hyperthyroidism
Excessive thyroid activity
Most common causes:
Graves’ disease
Thyroiditis
Toxic Multi-Nodal Goiter
Toxic Adenomas
Graves Disease
Most common cause of thyrotoxicosis
Autoimmune Disorder in which antibodies
directed against TSH receptors result in
continuous stimulation of thyroid gland to
produce and secrete thyroid hormones.
Symptoms: goiter, exophthalmos , pre-tibial
myxedema, palpitations, insomnia, weight loss,
heat intolerance, menses with lighter flow or
shorter duration and brittle hair.
Thyroid Storm
An acute exacerbation of hyperthyroidism.
It can be caused by inadequate treatment of hyperthyroidism
and stressful conditions such as surgery, infection, and DKA.
Excess thyroid hormone increases systemic adrenergic activity,
which results in epinephrine over production and severe
hyper-metabolism.
Thyroid storm: symptoms
Life threatening: heart failure & pulmonary edema can develop
High fever
Tachycardia
N&V
Tremulousness
Agitation
Psychosis
Can cause coma with hypotension later
MANIFESTATIONS OF
THYROID ALTERATIONS
Parathyroid glands
Pea-sized glands in thyroid tissue
Produce & secrete PTH
What does PTH do?
Hyper
Results in fracture’s, potential for kidney stones
Hypercalcemia
Hypo and Hyper
Hypo
parathyroidism
Results in muscle spasms (tetany), hyperreflexia, dry
skin
Hypocalcemia
Adrenal Glands
C o rte x s e c re t e s
M e d ul la s e c r e te s
G l u co c ort ic o ids
( c ort ic o st e roids)
–
C o rti so l
–
C o r ti s o ne
–
C o r ti c o ste r o n e
M i ne ral cort ic oids
–
A ldost erone
Adrenal estrogen
a n d a n d r o g e ns
C a te c h olamine s
–
E p inephri ne
–
N o repi nephrine
Lack of glucocorticoids produced by adrenal cortex
Glucocorticoids are essential in glucose metabolism
Addison’s Disease:
Causes
Lack of mineralocorticoids produced by adrenal cortex
Mineralocorticoids are essential in sodium and potassium
balance
Deficiency in the adrenal cortex to produce
glucocorticoid and/or mineralocorticoid
Adrenal Disorders
– Addison’s Disease
(hypocortisolism)
– Primary Hypocortisolism
– Addison’s Disease
– Secondary Hypocortisolism
– Low or absent ACTH levels
Cushing’s Syndrome
Hyperfunction of adrenal glands
Cushing’s syndrome:
Excess glucocorticoids
“Classic” syndrome:
Weight gain, truncal obesity, moon face, buffalo hump, purple striae,
HTN, muscle weakness
Cushing Syndrome