endocrine Flashcards
Endocrine System basic functions
Maintain metabolic equilibrium (homeostasis)
* Secrete chemical messengers (hormones)
* Regulate activity of various organs
how is the endocrine system regulated
feedback loops
- Process of feedback inhibition
- Increased activity of target tissue, typically down-regulates activity of gland secreting stimulating hormone**
- Endocrine diseases
a. hormone production?
b. diseases associated with development of?
a. diseases of under/over-production of hormones
b. diseases associated with development of mass lesions
Classification of Endocrine Diseases
- Too Little
- Too Much
- Other: Tumors
functional tumors
tumors of endocrine glands, whether benign or malignant, may secrete the hormone native to the gland. Such
tumors are said to be “functional” tumors. It may be the mass effect
of the tumor or the metabolic effect of the excessive hormone that
calls attention to the tumor.
Pituitary gland
where located?
connection?
role?
components?
how dx are divided?
- Base of brain-sella turcica
- Connected to hypothalamus
a. stalk composed of axons
b. venous plexus - Central role in regulation of other endocrine glands
- Two components
a. anterior lobe (adenohypophysis)
b. posterior lobe (neurohypophysis) - Diseases divided according to lobe mainly affected
ant and post additonalt names
ant: adenohypophysis
post: neurohypophysis
what do the produce?
cells of the adenohypophysis
Somatotrophs: Produces growth hormone
* Lactotrophs: Produces prolactin
* Corticotrophs: Produces adrenocorticotrophic hormone
* Thyrotrophs: Produces thyroid simulating hormone
* Gonadotrophs: Produces follicle stimulating hormone and luteinizing
hormone
hormones of the neurohypophysis
ADH and oxytocin
dx of the ant pituitary
a. Decreased/increased secretion of trophic hormones
b. Hypopituitarism/hyperpituitarism
Hypopituitarism causes
a. Destructive lesions/processes –ischemia, radiation, inflammation, neoplasms
local effects of the cause?
Hyperpituitarism cause
Hyperpituitarism
a. Functional adenoma within anterior lobe
b. Local mass effects –enlargement of sella turcica, visual field abnormalities, increased intracranial pressure
Hypopituitarism can result from?
- Pituitary Adenomas
- Radiation Treatment
- Neurosurgery
- Sheehan Syndrome/ Ischemic necrosis of pituitary gland
growth? fertility? sex? lactation? thyroid? adrenal?
Clinical Manifestation:
Hypopituitarism
- Pituitary Dwarfism
- Amenorrhea & Infertility
- Libido & Impotence
- Postpartum lactation failure
- Hypothyroidism
- Hypoadrenalism
Hyperpituitarism can result from?
- Pituitary Adenomas
- Pituitary Hyperplasia
- Pituitary Carcinomas
- Hypothalamic disorders
Possible clinical Manifestations of Hyperpituitarism
- Gigantism
- Acromegaly
- Cushing disease
usual cause? affects? when?
gigantism
- Primary tumor causing Excess growth hormone (GH)- Adenoma of anterior pituitary
- 2nd most common form
- Affects all “growing tissues”
- Gigantism- before growth
plate closure
head? fatique? bones/joints? bp? heart?
gigantism signs
*Generalized overgrowth= 3 standard deviations
*Headaches
*Chronic fatigue
*Arthritis, osteoporosis
* Muscle weakness
*Hypertension
*Congestive heart failure
when is it diagnosed? vision? enlarged?
acromegaly
- Late diagnosis, excess GH after plate closure
- Poor vision; photophobia
- Enlarged skull, hands, feet, ribs
- Soft tissue, viscera
- Enlarged maxilla, mandible, nasal and frontal bones, maxillary sinus
- Intraoral signs of acromegaly
- Diastemas
- Malocclusion
- Macroglossia
- Enlarged lips
- Sleep apnea
- open bite
classic acromegaly
Posterior Pituitary dx
- Diabetes Insipidus (Central)
- Secretions of Inappropriately High
Levels of ADH (SIADH)
- Diabetes Insipidus (Central) signs
- Polyuria
- Dilute urine
- Polydipsia
Na? cerebral? neruo? body water V? blood V? edema?
- Secretions of Inappropriately High
Levels of ADH (SIADH) signs
- Hyponatremia
- Cerebral edema
- Neurologic dysfuction
- increased Total Body Water
- Blood volume normal
- No peripheral edema
iodide of the thyroid
from diet
stored in the thyroid bound to thyroglobulin
thyroid hormones
T3 and T4, stored and produced in the thyroid
production of T3/4
T4 produced exclusively in the thyroid and majority of t3 is a result of T4 cleavge
how is T4/3 syn activated
stimulated by TSH released from the ant pit due to TRH from the hypothalamus
all this stiumlated with low T3/4
metabollically active forms of the hormones
only the non bound forms of thyroid horrmones are active
how is T3/4 syn shut off?
negative feedback with high levels of the hormones
BMR? carb metab? pro metab? lipid metab? thermogenesis? ANS?
hypothyroidism physio effects?
BMR? carb metab? pro metab? lipid metab? thermogenesis? ANS?
hyperthyroidism
primary Hypothyroidism causes
- Intrinsic abnormality
in the thyroid - Surgery
- Radiotherapy
- Autoimmune
secondary hypothyroidism due to
pituitary failure
types of hypothyroidism
myxedema and cretinism
when? signs? (energy? mental? cold? weight?)
myxedema
- Adult onset hypothyroidism
- Generalized fatigue
- Apathy
- Mental sluggishness
- Listless
- Cold intolerance
- Overweight
age? skeleton? mental? face? teeth?
- Cretinism
- Childhood
- Impaired skeletal development
- Severe mental retardation
- Short stature
- Course facial features
- Delayed tooth eruption
general signs of hypothyroidism
tongue with hypothyroid
macroglossia
hormone levels of hypothyroidism
high TSH/ TRH
Low T3/4
values retun to normal with tx
TSH levels of primary and secondary hypothyroid
- Increased= Primary
- Decreased= Secondary
tx hypothyroidism
supplementation
due to? enlargement of? risk of?
Hashimoto Thyroiditis
- Autoimmune
- Painless enlargement of thyroid: Symmetric & diffuse
- Risk of B-cell non-Hodgkins Lymphomas
- causes hypothyroidism
Large soft tissue lesion at midline in posterior of tongue?
refer to endocrinologist, could be thyroid tissue
neck? eyes? heat? weight? GI? heart? behavior?
Clinical signs and symptoms of hyperthyroidism
Goiter (small)
Exophtalmus (frequent)
Heat intolerance
Weight loss
Malabsorption and diarrhea
Tachycardia
Irritability and anxiety
common causes hyperthyroidism
Autoimmune - Graves’ disease
lab findings of hyperthyroidism
T4 and Free T4 elevated
T3 and Free T3 elevated
TSH and TRH suppressed
symptoms of hyperthyroidism
why is TSH/TRH low in hyper
T3/4 feedback inhibition
pathogenmic signs of the eyes for hyperthyroid
exopthalamy
Graves Disease s/s?
- Tachycardia
- Increased appetite
- Weight loss
- Exophthalmos
- Intolerance to heat
how does graves dx come about?
auto Ab to the TSH receptor= increased stimulation and hyperthyroidism
tx of graves dx
ablation
caused by? signs? fatal?
potential severe event of graves dx
- Thyroid storm
- Caused by infection, stress,
trauma - Elevated body temp.
- Tachycardia
- 20-40% mortality
can be due to?
Diffuse & Multinodular Goiter
- Thyroid enlargement causing Impaired synthesis of thyroid hormone (NON-CANCEROUS)
- can be due to: Iodine deficiency- (Endemic) OR Hyperplasia of follicles due to Pituitary stimulation
- Maintenance of minimal function
(euthyroid) - Diffuse early on, then nodular
Sequence Of Events In Endemic Goiter
- Diet deficient in iodine
- Decreased output of T3 & T4 by thyroid
- Pituitary responds by secreting TSH
- Thyroid hyperplasia
goiter
types of thyroid neoplasias
ademona
papillary carcinoma
follicular carcinoma
medullary carcinoma
number? malignant? sex? age? nodules?
thyroid adenoma
- Solitary, BENIGN
- Males
- Younger
- Warm/Cold nodules
% of neoplasias? ages? tx? worse in?
Papillary Carcinoma of thyroid
- 75-85% of neplasias, MALIGNANT
- All ages
- Radiation
- Worse in elderly
% neplasias? ages? due to? nodules?
- Follicular Carcinoma of thyroid
- 10-20%, MALIGNANT
- Older
- Iodine deficiency
- Cold nodules
% neoplasias? cells/origin? inherited disorders? depositon of?
- Medullary Carcinoma of thyroid
- 5%, MALIGNANT
- Neuroendocrine
- Calcitonin (C cells)
- Amyloid depostion in thyroid
- MEN 2 A/B (20%)
metastisis to thyroid
possible due to other tissue malignancies
clasts? renal? vit D? secretion of? absorbtion of?
PTH functions
Activates osteoclasts activity
Increases Ca renal tubular resorption
Increases conversion of Vit. D into the active dihydroxy form in the kidneys
Increases urinary excretion of phosphates
Increases Ca absorption by the GI tract.
sugical? congenital? IS?
how can hypoPTH be induced
*Surgically induced=Iatrogenic
*Congenital absence = DiGeorge Syndrome
*Autoimmune= APECED
Ca? tentay? signs/tests?
signs of hypoPTH
*Hypocalcemia
*Tetany
*Chvostek Sign- Tapping CN VII causes Muscle contraction of Eye, mouth, nose
*Trosseau sign- Occluding circulation of forearm (BP cuff) causes Carpal spasm
effect of hypoPTH on teeth
enamel hypoplasia, can lead to pitting and chipping appearence
eruption of teeth with hypoPTH
delayed
possible pathologies of hyperPTH
primary and secondary
% each
primary hyperPTH causes
- Adenoma (75-80%), One gland, benign
- Hyperplasia (10-15%): Multiglandular and MEN 1 & 2a,b
- Carcinoma (<5%), malignant
leads to?
secondary hyperPTH due to?
- Renal failure: Hyperphosphatemia, Chronic hypocalcemia, Vitamin D deficient
skeleton? tumors formed? renal? what calcification can occur?
morphological changes with hyperPTH
Skeletal changes - bone resorption
- Formation of bone cysts and hemorrhages
(osteitis fibroso –cystica)
- Brown tumors
-Urinary tract stones (nephrolithiasis)
- Metastatic calcification: Serum calcium levels, especially Ionized calcium levels are high
Primary Hyperparathyroidism
ion levels and urinary excretion
Primary Hyperparathyroidism=Hypercalcemia and Hypophosphatemia
* Increased urinary excretion of both calcium and phosphate
SECONDARY HYPERPARATHYROIDISM due to?
Calcium is chronically depressed and low serum calcium levels lead to compensatory hyperactivity of the
parathyroids
Serum phosphate levels are elevated
renal? vitamin? dietary? stool?
causes of secondary hyperPTH
Chronic renal failure
Vitamin D deficiency
Inadequate dietary calcium
steatorrhea
PTGs? bones? calcification?
morpholgy changes seen with hyperPTH
Hyperplastic parathyroid glands
Bone chages (see primary hyperparathyroidism)
Metastatic calcification
renal osteodystrophy
a complication of chronic kidney disease that weakens your bones. It’s caused by changes in the levels of minerals and hormones (PTH) in your blood.
The main signs are bone pain and fractures. There’s no cure except for a kidney transplant.
seen with hyper PTH
severity? bone? blood vessels?
clinical features of secondary hyperPTH
Not as severe as in primary hyperparathyroidism
Related to symptoms secondary to chronic renal failure
Bone abnormalities (due to renal osteodystrophy)
Calciphylaxis (Ca in small blood vessel)
Tertiary hyperparathyroidism
bones? common tumor? kidneys? ulcers where? mental?
hyperPTH signs
- Osteomalacia & loss of lamina dura
- Brown tumor
- Nephrolithiasis-kidney stones
- Peptic/duodenal ulcers
- Mental changes
Stones, Bones, Moans & Groans of hyperPTH
brown tumor of hyperPTH
resembles giant cell granuloma
would req a biopsy to distinguish
also req lab results to diagnose
palate in hyperPTH
palatal swelling
lamina dura with hyperPTH
lost
actions of PTH
- Increases serum calcium
- Activates osteoclasts
- Increases renal tubular reabsorption of calcium
- Increases renal conversion of Vit D
- Increases urinary excretion of phosphate
- Increased gastric absorption of calcium
layers of the adrenal gland
capsule
cortex
medulla
zones of the cortex
zona glomerulosa
zona fasiculata
zona reticularis
- Zona Glomerulosa
produces/reg by?
- Aldosterone
- Regulated by angiotensin II
- Zona Fasiculata
produces/reg by?
- Glucocorticoids (cortisol)
- Regulated by ACTH (biofeedback)
- Zona Reticularis
produces/ feedback?
- Androgens
- No feedback with ACTH
medulla produces?
Epi/ NE
acute? primary chronic?
Adrenal Cortex Pathology
Too Little:
- Adrenal insufficiency
- Acute: Waterhouse-Friderichsen
- Primary Chronic: Addison Disease
- Secondary