Endocrine Patho Part 1 - Disorders of the Pituitary Gland, Growth, Thyroid, and Adrenal

Question 1

What is a gland?

Answer 1

aggregation of cells which secrete substances not related to their ordinary metabolic needs

Question 2

What does an endocrine gland do?

Answer 2

secrete hormones into the circulation

Question 3

What are hormones?

Answer 3

Chemical messengers that exert action on specific targets, either singe or multiple. Their actions are determined by the amount of free hormones in the blood, along with the number of receptors available for binding

Question 4

Which hormones does the hypothalamus release?

Answer 4

Corticotropin releasing(CRH), Thyrotropin releasing(TRH), growth hormone(GHRH), gonadotropin releasing (GRH)

Question 5

Which hormones does the anterior pituitary gland release?

Answer 5

growth hormone(GH), adenocorticotropic(ACTH), thyroid stimulating (TSH), Follicle stimulating (FSH), Luteinizing(LH), Prolactin

Question 6

Which hormones does the poterior pituitary gland release?

Answer 6

antidiuretic

oxytocin

Question 7

Which hormones does the adrenal cortex release?

Answer 7

mineralicorticoids - aldosterone

glucocorticoids - cortisol

Question 8

Which hormones does the adrenal medulla release?

Answer 8

epinepherine

norepinephrine

Question 9

Which hormones does the thyroid release?

Answer 9

T3 & T4

Calcitonin

Question 10

Which hormones does the Parathyroid release?

Answer 10

parathyroid hormone

Question 11

Which hormones do the pancreatic islet cells release?

Answer 11

insulin

glucagon

Question 12

Which hormones does the kidney release?

Answer 12

Vitamin D

calcitriol

Question 13

Which hormones do the ovaries release?

Answer 13

estrogen

progesterone

Question 14

Which hormones do the testes release?

Answer 14

testosterone

Question 15

What happens in endocrine primary disorder?

Answer 15

problem occurring in the gland responsible for producing the hormone

Question 16

What happens in the endocrine secondary disorder?

Answer 16

problem in the gland sending messages (pituitary)

Question 17

What happens in tertiary disorder?

Answer 17

problem in the hypothalamus

Question 18

What happens in the Hypothalamic/ Pituitary Axis?

Answer 18

hypothalamus senses low hormone in blood then sends the paracrine message to the pituitary. The pituitary sends hormones to glands and then the glad produces hormones and releases into the blood. The hypothalamus sense and turns off message

Question 19

Pituitary Gland

Answer 19

• Pea sized gland at the base of the brain
• connected to the hypothalamus by the infundibulum
• 2 lobes
  
  • posterior lobe
  • anterior lobe
• master gland

Question 20

Posterior Pituitary

hormones released and pathologies

Answer 20

releases Oxytocin and ADH
-ADH responds to input from osmoreceptors, barorecpetors, and stress to increase water reabsorption in the kidneys

Pathologies

• Syndrome of Inappropriate ADH
  
  • urine output decreases, more water reabsorption, increased BP and edema
• Disbetes Insipidus
  - a lot of urine, decreased bp, show signs of dehydration
• most often found in patients with head injuries

Question 21

Anterior Pituitary

hormones

Answer 21

GH, TSH, ACTH, FSH, LH

Question 22

What is Pituitary Dysfunction caused by?

Answer 22

Pituitary tumors
trauma
dysfunction of hypothalamus

Question 23

What causes Hypopituitarism?

Answer 23

causes decrease in the release of pituitary hormones which affects many other part of the endocrine system
growth hormone is usually lost first, followed by FSH/LH
ACTH is usually lost last
can be life threatening, especially with a decrease in ACTH which causes adrenal insufficiency

Question 24

What is Hypopituitarism caused by?

Answer 24

either congenital or acquired

caused by tumors, radiation to the brain, ischemia/infarction, or traumatic brain injury

Question 25

When do problems become evident in hypopituitarism?

Answer 25

When 70-90% of the anterior pituitary is destroyed

Question 26

What is the treatment for hypopituitarism?

Answer 26

hormone replacement | ex. cortisol for decrease in ACTH

Question 27

What hormones are necessary for normal growth?

Answer 27

``` Growth hormone from pituitary Insulin-like growth factors (liver) Thyroid hormone Insulin Androgens (testosterone) -women, adrenal cortex, men, testes ```

Question 28

Where and when is the growth hormone released? | What is it needed for?

Answer 28

Released throughout life by pituitary Stimulated by: Hypothalamic GH-releasing Factor (GHRF) Release greatest in stage IV sleep, first 1-4 hours of sleep Needed for growth and to regulate metabolic functions (fluids, glucose)

Question 29

What are some effects of GH?

Answer 29

Acts through insulin-like growth factors (IGFs) produced by the liver Cartilage growth & bone growth Linear growth on epiphyseal growth plates Visceral and endocrine organs Cardiac and skeletal muscle growth Facilitates protein synthesis in cells Increases fatty acids Increases serum glucose by causing insulin resistance

Question 30

What are some causes of short stature in children?

Answer 30

Variants of normal- short parents Low birth wt –intrauterine growth retardation Life time consequence, small throughout life Chromosomal abnormalities – Turner’s syndrome ( X chromosome) Hypothyroidism Pan-hypopituitarism Protein calorie malnutrition Chronic kidney disease Poorly controlled diabetes Excess glucocorticoids – Cushings / iatrogenic Malabsorption syndromes like celiac disease Psychosocial dwarfism Neglect or abuse will have poor growth, take them out and they will catch up Environment plays a huge role in health IGF-1 deficiency (Laron-type) Skeletal abnormalities (achondroplasia) Most common cause, IGF is release but the bones do not have enough of the receptor GH deficiency

Question 31

What happens with congenital GH deficiency?

Answer 31

Slow growth -(nml IQ, obesity, immature facial features, delay in skeletal maturity & puberty) Hypoglycemia and seizures Obesity - no signal to break down fatty acids

Question 32

What happens in a growth hormone deficiency in adults?

Answer 32

``` either present since childhood or developed later, such as hypopituitarism from a tumor symptoms: fatigue, malaise decrease in lean body mass increased abdominal obesity increased cardiovascular disease ```

Question 33

What causes tall stature in children?

Answer 33

normal variant - genetic genetic or chromosomal disorder- Marfan or XYY Excess GH - gigantism (children) acromegaly (adults)

Question 34

When must gigantism occur? What does it cause? How can you treat it?

Answer 34

before epiphyseal plate fusion it may cause hypertrophy in the heart or hypertension in the veins possible treatment is sex hormones to cause epiphyseal fusion

Question 35

What is acromegaly caused by? What are some signs and symptoms? What is the treatment?

Answer 35

``` usually caused by pituitary adenoma S/S increased bone width not length soft tissue increases pain in joints coarse skin and body hair accelerated atherosclerosis hypertension sleep apnea elevated glucose headaches Tx normalizing IGF-1 or tumor removal ```

Question 36

What happens in the feedback mechanism for secretion of TRH and

Answer 36

Hypothalamus recognizes low thyroxine (T4) in blood Releases TRH (thyrotropin releasing hormone) Stimulates Thyroid Stimulating Hormone (TSH) from anterior pituitary Causes thyroid to produce thyroid hormone Increased thyroid hormone suppresses TRH & thus TSH Note: Cold temperatures also increase TRH and thyroid hormone release

Question 37

How do you test for Thyroid function?

Answer 37

Serum Thyroid Stimulating Hormone (TSH) level From pituitary gland Serum Free T3, T4 – amount available to enter cells From thyroid gland

Question 38

What are the functions of the thyroid hormone function?

Answer 38

Increases cellular metabolism and protein synthesis Growth and development of children, including sexual maturity Control of metabolic rate - ↑ metabolism of glucose, fat, protein Affects blood lipid levels CV function: increases oxygen consumption, blood flow, cardiac output GI function: ↑secretions, ↑motility, ↑appetite, ↓wt Neuro function: ↑ muscle activity and tremor (not at normal, but if there’s too much)

Question 39

What is the difference between the primary, secondary, tertiary, and Goiter Thyroid Disorders?

Answer 39

``` Primary: problems in thyroid Secondary: pituitary problems Tertiary: hypothalamus problems Goiter (enlarged thyroid gland) can occur in hypo- or hyper-thyroidism Wont know which until you look at other signs and symptoms ```

Question 40

What happens in hypothyroidism? In primary, secondary, and tertiary?

Answer 40

``` Decreased T3 & T4 from thyroid Primary Increased TSH as pituitary tries to increase production Low thyroxine (T3 & T4 ) Secondary High TRH Low TSH: no messages being sent to thyroid Low T3 and T4 Tertiary Low TRH, Low TSH, Low T3/T4 ```

Question 41

What happens in congenital hypothyroidism?

Answer 41

Lack of gland / or abnormal synthesis of hormone or deficient TSH secretion Symptoms appear after birth because of maternal hormone in utero Cretinism: s/s associated with UNTREATED congenital hypothyroidism Routine screen at birth Treat with thyroxine

Question 42

What are the signs and symptoms of cretinism?

Answer 42

``` Longer physiologic jaundice Hoarse cry/ enlarged tongue Choking with feeding Enlarged abdomen and umbilical hernia Sluggish – feeding Lack of interest and somnulence Mental retardation and impaired growth if not treated ```

Question 43

What happens in acquired primary hypothyroidism?

Answer 43

``` Primary hypothyroidism: destruction of thyroid gland – most common Secondary (lack of TSH) and tertiary (lack of TRH) less common Causes of Primary Acquired Hypothyroidism: Hashimoto thyroiditis Most common cause Autoimmune (Hype 2 antibodies) Iodine deficiency Idiopathic causes Postpartum thyroiditis Temp inflammation of thyroid Thyroidectomy Damage from radiation Medications: Lithium, antithyroid drugs, amiodarone * Everything sloes down, metabolism, weakness, fatigue, cold intolerance, weight gain ```

Question 44

What are the symptoms of hypothyroidism?

Answer 44

Slowed metabolism Weakness, fatigue, lethargy, mental dullness, cold intolerance Weight gain, decreased appetite Yellow skin (problem with metabolism carotene) Constipation Slow reflexes Elevated serum cholesterol – not using fatty acids for fuel Bradycardia Cold intolerance Myxedema: accumulation of fluid due to altered metabolism mucopolysaccharides (sugars) * when sugar sits in tissue, it draws fluids in Puffy face and tongue, legs Carpal tunnel/nerve compression – because tissue is swollen Effusions (pericardial, pleural) – build up of fluid in spaces Lab: Low T4, elevated TSH, thyroid antibodies to diagnose Hashimoto

Question 45

What happens in Myxedema Coma?

Answer 45

``` Progression of all the hypothyroid signs May be precipitated by acute illness or narcotics/sedative (overuse) Decreased/change LOC Hypothermia without shivering Hypoventilation – slow, shallow BR Bradycardia Hypotension Hypoglycemia, lactic acidosis ```

Question 46

What happens in hyperthyroidism?

Answer 46

``` Characterized by increased metabolism Increased thyroxine (T3, T4) from thyroid gland Low TSH if primary High TSH if secondary or Increased TRH if tertiary Types of Primary Hyperthyroidism Graves disease – autoimmune Antibodies binding to receptors on the thyroid and trigger release of T3 and T4 Adenoma of thyroid Thyroiditis Excess ingestion of thyroxine ```

Question 47

What happens in Graves Disease?

Answer 47

``` Most prevalent hyperthyroidism Onset 20-40 years old Genetic predisposition – HLA class Autoimmune hyperthyroidism Abnormal stimulation of thyroid by thyroid stimulating hormone receptor antibodies Act through normal receptors ```

Question 48

S/s of hyperthyroidism?

Answer 48

``` Opthalmopathy (exophthalmos) Lid lag- sclera shows above iris Protrusion beyond orbit Dermopathy (myxedema) Goiter Increased SNS sensitivity Increased blood pressure / pulse, RR, palpitations Nervousness, restlessness, tremor Heat intolerance – sweating Fatigue Weight loss despite inc. appetite Thin skin Moist (velvety) skin – increased perspiration Hair loss- fine, silky hair Muscle cramps Decreased menstruation Heat intolerance Atrial fibrillation – elderly Abnormal electrical stimulus ```

Question 49

Tx of hyperthyroidism?

Answer 49

``` Destruction of part of thyroid gland Radioactive Iodine Surgical removal of part Medication to stop thyroxine production Propylthiouracil (PTU) Methimazole (Tapazole) Treatment of SNS sx with beta blockers ```

Question 50

Thyroid Storm/ Thyrotoxic Crisis

Answer 50

Excessive amounts of thyroxine (T4) – life threatening (T4 usually above 7 ng/dL ( .7-1.8 ng/dL) Persons with hyperthyroidism not treated Or having severe stress reaction S/S thyrotoxic crisis High body temperature Extreme CV effects (tachycardia, AF, CHF, angina) Extreme CNS effects (delirium, agitation) Tx: cool patient, remove thyroid hormone by pheresis, etc. Beta blockers to block CNS stimulation

Question 51

What does Aldosterone do?

Answer 51

``` Stimulates Na+/K+ pump in renal tubule Na reabsorbed into blood Water follows K moves out to kidney filtrate Triggers: RAAS Renin ( decreased glomerular filtration rate) High K+ Low Na+ Stress ```

Question 52

What controls the release of glucocorticoids (cortisol)?

Answer 52

``` Bursts in early morning, 6-8AM Declines as day progresses Diurnal pattern reversed in night shift workers Also released in stress, depression Cortisol goes up in depression ```

Question 53

Actions of Cortisol?

Answer 53

``` Glucose metabolism effects Gluconeogenesis Insulin resistance Protein metabolism effects Breaks down proteins to amino acids Increasing serum amino acids Fat metabolism Mobilization of fatty acids Use of fats for energy Altered fat distribution Influences emotional behavior Suppression immune/inflammatory response ```

Question 54

Addison Disease (primary adrenal insufficiency)

Answer 54

Lack of all the adrenal cortical hormones Mineralocorticoids (Aldosterone) Glucocorticoids Androgens (testes still produce testosterone) Life-time replacement is necessary Adrenal cortex destruction (90% destroyed before sx). Causes: Autoimmune Infection (TB, histoplasmosis, cytomegalovirus, HIV, etc) Cancer of adrenal glands Bilateral hemorrhage (anticoagulants) Drugs (ketoconazole)

Question 55

Addisons Pathophysiology

Answer 55

Aldosterone, cortisol, and androgens all decreased ACTH level high as it tries to stimulate the adrenal cortex to produce hormones Aldosterone Deficiency Excessive urinary losses of Na+, Cl- and water Increased retention of K+ Dehydration Decreased blood pressure Decreased cardiac output Weakness, fatigue, possible circulatory shock

Question 56

Addison Disease

Answer 56

Glucocorticoid Deficiency Hypoglycemia – can’t control glucose levels w/o cortisol Lethargy & weakness Anorexia, nausea/vomiting Weight loss Androgen deficiency Males; no symptoms (testes still produce testerone) Females: sparse pubic/axillary hair Darkened pigmentation due to ACTH- bronze skin, blue/black mucous membranes

Question 57

Treatment of Addison Disease

Answer 57

``` Lifetime hormone replacement Can give just cortisol somtimes Daily PO hydrocortisone or Fludrocortisone (Florinef) Has both the mineralcorticoid and glucocorticoid effects Need increased doses during stress ```

Question 58

What are some causes of adrenal insufficiency? | Secondary and Tertiary

Answer 58

``` Secondary: Hypopituitarism Low ACTH No trigger for adrenal glands to produce Tertiary: Hypothalamic damage No CRH Long term steroid therapy – iatrogenic cause ```

Question 59

Acute Adrenal (Addisonian) Crisis

Answer 59

``` Life threatening May occur in: Person with Addison’s disease if exposed to a stressor Children with congenital disease Deficiency of adrenal hormones leads to: Severe hypotension due to water loss Vascular collapse Tx: replacement of sodium, fluids, sugar, steroid (cortisol) ```

Question 60

Cushing Syndrome: Glucocorticoid Excess

Answer 60

Pituitary form –Cushings Disease Excessive ACTH Pituitary tumor producing ACTH Adrenal form- tumor on adrenal gland Ectopic form –nonpituitary tumor that secretes ACTH (small cell lung cancer) Also: Iatrogenic Cushing Syndrome from exogenous steroids

Question 61

What happens with glucocorticoid Excess?

Answer 61

Glucocorticoids possess some mineralcorticoid (aldosterone) activity thus excess Result in hypokalemia HTN from water, Na+ retention Excess cortisol effects Excess androgen effects Females: Hirsuitism (male pattern hair growth), acne, menstrual irregularity

Question 62

Cushing's S/s, dx, and rx

Answer 62

Weight gain - “buffalo hump”, “moon face”, “truncal obesity” Muscle weakness - Muscle wasting Thin skin on forearms and legs Purple striae – breasts, thighs, abdomen Glucose intolerance/hyperglycemia Diabetes 20% Osteoporosis (due to decrease in bone building) Depressed immune / inflammation Gastric ulcers Irritability, depression Dx: Find cause of hypersecretion of cortisol Hormone suppression and stimulation tests Imaging to look for pituitary or other tumor Rx: Iatrogenic – taper, decrease steroid dose