Patho Endocrine need to knows

Which of the following is a characteristic of a hormone?

A.A single hormone can exert various effects in different tissues.

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B.A single function can be regulated by several hormones.

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C.Both

C. Both

Rationale: These are both characteristic of hormones and are at the heart of the functionality of hormones.

thyrotrophs

produce thyrotropin, also called thyroid stimulating hormone (TSH)

corticotrophs

produce corticotrophin, also called adrenocorticotropic hormone (ACTH)

gonadotrophs

produce the gonadotropins, luteinizing hormone (LH), and follicle-stimulating hormone (FSH)

somatotrophs

produce growth hormone (GH)

lactotrophs

produce prolactin

Is the following statement True or False?

Most hormones are regulated via positive feedback mechanism

False

Rationale: In fact, some are regulated via positive feedback, but the vast majority are regulated by negative feedback mechanisms

causes of endocrine hormone hypofunction (underproduction of hormone)

oCongenital defects

oDisruption in blood flow, infection, inflammation, autoimmune responses, or neoplastic growth

oDecline in function with aging

oAtrophy as the result of drug therapy or unknown reasons

oReceptor defects

can also be d/t absence of impaired development of a gland, or deficiency of an enzyme needed for hormone synthesis

causes of endocrine hormone hyperfunction (excessive hormone production)

oExcessive stimulation and hyperplasia of the endocrine gland

oHormone-producing tumor of the gland

primary endocrine disorders

oOriginate in the target gland responsible for producing the hormone

ex: In Addison’s Disease, the adrenal cortex is damaged by autoimmune mechanisms, and there is underproduction of adrenal cortical hormones

secondary endocrine disorders

dysfunction of the pituitary gland

The target gland is essentially normal, but its function is altered by defective levels of stimulating hormones or releasing factors from the pituitary system

ex: A pituitary adenoma (base of the brain) is a secondary endocrine disorder that results in increased secretion of pituitary hormones and excessive stimulation of target endocrine glands such as the adrenal glands (kidneys) and thyroid gland (neck)

tertiary endocrine disorder

result from hypothalamic dysfunction, may occur with craniopharyngiomas or cerebral irradiation.  Both the pituitary and target organ are understimulated

manifestations of hypopituitarism

oBeing chronically unfit

oWeakness and fatigue

oLoss of appetite

oImpairment of sexual function

oCold intolerance

role of ACTH (Adrenocorticotrophic hormone)

blood sugar control, regulate metabolism, reduce inflammation, memory formation,  controls sodium and water balance, controls BP. It is responsible for functions in the fight-or-flight responses.

hormone produced by the pituitary gland that stimulates the adrenal glands to release cortisol

A ______________ disorder results from lesions or damage at the gland.

A.primary

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B.secondary

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C.tertiary

A. primary

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Rationale: Primary disorders arise directly from damage or disturbance at the gland

How does Growth Hormone affect bone growth?

doesn’t directly affect bone growth, instead it acts indirectly by causing the liver to produce IGF (Insulin-like growth factor) which are peptides that act on cartilage and bone to promote growth

factors that inhibit GH

increased glucose levels, high levels of free fatty acids in the blood, higher than normal cortisol levels, and obesity. GH levels decrease with aging

Causes of short stature

Low birth weight

Chronic illness and malnutrition

Functional endocrine disorders

Chromosomal disorders ex: Turner’s

Skeletal abnormalities

Unusual syndromes

Inadequate levels of hypothalamic GHRH will result in adequate production but inadequate release of GH by the pituitary – causing short stature

Protein–calorie malnutrition

Chronic diseases

oEnd-stage renal disease

oPoorly controlled diabetes mellitus

Malabsorption syndromes

Excessive glucocorticoid administration

Emotional disturbances

genetic short stature

oBe well proportioned and to have a height close to the midparental height of their parents

constitutional short stature

oHave moderately short stature, thin build, delayed skeletal and sexual maturation, and absence of other causes of decreased growth

manifestations of excess GH in adults

 tumor formation and consequent compression of cranial nerves responsible for vision

Overgrowth of the cartilaginous parts of the skeleton

Enlargement of the heart and other organs of the body

Metabolic disturbances resulting in altered fat metabolism and impaired glucose tolerance

causes of tall stature

Constitutional tall stature

oA child who is taller than his or her peers and is growing at a velocity that is within the normal range for bone age

Genetically tall

Others

oMarfan syndrome

oEndocrine causes

Sexual precocity

Early onset of estrogen and androgen secretion and excessive GH

most common cause of acromegaly

Somatotrope adenoma (in the pituitary gland)

Which of the following is cause of tall stature?

A.Malabsorption syndromes

B.Marfan syndrome

C.Excessive glucocorticoid administration

D.Emotional disturbances

B. Marfan syndrome

Rationale: Marfan syndrome is a genetic condition that results in rapid bone growth and late/absence of epiphyseal capping

precocious puberty

early activation of the hypothalamic–pituitary–gonadal axis

signs are noted at the age of 8 or younger in girls and 9 or younger for boys

causes of precocious puberty

Idiopathic

Gonadal disease

Adrenal disease

Hypothalamic disease

Benign and malignant tumors of the central nervous system

Three major thyroid binding proteins

thyroid hormone-binding globulin (TBG): carries most of T3 and T4

thyroxine-binding prealbumin (TBPA)

albumin

major functions of thyroid hormone

Increases metabolism and protein synthesis

Influence growth and development in children

oMental development and attainment of sexual maturity

functional units of the thyroid

composed of a large number of tiny sac-like structures called follicles that are formed by a single layer of epithelial cells, and filled with a secretory substance called colloid, which consists largely of a glycol-protein iodine complex called thyroglobulin

T3 and T4

play important part in metabolism -  regulating weight, energy levels, internal temperature, skin, hair and nail growth

Only the free T3 or T4 hormones can enter target cells to exert hormonal effects, the protein-bound forms cannot enter the cells

hypothyroidism

low serum T4

elevated TSH

hyperthyroidism

low TSH

manifestations of hypothyroidism

weakness, fatigue, weight gain, cold intolerance, dry skin and hair, brittle nails, facial puffiness, thinning eyebrows and hair, constipation, abdominal distention, and can progress to CNS symptoms of dullness, lethargy and impaired memory.  Bradycardia can be present in hypothyroidism

Congenital hypothyroidism can cause developmental delays and impair physical growth

-manifestations of untreated congenital hypothyroidism are referred to as cretinism

most common cause of acquired hypothyroidism

Hashimoto’s (autoimmune disorder where the body attacks the thyroid)

manifestations of hyperthyroidism

Thyroid storm

Restlessness, irritability, anxiety, wakefulness

Increased cardiac output, tachycardia, palpitations, tremor

Diarrhea, increased appetite

Dyspnea

Heat intolerance, increased sweating

Thin and silky skin and hair

Weight loss, muscle wasting

goiter, exophthalmos

Pretibial myxedema (thickening and swelling of the skin on the lower legs)

oligomenorrhea (infrequent menses)

Grave’s Disease

autoimmune disorder characterized by abnormal stimulation of the thyroid gland by thyroid-stimulating antibodies (thyroid-stimulating immunoglobulins [TSI]) that act through the normal TSH receptors

manifestations of thyroid storm

Very high fever

Extreme cardiovascular effects

oTachycardia, congestive failure, and angina

Severe CNS effects

oAgitation, restlessness, and delirium

High mortality rate

Is the following statement True or False?

Thyroid storm results in delayed puberty

False

Rationale: Thyroid storm is a severe condition that results in dangerously high temperatures

Primary adrenal cortical insufficiency

Addison’s disease, all layers of the adrenal cortex are destroyed, most commonly d/t autoimmune destruction

ACTH levels are elevated because of lack of feedback inhibition

secondary adrenal cortical insufficiency

oOccurs as a result of hypopituitarism or because pituitary gland has been surgically removed

acute adrenal crisis

life-threatening situation.

Exposure to even a minor illness or stress can cause a client with Addison's disease to develop nausea, vomiting, muscular weakness, hypotension, dehydration, and vascular collapse (which causes a change in LOC - ). Hemorrhage (low BP) can be caused by septicemia, adrenal trauma, anticoagulant therapy, adrenal vein thrombosis, or adrenal metastases

clinical findings of Adrenal insufficiency (Addison’s)

Anorexia and weight loss

hypoglycemia

Fatigue and weakness

Gastrointestinal symptoms, nausea, diarrhea

Myalgia, arthralgia, abdominal pain

Orthostatic hypotension

Hyponatremia, Hyperkalemia

Hyper pigmentation

Secondary deficiency of select hormones

Associated autoimmune conditions

mineralocorticoids (aldosterone)

steroid hormone produced by the adrenal cortex that functions in sodium, potassium, and water balance

glucocorticoids (cortisol)

steroid hormone produced by the adrenal cortex that aids in regulating metabolic functions of the body and controlling inflammation

essential for survival in stress situations

actions of cortisol

Glucose metabolism

Protein metabolism

Fat metabolism

Anti-inflammatory action

Psychic effect

Permissive effect

Adrenal sex hormones (androgens)

steroid hormone produced by the adrenal cortex that serves mainly as a source of androgens for women

congential adrenal hyperplasia

oIncreased levels of ACTH overstimulate production of adrenal androgens, mineralocorticoids

Glucocorticoid hormone excess (Cushing’s Syndrome) definition and manifestations

hypercortisolism

vAltered fat metabolism

vMuscle weakness

vMuscle wasting

vPurple striae

vOsteoporosis

vDerangements in glucose metabolism

vHypokalemia

vGastric acid secretion

vHirsutism, mild acne, and menstrual irregularities

vMoon Face

vBuffalo Hump

Addison’s Disease vs Cushing’s Syndrome

Addison is due to cortisol  insufficiency and Cushing is due to excessive cortisol

Type 1 vs Type 2 Diabetes

Type 1 there is destruction of beta cells of pancreas – so no production of insulin

-polyuria, polydipsia, polyphagia occur suddenly

Type 2 there is lack of insulin availability or effectiveness

-3 Ps occur gradually

Risks with gestational DM

mortality and fetal abnormalities (macrosomia – large baby!!,  hypoglycemia, hypocalcemia, polycythemia, and hyperbilirubinemia) 

Women have increased risk of developing Type 2 diabetes and polyhydramnios

How is BG regulated by the liver?

Approximately two thirds of the glucose that is ingested with a meal is removed from the blood and stored in the liver as glycogen.

Between meals, the liver releases glucose as a means of maintaining blood glucose within its normal range

DKA

occurs mostly in Type 1 – lack of insulin leads to increased release of fatty acids, which leads to ketone production by liver. There is hyperglycemia, ketosis, and metabolic acidosis.

Hyperglycemia results to dehydration, and critical loss of electrolytes – A day or more of pt having polyuria, polydipsia, N/V, marked fatigue, and eventual stupor that can lead to coma.  Breath has a characteristic fruity smell because of presence of volatile keto acids.  Hypotension, tachycardia can be seen

hyperosmolar hyperglycemia state

characterized by high blood glucose (> 600 mg/dL), dehydration (dry lips), depression of sensorium, hemiparesis, seizures, and coma. Also weakness, polyuria, excessive thirst.

can be mistaken for stroke d/t neuro symptoms

may occur in type 2 diabetes, acute pancreatitis, severe infection, MI, and treatment with oral or parenteral nutrition solutions

hypoglycemia

has rapid onset – can have headache, altered thought process, altered behavior, coma, seizures

long-term complications of DM

HTN, MI

nephropathy, kidney failure needing dialysis

neuropathy (abnormal sensory and motor function), gangrene

suboptimal response to infection

bladder stasis and infection, ED

delayed gastric emptying

dizziness, syncope

blindness

somogyi effect

occurs when you take insulin before bed and wake up with high blood sugar levels

dawn phenomenon

increased fasting bG and or insulin requirements during the early morning hours that are not triggered by a preceding hypoglyemic event (in contrast to Somogyi effect).