patho exam 4 deane

What is the main function of hormones?

To secrete chemical messengers into the bloodstream.

What part of the brain acts as the master switchboard for the endocrine system?

Hypothalamus.

What does the pituitary do?

Receives signals from the hypothalamus and releases hormones.

What is the function of the hypothalamus-pituitary hormonal axis?

It links the hypothalamus with the pituitary and end organs.

What hormones are released by the anterior pituitary?

Growth hormone, prolactin, ACTH, TSH, FSH, and LH.

What hormones does the posterior pituitary release?

Antidiuretic hormone (ADH) and oxytocin.

What is the negative feedback system in the endocrine system?

The end-product hormone negatively feeds back to prevent further stimulations.

What is upregulation in receptor activity?

Increased receptor sensitivity and number.

What is downregulation in receptor activity?

Decreased receptor sensitivity and number.

What are the three major types of endocrine conditions?

Hormone deficiency, hormone excess, and hormone resistance.

What causes hormone deficiency?

Gland destruction, which can be due to autoimmune issues, infection, or tumors.

What causes hormone excess?

Tumors, autoimmune disorders, or genetic mutations.

What is meant by hormone resistance?

Usually genetic; it involves a lack of hormone receptor or ability to respond.

What is hypofunction of endocrine glands?

Not enough hormone is produced.

What is hyperfunction of endocrine glands?

Excessive hormone production.

What is primary endocrine dysfunction?

Dysfunction occurs in the endocrine gland itself.

What is secondary endocrine dysfunction?

Dysfunction occurs in the pituitary gland.

What is tertiary endocrine dysfunction?

Dysfunction occurs in the hypothalamus.

What are common causes of endocrine dysfunction?

Autoimmune issues, neoplasia (cancers), and endocrine-disrupting compounds (EDCs).

Endocrine disorders are often….

Multisystem involvement, resulting in mood changes

What are some diagnostic methods for endocrine disorders?

Immunoassays, blood and urinary hormone levels, suppression and stimulation tests, and imaging techniques.

What is one common treatment for hormone deficiencies?

Hormone replacement therapy.

What are some common hormonal replacements used in therapy?

Glucocorticoids, thyroid hormones, sex steroids, and ADH.

What is hypopituitarism?

Affecting one or more pituitary hormones.

What is panhypopituitarism?

Complete loss of all pituitary hormones.

What can cause hypopituitarism?

Pituitary tumors, brain surgery, and trauma.

What syndrome develops due to severe hemorrhage after childbirth?

Sheehan's syndrome.

What indicates rapid deterioration in hypopituitarism?

Acute hypopituitarism.

What is diabetes insipidus?

A condition characterized by a lack of ADH or response to ADH, leading to dilute urine and excessive thirst.

What are the main symptoms of diabetes insipidus?

Frequent urination, thirst, dehydration, and disorientation.

What differentiates central from nephrogenic diabetes insipidus?

Central DI is due to lack of ADH, while nephrogenic DI is due to the kidneys failing to respond to ADH.

What is acute hypopituitarism?

A sudden and rapid deterioration of pituitary function.

What tests are involved in diagnosing diabetes insipidus?

Blood tests for osmolarity, urine osmolarity, and specific gravity.

What is desmopressin used for?

Treatment for central diabetes insipidus.

What does desmopressin replace?

Vasopressin (ADH).

What indicates the presence of SIADH?

Excessive ADH leading to fluid retention.

How does SIADH affect urine and plasma concentration?

Causes concentrated urine and dilute plasma.

What are the symptoms of SIADH?

Nausea, CNS depression, edema, fatigue, muscle cramps, and seizures.

What distinguishes diabetes insipidus from SIADH?

DI is characterized by little ADH and hypernatremia with diluted urine, while SIADH is characterized by excessive ADH, fluid retention, and hyponatremia.

What are common symptoms of hyperpituitarism?

Headaches and symptoms depending on specific hormone excess.

What childhood condition can occur due to growth hormone secreting adenoma?

Giantism.

What can occur if there is excessive ACTH production?

Cushing's syndrome symptoms.

hypothalamus

Sends signals to the pituitary gland

Anterior pituitary

Receives hormonal signals from hypothalamus

Posterior pituitary

Releases hormones synthesized by hypothalamus

End organs

Targets for pituitary hormones, may or may not secrete additional hormones

ANTERIOR

Growth hormone

● Prolactin

● Adrenocorticotropic hormone

● Thyroid-stimulating hormone

● Follicle-stimulating hormone

● Luteinizing hormone

POSTERIOR

Antidiuretic hormone • AKA: vasopressin

● Oxytocin

Negative feedback mechanism

End-product hormone negatively feeds back to prevent

further stimulatory signals

what is an example of negative feedback mechanism

thyroid hormones suppress thyroid-stimulating hormone production

Upregulation

Increased receptor sensitivity and number

Downregulation

Decreased receptor sensitivity and number

endocrine dysfunction causes - autoimmune

Antibodies target endocrine gland, may cause hypofunction

or hyperfunction

endocrine dysfunction causes - Neoplasia

Hypofunction or hyperfunction of gland itself or any

endocrine tissue the gland affects

Endocrine-disrupting compounds (EDC’s)

Chemical in environment that can alter endogenous hormone functions

assessment of endocrine disorders

● Current and past medical history
● Some endocrine disorders present with wide-

ranging, multi-system signs and symptoms.

● Endocrine dysfunction may affect mood and behavior, often misinterpreted as psychological issues.

diagnosis of endocrine disorders

● Blood levels of hormones most important.
● Urinary hormone levels assessed in some instances ● Urinary collection over 24 hours
● Suppression/stimulation tests
● CT scan/MRI
● Ultrasound

treatment of endocrine disorders

hormone replacement therapy, suppression of hormone overproduction

hormone replacement therapy

Dosage schedules attempt to mimic physiological effects

• Glucocorticoids, thyroid hormones, sex steroids, ADH most common replacements

Suppression of hormone overproduction

Medications, surgery, radiation

causes of hypopituitarism

• Pituitary tumor, brain surgery, radiation of brain tumor,

congenital disorder

• Trauma, ischemia, and infarction can cause sudden loss of pituitary function

pituitary hormones that are suppressed

age of the onset

if hypopituitarism acute, rapid deterioration of the patient

Primary adenoma (Benign neoplasm)

• Most common cause
• With growth, can compress pituitary gland in sella turcica

‒ Interfere with pituitary function

Craniopharyngioma

Benign neoplasm close to pituitary gland or pituitary stalk

Pituitary apoplexy

Sudden destruction of the pituitary tissue due to infarction or hemorrhage into gland.

• Traumatic brain injury most common cause

manifestations of hypopituitarism

muscle cramps (low calcium), irritability, tetany, convulsions, chovoke’s sign, trousseau’s sign.

diagnosis of hypopituitarism

blood tests to assess hormone levels

Corticotropin stimulation test: give ACTH

● MRI
● CT scan

If cortisol levels rise with ACTH administration

pituitary

problem

If cortisol levels do not rise with ACTH administration

adrenal gland problem

diabetes insipidus (DI)

● Posterior pituitary hypopituitarism

● Lack of ADH or response to ADH

● Dilute, large volumes of urine

manifestations of DI

• Frequent urination, thirst, dehydration, disorientation,

seizures.
• Blood test will show high osmolarity and hypernatremia

• Urine osmolarity and specific gravity will be low

treatment of DI

ADH administration (desmopressin**)

desmopressin action

an analogue of naturally occuring vasopressin, prevention of nocturnal enuresis

desmopressin indications

central DI caused by a deficiency of vasopressin

desmopressin contraindications

hypersensitivity to chlorobutanol, severe type 2 diabetes, von willebrand disease

desmopressin caution

angina pectorisis, HTN, pt at risk for hyponautremia, pt at risk for increase intracranial HTN, women, urinary retention

desmopressin adverse effects

hyponatremia, seizures, dry mouth

drug to drug interactions desmopressin

loop diuretics, systemic glucocorticoids, inhaled glucocorticoids, concurrent use of nocturna, NSAID, opioids

large tumors may cause — and — (bc of proximity to optic nerves)

headache; visual disturbances

hyperpituitarism - children

• ACTH-producing adenoma
• Corticotropinomas, common before puberty

• Cushing-like symptoms

GH-secretion adenoma

Children

‒ Gigantism

Adults

‒ Acromegaly

hyperpituitarism diagnosis

• Serum hormone levels

• Urine hormone levels may also be assessed

• Dexamethasone suppression test to assess ACTH response

hypopituitarism treatment

• Depends on elevated

hormone
• Prolactinoma

‒ Bromocriptine • Transsphenoidal

surgery

• Adrenal enzyme inhibitors

• GH inhibitors

Syndrome of Inappropriate ADH

(SIADH)

Excessive ADH

excessive ADH causes

excess water reabsorption at the nephron and consequent dilution of electrolytes, such as dilutional hyponatremia

treatment of excessive SIADH

• Fluid restriction
• Slow correction of hyponatremia
• ADH receptor antagonists may be used

DM is a disorder of the — metabolism and consist of high levels of —

carbs, blood glucose

DM = the body’s inability to produce or utilize —

insulin

increases in DM include

• Morbidity and mortality
• CVD, renal damage
• Peripheral vascular disease, neurological disorders • Blindness

• Amputation

TY1 DM

Autoimmune destruction of beta cells of pancreas

● Antibodies present

● No insulin

important on why sensation is difficult

TY 2 DB

● More gradual onset
● Insulin resistance
● Insulin still produced ● Sedentary behavior
● Obesity

insulin + glucose = energy source for cell function

Insulin-supported process of facilitated diffusion moves glucose from blood into cells

● Insulin produced by beta cells of islets of Langerhans in pancreas

● After eating:

• Synchronous rise and fall of glucose and insulin

glucose is used for —

energy

Gluconeogenesis

• Amino acids and glycerol of lipids (fats) converted to

glucose

● Fatty acids remains as lipids

• Converted to acetoacetic acid, beta-hydroxybutyric acid,

and acetone

ketones

‒ Fruity odor: breath, saliva, sweat

**** Accumulation of ketones may lead to

diabetic ketoacidosis (DKA)

normal BG

70-100mg/dL

BG less than 70

hypoglycemia

BG greater than 200

hyperglycemia

fasting BG

100-125mg/dL