Endocrine System: Glands, Hormones, and Disorders

Endocrine System Overview

• The endocrine system involves glands, which secrete hormones and affects bodily functions.
• Endocrine glands include the hypothalamus, pituitary gland, adrenal glands, thyroid glands, parathyroid glands, gonads, and islet cells of the pancreas.
• Hormones are secreted directly into the bloodstream
• Hormone actions are related to secretion and hormone levels in blood

Endocrine Disorder Classifications

• Primary endocrine disorders originate with endocrine glands
• Secondary disorders involve dysfunction the anterior pituitary gland
• Tertiary disorders involve hypothalamus dysfunction
• Quaternary disorders stem from tissues being unable to respond to hormones

Endocrine System Functions

• Coordinates sexual functioning, blood glucose control, metabolism, and growth and development
• Select hormone under or overproduction often leads to endocrine dysfunction

Endocrine Anatomy and Physiology

• Linked to the nervous system through Neuroendocrine Regulation
• Hormonal secretions are regulated by negative feedback loops

Hypothalamus

• Located beneath the thalamus
• Hormones secreted work directly on the other endocrine glands

Pituitary Gland - Anterior

• Regulated by hypothalamus via secreted hormones that target gland tissue
• Secretes two gonadotropin hormones, follicle-stimulating hormone (FSH) & luteinizing hormone (LH), and thyroid-stimulating hormone (TSH)
• Secretes adrenocorticotropic Hormone (ACTH), prolactin, growth hormone (GH), and melanocyte-stimulating hormone

Pituitary Gland - Posterior

• Composed of nerve fibers
• Is responsible for neuroendocrine reflexes that result in hormone secretion from signals in the nervous system
• Secretes antidiuretic hormone (ADH) and oxytocin

Adrenal Glands

• The adrenal cortex accounts for 90% of the adrenal gland, secreting mineralocorticoids, glucocorticoids, and androgens
• Mineralocorticoids = Aldosterone
• Glucocorticoids = Cortisol
• Androgens = Male sex hormones
• The adrenal medulla is controlled by the sympathetic nervous system (SNS)
• It secretes epinephrine and norepinephrine
• Production of Epi and NorEpi by the SNS and adrenal Medulla is not essential to sustaining life

Thyroid Gland

• Located in the anterior neck beneath the cricoid cartilage
• Produces triiodothyronine (T3), thyroxine (T4), and thyrocalcitonin (calcitonin)
• Regulates heart rate and contractility, respiration rate and depth, oxygen and glucose intake by cells, and glycolysis
• Also regulates gluconeogenesis, protein synthesis, metabolism of fatty acids, and oxidation of free fatty lipids, cholesterol and phospholipids

Parathyroid Gland

• Can be found partially embedded into the thyroid gland or above the hyoid bone
• Secrets PTH, which increases serum calcium through bone reabsorption and stimulating renal reabsorption of calcium
• PTH stimulates activation of Vitamin D and decreases serum phosphate, causing reabsorption of phosphate in kidneys, bone resorption, & small intestine absorption of phosphate

Gonads

• Sexual development and function are based on hormones secreted from designated sex organs
• Testes (male) & ovaries (female)
• Sex organs are controlled by by tropic hormones released by the anterior pituitary gland, based on the designated gonadotropin releasing hormone from the hypothalmus.
• Folicle-stimulating hormone (FSH) and Luteinizing hormone (LH) stimulate maturation of male and female organs
• Males: FSH & LH = testosterone
• Females: FSH & LH = estrogen/progesterone

Pancreas

• Located in the upper left quadrant of the abdomen, exhibiting endocrine and exocrine functions
• Islet cells are involved in blood glucose control via insulin and glucagon

Endocrine System Assessment

• Includes history (comprehensive, family) and physical assessment
• Physical assessments include inspection (head to toe, specific manifestations), auscultation (heart rate/rhythm, carotid and thyroid bruits), and palpation (thyroid and/or testes for size, shape, symmetry, and nodules)

Diagnostic Studies for Endocrine System

• Include lab studies (serum hormone levels, TSH, T3 and T4, stimulation and suppression testing
• Imaging includes a CT, X-ray, MRI, and thyroid scan

Pituitary Gland Disorders

• Anterior pituitary gland disorders include hypopituitarism and hyperpituitarism
• Posterior pituitary gland disorders include diabetes insipidus (DI) and syndrome of inappropriate antidiuretic hormone (SIADH)

Hypopituitarism

• Also called pituitary insufficiency & is the hyposecretion of hormones from the anterior pituitary gland.
• Can cause decreased body functions
• Epidemiology; rare disorder affecting less than 200,000 individuals in the U.S.
• Possible damage, compression or inflammation of the pituitary can contribute to secondary pituitary tumor or damage to hypothalamus
• Pathophysiology- Deficiency of anterior pituitary hormones can lead to metabolic sexual function change
• Adrenocorticotropic Hormone (ACTH) Decreases release of aldosterone and cortisol from adrenal cortex.
• Thyroid stimulating hormone (TSH) Decreases thyroid hormone .
• Luteinizing Hormone (LH) & Growth Hormone (GH) Changes in sexual and reproductive functioning

Manifestations and Diagnostics of Hypopituitarism

• General manifestations include weakness, fatigue, decreased appetite, weight loss, sensitivity to cold, and swollen facial features.
• ACTH glucocorticoid decrease leads to hypoglycemia and decreased cortisol levels, resulting in lessened ability to handle stress.
• Decreased mineralocorticoids cause hypotension, hyperkalemia, and hyponatremia
• Decreased bone density for decreased growth hormone
• Decreased muscle strength and increased risk of bone fractures
• In females, can cause irregular menses or amenorrhea, and decreased ovulation
• In males decreased testosterone
• Decreased FSH can effect/ decrease ovulation, decreased estrogen & sperm production
• Decreased TSH- decreased T3,T4 and metobolic rate and increased weight gain and thinning of hair
• Diagnosis and the hormone replacement is dependent on the suspected missing hormone(s); ACTH stimulation tests, TSH, FSH, LH, prolactin and GH,rule out Brain tumor through CT/MRI and blood test to rule out other causes of weakness.
• Deficient anterior pituitary hormones can result in hypotension and circulatory issues
• Lack TSH decreases metabolism and women w/ estrogen therapy are at risk for HTN and DVT.

Nursing Management and Complications of Hypopituitarism

• Assessment & Analysis: dependent on the hormone deficiency
• Nursing diagnosis/problems: Fluid volume deficit, Risk for injury, Impaired mobility, Hypoglycemia, Hyponatremia, Hyperkalemia, Osteoporosis
• Nursing Actions/ Intervention Teachings implement safety measure, increase vit D & calcium, Collaborate w/ physical therapy, Consult w/ dietitian/nutritionist.
• Teach clinical manifestations (Acute adrenal insufficiency) and importance of taking medicines,
• Complications: Panhypopituitarism (hyposecretion of all hormones from the hypothalamus)

Hyperpituitarism

• Epidemiology; associated w/ hypersecreting tumor, higher incidence in female patients, can be in Children or Adults
• genetic link w/ secondary to hypersecretion of hormone leading to specific dysfunction based on dependant
• Manifestations: ACTH- Increased Glucocorticoid is leading to, hyperglycemia and increase cortisol levels and Increase Minerocorticoid also lead to hypernatremia
• Growth homorne (GH): increased bone density, and Coarse facial features and menstrual irregularities Prolactin: leads to Hypogonadism, Galactorrhea increase body fat increased T3 &T4 levels Assessment:
• Assess of hands, feet, and broadening of facial bones. Assess ment is based on the hormone which is increased through ACTH measurements and CT scan studies. Medical Management:
• Treat symtpom- Hormones replacement and If tumor is present: Medication might the Tumor size prior to removal Surgical Management
• TRANSSPHENOIDAL HYPOPHYSECTOMY Sublabel TRANSSPHENOIDAL HYPOPHYSE and STEREOTACTIC RADIOSURGERY Complications:
• Increase ACTH can cause, Hyperglycemia HTN Acromegaly and increase GH can cause Organ overgrowth Heart, Thyroid, Liver, Nerve entrapment, pain and changes in Sensations.

Nursing Managment for Hyperpituitarism

• Assessment& interventions: Neurological,Vision assessment, Assessment- Daily assesment w/ specific hormone level/ and neurological assesment. Also, perform neuro vascual check q 4 hrs with actions such as, Mangement in teach patients how to medicate w/ dopamine, somatostatin teaching disease management .

Post Transsphenoidal hypophysectomy actions:

• Assessment- neuro, Vital Signs ,Mucuus mebrane Actions: Maintain adequate nutrition and hydration. Administer humidify air to Thin secretion.
• Teaching: Report any signs of meningitis and Avoid activity increase in the Intercranial Pre

Diabetes insipidus (DI)

• The lack of ADH to help conserve H2O
• Rare - lack of ADh is 30% of the diagnosis and post surgery can be 20 % due to tumors/ head trauma can cause decrease seretion of the ADH
• Pathopysiology: ADH deficiency leads to minimal production . Clinical manifestations:
• Weight less Polyuria, Nocturia and Hemoconcentation cause serum sodium and hemo concentration. Other signs are postural hypotension related to hypovolemia
• Assess Hypovelemia/ hypotention
• Test labs Mangement: Fluid 04- and Hypotonic fluid and monitor glucose and treat hyponatrmia . Provide Vasoproessin, The teaching need to be long term and weigh the same time.

SIADH (Syndrome of Inappropriate Anti-Diuretic Hormone)

• Increase ADH and overload of 20water decrease sodium.
• ADH = Overload of water
• ADH = decreased water loss= sodium dilution= hyponatremia
• Asssment and Mainfiestion : Anorexia/ Headache . Weakness Neurological Signs such as, Seizure.
• Diagnostic- Urine output decrease and serums osm increasing electrolyte; sodium test
• Mange fluid 100ml/ daily, use tetracycline. And use osmotic such is as diuretics/

HYPOTHYROIDISM

• Epodemiology" Decrease antiteriory gland of the TSh can come from Hashimoto's thyroid and Radioactive iodine for the hyperthyroidism
• Pathophysiology: Decrese metabolic and thyroid disorder affect the Anterior Pititutorty gland or from other thyroid issue.
• Mamifestiation energy, sleep decrease with brittle hair, and Diognosi" Labs: increase TSH and antibodie levles,
• Medcations" History of cardiovascular disease:
• Treatment and comptications" Coma from hyperthermia Nursing Actions:
• Administer eye lubricane and Beta blocker teaching is how to reduce over weight , avoid stress , and main weight daily/ Monitor I& Os.

HYPERTHYOIDISM

• Epidemiology” Autoimmune grave's' decrease in T 3 &t 4
• Mamifestications:: H/R Weight Loss Goilet
• Lab testing” Thyroid scan-
• Treatment” Identify cause for the for hormone replacement, radioactive iodine, Surgery; decrease release of thyroird
• Medciatgions : anti- medcations prevent secretion NursingActions": Monitor O2, promote rest and support. Administer medication. Teach pt sign of hyperthyroididsim.

Thyroid Storm (Thyrotoxicosis)

• Complication of hyperthyroidism
• Management- Airway fluid management and cooling blanket for hypothermia
• Medications: Antithyroid prepartations, Beta adrenergic blockers and glucocorites
• Monitor cardiac rhythm and avoid seisures.