NURS 202 Exam 3: Endocrine System

• The study guide is for the NURS 202 Exam 3, Spring 2025
• The exam may include dosage calculation questions

Endocrine System Anatomy and Physiology

• Endocrine glands include the hypothalamus, pituitary gland, adrenal glands, thyroid glands, parathyroid glands, gonads, and select cells of the pancreas (islet cells)
• These glands secrete hormones that act on specific target tissues, resulting in physiological functions
• Underproduction and overproduction of selected hormones can cause endocrine dysfunction
• Hormones from endocrine glands are secreted directly into the blood system
• Exocrine glands include lacrimal, salivary, and sweat glands, and the part of the pancreas that secretes pancreatic juices
• Hormones secreted from exocrine glands are released through ducts

Overview of Anatomy & Physiology

• The endocrine system is closely linked to the nervous system, referred to as neuroendocrine regulation
• The hypothalamus and pituitary gland play a role in endocrine function
• Hormone secretion is regulated via signals from the nervous system, levels of hormones in the blood, and other chemical changes such as glucose, sodium, and potassium levels

Hormone Release

• Hormone release is controlled by a negative feedback system; secretion increases when circulating levels decrease, and vice versa
• The hypothalamus and pituitary gland play key roles in a feedback system that regulates homeostasis, also referred to as the hypothalamic-pituitary system or complex

Hypothalamus

• The hypothalamus is a small structure located beneath the thalamus
• Hypothalamic hormones act directly on other endocrine glands, including the pituitary gland
• The hypothalamus connects to the pituitary gland via the infundibulum, a funnel-shaped structure below the third ventricle and above the sphenoid sinus

Pituitary Gland

• The pituitary gland is at the base of the brain in the sella turcica, a depression of the sphenoid bone
• It is approximately the size of a lima bean
• The pituitary gland communicates directly with the hypothalamus
• The pituitary gland has two lobes: the anterior (adenohypophysis) and posterior (neurohypophysis), each with distinct functions
• Anterior pituitary gland hormones include Follicle-Stimulating Hormone (FSH), Luteinizing Hormone (LH), Thyroid Stimulating Hormone (TSH), Adrenocorticotropic Hormone (ACTH), Prolactin, Growth Hormone (GH), and Melanocyte-Stimulating Hormone (MSH)
• Posterior pituitary gland hormones include Antidiuretic Hormone (ADH) and Oxytocin

Adrenal Glands

• The adrenal glands sit on top of each kidney
• Each gland has an inner medulla and a thick outer cortex with distinct endocrine functions
• The adrenal cortex (90% of the adrenal gland) secretes three types of hormones

Mineralocorticoids

• Mineralocorticoids control fluid balance through kidney effects
• Target cells of mineralocorticoids are collecting ducts in the kidney
• Stimulation leads to reabsorption of sodium and water, and excretion of potassium
• Aldosterone is the primary mineralocorticoid

Glucocorticoids

• These hormones affect carbohydrate, protein, and fat metabolism, and suppress inflammatory and immune functions
• Glucocorticoids also cause reabsorption of sodium and excretion of potassium in kidneys
• Cortisol is the primary glucocorticoid

Sex Hormones

• Androgens and estrogens are the sex hormones

Adrenal Medulla

• The adrenal medulla releases catecholamines (epinephrine, norepinephrine) under SNS control
• Secretion occurs when stimulated by the SNS, with actions varying by receptor sites
• The two major receptor types are alpha (alpha1, alpha2) and beta (beta1, beta2, beta3)

Thyroid Gland

• The thyroid gland has two lobes connected via the isthmus, and produces three thyroid hormones:
  • Triiodothyronine (T3)
  • Thyroxine (T4)
  • Thyrocalcitonin (Calcitonin)

Thyroid Hormone Production

• Adequate dietary intake of protein and iodine is required for thyroid hormone production
• T3 and T4 release is controlled by the hypothalamic-pituitary system, based on circulating thyroid hormone levels
• Low T3 and T4 causes the hypothalamus to secrete TRH, which stimulates TSH release from the anterior pituitary, and TSH acts on the thyroid gland to secrete T3 and T4
• High T3 and T4 causes the hypothalamus to decrease TRH release

Regulation of Metabolism

• T3 and T4 regulates metabolic activity and increases metabolism which includes:
  • Increased rate and contractility of the heart
  • Increased rate and depth of respirations
  • Increased oxygen use
  • Increased glucose intake by cells
  • Increased glycolysis and enhanced gluconeogenesis
  • Increased protein synthesis and catabolism
  • Increased mobilization of fatty acids
  • Increased oxidation of free fatty acids
  • Decreased cholesterol and phospholipids

Thyrocalcitonin (Calcitonin)

• Thyrocalcitonin (calcitonin) regulates calcium with parathyroid hormone (PTH), secreted from the PTH glands
• Serum calcium and phosphorus levels are lowered by calcitonin's action on bones
• Bone resorption, is the breakdown of bone through osteoclastic activity decreases in response to calcitonin, and releases less calcium into the circulation

Release of Calcitonin

• Calcitonin release is regulated by serum calcium levels
• When serum calcium levels decrease, calcitonin secretion is inhibited
• When serum calcium levels increase, calcitonin secretion is increased

Parathyroid Glands

• They secrete parathyroid hormone (PTH)
• They are usually partially embedded in the thyroid gland
• Target tissues of PTH include the bones, kidneys, and small intestine. It responds to low serum calcium levels

Parathyroid Hormone

• PTH increases serum calcium by: -- Increasing bone resorption through osteoclastic activity -- Stimulating renal reabsorption of calcium -- Stimulating activation of vitamin D, increasing intestinal reabsorption of calcium

• PTH's action opposes that of calcitonin, which decreases serum calcium levels

Parathyroid Hormone Affects on Phosphorus Levels

• Parathyroid hormone affects phosphorus levels through these actions: -- Reducing phosphate reabsorption from the proximal tubules in the kidneys -- Increasing bone resorption -- Increasing small intestine absorption of phosphate
• The overall impact is reduced serum phosphate levels, mainly due to phosphorus excretion through kidneys.
• They regulate sexual development and function through hormones secreted from ovaries and testes, with tropic hormones being released from the anterior pituitary gland by secretion of gonadotropin-releasing hormone from the hypothalamus

Follicle Stimulating Hormone and Luteinizing Hormone

• FSH and LH stimulate the maturation of male and female reproductive organs
• FSH and LH simulate production of testosterone in males
• LH and FSH simulate production of estrogen and progesterone that influence development of secondary sexual characteristics, ovarian maturation, and ovulation in females
• Estrogen and progesterone maintain normal pregnancy through effects on the cervix, uterus, and breasts
• Testosterone in males manages male sexual characteristics, as well as sperm production

Pancreas

• The pancreas is in the upper left quadrant of the abdominal cavity
• The exocrine function involves digestion-aiding pancreatic juices secreted into the small intestine
• The endocrine function is blood glucose control by islet cells
• Insulin (from beta cells) and glucagon (from alpha cells) play a central role

Blood Glucose Levels

• Glucose arrives in the bloodstream from: -- Carbohydrates that are converted to glucose via digestion and absorbed in the gastrointestinal tract -- Stored glycogen released as glucose from muscles and liver cells -- Newly created glucose (gluconeogenesis) in the liver.

Insulin

• Glucose is transported to the target cells
• Insulin facilitates glucose transport across the cell membrane to the cell’s interior
• Inside the cell, glucose is metabolized as fuel
• When blood glucose levels are high, more insulin is secreted to drive glucose into cells where it is metabolized, decreasing blood glucose levels
• Insulin release is suppressed when blood glucose levels are low
• Glucagon is released, stimulating glucose production and release from stores in the liver

Endocrine System Assessment

• The nurse completes a head-to-toe assessment due to physical changes that may indicate an endocrine disorder -- Patients with elevated growth hormone (GH) levels may show a broadening of the forehead or jaw
• • Patients with elevated cortisol may show a puffy face

Auscultation

• Auscultate to assess the heart because some endocrine disorders affect cardiovascular function. Patients with hyperthyroidism may have tachydysrhythmias
• Listen over the carotid arteries for carotid bruits
• Direct auscultation over the thyroid gland may reveal a thyroid bruit

Palpation

• Palpate the testes and thyroid glands to assess size, symmetry, shape, nodules, and texture
• Palpate the thyroid gland by standing behind the patient -- Place the thumbs on the back of the neck with fingers curved to the front on either side of the trachea -- Ask the patient to swallow to locate the isthmus as it rises
• Assess the right and left lobes of the thyroid gland -- Palpate the right lobe while the patient turns their head to the right, assessing for irregularities -- Palpate the left lobe with the the head turned to the left

Pituitary Disorders

• Hypopituitarism, Hyperpituitarism, Diabetes Insipidus, and SIADH
• Review pathophysiology and clinical manifestations, assessment findings, and diagnostic tests and treatments

Hypopituitarism Pathophysiology

• Deficiency of one or more pituitary hormones related to: -- Intracranial tumors -- Infarction of the brain --Idiopathic causes
• Panhypopituitarism is a deficiency of all six hormones

Hypopituitarism Assessment

• Signs and symptoms depend on the affected hormone, resulting in general symptoms of weakness, fatigue, and sensitivity to cold

Hypopituitarism Diagnostics and Nursing Care

• Diagnostics: Lab tests and imaging
• Draw six hormones to determine the issue, use MRI/CT scans of the brain, and check blood glucose levels
• Nursing Care: -- Check vital signs for hypotension -- Ensure safety, get up and change positions slowly -- Check routine blood sugars -- Dexa scan to check bone density

Additional Considerations for Hypopituitarism

• Risk for falls and fractures
• BMP for decreased aldosterone, hyponatremia, and hyperkalemia
• Patient Education: Take medication at the same time daily, typically in the morning

Hyperpituitarism Pathophysiology

• Hypersecretion of one of the pituitary hormones caused by a hypersecreting tumor, and is high in females

Hyperpituitarism Assessment

• Signs and symptoms depend on the hormone affected

Hyperpituitarism Diagnostics & Nursing Care

• Diagnostics: Lab tests & imaging
• Check blood glucose (high) and all six hormone levels, MRI/CT images
• Nursing Care: -- Monitor for increased bone density (enlargement of hands, face, and feet [acromegaly]), hypertension (increased risk of stroke, and MI), and neurological changes, -- Monitor intake and output because of increased aldosterone, weight, sodium, infection. -"Go Look For The Adenoma, Please"

Hyperpituitarism Patient Education

• Adhere to the medication regimen

Hyperpituitarism Medications

• Dopamine Agonists: Inhibit release of hyper-releasing anterior pituitary hormones
• Somatostatin Analogs: Inhibit the release of insulin, GH, and glucagon
• Hormone Supplements: They can help with LH and FSH to think fertility issues

Transphenoidal Hypophysectomy

• A surgical procedure to remove hypersecreting tumors of the pituitary gland
• An incision is made under the top lip, entering the nasal cavity through the floor of the nose
• The nasal septum is moved aside, and the sphenoid sinus is opened to access the Sella turcica and the pituitary gland

Post-Surgical Transphenoidal Hypophysectomy

• Assessments/Actions: Airway management, vital signs and neurological assessments (LOC, vision changes, pupil changes).
• Watch for meningitis
• Monitor intake and output, ensure humidified oxygen for the patient, good oral care, place HOB at 45-degree angle, instruct the patient to avoid coughing, bending over, and sneezing, encourage oral fluids if awake or IV
• Patient Education: Provide instruction on the signs and symptoms of meningitis, proper coughing, bending and sneezing techniques, brushing after 2 weeks, and the drainage from the nose or mouth

Diabetes Insipidus Pathophysiology

• Central: Lack of ADH (vasopressin) production in the hypothalamus
• Nephrogenic: The kidneys don't respond to ADH
• Epidemiology: 30% idiopathic, 25% secondary to brain tumors and 20% after intracranial brain surgery, or 16% Head Trauma

Diabetes Insipidus Assessment

• Polyuria, polydipsia, nocturia, fatigue, hypotension, hemoconcentration of blood, skin turgor (tenting) Specific gravity < 1.005
• Diagnostics: Lab tests and imaging
• Urine osmolality < 200, sodium = > 145 *HYPERnatremia, Brain/Kidney MRI/CT, and Water deprivation test

Diabetes Insipidus Nursing Care and Medications

• Nursing Care: I/O, and oral rehydration and monitor serum sodium levels if the patient is awake and alert
• Administer IV fluids if the patient is unconscious
• Central Cause Medications: Desmopressin (watch sodium closely)
• Nephrogenic Cause Medications: Thiazide diuretic, and NSAIDS

Diabetes Insipidus Complications & Patient Education

• Complications: Hypovolemic shock r/t dehydration and seizures linked to sodium imbalance
• Patient Education: Medication adherence, daily weight schedule, symptoms of fluid overload and hypernatremia

Syndrome of Inappropriate Antidiuretic Hormone (SIADH) Pathophysiology

• Excess secretion of ADH leads to reabsorption of water by the body

Syndrome of Inappropriate Antidiuretic Hormone (SIADH) Epidemiology

• CNS disorders, brain tumors, tumors in the neck, NSAIDs, psychotropic meds, and bronchogenic carcinoma (lung cancer)

Syndrome of Inappropriate Antidiuretic Hormone (SIADH) Assessment

• Assessment (Signs/Symptoms): Fluid Overload, headaches, irritability/confusion, anorexia, malaise and hyponatremia
• Diagnostics: Lab Tests and Images
• Imaging: MRI or CT scans, chest x-ray (lung cancer scan-look at other causes)
• Big Bad= <120 increased seizure risk
• Lab Tests: Urine and Blood Osmolality, Serial Sodium, and Urine Specific Gravity

Syndrome of Inappropriate Antidiuretic Hormone (SIADH) Nursing Care

• Nursing Care: -Fluid restriction and urine tests -Monitor-neurological status, and sodium.
• Monitor serum sodium levels, and administer IVs (3% NS)-hypertonic solution!
• Medications: Diuretics, loop diuretics (furosemide) and demeclocycline-increases urine production which causes a-pull of excess fluid Complications: Seizures Coma

Syndrome of Inappropriate Antidiuretic Hormone (SIADH) Patient Education

• Patient Education: Educate on the disease process and the need to restrict fluids

Adrenal Insufficiency and Hyperfunction

• Patho, assessment, diagnosis, medications & nursing assessment
• The Adrenal Cortex produces Mineralocorticoids *diamonds, Glucocorticoids *sugar, Androgens *sex Note: Not enough = Adrenal Cortical Insufficiency, Too much = Adrenal Cortex Hyperfunction

Adrenal Cortical Insufficiency Pathophysiology

• Primary (Addison's Disease) is low cortisol and High ACTH levels
• Diagnosed as Secondary, and stemming from the pituitary
• Other causes stem from infections of the adrenal glands, trauma, tumors to the kidney, AIDS
• Symptoms darkened and bronze hyperpigmentation, muscle weakness, abdominal pain, diarrhea, fatigue
• "Addison's Disease"

Addison's Disease Diagnostic Testing

Increase ACTH is linked to low levels of the body's cortisol Diagnostics: Lab and Imaging tests are performed

• Lab tests CRH, ATCH, high Cortisol.
• Low Aldosterone high Hyponatremia ,-High Hyperkalemia and check CBC levels
• Ensure brain CT/MRI scans are taken
• Look for tumor during diagnosis imaging scans

Addison's Disease Medications and Nursing Care

• Meds:
• Replacement medication for all hormones are needed
• Replace cortisol; give dexamethasone: know this!
• Replace fluids; give fludrocortisone,
• Nursing Interventions:
• Administer ensure vascular access, give cortisol as ordered, monitor electrolyte levels, telemonitoring, safety precautions and get up slowly, change positions slowly Complications: Adrenal system and hormone crisis.

Addison's Disease Pt Education

• Pt Education and Planning:

• Take hormone imbalance medications, encourage bracelets warning signs, and educate and increase risk awareness

• Increased blood sugar, irritability, insomnia, osteoporosis, -Risk of infection or steroid mania,

• DO NOT abruptly stop-risk of steroid mania: taper meds

Adrenal Crisis

• It a life threatening of very low crucial hormone, the Triggered by stress, sudden discontinuation of meds:or autoimmune process

• It diagnosed a signs and Symptoms (4H's) Acute hypovolemia & HYPOTENSION ,-Hyperkalemia & Hypoglycemia

Medication: Stabilizing the patient with medication, sugar, salt, and support

"Cushing's" or Adrenal cortical Hyperfunction

Pathophysiology-High Levels of hormones are formed from the adrenal glands

• It more often more in females, high in levels of cortisone and glucocorticoid
• Excessive and high secretion of ACTH is also formed

Diagnostics:

• Monitor PT: Assessment of fat distributions, fractures, masses, glucose, hypertension and hormones

Meds: _ Given Meds that suppress ACTH & Glucocorticoid production

• Nursing Care:
• Elevate bed, frequent check-ups: and vitals
• Complications: Check lab levels and check all levels

Pt education- watch and see if there is any change of hormones. Other Thyroid Disorders: kidney injuries, UTI"S

Study guide for NURS 202 Exam 3 (Spring 2025), covering endocrine system anatomy and physiology. Includes endocrine vs exocrine glands and neuroendocrine regulation. Dosage calculation questions may be included.