Metabolism and Elimination

• Endocrine System


  Interconnected network of glands that links with the nervous system and the immune system
• Hormones

  Work with Negative Feedback System
• History and Clinical Manifestations

  • Specific vs. General
  • Changes in energy level and fatigue
  • Changes in heat and cold tolerance
  • Recent changes in weight
  • Changes in sexual function and secondary sex characteristics
• Early Puberty Indication (Female)

  • Breasts Changes (breasts develop, hips widen, and pubic hair begins to grow)
• Early Puberty Indication (Male)

  • Testicular Changes (growth of pubic hair, facial hair and the voice deepens)
• Stop Height


  Peak of Puberty
• Growth Spurts

  • 1st Growth Spurt = Infancy
  • 2nd Growth Spurt = Puberty
• Physical Assessment Observations

  • Exophthalmos
  • Appearance of facial hair in women
  • "Moon face"
  • "Buffalo hump"
  • Thinning of the skin
  • Obesity of the trunk and thinness of the extremities
  • Increased size of the feet and hand
• Diagnostic Evaluation

  • Blood tests (measures the levels of hormone)
  • Urine tests
  • Stimulation and suppression tests (determine the cause)
• Adenoma

  Technically benign tumours; secretes too much hormones

  
• Pheochromocytoma

  Secretes too much epinephrine and norepinephrine; Symptoms: hypertension
• Pituitary Gland


  Master gland that secretes hormones that control the secretion of hormones

  
• Pituitary Gland


  Controlled by the hypothalamus

  
• Pituitary Gland Divisions


  • Anterior (aka Adena Hypophysis)
  • Intermediate
  • Posterior (aka NeuroHypophysis)

  
• Anterior Pituitary


  Releasing (or inhibiting) factors are secreted into the special portal system from the hypothalamus to control the release of hormones

  
• Posterior Pituitary


  Special nerve cells, whose cell bodies are located in the hypothalamus, produce and store hormones, then released from the cell's axon terminal into the circulation
• Hormones Secreted by the Anterior Pituitary

  • Prolactin
  • Thyroid stimulating hormone (TSH)
  • Adrenocorticotropic hormone (ACTH)
  • Luteinizing hormone (LH)
  • Follicle stimulating hormone (FSH)
  • Growth hormone (GH)
• Hormones Produced in the Hypothalamus and Released by the Posterior Pituitary


  • Antidiuretic hormone
  • Oxytocin
• Primary Cushing Syndrome

  Usually the problem is the BRAIN
• Secondary Cushing Syndrome

  Usually the problem is the ADRENAL GLAND
• Hormones Secreted by the Anterior Pituitary

  • FSH (graafian follicle growth and oestrogen secretion, Spermatogenesis)
  • LH (induces ovulation and development of corpeus luteum, stimulates testosterone secretion)
  • ACTH (stimulates secretion of hormone from the adrenal cortex)
  • TSH (regulates the secretory activity of thyroid gland)
  • GH (stimulates growth of cells, bones, muscle, soft tissue, insulin antagonist)
• Vasopressin/ADH

  Helps body retain water, only affects water
• Oxytocin

  Stimulates uterine contraction during labor and milk secretion
• Pituitary Disorders


  • Gigantism And Acromegaly (too much GH)
  • Dwarfism (less GH)
  • Secondary Cushing's (too much ACTH)
  • Addison's disease (less ACTH)
  • Hyper VS Hypothyroidism (too much/less TSH)
  • Precocious Puberty VS No Secondary Sexual Characteristics (too much/less FSH and LH)
  • SIADH VS Diabetes Insipidus (too much/less ADH)
• Hyperpituitarism


  Chronic disease marked by excess GH and tissue overgrowth
• Forms of Hyperpituitarism


  • Gigantism (excess GH before puberty, rapid skeletal growth)
  • Acromegaly (excess GH after puberty, slow soft tissue growth)
• Acromegaly


  • Local expansion of adenoma causes both neurologic (increased ICP, HA, visual changes) and secretory effects (endocrine)
  • Optic and trigeminal nerve involvement causes visual disturbances
  • Skeletal growth is not possible so the soft tissues are influenced by the excess GH
  • Facial Features: Prognathism (prominent jaw), big foots
• Cause of Hyperpituitarism

  Anterior pituitary adenoma
• Interventions for Hyperpituitarism


  • Counselling re changed body image visual disturbances
  • Somatostatin (Octreotide) (GH analogue that suppresses GH production)
  • Bromocriptine (Parolodel) (Dopamine agonist that inhibit GH synthesis and suppress hormone secretion)
  • Tumor removal by cranial or transsphenoidal hypophysectomy
  • Pituitary radiation therapy
• Hypophysectomy


  Transphenoidal, subfrontal or cranial procedure to remove pituitary tumor
• Considerations for Hypophysectomy


  • Do not brush teeth, sneeze, cough, blow the nose or bend forward after surgery
  • Monitor for CSF leakage
  • Provide mouth care
• Hypopituitarism


  Deficient secretion of anterior pituitary hormones, marked by dwarfism, metabolic dysfunction, sexual immaturity and growth retardation

  
• Causes of Hypopituitarism

  • Tumors
  • Congenital defects
  • Head injury
  • Radiation therapy to the head and neck area

  
• Sheehan's syndrome


  Postpartum pituitary necrosis
• Gland must be 75% dysfunctional for hypopituitarism
• Pituitary gland under secretes hormones


  Then all target organs affected

  
• Management of Hypopituitarism

  • Treat and replace hormones as necessary (cortisol, thyroxine, estrogen, androgens)
• Dwarfism should be detected early before puberty
• Tanner Staging

  Helps nurses determine if a patient is normally growing
• Diabetes Insipidus


  Permanent or transient disorder characterised by deficiency in ADH/vasopressin, resulting in large volume excretion of dilute urine & polydipsia