Week 2 Endocrine Anatomy and Physiology
review & Pituitary Disturbances
Ann MacLeod, MPH, BScN, RN
Agenda
 General Anatomical Overview
 Endocrine vs Exocrine
 Classes of Hormones
• proteins
• steroids
 Positive and negative feedback mechanisms
 Pituitary disturbances
Endocrine system
 Functions as chemical communication & control
 slower than the nervous system
 may target one type of cells or many
 Glands secrete hormones into the blood stream, not into a duct like the exocrine glands
Hormone secreting glands of the endocrine system
Classification of Hormones
Protein Hormones
Steroid Hormones
Feedback mechanisms
 Negative
• elevated blood levels of substance ( sugar )
• gland releases hormone (insulin)
• hormone works to decrease the levels of the substance ( sugar transferred
intracellularly with help of insulin)
• blood levels are decreased (sugar )  pancreas ceases to produce insulin
Feedback mechanisms
 Positive
• elevated blood levels of substance (oxytocin)
• gland (pituitary) releases hormone (oxytocin )
• hormone works to further increase the levels of the substance (oxytocin stimulates
the pituitary to increase more oxytocin release during labour)
Disturbances
Hypersecretion
• Tumors, genetic disorders
Hyposecretion
• Target cells damaged
• Receptors on target cells malfunctioning
• damaged gland due to age, injury, genetics
see table in handout or pg 1030 in Brunner
Hypothalmus affects Pituitary
Anterior Pituitary: Hypothalmus secretes releasing hormones for the following:
TSH
Thyroid  growth
ACTH
Adrenal cortex 
homeostasis
FSH
ovary/seminiferous  sexual dev’p
LH ovary & egs/testes estrogrogen/
testosterone fertile
GH all organs  blood glucose used for growth
(somatotropin)
Prolactin Breast tissue  milk production
Hypothalmus affects Pituitary
 Posterior Pituitary directly stimulated by neurohormones released from the
hypothalmus
ADH(vasopressin)  kidney  H2O retention/diuresis
Oxytocin  milk ducts and uterine muscle  contraction
Posterior pituitary
Pituitary Gland
Disturbances of the Anterior Pituitary : Hyposecretion Hypopituitarism
 May result from the pituitary gland itself or from a disease of the hypothalmus
however, the result is the SAME
 may occur d/t radiation to the head and neck, trauma, tumors, vascular lesions
Dwarfism
 Hypo secretion of GH, TSH, FSH, LH, ACTH
 metabolic dysfuction
 sexual immaturity
 growth retardation
 causes: tumors, congenital defects, pit. Ischemia, radiation, surg, brain injury,
chemical agents
Dwarfism
 May be perm. Or reversible, the gland may be 75% dysfunctional before you see
findings
Assessment:
 Delayed puberty
 obesity
 fine scant hair
 small bones
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Loss of libido
decreased body temp
decreased resistance to colds and infection
small stature
delayed growth according to scales
Disturbances of the Anterior Pituitary : Hypersecretion
  ACTH Cushings’s syndrome ( cover during adrenal cortex discussion)
  GH acromegaly & giantism
Assessment findings
 Excessive growth of bones and soft tissues
 enlargment of facial features, tongue, and viscera
 Skin is warm, moist, coarse and oily
Diagnostic
Tests
 Skull x-ray may show enlarged pituitary gland
 CT/MRI: shows thick long bones
 Blood work: may indicate Increased prolactin, GH, and ACTH
 urine: hypo: decreased cortisol, gonadotropin, decreased GH
Management:
 Hormone replacement therapy is nec. For hyposecretion that isn’t r/t pit. Tumours
 Hormone suppression therapy for hormone secreting tumors
 ie. Parlodel: inhibits the synthesis and release of ant. Pit. Hormones by the gland
Surgery
 Hypophysectomy: Rx. Of choice for pituitary tumors
 transphenoidal: entry is gained through the inner aspect of upper lip through the
sphenoid sinus
Post -op hypophysectomy
 Monitor LOC
 measure I+O
 assess for hemorrhage inspect nasal packing for blood and CSF
 monitor for excess swallowing (hemorrhage)
 Avoid nose blowing, HT: may lose sense of smell
 monitor for edema
 watch for addisons disease and thyroid problems
 replacement hormones are for life
Posterior Pituitary lobe hyposectretion
 Diabetes insipidus: deficient production of vasopressin, kidneys excrete large amounts
of urinedue to trauma, tumors infections or renal tubules don’t respond to ADH
Posterior Pituitary lobe hyposectretion Assessment & Management
 Urine SG 1.001-1.005 4-40 litres
 Desmopressin DDAVP synthetic vasopressin (nasal spray)
 IM Vasopressin