Endocrine Pathology Flashcards
Describe the pituitary gland
-Small bean-shaped gland at base of brain within sella turcica
-Composed of two distinct lobes:
1. Anterior pituitary = “Adenohyphysis”
2. Posterior pituitary = “Neurohypophysis”
Describe the two lobes of the pituitary gland
- Anterior pituitary =
Adenohypophysis”
-Develops from epithelial cells derived embryologically from oral cavity (posterior pharynx) - Posterior pituitary = “Neurohypophysis”
-Develops from the floor of the diencephalon
What is the function of the pituitary gland?
Regulation of most endocrine glands via hormones (hypothalamus controls the release of hormones from pituitary gland)
List the anterior pituitary hormones
- TSH - thyroid stimulating hormone
- FSH - follicle stimulating hormone
- LH - luteinizing hormone
- GH - growth hormone
- ACTH - adrenocorticotrophic hormone
- PRL - prolactin
*produced in anterior pituitary cells –> Hypothalamic control
Describe TSH
Thyroid stimulating hormone –> thyroid gland
-stimulatory; controlled by TRH thyrotropin releasing hormone
Describe FSH
Follicle stimulating hormone –> ovaries/testes
-stimulatory; controlled by GnRH gonadotropin releasing hormone
Describe LH
Luteinizing hormone –> ovaries/testes
-stimulatory; controlled by GnRH gonadotropin releasing hormone
Describe GH
Growth hormone –> fat/muscle/bones/liver
-stimulatory; controlled by GHRH growth hormone releasing hormone
-inhibitory; controlled by GIH growth hormone inhibitory hormone
Describe ACTH
Adrenocorticotrophic hormone –> adrenal cortex
-stimulatory; controlled by CRH corticotropin releasing hormone
Describe PRL
Prolactin –> mammary glands
-inhibitory; controlled by PIF prolactin inhibitory hormone/dopamine
List the posterior pituitary hormone
- ADH
- Oxytocin
*Produced in hypothalamic neurons and stored in posterior pituitary –> hypothalamic control
Describe ADH
Anti-diuretic hormone –> kidney
-promotes resorption of water in collecting tubules of kidney
Describe Oxytocin
Oxytocin hormone –> uterus
-promotes contraction of smooth muscle in pregnant uterus
What is the most common cause of hyperpituitarism?
Functional Adenoma
What is the pathogenesis and histology of Adenomas?
Pathogenesis: G-protein mutations (most common)
Histology: Single cell type - producing single hormone
Describe Craniopharyngioma
Most common pituitary tumor of CHILDHOOD (rare)
What is the pathogenesis of Craniopharyngioma? The histology? The clinical/oral signs?
Pathogenesis: Neoplasia
Histology: resembles odontogenic tumors
Clinical/Oral:
-usually in children*
-trouble walking*
-loss of balance
-slow growth
-fatigue
-vomiting
Describe Giantism
Enormous growth in stature before bone epipyhses close
What is the pathogenesis of Giantism? The histology? The clinical/oral signs?
Pathogenesis: Functioning adenoma in CHILDHOOD
Histology:
-pituitary cell type = somatotroph
-hormone produced = increased GH
Clinical/Oral:
-short lifespan (increased cardiac output/heart failure)*
-height usually over 7ft*
-proportionally large
Describe Acromegaly
Increase in appositional bone growth and organ growth (changes occur very slowly - bony epiphyses are closed)
What is the pathogenesis of Acromegaly? The histology? The clinical/oral signs?
Pathogenesis: Functioning adenoma in ADULTHOOD
Histology:
-pituitary cell type = somatotroph
-hormone produced = increased growth hormone
Clinical/Oral:
-mandibular prognathism*
-macroglossia*
-new diastema develops*
-large hands/feet - normal height*
-patients develop hypertension and CHF
Describe Pituitary Dwarfism
Proportionate decrease in height when bony epiphyses are open
(Don’t confuse this with achondroplastic dwarfs (genetic))
What is the pathogenesis of Pituitary Dwarfism? The histology? The oral/clinical signs?
Pathogenesis: Pituitary hyposecretion of GH in CHILDREN (trauma; autoimmune; congenital; tumor)
Histology: decreased hormone produced = decreased growth hormone
Oral/Clinical:
-small teeth and jaws *
-proportionate small stature *
Describe Simmond Disease
Atrophy or decreased function of pituitary gland target organs