Endocrine Histology Flashcards
What are major endocrine glands? (5)
Pituitary, thyroid, parathyroid, adrenal, pancreas
Common features of endocrine tissues (6)
Ductless, vascular, organization (blocks/plates/cords), epithelial, polyhedral, numerous organelles
What is special about endothelium in endocrine tissue? Why is that way?
Fenestrated endothelium in endocrine tissue allows for easy diffusion of large molecules
Patterns of endocrine cells (4)
Epithelial, mesenchymal, neural, individual cells
What areas have epithelial growth pattern?
Thyroid, parathyroid, pancreas, adrenal cortex, anterior pituitary
Which epithelial endocrine tissue is not derived from ectoderm or endoderm?
Adrenal cortex is mesoderm derived
Mesenchymal Pattern Endocrine cells:
Lydia cells and ovarian storm
Granulosa/luteal cells
Neural Pattern Endocrine Cells (2): Location
Posterior pituitary
Adrenal medulla
Individual Cell Pattern: (3)
GI tract (gastrin/somatostatin producing) Throughout body Renal cortex (renin producing)
Portions of Pituitary Gland
Anterior: ectoderm of oropharynx
Posterior: neuroectoderm of floor of 3rd ventricle
Anterior Pituitary: Function and hormones secreted
Master gland: Regulates most endocrine glands
GH, prolactin, LH, FSH, TSH, ACTH
Regulation of Ant Pituitary
Hypothalamic neurons
Posterior pituitary secretions (2)
Oxytocin and ADH
Pituitary Cell Types in Pars Distalis: Acidophils (2)
Appear more pink
Somatotropes: produce GH (50%)
Lactotropes: produce PRL (10-20%)
Cell Types in Pars Distalis: Basophils (3)
Appear more purple
Corticotropes: produce ACTH (15-20%)
Gonadotropes: produce LH/FSH (10%)
Thyrotropes: produce TSH (5%)
Cell Types in Pars DIstalis: Chromophobes
Will not have color appearing; no granules
Exhausted/dying cells?
Pars Nevosa: What are pituicytes?
Unmyelinated nerve axons and supporting cells
Cell bodies lie in hypothalamus
What hormones are produced in pars nervosa?
ADH, oxytocin
What are herring bodies?
Terminal end of axons that store ADH/oxytocin
What is unique about thyroid?
Extracellular storage of thyroglobulin accumulates in follicles– this is unlike other endocrine organs
Thyroid: Function of follicular cells in thyroid?
Store thyroglobulin in follicles Secrete T3 (thyroxin), T4
Thyroid: Function of parafollicular cells (C cells)
Produce calcitonin
Found between follicles
Parathyroid glands: how many? where? function?
Usually 4
Located near thymus
Function: Regulate calcium metabolism
Histology of Parathyroid gland: Cell types (3)
Chief cells: Secrete PTH
Oxphil cells: Large/acidophilic
Adipocytes: increasing fat with age
Parts of Adrenal Gland (2)
Cortex (90%)
Medulla: neuron-like; secrete catecholamines
Adrenal Cortex Zones and Function
From out-in:
Zona Glomerulosa: minealocorticoids (aldosterone)
Zona fasciculata: glucocorticoids (cortisol)
Zona reticularis: gonadotropins (androgenic steroids)
Zona Glomerulosa (15%)
Makes aldosterone
Closely packed clusters
Zona fasciculata (80%)
Secretes glucocorticoids
Long cords separated by capillaries
Small nuclei
Lipid droplets containing steroid precursors
Zona reticularis (5-7%)
Secretes androgenizing steroids (DHEA)
Adrenal medulla cells: Types
Chromaffin cells: postsynaptic neurons without axons
Large dense core vesicles: secrete NE
Small less dense core vesicles: secrete epinephrine
Islets make up ____% of pancreatic volume
1-2
Cell types of Islets (4)
A
ß
∆
PP
