ENDOCRINE HISTOLOGY LAB

Examine slides of the following glands/organs and identify key structures (in bold type). As you view slides, think about the hormones released. Make rough sketches to remember the appearance of the glands. Use any available references.


Adrenal Gland

  1. connective tissue called a capsule surrounds the gland

  2. outer cortex (3 main parts):

    3. (i) zona glomerulosa - outermost cortex layer
    - dark pink
    - produces mineralocorticoids (ie. aldosterone)
    (ii) zona fasciculata - middle cortex layer
    - lighter pink
    - produces glucocorticoids (ie. cortisol)
    (iii) zona reticularis - inner cortex layer
    - dark pink
    - produces androgens (ie. testosterone)

  3. inner medulla


Pancreas

  1. exocine parts (acini ) appear dark purple (most of pancreas) which produce pancreatic enzymes

  2. endocrine parts (islets of Langerhans) appear as clusters of cells which produce insulin, glucagon, and somatostatin

Pituitary Gland

  1. also called the hypophysis and is located inferior to hypothalamus

  2. extends from a stalk called the infundibulum

  3. consists of two major lobes:

    4. (i) anterior lobe - also called the adenohypophysis
    - appears bluish/purple in colour
    - largest lobe
    (ii) posterior lobe - also called the neurohypophysis
    - continuous with stalk (infundibulum)

Thyroid Gland

  1. includes many spherical masses of cells called follicles

  2. follicle wall is a single layer of epithelial cells called principal cells which produce thyroid hormones

  3. in the middle (lumen) of the follicle is a mass of pinkish material called a colloid which is the storage form of thyroid hormones

  4. outside follicles in surrounding tissue are parafollicular cells which produce calcitonin

Pineal Gland

  1. flattened cone-shaped structure

  2. consists of many dark purple stained cells (called pinealocytes and glial cells)

  3. pineal gland produces melatonin which regulates sleep-wake cycles