Microanatomy Lecture 1 Flashcards
List common histological features of the endocrine glands. How are they different from the exocrine glands?
epithelial tissue, no ducts (unlike exocrine), highly vascular, hormones stored in secretory granules
Compare embryonic origin and major cell types of the the anterior and posterior pituitary
anterior: oral ectoderm consisting of epithelial tissue
posterior: neural ectoderm consisting of neurons and glia
Name hormones produced by the chromophil cells of the adenohypophysis. What are their physiologic effects?
somatotropin (GH): growth of long bones and other growth-related processes
prolactin: stimulation of milk secretion
FSH: stimulation of gametogenesis
LH: regulation of estrogen and androgen secretion - promotes ovulation
TSH (thyrotropin): stimulate thyroid secretion
ACTH: stimulation of adrenal cortical hormone secretion
Beta-liptropin: promotes utilization of fat
What hormones are secreted by the neurohypophysis? Where are these hormones synthesized?
vasopressin (ADH): increase water reabsorption in kidney
oxytocin: stimulate uterine contraction
synthesized herring bodies: eosinophilic dilation of axons
How is the activity of the anterior hypophysis regulated by the hypothalamus?
specialized blood vessels called the portal system
Name the tissue layers of the adrenal glands and hormones produced by each layer
Cortex: steroid producing cells
1. zona glomerulosa = mineralocorticoids (aldosterone)
2. zona fasciculata = glucocorticoids (mostly cortisol) and some DHEA
3. zona reticularis = cortisol and weak DHEA
Medulla: neuronal origin = catecholamines (epi &norepi)
What are the characteristic features of steroid-producing cells?
- central nucleus
- acidophilic cytoplasm with lipid droplets
- smooth ER
- spherical mitochondria with tubular cristae (for cholesterol synthesis)
Which cells in the adrenal gland react with silver salts and chromium?
cells of neuronal origin in the medulla
cells that produce catecholamines
Name cell types and corresponding hormones in the islets of Langerhans
protein secreting cells in pancreas:
alpha: glucagon
beta: insulin
delta: somatostatin
F: pancreatic polypeptide
What is the major secretory product of the thyroid follicular cells?
protein secreting cells:
Thyroid hormones T3 and T4
What is the function of the parafollicular cells of the thyroid? What is it regulated by?
produce hormone calcitonin: inhibits bone resorption and promotes calcification (opposite of PHS)
regulated by blood calcium levels
What are the physiologic effects of the hormone produced by the chief cells of the parathyroid gland?
produce parathyroid hormone - increases blood calcium level by regulating osteoclast activity, kidney excretion of calcium, vita D syntehsis, intestinal absorption of calcium
Give examples of hormones produced by the adipose tissue
leptin: regulates appetite and metabolism
adiponectin: regulates fatty acid and glucose metabolism
steroid hormones: androgens and estrogens
What are the characteristics of cells producing protein hormones?
abundant rough ER
prominent golgi
hormones are often stored in secretory granules
What are the characteristics of cells producing steroid hormones?
centrally located nucleus
lipid droplets
smooth ER (cholesterol synthesis)
spherical mitochondria with tubular or vesicular cristae
