Endocrine System Flashcards
direct communication
intercellular transmission through GAP junctions, ions and small solutes
paracrine communication
intercellular transmission through extracellular fluid space, paracrine factors or mediators
neuroendocrine communication
intracellular transmission from neuronal tissue through the bloodstream to target cells, regulatory hormones
endocrine communication
intercellular transmission from endocrine tissue through the bloodstream to target cells, hormones
synaptic communication
intercellular transmission from nerve cells across synapses to target nerve cells, neurotransmitters
How do signaling peptides reach their targets?
except for direct communication, target cells must have the appropriate cell surface receptors
What are the parts of the pituitary gland?
neurohypophysis (posterior lobe, an extension of the hypothalamus) and adenohypophysis (anterior lobe)
What are the two parts of the pituitary gland separated by?
pars intermedia
What is the pituitary gland also called?
hypophysis
What is another name for the pineal gland?
epiphysis
What does the pineal gland produce?
melatonin
What is melatonin and when is it secreted?
has a role in seasonal hormonal fluctuations and it is secreted under control of the endogenous circadian clock in the hypothalamus and is secreted during the night
Where is the thyroid gland located and what animal is it palpable on?
on the trachea immediately behind the larynx and cats especially when enlarged
What are thyroid gland follicles lined with?
Follicular cells and lined with colloid surrounded by parafollicular cells
What do parafollicular cells produce?
calcitonin (regulated calcium levels)
How many parathyroid glands are there?
usually 4 (2 on each side)
What do follicular cells produce?
thyroxin converted to T4 and T3
Where is the adrenal gland?
retroperitoneal, paired and craniomedial to the kidney
What does the cortex of the adrenal gland produce?
- mineralocorticoid (aldosterone) sodium, potassium, and water balance
- glucocorticoids (cortisol) “stress hormone”
- sex steroids (androgens)
What does the medulla of the adrenal gland produce?
norepinephrine and epinephrine (adrenaline)
What are the cells in the pancreas?
islets of langerhans (islet cells)
What does the alpha cells of the pancreas create?
glucagon
What do beta cells of the pancreas create?
insulin
