Term
| What is an 'endocrine' hormone? |
|
Definition
-produced & secreted within the body
-acts at a distance from where it is released |
|
|
Term
| Where does a paracrine hormone act? |
|
Definition
|
|
Term
| Where does an autocrine hormone act? |
|
Definition
| on its own secreting cell |
|
|
Term
| What is a neuroendocrine hormone? |
|
Definition
| hormone synthesized by nervous tissue & carried in the blood |
|
|
Term
|
Definition
cluster of cells organized for synthesis/release of compound
-can be endocrine or exocrine |
|
|
Term
| How are hormones regulated? |
|
Definition
| feedback systems from their target glands |
|
|
Term
|
Definition
| chemicals produced in an endocrine gland/scattered cells, secreted into blood & carried to a target cell where it alters its metabolism |
|
|
Term
| What are the 4 structural classifications of hormones? |
|
Definition
Steroid
Peptides, proteins & glycoproteins
Amino-acid derivatives
Fatty acid derivatives / eicosanoids |
|
|
Term
| What are the characteristics of steroid hormones? |
|
Definition
-various isoforms of cholesterol
-lipid soluble, enter target cells by diffusing through mmb |
|
|
Term
| What are the characteristics of peptides, proteins & glycoproteins? |
|
Definition
-sequence of AA chains which determines structure & function
-post translational modification e.g. glycosylation & phosphorylation, then packaged and secreted by exocytosis |
|
|
Term
| What is glycosylation? Phosphorylation? |
|
Definition
adding carbohydrate chains to a peptide
adding phosphate groups to a peptide |
|
|
Term
| Thyroid hormones & catecholamines are examples of _______ generally derived from ____ and _____ |
|
Definition
Amino-acid derivatives
tyrosine
tryptophan |
|
|
Term
| What are prostaglandins derived from? What is their typical effect? |
|
Definition
derived from call membrane phospholipids e.g. arachidonic acid
have autocrine & paracrine effects |
|
|
Term
| Name 2 examples of fatty acid derivatives / eucisanoids |
|
Definition
Prostaglandins (PGE2 & PGF2a)
Prostacyclins (PGI2)
Thromboxanes (TXA2) |
|
|
Term
Where is the pineal gland found?
How is it innervated?
What does it secrete? |
|
Definition
Found: on roof of 3rd ventricule, encapsulated by meninges
Innverated by sympathetic neurons
Secretes melatonin |
|
|
Term
| What influences the pineal gland? What is its major role? |
|
Definition
-directly influenced by hypothalamic circadian center
-major role during sleep patterns & recognition of seasons |
|
|
Term
| When is melatonin secretion stimulated? |
|
Definition
|
|
Term
What hormones act on the GI tract? (4)
What organ secretes them? On which organ do they act? |
|
Definition
Gastrin - secreted by stomach wall - stimulates acid secretion in stomach
Secretin - secreted by SI - stimulates pancreas
Cholecystokinin - secreted by SI - acts on pancreas & gall bladder
Gastric inhibitory peptide - secreted by SI - inhibits stomach activity |
|
|
Term
| What hormones are secreted by the kidneys? (2) What effect do they have? |
|
Definition
Renin - increases aldosterone production by adrenal cortex
Erythropoietin - increases RBC production in bone marrow |
|
|
Term
| What hormones are secreted by adipose tissue? Where are their receptors found? What is their function? |
|
Definition
-adipocytes release leptins
-receptors in hypothalamus
-give info about energy storage status
-regulates appetite |
|
|
