Endocrine System Flashcards
What are the differences between exo-, endo-, auto-, neuro-, para- crine secretion?
Endocrine: secreted molecules diffuse into the blood- stream and trigger responses in target cells anywhere in the body. Autocrine: secreted molecules diffuse locally and trigger a response in the cells that secrete them. Neurocrine: neurohormones diffuse into the bloodstream and trigger responses in target cells anywhere in the body.
Paracrine: secreted molecules diffuse locally and trigger a response in neighboring cells. Exocrine:
What are hormones and pheromones?
Hormones are chemicals produced by glands and used by the endocrine system to signal distant target cells. Hormones secreted by endocrine cells regulate reproduction, development, energy metabolism, growth, and behaviour. Pheromones are environmental signals that act at a distance between individual organisms.
What are the two basic types of hormones? Peptide (protein based) vs steroid (lipid based).
Peptide hormone binds to receptor protein; relay system leads to conversion of ATP to cyclic AMP. Cyclic AMP (cAMP) is made from ATP; it has one phosphate group attached to adenosine at two locations. Peptide hormones are the first messenger; cAMP and calcium are often the second messenger. cAMP sets an enzyme cascade in motion. Activated enzymes can be used repeatedly, resulting in a thousand-fold response. Steroid hormones are smaller and have the ability to cross cell membranes. Steroid hormones are lipids. Inside a nucleus, hormones such as estrogen and progesterone bind to a specific receptor. Hormone-receptor complex binds to DNA resulting in activation of genes that produce enzymes.
What are tropic vs non-tropic hormones?
Tropic hormones regulate the function of other endocrine cells or glands.
What other organs (besides glands) secrete hormones? Give an example.
The Heart secretes A-type Natriuretic Peptide (ANP) and B-type Natriuretic Peptide (BNP) they both help in lowering blood pressure by relaxing arterioles, inhibiting the secretion of renin and aldosterone and inhibiting the reabsorption of sodium ions by the kidneys.
Be able to make connections between DNA regulation and hormones – that is, once a hormone is joined with a receptor (either on the cell membrane or in the cytoplasm) how does it influence the DNA to perhaps make a product such as a protein?
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