Tissues producing & secreting mixtures of chemicals
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2. What are Endocrine glands?
a gland where hormones secrete into blood through capillaries.
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3. What are Exocrine glands?
glands where substances other than hormones (such as sweat and tears) secerete through a duct to the site of actication.
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4. What are hormones?
Signalling molecules secreted by endocrine glands directlly into the blood, travelling to target organs where they have an effect.
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5. What are target organs?
those with complementary receptors for the hormone.
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6. What happens when the hormone reaches its target organ?
Changes to permiability of the membrane, release of a second messenger, hormone enters.
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7. what does the Adrenal Medulla do?
Uses amino acids to produse catecholamine hormones. These are fat insolubles so they can't pass through the plasma membrane. Examples are Adrenaline & horadenaline which prepare the body for flight or fight action.
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8.What does the Adrenal Cortex do?
Uses amino acids to produce steroid hormones. these are fat solubles so they pass through the plasma membrane and affect DNA directly. e.g Glucorticoids stimulate the synthesis of glycogen in the liver.
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9. Cell signalling step 1
First messenger e.g a hormone reaches cell, travelling in the blood.
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9. Cell signalling step 2
First messenger locks into the receptor molecule
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9. Cell signalling step 3
This causes a conformational change in the receptor
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9. Cell signalling step 4
The hormone receptor complex activates G-Proteins in the membrane
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9. Cell signalling step 5
Active G-proteins activate the membarne bound enxyme, Adenyl cyclase
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9. Cell signalling step 6
Adenyl Cyclase breaks down ATP into cAMP
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9. Cell signalling step 7
cAMP now acts as a second messenger, switching on or off other enzyme cascades inside the cell.
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9. Cell signalling step 8
cAMP activates kinase enzymes whuch then begins other cascades, amplifying the inital signalling.
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10.What are the 2 funcctions of the pancreas?
Production of digestive enzyme (NaHCO3), exocrine and ducts and production of endocrine glands with no ducts.
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11. Where is insulin produced?
In beta cells, Islet of Langerhans, pancreas
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12. Where is glycagon produced?
In alpha cells, Islet of Langerhans, pancreas
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20. What is normal blood glucose concentration?
90mg of glucose per 100cm3 of blood
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Other cards in this set
Card 2
Front
2. What are Endocrine glands?
Back
a gland where hormones secrete into blood through capillaries.
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