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39 Cards in this Set
- Front
- Back
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What is the function of an endocrine gland? |
To secrete hormones directly into the blood. |
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What is the function of an exocrine gland? |
To secrete enzymes into a duct. |
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What is a first messenger? |
A hormone that carries a chemical message from endocrine gland to target cell. |
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What is a second messenger? |
A signalling molecule that carries the chemical message from receptor to other parts of target cell. |
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What is glucagon? |
A hormone that raises blood glucose conc. (by stimulating glycogenolysis). |
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What is insulin? |
A hormone that lowers blood glucose conc. (by stimulating glycogenesis). |
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What is glycogenolysis? |
The breaking down of glycogen into glucose. |
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What is the process of gluconeogenesis? |
The production of glucose from non-carbohydrate sources, e.g. amino acids and glycerol. |
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What is the process of glycogenesis? |
The production of glycogen from glucose. |
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What part of the adrenal gland is the medulla and what does it secrete? |
Inner part, secretes non steroid hormones (e.g. adrenaline and noradrenaline). |
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What part of the adrenal gland is the cortex and what does it secrete? |
Outer part, secretes steroid hormones (e.g. cortisol and aldosterone). |
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What is the first messenger in adrenaline action? |
Adrenaline. |
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What is the second messenger in adrenaline action? |
Cyclic AMP (cAMP). |
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What enzyme catalyses the production of the second messenger in adrenaline action? |
Adenylyl cyclase. |
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What is the outcome of adrenaline action? |
More glucose is made available through glycogenolysis. |
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What is the area in the pancreas that contains endocrine tissue called? |
Islets of Langerhans. |
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What do α cells secrete? |
Glucagon. |
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What do β cells secrete? |
Insulin. |
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What is the normal blood glucose concentration in humans? |
90mg100cm-3. |
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What is the role of ATP in insulin secretion? |
Glucose is metabolised into ATP in mitochondria, ATP binds to K channels causing them to close leading to depolarisation. |
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What is the role of calcium ions in insulin secretion? |
Depolarisation causes calcium channels to open, calcium ions enter cell causing vesicles to release insulin by exocytosis. |
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Describe a possible cause of type 1 diabetes. |
The body is unable to produce insulin because beta cells are attacked by immune system. |
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Name three ways of treating type 1 diabetes. |
Insulin injections, islet cell transplantation, monitoring of diet and exercise. |
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Name three factors that increase risk of type 2 diabetes. |
Frequent intake of carbs, lack of exercise, obesity, high blood pressure, family history. |
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Name the two main ways of controlling type 2 diabetes. |
Lifestyle changes: balanced diet, regular exercise, losing weight. Medication: e.g. metformin. |
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What makes up the CNS? |
Brain and spinal cord. |
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What makes up the peripheral nervous system? |
Neurones that connect CNS to rest of body. |
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Describe the function of the Somatic nervous system. |
Controls conscious activities. |
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Describe the function of the autonomic nervous system. |
Controls unconscious activities. |
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Describe the function of the sympathetic nervous system. |
‘Fight or flight' system (neurones release neurotransmitter noradrenaline). |
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Describe the function of the parasympathetic nervous system. |
Calms body down, ‘rest and digest’ system, releases ACh. |
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What is the role of the hormone ACTH in the fight or flight response? |
Released by pituitary gland, causes cortex of adrenal glands to release steroid hormones. |
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What triggers the release of adrenaline from medulla of adrenal gland? |
Activation of sympathetic nervous system. |
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Name three effects of the fight or flight response. |
Increased heart rate, relaxation of muscles around bronchioles (deeper breathing), glycogenolysis (glycogen => glucose), constriction of muscles in arterioles supplying skin and gut, erector pili muscles in skin contract. |
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What part of the brain controls heart rate? |
Medulla. |
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What are baroreceptors stimulated by? |
Changes in blood pressure. |
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What are chemoreceptors stimulated by? |
Changes in O2 levels. pH and CO2 are indicators of this. |
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Which pathway from the medulla decreases heart rate? |
Medulla => vagus nerve. Vagus nerve secretes ACh which binds to receptors on SAN. |
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Which pathway from the medulla increases heart rate? |
Medulla => accelerator nerve. Accelerator nerve secretes noradrenaline which binds to receptors on SAN. |
