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21 Cards in this Set
- Front
- Back
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Define Endocrine? |
Ductless glands which secrete hormones or other products directly into the blood. |
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Define Exocrine? |
Glands which secrete their products through ducts opening on to an epithelium rather than directly into the blood. Their secretions are carried to a particular site. |
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What are the different Endocrine glands? |
- Pineal gland (in brain) - Hypothalamus (brain) - Pituitary gland (brain) - Thyroid gland (neck) - Parathyroid gland (on dorsal aspect of thyroid gland) - Thymus (under upper sternum) - Anrenal glands (on kidneys) - Pancreas (between kidneys) - Gonads (Ovarys and testies) |
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Differences between Exocrine and Endocrine glands? |
Exocrine glands - Ducts, nemerous, mucous, sweat, oit, saliva, bile duct in the liver. . Endocrine glands - Ductless, produce hormones, secreted directly into extracellular space, pituitary/thymus, thyroid/parathyroid, adrenal/pineal. |
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What are some organs that can be both endocrine and exocrine? |
pancreas, testies and ovaries, hypothalamus |
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What are hormones? |
Chenical messengers released to the blood to be transported throughout the body so to influence metabolic activitie of the cells. . Steroidal or amino acid-based molecules released to the blood that act as chemical messengers to regulate specific body function. |
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What are the two different types of hormones? |
1) Steriods - corticosteriods, sex hormones: androgen and oestrogen. 2) Amino Acid based/proteins - form structural material and regulators of function. |
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What are the different changes that hormones make? |
1) changes in plasma membrane permiability and/or electrical state (membrane potential by opening and closing ion channels) 2) Synthesis of proteins or certian regulatory molecules such as enzymes within the cell. 3) Enzyme activation or deactivation 4) Induction of secretory activity 5) Stimulation of mitosis (cell devision) |
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How to simply put Hormones.. |
They are ways of sening messages around the body, they travel everywhere within the body but only affects specific tissue cells. These are call TARGET CELLS and RECEPTORS - either on the plasma membrane or within the cell so that hormone can bind. |
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What three components do the homeostasis and endocrine system require when responding to variables? |
1) Receptor 2) Control centre 3) Effector |
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What is the receptor? |
Monitors variables such as temp, BSL. Responds to stimuli. Imput - sends information Occurs along the Afferent pathway. |
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What is the control centre? |
It interprets the information sent by the receptor. It provides information as to the desired levels (thermostat for central heating or A/C, our thermostat is housed in the hypothalamus. In turn it relays the information to the Effectos... |
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What is the effector? |
This component; is the means for the control centres response to stimulus (change in variable) -out put - occurs along the efferent pathway |
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Explain the two feed back mechanisms. |
Negative feedback (most common homeostatic control mechanism) - either chuts off or reduces the intensity of the original change. . Positive feedback (less common and harder for the body to control) - childbirth (more specifically contratctions during labor - triggers oxytocin release which increases force of contractions) and the clotting cascade (platelets attract more platelets which then develops into a clot) |
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What does the increase of BSL stimulate? |
It stimulates the release of INSULIN by the pancreas (Beta cells, islets of langerhans) into the blood. Insulin hastenbs blood glucose take up by the cells. Insulin facilitates (glycogenesis) storage of excess glucose in the blood by turnin gflucose into glycogen so that it ma be stored in the liver. Once blood glucose evels return to normal insulin is no longer required, its job is done, therefore the stimulus diminishes. |
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What does a decrease in BSL stimulate? |
Stimulates the release of glycagon by the pancreas (alpha cells, lslets of landerhans) into the blood. Glucagon causes the liver to release its storage of glycogen as glucose (glycogenolysis) back into the blood stream. |
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What does the hypothalamus and the pituitary gland do? |
Antidiuretic hormone (ADH - reabsorbe fluid from the kidneys) - aviods dehydration or water overload by targeting kidney tubules. - made by hypothalamic neirons and stored in posterior pituitary gland. - Stimulated by - increased osmolarity of the blood, decrease blood vol, pain and nicotine/morphine/barbiturates. - Its inhibited by - adequate hypration of the body and ETOH. |
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What does the thyroid gland do? |
Affects basal metabolic rate (BMR) Affects oxygen consumption Enhances effects of the sympathetic nervous system Promotes the breakdown of glycose to be stored as glycogen in the liver. Promotes normal functioning of the heart Promotes normal growth and maturation of the skeleton. Encourages gastric motility and tone, and increases secretion of digestive juices. Promotes aspects of the reproductive and integumentary (skin system) |
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What does the adrenal glands/suprarenal do? |
- Kidneys - stimulated by renin angiotensin mechanism: Dencreased blood vol or BP. Water reabsorption accompanies Na+ - blood vol/bp increases. - body cells - promotes glyconrogenesis, energy metabolism and protein catabolism. - Sympathetic nervous system - increase heart rate, increase metabolic rete and causes vasoconstriction .... Increases bp. |
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What do the suprarenal glands do? |
- Exocrine glands located on the top of each kidney. - each has a mudulla (centre) and is surrounded by a cortex. - Mudella produces adrenaline and noradrenaline. - Cortex produces other hormaoes necessary for fluid and electorlyte blance such as cortisole (stress hormones) (hydrocortisone) and aldosterone - adrenal cortex also produces sex hormones. |
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What does the pancreas do? |
- Mixture of endocrine and exocrine gland cells. - Pancreatic islets: islets of langerhans - Alpha and beta cells. Alpha cells - secrete glucagon - glycogenolysis and gluconeogenosis. Beta cells - secrete insulin - increase glucose transport into the cells, increase liver glycogen levels and decrease the blood glycose concentration toward normal. |
