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23 Cards in this Set
- Front
- Back
- 3rd side (hint)
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What are hormones |
- Chemical substances which are produced in minute quantities by endocrine glands - Transported by blood to target organs - Responsible for the growth, development and activity of organism - Destroyed in the liver and excreted via the kidneys |
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Why is production of hormones carefully controlled? |
- Too little or too much hormones produced can adversely affect an organisms - Too little thyroxine = inhibit growth of tadpole into adult frog - Too much thyroxine = tadpole becomes to have an adult form too quickly = result to tiny frog |
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How is hormone production controlled? |
- The nervous system ☆ e.g. adrenal gland - certain chemical substances (Hormones from other endocrine glands) |
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Where are hormones produced? |
- Endocrine glands ☆ released them directly into blood ☆ have an extensive network of blood vessels to transport hormone to their target organs |
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Endocrine glands |
- Ductless glands - Transports secretions to the target organs via bloodstream -Examples ☆ adrenal gland ☆ pituitary gland ☆ pancreas (islets of langerhaans) |
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Exocrine glands |
- Have ducts which helps secretions to be transported to their target organs - Examples ☆ Sweat glands (sweat duct) ☆ Salivary glands (salivary duct) ☆ Pancreas (duct btw small intestine and pancreas) (specifically enzymes) |
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Pituitary glands |
- Controls functions of several other endocrine glands - Secretes ☆ Growth hormone ☆ Anti-Diuretic Hormone ☆ Thyroid Stimulating Hormone - Some hormones control other endocrine glands (ADH) - Secretions of some of its hormones is controlled by the hypothalamus |
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Thyroid gland |
- Stimulated by thyroid-stimulating hormone produced by pituitary gland - Secretes thyroxin ☆ Controls metabolism rate ☆ Influences physical development - exerts short and long term effects in the body |
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Adrenal gland |
- Situated on top of the kidneys - Adrenaline released when stimulated by nervous system |
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Pancreas |
- Both a endocrine and exocrine gland - Exocrine ☆ Secretes pancretic juice via the pancreatic ducts - Endocrine ☆ Islet of Langerhaans secrete insulin and glucagon to control blood glucose levels |
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Gonads ☆☆ |
Ovaries - Secretes oestrogen ☆ controls development of breasts ☆ controls widening of hips - Secretes progesterone ☆ maintain a healthy pregnancy Testes - Secretes testosterone ☆ causes deepening of voice and growth of facial hair |
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Is hypothalamus an endocrine gland? |
Yup! |
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Effects of insulin hormone |
- Decreases blood glucose concentration - Increase rate of uptake of glucose by cells by increasing the permeability of cell membrane to glucose - Stimulates liver to convert glucose to glycogen which is to be stored in the liver or the muscles - Increase oxidation of glucose during respiration |
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Over secretion of insulin results to what? |
- Lead to abnormally low blood glucose concentration - Symptoms ☆ Hunger ☆ Rapid heartbeat ☆ Irritability - Serious cases can cause coma or even death |
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Insufficient secretion of insulin results to what? |
- Abnormally high blood glucose concentration - Tissue cells unable to utilise and store glucose - Symptoms ☆ weak body ☆ continuous weight loss ☆ glucose present in urine - Can lead to a development of a disease called diabetes mellitus |
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What is diabetes mellitus? |
- Insufficient secretion of insulin to control blood glucose concentration - Lead to persistently high levels of glucose in blood - Kidneys cannot completely reabsorb kidney in the body - Causes glucose to be excreted in urine |
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What are the signs of diabetes mellitus? |
- Slow and difficult healing of wounds - Constant high blood glucose concentration - Glucose in urine after meal |
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Types of diabetes |
Type I - Early onset diabetes - Insufficient or no insulin secreted/produced - Solution ☆ Treatment by insulin injection Tyle II - Late onset diabetes - Insulin present but target cells does not respond to it well - Solution ☆ Treatment by control dietary intake and exercising regularly |
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What are the effects of glucagon? |
- Increases blood glucose concentration ☆ Convert glycogen to glucose ☆ Fats and amino acids to glucose ☆ Lactic acid to glucose - Effects occurs in liver |
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What are the effects of adrenaline? |
- Secreted in response to stress or excitement - Enables the body the respond quickly to sudden demands of energy - Effects only short-lived |
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Nervous pathway for adrenaline to take effect |
- Hypothalamus stimulated - Nerve impulses produced - Transmitted from brain to the spinal cord via the sensory neurones - Sensory neurone -> Relay neurone -> Motor neurone -> Effector (Adrenal gland) - Adrenal gland stimulated by nervous system to secrete adrenaline - Released to blood and to target organs - Target organs effect over adrenaline is short lived |
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8 effects of adrenaline |
(PRESSURE) Raises blood pressure and rate of heartbeat (VENTILATION) Increase in rate and depth of ventilation (METABOLIC RATE) Increased (BLOOD GLUCOSE LEVEL) Increased (HAIR MUSCLES) Contracts and forms goose pumples (CONSTRICTS) Arterioles of skin (BLOOD COAGULATION) Rate increases (DILATE) Pupils |
Many People Vote Many Helpful Candidates with inCredible Decisions |
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Differences between endocrine and nervous control |
☆☆☆Endo☆☆☆☆☆Nervous☆☆☆ - Involves hormones, Involves neurones - Chemical Transmission, Electrical + Chemical Transmission - Hormones are transmitted by blood, Nerve impulses are transmitted by neurones - Slow transmission + acting, Rapid transmission and response - Short term and Long term, Short term - Involuntary, Involuntary or Voluntary - Widespread effects, Localised effects |
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