B5 Homeostasis & Response Flashcards
<p>What is <b>Homeostasis</b>?</p>
<p style="text-align: center;">Homeostasis is the regulation of the internal conditions of a cell or organism to maintain optimum conditions for function in response to internal and external changes.</p>
<p>What three internal factors are controlled by Homeostasis in the human body?</p>
<ul><li>Body Temperature</li><li>Blood Glucose Concentration</li><li>Water content in blood and cells</li></ul>
<p>Why does homeostasis maintain optimum conditions?</p>
<p>Homeostasis maintains optimum conditions for:</p>
<ul><li>Enzyme Action</li><li>Cell Structure</li><li>Chemical Reactions</li> so the can function in optimum conditions</ul>
<p>What are the two types of responses that are used to control conditions in the human body?</p>
<ul><li>The Nervous System</li><li>The Endocrine System (Hormones)</li></ul>
<p>What is the order of how the human nervous system works?</p>
<p>Stimulus→Receptor→Sensory Neurone→Relay Neurone→Coordination Centre→Motor Neurone→Effector→Response</p>
<p>What is a <b>receptor cell</b>?</p>
<p>A receptor cell is a cell that detects stimuli (changes in the internal or external environment)</p>
<p>What is the purpose of a <b>coordination centre</b>?</p>
<p>Coordination centres receive and process information from receptor cells and then send out signals to coordinate the response of the body</p>
<p>Name the three coordination centres in the human body?</p>
<ul><li>Brain</li><li>Spinal Cord</li>Pancreas</ul>
<p>Name the two types of effectors?</p>
<ul><li>Muscles</li><li>Glands</li></ul>
<p>What do effectors do to bring about a response?</p>
<ul><li>Muscles will contract</li><li>Glands secrete enzymes/hormones</li></ul>
<p>What is a <b>Negative Feedback loop</b>?</p>
<p>A continuous cycle of events that responds when conditions change away from the optimum point and causes it to return conditions back to this optimum point</p>
<p>What is the role of the Human Nervous System?</p>
<p>The Human Nervous System enables humans to react to their surroundings and coordinate their behaviour</p>
<p>What are the two organs in the <b>Central Nervous System</b>?</p>
<ul><li>Brain</li><li>Spinal Cord</li></ul>
<p>What is the purpose of the <b>Peripheral Nervous System</b>?</p>
<p>The Peripheral Nervous System carries information to and from the CNS</p>
<p>What are the three types of neurons?</p>
<ul><li>Sensory (Receptor Cells→CNS)</li><li>Relay (CNS→CNS)</li><li>Motor (CNS→Effector [Muscle or Gland])</li></ul>
<p>What is a <b>synapse</b>?</p>
<p>A synapse is a gap between two neurons</p>
<p>What is the <b>Endocrine</b> system?</p>
<p>The endocrine system is the collection of glands that produce hormones that regulate internal conditions</p>
<p>Name the hormone that controls the 'flight or fight' reaction in humans</p>
<p>Adrenaline</p>
<p>Where is <b>adrenaline</b> produced?</p>
<p>Adrenal Gland</p>
<p>What are the effects of adrenaline on the body?</p>
<ul><li>Increases heart rate<ul><li>This increases the delivery of oxygen and glucose to the brains and muscle</li></ul></li></ul>
<p>Where is <b>Thyroxine</b> made?</p>
<p>Thyroid Gland</p>
<p>What does Thyroxine do to the body?</p>
<p>Thyroxine increases the basal metabolic rate which increases growth and development?</p>
<p>What is <b>Negative Feedback</b>?</p>
<p>Negative feedback is a mechanism used by the body to bring its internal environment back to normal when the level of something gets too high or too low</p>
<p>How is Thyroxine controlled?</p>
<p>Thyroxine is controlled by Negative Feedback</p>
<ul><li>The <b>hypothalamus</b> monitors the concentration of Thyroxine in the blood</li><li>If levels of Thyroxine are too low, the hypothalamus produces <b>thyroid releasing hormone (TRH)</b></li><li>TRH stimulates the <b>pituitary gland</b> to produce <b>thyroid stimulating hormone (TSH)</b></li><li>TSH stiulates the <b>thyroid gland</b> to produce thyroxine</li><li>When thyroxine levels return back to normal, TRH is no longer released - causing the production of TSH to stop</li></ul>
=<p style="text-align: center;">What internal conditions are controlled by negative feedback?</p>
<ul>Thyroxine levels<li>Temperature</li><li>Water levels</li><li>Blood sugar levels</li></ul>
<p>How are hormones transported around the body?</p>
<p>Via the bloodstream</p>
<p>What is monitored for changes in glucose concentration?</p>
<p>The blood</p>
<p>What controls the response to changes in blood glucose concentration?</p>
<p>The Pancreas</p>
<p>What hormone is produced if blood glucose concentration is too high?</p>
<p>Insulin</p>
<p>How does insulin help lower blood glucose concentration?</p>
<p>Insulin causes glucose to move from the blood to the cells and triggers the conversion of glucose into glycogen</p>