Homeostasis (Human Anatomy & Physiology) PDF

HOMEOSTASIS Human Anatomy & Physiology LEARNING OBJECTIVES: Define homeostasis and explain its importance. Define and understand negative & positive feedback and describe its role in maintaining homeostasis and normal body function. HOW DO YOU RESPOND TO STRESS?  HOMEOSTASIS...

HOMEOSTASIS Human Anatomy & Physiology LEARNING OBJECTIVES: Define homeostasis and explain its importance. Define and understand negative & positive feedback and describe its role in maintaining homeostasis and normal body function. HOW DO YOU RESPOND TO STRESS?  HOMEOSTASIS Homeostasis is the body’s ability to maintain relatively stable internal conditions even the outside environment or world is constantly changing.  HOMEOSTASIS Homeostasis – unchanging Home – the same Stasis – standing still It indicates a dynamic state of equilibrium or balance. Internal conditions change but managed to adjust within normal limits.  HOMEOSTASIS The organ systems are responsible in maintaining equilibrium by doing their respective functions. Example: Circulatory System (blood-oxygen levels, normal heart activity, blood pressure & distribution of nutrients).  HOMEOSTASIS Communication within the body is essential for homeostasis. Nervous and Endocrine System. Electrical signals were sent then hormones were released in the bloodstream.  COMPONENTS OF HOMEOSTATIC CONTROL SYSTEM All homeostatic control mechanism have at least three components: receptor, control center and effector. 1. RECEPTOR It is a type of sensor that monitors and responds to changes in the environment. It is very sensitive to change The information flows from the receptor – control center – afferent pathway. 2. CONTROL CENTER It determines the level or set point at which a variable is to be maintained. It analyzes information it receives Determines the appropriate response or course of action. 3. EFFECTOR Provides the means for the control center’s response (output) to the stimulus. Information flows from the control center – effector – efferent pathway. 3. EFFECTOR It will reduce the amount of change (negative feedback). It will increase the amount of change (positive feedback) RECEPTOR FEEDBACK MECHANISM Most homeostatic control mechanism are negative feedback mechanism. The effect of the response to stimulus: shut off the original stimulus or reduce its intensity. FEEDBACK MECHANISM Other feedback mechanisms regulate the heart rate, blood pressure, breathing rate, release of hormones, blood glucose levels, oxygen, carbon dioxide and minerals. FEEDBACK MECHANISM Positive feedback mechanisms are rare because they tend to increase the original stimulus. Example: blood clotting & childbirth  HOMEOSTATIC IMBALANCE Homeostasis is important because most disease can be regarded as a result of its disturbance. As we age our organs becomes less efficient. Internal condition becomes less stable.  HOMEOSTATIC IMBALANCE These conditions will place us at an increasing risk for illness and produces the changes we associate with aging.  FIGHT OR FLIGHT RESPONSE "How do you typically experience and manage stress during the academic year, particularly in relation to your coursework and exams?  FIGHT OR FLIGHT RESPONSE Share specific challenges you've encountered and any strategies or resources that have helped you cope."  FIGHT OR FLIGHT RESPONSE The fight or flight response is the automatic physiologic reaction to an event that is perceived as stressful or frightening.  FIGHT OR FLIGHT RESPONSE The perception of threat – activate the sympathetic nervous system – acute stress response – prepares the body for “fight or flight”.  FIGHT OR FLIGHT RESPONSE These responses are evolutionary adaptations to increase the chances of survival.  FIGHT OR FLIGHT RESPONSE Intense or inappropriate activation of the fight or flight response is implicated in a range of clinical conditions including most anxiety disorders  WHAT HAPPENS DURING FIGHT OR FLIGHT? Sympathetic nervous system is activated to release hormones. SNS stimulates the adrenal glands – release catecholamines Adrenaline and noradrenaline  WHAT HAPPENS DURING FIGHT OR FLIGHT? Increase in heart rate, blood pressure and breathing. After the threat is gone (20-60 minutes) for the body to recover and return in its pre-arousal state. WE EXPERIENCE FIGHT OR FLIGHT DURING: Imminent physical danger Psychological threat Preparing to give a big presentation at school or work. PHYSICAL SIGNS: FIGHT OR FLIGHT Dilated pupils (allows more light for better vision) Pale or flushed skin (blood rushes to the brain and head) Clotting ability increases to prevent injury. PHYSICAL SIGNS: FIGHT OR FLIGHT Rapid heart rate (to increase oxygen supply to fuel a rapid response to danger) Trembling (tense muscles) WHY IS IT IMPORTANT TO UNDERSTAND FIGHT OR FLIGHT? It plays a critical role on how we deal with stress and danger in the environment. By priming your body for action, you are better prepared to perform under pressure. The stress created by the situation can be helpful, making it more likely that you will cope up effectively with threat. “The greatest weapon against stress is our ability to choose one thought over another”. WILLIAM JAMES