Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Meghan Stewart
Physiology 221-08 Set 1 week 1 chapter 2 Homeostasis Spring 2025
| Question | Answer |
|---|---|
| Define Homeostasis | refers to stability, balance, or equilibrium within a cell or the body. It is an organism’s ability to keep a constant internal environment. |
| Define Pathology | The study of disease |
| Virus | intracellular parasites made of a DNA or RNA core wrapped in a protein coat and a lipoprotein envelope. invade human cells making them produce viral components. |
| Bacteria | are tiny, primitive cells that lack nuclei. They cause infection by parasitizing tissues or otherwise disrupting normal function. |
| Fungi | simple organisms similar to plants but lack the chlorophyll pigments that allow plants to make their own food. Because they cannot make their own food, fungi must parasitize other tissues. |
| Protozoa | are protists, one-celled organisms larger than bacteria whose DNA is organized into a nucleus. Many types of protozoa parasitize human tissues. |
| Pathogenic Animals | are large, multicellular organisms such as insects and worms. Such animals can parasitize human tissues, bite or sting, or otherwise disrupt normal body function. |
| Tumors and Cancer | Abnormal tissue growths, or neoplasms, can cause various physiological distur-bances, |
| Malnutrition | Insufficient or imbalanced intake of nutrients causes various diseases; |
| Autoimmunity | literally “self-immunity”. Some diseases result from the immune system attacking one’s own body (auto-immunity) or from other mistakes or overreactions of the immune response. |
| Inflammation | a normal mech that usually speeds recovery from an infection or injury. when the inflammatory response occurs at inappropriate times/is abnormally prolonged/severe, normal tissues may become damaged. Some disease sx are caused by the infl. resp. |
| Degeneration | tissues sometimes break apart or degenerate. Although a normal consequence of aging, degeneration of one or more tissues resulting from disease can occur at any time. |
| The fishbowl model of homeostasis | the body is the bowl of fluid that must be kept constant, the cells of the body are like fish, and the organ systems are like the accessories used to maintain stability |
| The Walled model of homeostasis | The body is compared with a circus high walker. |
| The Heating system model of homeostasis | the body is like a home with a thermostat acting as a control |
| Feedback loops | Comm. networks for maintaining/restoring homeostasis by self-regulation through feedback. Afferent comm. goes toward a control center or other point of reference. Efferent comm. goes away from a control center or other point of reference |
| Sensor Mechanism portion (control mechanism) | specific sensors detect and react to any changes from normal in a physiological variable |
| Integrating, or Control Center (control mechanism) | information is analyzed and integrated, and then, if needed, a specific action is initiated |
| Effector Mechanism (control Mechanism) | effectors directly influence controlled physiological variables |
| Feedback (control mechanism) | process of information about a variable constantly flowing back from the sensor to the integrator |
| Negative feedback in control systems | Are inhibitory; they negate changes in a variable. Produce an action that is opposite to the change that activated the system. Resp for maint. homeostasis, more common than +feedback, described interns of stimulus &response. Ex Shivering. |
| Positive feedback in control systems | Are stimulatory a. Amplify or reinforce the change that is occurring b. Tend to produce destabilizing effects and disrupt homeostasis |
| Positive feedback in control systems | Can sometimes bring specific body functions to swift completion; exam-ples include: a. Increased labor contractions in response to stretch of the birth canal b. Blood clotting |
| Positive feedback in control systems | Can result from damage, which may cause negative feedback loops to operate improperly |
| Changing the set point | 1 Like the set point on a thermostat, physiological set points can change 2. Not all indiv. have the same set points, so “normal” is a range of diff values among humans 3. Fever is an ex. of the body changing a set point temporarily to fight infection |
| Changing the set point | 4. There are circadian (daily) patterns of changes in set points—for example, nightly increase in blood melatonin levels 5. Lower than normal variability of functions, such as heart rate, may indi-cate dysfunction of the body’s regulatory balance |
| Feed-Forward | Feed-forward in control systems occurs when information flows ahead to another process or feedback loop to trigger a change in anticipation of an event that will follow |
| Intracellular control | 1. Regulation within cells 2. Genes or enzymes can regulate cell processes |
| Intrinsic control (autoregulation) | 1. Regulation within tissues or organs 2. May involve chemical signals (e.g., prostaglandins) 3. May involve other “built-in” mechanisms |
| Extrinsic control | 1. Regulation from organ to organ 2. May involve nerve signals 3. May involve endocrine signals (hormones) |
| Cycle of Life: Life Span Considerations | A. Structure & fx of body undergo changes in the early and late years B. Infancy & old age are periods when the body fx least well C. Young adulthood is period of greatest homeostatic efficiency D. Atrophy—describe the wasting effects of advancing age |
Created by:
meghans0931
Popular Science sets