Construct and interpret negative feedback loops
Construct and interpret negative feedback loops that show homeostasis by using a range of sources, including but not limited to: (ACSBL101, ACSBL110, ACSBL111)
- Temperature (ACSBL098)
- Glucose
Homeostasis:
- Processes by which biological systems maintain stability and equilibrium by controlling different factors that play direct role for survival (temperature, pH, different chemicals etc).
Negative Feedback Loops:
- Collection of processes that minimize/counteract the effect that causes disbalance in the normal body conditions.
- Mechanism involves opposing the condition that caused the normal body condition to deviate.
- Generally, a signal of change is sent to the control centre which in response, activates effectors which oppose the stimulus.
Temperature Homeostasis by Negative Feedback Loop:
- Rise or fall in the temperature is detected by sensors that relay this message to the temperature regulation centre of the brain located in the hypothalamus.
- Responses may occur in the following ways:
| Temperature Rise | Temperature Fall |
|---|---|
| Vasodilation: Arterioles dilate (enlarge) so more blood enters skin capillaries and heat is lost. | Vasoconstriction: Arterioles get smaller to reduce blood going to skin: keeping core warm. |
| Sweating: Sudorific glands secrete sweat which removes heat when water changes state. | Shivering: Rapid contraction and relaxing of skeletal muscles. Heat produced by respiration. |
| Pilorelaxation: This means the hairs flatten. | Piloerection: Hairs on skin stand up. |
| Stretching Out: By opening up, the body was a larger surface area. | Curling Up: Making yourself smaller so smaller surface area. |
Glucose Homeostasis by Negative Feedback Loop:
- Blood glucose level is controlled by hormones produced in the pancreas in the Islets of Langerhans.
- After intake of food, glucose level increases in blood which is detected by Beta Cells in the Islets of Langerhans.
- Beta Cells produce a hormone called Insulin.
- Insulin acts as a signal that triggers cells of the body, such as fat and muscle cells, to take up glucose for using as fuel.
- Insulin also encourages glycogenesis.
- If our body lacks glucose, Alpha cells produce Glucagon that convert glycogen to glucose and maintains blood sugar level.
Extract from HSC Biology Stage 6 Syllabus. © 2017 Board of Studies NSW.
EasyBio > Non-infectious Disease and Disorders > Homeostasis > Construct and interpret negative feedback loops
Construct and interpret negative feedback loops that show homeostasis by using a range of sources, including but not limited to: (ACSBL101, ACSBL110, ACSBL111)
- temperature (ACSBL098)
- glucose
Homeostasis:
- Processes by which biological systems maintain stability and equilibrium by controlling different factors that play direct role for survival (temperature, pH, different chemicals etc).
Negative Feedback Loops:
- Collection of processes that minimize/counteract the effect that causes disbalance in the normal body conditions.
- Mechanism involves opposing the condition that caused the normal body condition to deviate.
- Generally, a signal of change is sent to the control centre which in response, activates effectors which oppose the stimulus.
Temperature Homeostasis by Negative Feedback Loop:
- Rise or fall in the temperature is detected by sensors that relay this message to the temperature regulation centre of the brain located in the hypothalamus.
- Responses may occur in the following ways:
| Temperature Rise | Temperature Fall |
|---|---|
| Vasodilation: Arterioles dilate (enlarge) so more blood enters skin capillaries and heat is lost. | Vasoconstriction: Arterioles get smaller to reduce blood going to skin: keeping core warm. |
| Sweating: Sudorific glands secrete sweat which removes heat when water changes state. | Shivering: Rapid contraction and relaxing of skeletal muscles. Heat produced by respiration. |
| Pilorelaxation: This means the hairs flatten. | Piloerection: Hairs on skin stand up. |
| Stretching Out: By opening up, the body was a larger surface area. | Curling Up: Making yourself smaller so smaller surface area. |
Glucose Homeostasis by Negative Feedback Loop:
- Blood glucose level is controlled by hormones produced in the pancreas in the Islets of Langerhans.
- After intake of food, glucose level increases in blood which is detected by Beta Cells in the Islets of Langerhans.
- Beta Cells produce a hormone called Insulin.
- Insulin acts as a signal that triggers cells of the body, such as fat and muscle cells, to take up glucose for using as fuel.
- Insulin also encourages glycogenesis.
- If our body lacks glucose, Alpha cells produce Glucagon that convert glycogen to glucose and maintains blood sugar level.
Extract from HSC Biology Stage 6 Syllabus. © 2017 Board of Studies NSW.