Homeostasis

?
  • Created by: Thabisa18
  • Created on: 23-05-23 07:33
What is negative feedback?
Negative feedback is a biological mechanism that counteracts or reverses a change in a physiological variable, restoring it to its original set point or target value.
1 of 28
What is the purpose of negative feedback?
Negative feedback serves to maintain stability or homeostasis in a system by reversing changes or imbalances.
2 of 28
What are the steps involved in negative feedback?
Change occurs (stimulus) causing an imbalance in the body.
Receptor detects the change and sends a signal.
Effector receives the signal and responds to reverse the change.
The change is corrected, and homeostasis is restored.
3 of 28
What is the role of TSH (thyroid stimulating hormone) in the body?
TSH plays a critical role in regulating the production of thyroxin by the thyroid gland.
4 of 28
How are TSH and thyroxin levels regulated through negative feedback?
When there is an excess of thyroxin in the bloodstream, TSH production is reduced through negative feedback inhibition. Conversely, when there is a deficiency of thyroxin, TSH production is >>.
5 of 28
How does negative feedback ensure balance in TSH and thyroxin levels?
Excess thyroxin signals the pituitary gland to reduce TSH production, leading to << thyroxin production. On the other hand, a deficiency of thyroxin stimulates >> TSH production, which promotes greater thyroxin synthesis.
6 of 28
What is the significance of the negative feedback loop between TSH and thyroxin?
The negative feedback loop helps maintain normal thyroid function and ensures that thyroxin levels remain within a healthy range. Imbalances in this feedback system can lead to conditions such as hypothyroidism or hyperthyroidism.
7 of 28
Describe the negative feedback mechanism that occurs when the level of hormone thyroxine is higher than normal in the blood. [5]
High levels of thyroxin are detected ✓ by the pituitary gland ✓
This leads to a << in the secretion of TSH ✓
Thyroid activity is slowed down / less thyroxin is produced ✓
Thyroxin levels return to normal ✓
8 of 28
Explain the consequences for a person if hormone B remained abnormally low for extended periods of time. [4]
- Basal metabolic rate will be low ✓
- Body temperature will be low ✓
- Chronic fatigue ✓
- Weight gain ✓
9 of 28
What is glucose control?
Glucose control refers to the processes by which the body maintains a stable level of glucose (sugar) in the blood.
10 of 28
Which hormones are involved in glucose control?
Insulin and glucagon are the main hormones involved in glucose control.
11 of 28
How does negative feedback play a role in glucose control?
Negative feedback is involved in glucose control as it counteracts changes in blood glucose levels, bringing them back towards the set point.
12 of 28
What is the role of insulin in glucose control?
Insulin promotes the uptake of glucose from the blood and its storage as glycogen, thus << blood glucose levels.
13 of 28
How does glucagon contribute to glucose control?
Glucagon promotes the release of glucose from glycogen stores, >> blood glucose levels.
14 of 28
Why is the control of blood glucose levels vital for survival?
Maintaining blood glucose levels within a narrow, optimal range is crucial to prevent harmful effects on the body, including diabetic coma and death.
15 of 28
What is diabetes?
Diabetes is a condition characterized by the body's inability to properly use glucose for energy due to insufficient insulin production or insulin resistance.
16 of 28
What are the two main types of diabetes?
The two main types of diabetes are type 1 and type 2.
17 of 28
How does type 1 diabetes differ from type 2 diabetes?
Type 1 diabetes is an autoimmune condition where the body doesn't produce enough insulin, while type 2 diabetes involves insulin resistance or insufficient insulin production.
18 of 28
What causes type 1 diabetes?
Type 1 diabetes is caused by the immune system attacking and destroying the insulin-producing beta cells in the pancreas.
19 of 28
What lifestyle factors are associated with type 2 diabetes?
Type 2 diabetes is often associated with factors such as being overweight, having a sedentary lifestyle, or having a diet high in sugar and processed foods.
20 of 28
What are common symptoms of diabetes?
Common symptoms of diabetes include frequent urination, excessive thirst, hunger, fatigue, blurred vision, and slow-healing wounds.
21 of 28
How is diabetes managed?
Diabetes is managed through lifestyle changes such as diet and exercise, along with medication such as insulin injections or oral medications.
22 of 28
What are potential complications of untreated diabetes?
Untreated diabetes can lead to complications such as cardiovascular disease, nerve damage, kidney damage, and blindness.
23 of 28
How is carbon dioxide (CO2) regulated in the body?
>> CO2 concentration in the blood leads to a << in blood pH. Chemoreceptors detect this change and the medulla oblongata >> the breathing rate to excrete > CO2, restoring normal blood pH.
24 of 28
What role does aldosterone play in salt regulation?
A hormone that controls sodium (Na+) levels in the body. If Na+ levels are <, aldosterone is secreted, causing the kidneys to reabsorb Na+ and >> its levels. If Na+ levels are >, aldosterone is not secreted, and Na+ is excreted in urine.
25 of 28
How is water regulated in the body?
The pituitary gland secretes antidiuretic hormone (ADH) in response to > osmotic pressure[OP] (< water levels). ADH >> the permeability of the collecting ducts in the kidneys, leading to >> water reabsorption.
26 of 28
What happens if OP is too high?
The pituitary gland secretes ADH, leading to increased water reabsorption in the kidneys and a decrease in osmotic pressure.
27 of 28
What happens if OP is too low?
The pituitary gland stops secreting ADH, resulting in << water reabsorption in the kidneys and >> water excretion, which helps >> OP.
28 of 28

Other cards in this set

Card 2

Front

What is the purpose of negative feedback?

Back

Negative feedback serves to maintain stability or homeostasis in a system by reversing changes or imbalances.

Card 3

Front

What are the steps involved in negative feedback?

Back

Preview of the front of card 3

Card 4

Front

What is the role of TSH (thyroid stimulating hormone) in the body?

Back

Preview of the front of card 4

Card 5

Front

How are TSH and thyroxin levels regulated through negative feedback?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Homeostasis in Humans resources »