Positive and Negative Feedback loops: 9/24/25

During childbirth, the hormone oxytocin causes the uterus to contract. If a medicine makes the uterus less sensitive to oxytocin (so more oxytocin is needed to cause the same contractions), what is most likely to happen? How does this relate to how the body controls processes?

• Contraction strength will gradually decline (negative feedback), because the lower sensitivity weakens signaling.
  

• The pituitary will secrete even more oxytocin in response to weaker contractions (positive feedback), reinforcing labor until delivery.
  

• 
  A completely different hormonal axis (e.g. prolactin) will activate to substitute, overriding the feedback loop.
  

• 
  The feedback loop will fail, and contractions will cease entirely.

Tags

NGSS.HS-LS1-3

A person sustains a minor cut, initiating the blood clotting process. Which of the following best describes the feedback mechanism involved in blood clotting?

• Positive feedback leading to the rapid formation of a clot.
  

• 
  Negative feedback reducing clot formation once bleeding stops.
  

• 
  Positive feedback enhancing the inflammatory response.
  

• 
  Negative feedback inhibiting platelet aggregation.

Tags

NGSS.HS-LS1-3

During labor, the cervix stretches, triggering the release of oxytocin, which intensifies uterine contractions.

Which type of feedback loop is exemplified by the hormonal regulation during childbirth?

• Positive feedback loop.
  

• Negative feedback loop.
  

• 
  Homeostatic feedback loop.
  .

• 
  Adaptive feedback loop.

Tags

NGSS.HS-LS1-3

An individual exercises vigorously in a warm environment, leading to an increase in body temperature.

Which physiological response is primarily responsible for cooling the body during physical activity?

• Vasoconstriction of blood vessels to reduce heat loss.
  

• 
  Increased heart rate to pump blood more efficiently.
  

• 
  Sweating and subsequent evaporation to dissipate heat.
  

• .Shivering to generate heat through muscle activity.

Tags

NGSS.HS-LS1-3

What is homeostasis?

• The process of breaking down food for energy
  

• The maintenance of a stable internal environment
  

• The production of hormones by glands
  

• 
  The movement of muscles during exercise

Tags

NGSS.HS-LS1-3

Which organ in the brain is primarily responsible for regulating body temperature?

• Cerebellum
  

• 
  Medulla oblongata
  

• Pituitary gland

• Hypothalamus
  

Tags

NGSS.HS-LS1-3

How does positive feedback differ from negative feedback?

• Positive feedback decreases changes; negative feedback increases changes
  

• 
  Positive feedback amplifies changes; negative feedback reduces changes
  

• Both feedback types amplify changes equally
  

• Both feedback types reduce changes equally

Which of the following is an example of positive feedback in the human body?

• Blood clotting
  

• Blood sugar regulation
  

• Sweating to cool the body
  

• 
  Breathing rate control

Tags

NGSS.HS-LS1-3

In the context of thermoregulation, positive feedback loops are rare but can occur in certain conditions such as fever. Analyze how positive feedback contributes to fever progression and its potential risks to homeostasis

• Positive feedback increases body temperature to fight infection but can lead to dangerously high temperatures if unchecked.
  

• 
  Positive feedback reduces heat production to restore normal temperature quickly.
  

• 
  Positive feedback induces sweating to lower body temperature effectively.
  

• Positive feedback triggers vasodilation to prevent heat buildup.

Tags

NGSS.HS-LS1-3

A patient experiences a malfunction in the positive feedback loop involved in blood clotting. Predict the potential consequences on homeostasis and explain the underlying reason.

• Increased risk of excessive bleeding due to failure in amplifying clot formation.
  

• Excessive clotting causing frequent blockages due to over-amplification of clotting signals.

• No change in clotting because negative feedback will compensate completely.

• Reduced blood pressure caused by constant vasodilation.

Tags

NGSS.HS-LS1-3