Biology 5.3.4

Question 1

What is ‘Negative Feedback’?

Answer 1

Negative Feedback Mechanisms in Homeostasis help to Maintain Conditions in the Body within an Optimal Narrow Range.

Question 2

When and Where is Adrenaline Produced?

Answer 2

In Times of Fear/ Stress. Produced by the Adrenal Glands, right above the Kidneys.

Question 3

How does the Release of Adrenaline help us in times of Fear/ Stress?

Answer 3

Adrenaline Increases Heart Rate & Increases Oxygen & Glucose delivery to the Brain & Muscles, preparing the Body for a ‘Fight or Flight’ Response.

Question 4

Why are you still in Oxygen Debt after a Flight Response even after a spike in Adrenaline?

Answer 4

Even with Adrenaline, there isn’t enough Oxygen being Delivered to your Body to warrant no Oxygen Debt.

Question 5

What are the Main Roles of Thyroxin? (2)

Answer 5

-Stimulates Basal Metabolic Rate (BMR); this is the Speed at which Chemical Reactions Occur in the Body when it is at rest.

-Stimulates Protein Synthesis in Cells, which is Important for Growth & Development.

Question 6

Thyroxine Levels in the Body are Controlled by…

Answer 6

Negative Feedback.

Question 7

Two Conditions Related to the Thyroid Gland are: Explain them.(2)

Answer 7

-Hyperthyroidism: Caused by an Overactive Thyroid Gland Secreting too much Thyroxine into the Bloodstream, which Causes an Increase in BMR & Protein Synthesis.

-Hypothyroidism: Caused by an Underactive Thyroid Gland Secreting too little Thyroxine into the Bloodstream which can lead to Heart & Nerve Problems, & Death.