Maintaining internal environments

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Question 6
Medium
a.

Explain why maintaining a constant internal body temperature is important for chemical reactions in human cells.

[2]
b.

The skin plays a major role in thermoregulation. When body temperature increases above normal, changes occur in the skin to increase heat loss. Describe two such changes (other than increased blood flow to the skin surface).

[2]
c.

What structural feature of arteriole walls allows them to change the rate of blood flow to the capillaries in the skin?

[1]
d.

Peripheral Arterial Disease (PAD) is a condition where narrowed arteries reduce blood flow to the limbs. The thermogram shows the feet of two patients after staying in a cool room.

Thermogram of two feet, labeled Foot A and Foot B. Foot A shows toes with very dark shading, corresponding to a temperature scale of 22 to 24 ^\circ\text{C}. Foot B shows toes with light grey shading, corresponding to a temperature scale of 27 to 29 ^\circ\text{C}. A vertical temperature scale bar on the right side goes from 20 ^\circ\text{C} (darkest/black) at the bottom to 30 ^\circ\text{C} (lightest/white) at the top.

Explain which foot is more likely to belong to a patient with PAD.

[2]
e.

Insulin and glucagon maintain blood glucose levels around a constant set point. Explain how physiological variables in the body are kept near a fixed reference point using negative feedback.

[2]

Maintaining internal environments Questions

  1. GCSE
  2. /Biology
  3. /Maintaining internal environments