Control in Biological Systems

Question 1

What is the definition of homeostasis?

Answer 1

The control of constant internal conditions

Question 2

Define a hormone?

Answer 2

A chemical, produced by a gland & transported in the bloodstream to the target organ.

Question 3

How does the eye accommodate to an object at a long distance?

Answer 3

• The cilary muscles relax
• Suspensory ligaments tighten
• Lens is long & thin
• Less refraction

Question 4

How does the eye accommodate for an object being close?

Answer 4

• The cilary muscles contract
• Suspensory ligaments relax
• Lens is short & fat
• More refraction

Question 5

How is temperature regulated when the body is too hot?

Answer 5

• Increased sweat production
• Hairs lie flat
• Vasodilation

Question 6

How is temperature regulated when the body is too cold?

Answer 6

• Decreased sweat production
• Piloerection
• Vasoconsctriction
• Shivering (rapid muscle contractions)

Question 7

What is vasoconstriction?

Answer 7

Vasoconstriction is where blood vessels constrict allowing less blood to flow near the outside of the body maintaining core body temperature.

Question 8

What is vasodilation?

Answer 8

Vasodilation is where the blood vessels dilate allowing more blood to flow near the skin allowing more heat to be lost.

Question 9

What is piloerection?

Answer 9

Where the hair muscles contract, the erect hair traps air and makes it harder for heat to leave the body.

Question 10

What are differences between Hormones and Nerves?

Answer 10

• Nerves are fast acting where hormones are slow acting.
• Nerves are electrical signals where hormones are chemical signals.
• Nerves are short lived where hormones are long lasting.
• Nerves affect a small area where hormones have widespread affects.