The Skeletal System

Mr. Andersen discusses the skeletal system, focusing on the differences between exoskeletons and endoskeletons. He explains the structure and function of bones, including compact and spongy bone, marrow, and the role of osteocytes. The video also covers the chemical composition of bones and their role in maintaining homeostasis, particularly in regulating blood calcium levels through the thyroid and parathyroid glands.

What is one advantage of having an endoskeleton compared to an exoskeleton?

• It allows for greater flexibility.

• It can support greater weight.

• It provides better protection.

• It requires less energy to maintain.

What is the primary function of red marrow in bones?

• Storing fat

• Producing blood cells

• Providing structural support

• Storing calcium

Which part of the bone is responsible for nutrient exchange with the blood system?

• Compact bone

• Spongy bone

• Capillaries

• Marrow

What are osteocytes responsible for in the bone?

• Producing blood cells

• Storing fat

• Laying down new bone

• Transporting nutrients

Which chemical is secreted by the thyroid gland to lower blood calcium levels?

• Parathyroid hormone

• Calcitonin

• Insulin

• Adrenaline

What happens when blood calcium levels are too low?

• Calcium is absorbed by the intestines.

• The thyroid gland secretes calcitonin.

• The parathyroid gland secretes parathyroid hormone.

• Calcium is stored in the kidneys.

How do bones contribute to maintaining a stable internal environment?

• By regulating blood calcium levels

• By storing oxygen

• By generating heat

• By producing hormones