1. What is the difference between osteoblasts and osteoclasts? How do

they regulate bone remodeling?

- Osteoblasts are bone-forming cells that secrete osteoid, the organic

matrix of bone. Osteoclasts are bone-resorbing cells that break down bone

tissue by secreting acids and enzymes. Bone remodeling is the process of

replacing old bone tissue with new bone tissue, which involves both

osteoblasts and osteoclasts. Osteoblasts and osteoclasts are regulated by

hormonal and mechanical factors, such as parathyroid hormone,

calcitonin, vitamin D, estrogen, and mechanical stress.

2. What are the three types of cartilage? Where are they found in the

human body?

- The three types of cartilage are hyaline cartilage, elastic cartilage, and

fibrocartilage. Hyaline cartilage is the most abundant type of cartilage,

which provides support and flexibility to various parts of the body, such as

the nose, trachea, larynx, ribs, and articular surfaces of bones. Elastic

cartilage is similar to hyaline cartilage, but contains more elastic fibers,

which make it more resilient and flexible. Elastic cartilage is found in the

external ear, epiglottis, and auditory tube. Fibrocartilage is the strongest

and most durable type of cartilage, which contains dense collagen fibers

that resist compression and tension. Fibrocartilage is found in the

intervertebral discs, pubic symphysis, menisci of the knee, and the TMJ.

3. What are the four types of bones? Give an example of each type.

- The four types of bones are long bones, short bones, flat bones, and

irregular bones. Long bones are longer than they are wide, and have a

shaft and two ends. They function as levers for movement and support.

Examples of long bones are the humerus, femur, radius, ulna, tibia, and

fibula. Short bones are roughly cube-shaped or round, and have a thin

layer of compact bone surrounding a spongy core. They function as shock