Interview part 5

Question 1

Which are the 3 types of cells you can find in bones?

Answer 1

OSTEOCLASTS
OSTEOBLASTS
OSTEOCYTES

Question 2

Describe osteoclasts

Answer 2

are large cells that dissolve the bone. They come from the bone marrow and are related to white blood cells. They are formed from two or more cells that fuse together, so the osteoclasts usually have more than one nucleus. They are found on the surface of the bone mineral next to the dissolving bone

Question 3

Describe osteoblasts

Answer 3

are the cells that form new bone. They also come from the bone marrow and are related to structural cells. They have only one nucleus. Osteoblasts work in teams to build bone. They produce new bone called “osteoid” which is made of bone collagen and other protein. Then they control calcium and mineral deposition. They are found on the surface of the new bone.

Question 4

Describe osteocytes

Answer 4

are cells inside the bone. They also come from osteoblasts. Some of the osteoblasts turn into osteocytes while the new bone is being formed, and the osteocytes then get surrounded by new bone. They are not isolated, however, because they send out long branches that connect to the other osteocytes. These cells can sense pressures or cracks in the bone and help to direct where osteoclasts will dissolve the bone.

Question 5

What are lining cells?

Answer 5

When the team of osteoblasts has finished filling in a cavity, the cells become flat and look like pancakes. They line the surface of the bone. These old osteoblasts are also called LINING CELLS. They regulate passage of calcium into and out of the bone, and they respond to hormones by making special proteins that activate the osteoclasts.

Question 6

Describe the essential process of bone formation in the development of the human body

Answer 6

It starts during the development of the foetus, and continues throughout childhood and adolescence as the skeleton grows. Bone remodelling meanwhile is a life-long process, consisting of resorption (the breaking down of old bone) and ossification (formation of new bone), and is key to shaping the skeleton and to the repair of bone fractures.

Question 7

Which are the 2 mechanismn in foetal development for creating bone tissue

Answer 7

Endochondral ossification

Intramembranous ossification

Question 8

What is intramembranous ossification?

Answer 8

Intramembranous ossification occurs in the formation of flat bones such as those in the skull.

Question 9

What involved endochondral ossification?

Answer 9

This involves bone growth from an underlying cartilage model, and is seen in the formation and growth of long bones such as the femur.

Question 10

In what way is ossification essential in the remodeling of bone?

Answer 10

The remodeling of bone occurs throughout a person’s lifetime, with ossification and resorption (removal of bone tissue) working together to reshape the skeleton during growth, maintain calcium levels in the body, and repair micro-fractures caused by everyday stress.
The remodelling of cortical bone follows the same process as shown above, but with a different geometry in order to form the concentric lamellae seen in osteons.

Question 11

periosteum (bone)

Answer 11

a dense fibrous membrane of nerves and blood vessels that covers the surface of bones except at the joints. It nourishes the bone and serves as an attachment for the muscles and tendons.

Question 12

cortical bone

Answer 12

the hard outer wall of the bone.

Question 13

cancellous bone

Answer 13

a spongy interior bone tissue. It is less dense, softer, and more flexible than the outer layer.

Question 14

bone marrow

Answer 14

the soft, fatty tissue that occupies the cavity of most bones and is responsible for blood cell production.

Question 15

What are the functions of the skeleton?

Answer 15

• Structural support for heart, lungs and marrow
• Protection for brain, uterus, and other internal organs
• Attachment sites for muscles allowing movement of limbs
• Mineral reservoir for calcium and phosphorus
• Defense against acidosis
• Trap for some dangerous minerals such as lead

Question 16

Bones

Answer 16

provide the hard framework for stability and acts as levers to facilitate movement

Question 17

Ligament

Answer 17

Hold bones together

Question 18

Muscles

Answer 18

provide the force required for movement by one bone in the relation to another

Question 19

Tendons

Answer 19

connect muscles to bones

Question 20

Nerves

Answer 20

Motor neurons provides the stimulus for muscle movement and coordinates sets of antagonistic muscles

Question 21

Cartilage

Answer 21

allows easy movement. Reduces friction and absorbs compression

Question 22

Synovial fluid

Answer 22

provides food, oxygen and lubrication to the cartilage

Question 23

Joint capsule

Answer 23

surrounds the joint, encloses the synovial cavity, and unites the connected bones

Question 24

Describe the effect of aging on the sceletal syetem

Answer 24

Bone is living tissue that changes constantly. Old bone tissue dies and is replaced by new bone tissue. The human skeleton grows and strengthens until about the age of 18 in women and 21 in men. Bone mass, which is the amount of bone tissue in the skeleton, continues to grow until about the age of 30. After the age of 30 our bones gradually deteriorate.

Question 25

What happes with the skeletal system after the age of 30?

Answer 25

* The first few years after menopause, bone loss is especially rapid. * Bone density decreases and bones become thinner and more fragile. * Bones lose calcium and other minerals. * Posture can become progressively hunched over as the spinal vertebrae and the discs between them become thinner and compressed due to loss of minerals and moisture. * Joints may become inflamed and less flexible as fluid in joints decrease and cartilage erodes. This is especially common in knee and hip joints. * Joints can become stiff due to mineral deposits (bone calcification), common in the shoulders. * Movement slows down and may become limited and unstable. * Risk of injury increases due to a combination of instability and brittle bones

Question 26

What are the common skeletal disorders?

Answer 26

Osteopenia, osteoporosis, arthritis and other chronic joint problems

Question 27

What is Arthritis and other chronic joint problems?

Answer 27

a group of diseases that can cause pain, stiffness and swelling in joints.

Question 28

What are osteopenia and osteoporosis?

Answer 28

both are conditions that cause low bone density, but with osteoporosis, bones are more fragile with a high risk of fracture.