The Skeletal system

Question 1

The skeletal system

Answer 1

Consists of bobes(skeleton), cartilage, ligaments( binds bones together) and other connective tissues
Orthopaedics and physiatry: The medical specialties for the diagnosis and treatment of the musculoskeletal system

Question 2

What are the functions of the skeletal system

Answer 2

Support: framework that gives shape to the body.
• Protection: lungs, heart, brain, and other organs.
• Anchorage: serves as lever for movement.
• Site of hematopoiesis: blood cell formation within the red bone marrow.
• Mineral storage: mostly for calcium and phosphate.
• Fat storage: within the yellow bone marrow.

Question 3

Based on shape, bones are classified as

Answer 3

• long bones
• short bones
• flat bones
• sesamoid(round) bones
• irregular bones

Question 4

Long bone

Answer 4

Description: Long bones are longer than they are wide.
Examples:
• collar bone, bones in the limbs, hands, feet and fingers
• femur (thigh bone) is the longest bone in the body

Question 5

Short bone

Answer 5

Description: Short bones are as long as they are wide.
- squarish in size
Examples:
• most bones in the wrists and ankles

Question 6

Flat bones

Answer 6

Description: Flat bones are thin, curved and contain flat surfaces that are used for muscle anchorage or for protection.
Examples:
• breastbone, ribs, some bones of the skull and shoulder blades

Question 7

Sesamoid Bones

Answer 7

Description: resembles a sesame seed and are embedded in tendons

Examples:
- knee caps and 1 type of writ bones called the pisiform found in the wrist
Other bones may may be found in the tendons near the joints of carpals and tarpals

Question 8

Irregular Bones

Answer 8

Description: have complex and varying shapes and does not fit into any other category
- there like interlocking bones like Lego
Description:
- vertebral column, hip bones, some bones of the skull(jaw bones), bones in the ear

Question 9

Bones: Based os structure, they’re classified as

Answer 9

Compact(cortical) and Spongy(trabecular or cancellous)

Question 10

Compact bones

Answer 10

• are strong and dense
• form the outer layer of the bone which is the thicker layer
• composed of units called osteons

Question 11

Osteon

Answer 11

• are circular tubes of bone matrix made up of collagen fibres
• separately they are called a lamella

Question 12

Within an osteon

Answer 12

Central canal: contains the blood vessels and nerve that serve each osteon
Lacunae: the space found between adjacent lamella that contain osteocytes
- Canaliculu: forms Casals that connect lacunae together and to the central canal

Question 13

Spongy bones

Answer 13

Are found on the inside of the bone
- contain a honeycomb structure called a trabeculae which are irregularly aligned lamellae

Question 14

The long bone consists of

Answer 14

The Diaphysis and the Epiphysis

Question 15

Diaphysis

Answer 15

• the shaft(length) of the long bone

Has compact bone surrounding a medullary cavity filled with fatty tissue and yellow bone marrow

Question 16

Epiphysis

Answer 16

• the 2 end of the long bone
• the distal, side further from the attachment site and proximal side, side closer to the attachment site
• filled with red bone marrow for blood synthesis
• joint surfaces are covered by articulating hyaline cartilage that protect it from movement

Question 17

Metaphysics

Answer 17

The region between the diaphysis and epiphysis
- also know as the epiphyseal line in adults or the epiphyseal(growth) plate during bone growth period

Question 18

Bone surfaces are covered by 2 membranes

Answer 18

• periosteum
• endosteum

Question 19

Periosteum(outside of bone)

Answer 19

Covers the external bone surfaces except the joints
- like a plastic wrap
Had 2 layers
Outer fibrous layer: made up of dense irregular connective tissue
Inner osteogenic layer: contains blood cells for bone growth and maintenance

Question 20

Has holes called foremen in the diaphysis

Answer 20

Which is a bone marking that means opening
This is to allow nutrient artery and vein serve the bone marrow and spongy bone

Question 21

Endosteum(inner bone)

Answer 21

Covers the internal bone surfaces( trabeculae of sponges bones and central canals of compact bones
- contains 1 layer that has bone cells for growth and maintenance

Question 22

Endosteum(inner bone)

Answer 22

Covers the internal bone surfaces( trabeculae of sponges bones and central canals of compact bones
- contains 1 layer that has bone cells for growth and maintenance

Question 23

In short, irregular and flat bones

Answer 23

• compact bones outside sandwich the sponges bones inside
• periosteum covers the external surfaces
• endosteum covers the interior surfaces

Question 24

Where does hematopoiesis occur in adults? [Multi-select]
A. Medullary cavities of long bones (*in infants).
B. Proximal heads of some long bones
C. Diploë of some cranial bones
D. Epiphyseal plate

Answer 24

B and C

Question 25

Osseous Tissue

Answer 25

Are the type of connective tissue bones are
- it is composed of bone cells and a solid extracellular matrix

Question 26

Bone cells

Answer 26

Make up only 2% of the bone’s mass

Question 27

Osteoblasts

Answer 27

Are bone building cells that produce the organic bone matrix called osteoid
- produces collagen and calcium binding proteins

Where are they found?
In the osteogenic layer of periosteum and in the endosteum

Question 28

Osteocytes

Answer 28

Are bone maintaining cells that develop from osteocytes and no longer divide
- matured bone cells
- regulates bone mass and mineral storage
Where are they found?
In the lacunae and canaliculi

Question 29

Osteoclasts

Answer 29

Are bone chipping(crushibf) cells that remove matured bone bone matrix(osteolysis) that may be damaged
- Multinucleated due to the fusion of multiple stem cells
- secretes causes to remove the inorganic matrix and protein digesting enzymes to remove the organic ones

Where are they found?
In the osteogenic layer of the periosteum and in the endosteum

Question 30

Extracellular Matrix

Answer 30

Contains 2 major components:
Organic: osteoid framework
Inorganic: mineral salts

Question 31

Mineral salts called

Answer 31

Hydroxyapatite are deposited around the organic framework and crystallize through calcification

Question 32

What would happen to a bone if we soaked it in vinegar for several days?

Answer 32

• vinegar dissolves mineral salt inside a bone, which takes away the hardness. -Only organic framenark left
  • bone becomes rubbery and flexible

Question 33

What would happen to a bone if we baked it for several hours at high temperature (250°F)?

Answer 33

• high temperature breaks down collagen and other proteins, which takes away the tensile strength and flexibility of a bone
  • bone becomes brittle