MUSCULOSKELETAL SYSTEM 2 (SKELETAL)

Question 1

Function of the skeleton

Answer 1

• Provides a scaffold to support the weight of the human-body.
• It facilitates movement by being points of attachment for muscle.
• Protects vital internal organs.
• Produces red blood cells.
• Stores and releases minerals and fats

Question 2

Articulation

Answer 2

Bones move in relation to muscles during contraction

Question 3

Types of bones (5 types)

Answer 3

1. Flat - Protects internal organs
2. Long - Supports weight and allows movement
3. short - provide stability and some movement
4. sesamoid - protects tendons
5. irregular - Helps protect different structures.

Question 4

Axial skeleton

Answer 4

• Consists of bones that lie in the central axis of the body.
• provides main support for erect posture and protection of the central nervous system and organs contained within the thorax

Question 5

Appendicular skeleton

Answer 5

Consists of bones of the upper and lower limbs, the pectoral and pelvic gridle), these 2 gridles allow for the articulation of the limbs with the axial skeleton

Question 6

Bones

Answer 6

Connective tissue, consisted of cells separated by a non- cellular material called a matrix.

They are living organs containing living cells and are capable of growth and repair

Question 7

Osteoblasts

Answer 7

osteoblasts secrete the organic matrix which binds to the minerals that form the bone.

Question 8

osteoclasts

Answer 8

are large cells that reabsorb bone matrix. This is necessary for repair of damaged bone, but also for remodelling of growing bones.

Question 9

Osteocytes

Answer 9

were once osteoblasts that got trapped in their own matrix layer. Once they stop producing matrix and are trapped they sense stress on the bone and can co-ordinate the appropriate remodelling

Question 10

Structures of a long bone

Answer 10

1. Diaphysis - shaft making main portion of a bone. Cutting in length wise, there is a hollow cylinder of compact bone, surrounding the medullary cavity.
2. Epiphysis - enlarged ends of bones, covered with a thin layer of articular cartilage. Have compact bone on the outside but spongy bone on the inside
3. Periosteum - Dense white, fibrous outer covering of the bones.

Question 11

Spongy bone

Answer 11

Spongy bone is the lighter, inner part of bones

Spongy bones are more porous than compact bones

Question 12

Compact bone

Answer 12

Compact bone is the hard, dense outer layer of your bones. It gives the bone its strength and structure.

It consists of many similar units called osteons

Question 13

Structure of compact bones

Answer 13

consists of:

1. a central canal at its centre
2. Concentric layers of bony matrix called the lamellae surrounding the centre.
3. lacunae, small spaces in the matrix between the lamellae
4. an osteocyte, occupying lacuna
5. projection from bone cells entering canaculi making contact with adjacent bone cells, allowing material to be passed from cell to cell.
6. At least one blood capillary, and possibly nerves and lymph capillaries, in the central canal of each osteon.

Question 14

Structure of spongy bone

Answer 14

• consists of an irregular arrangement of thin, bony plates called trabecullae.
• The bone cells occupy spaces in the trabecular, and nerves and blood vessels pass through irregular spaces in the matix.

Question 15

Structure of cartilage

Answer 15

• Cartilage is a connective tissue.
• It contains protein fibres called collagen.
• which are embedded in a firm matrix called the chondrin.
• Firm matrix allows cartilage to function as a structural support.
• the presence of fibres also gives it flexibility.

Question 16

Chondroblasts

Answer 16

cells of cartilage that produce matrix and gradually become surrounded by it until they are trapped in small spaces called lacunae.

Question 17

Chondrocytes

Answer 17

Chondrocytes are the cartilage cells that keep it healthy, strong, and flexible, these are cells that have matured from chondroblasts.

Question 18

Hyaline cartilage

Answer 18

• contains closely packed collagenous fibres throughout the matrix.
• give cartilage strength with flexibility
• Makes up rings of the trachea.

Question 19

Elastic cartilage

Answer 19

• Has conspicuous elastic fibres.
• Collagen fibres not closely packed together.
• Provides flexible elastic
• Makes up the external part of the ears and epiglottis.

Question 20

Fibrocartilage

Answer 20

• contains thick collagenous fibres that make up this tissue.
• fibres not compacted as much as hyaline.
• able to be compressed slightly
• Ideal for regions where the weight of the body is being supported or where theres is a need to withstand heavy pressure.

Question 21

Material exchange of the cartilage

Answer 21

• cartilage does not contain blood vessels, so all the nutrition and waste removal of cells depends on the diffusion through the matrix. It is known to be a slow process.
• blood supply to cartilage comes from blood vessels located in the inner layer of the perichondrium

Question 22

Perichondirum

Answer 22

fibrous membrane of connective tissues that covers the external surface of cartilage, except where the cartilage forms the articular surfaces of the joint.

Question 23

Joint

Answer 23

Site at which two or more bones come together

Question 24

How are joints classified

Answer 24

Through functional and structural classifications

Question 25

Functional classifications

Answer 25

Fibrous, cartilaginous, synovial

Question 26

Structural classifications

Answer 26

immobile, slightly movable, freely moveable

Question 27

Fibrous joint

Answer 27

when no movement occurs between the bones concerned, it is immovable. Example - Bones held by connective tissue in the skull

Question 28

Cartilaginous

Answer 28

Held in place by cartilage, which allows slight movement to occur. Example - Joints between ribs and sternum

Question 29

Synovial joints

Answer 29

Freely moveable joints, with the amount of movement limited by ligaments, tendons, bones and muscles.

Question 30

Pivot joints

Answer 30

These joints allow for rotation of one bone against the other Example, Rotation of the hand, with radius and ulna

Question 31

Hinge joint

Answer 31

These joints allow movement in one plane only – flexion and extension. The elbow is an example of this type of joint.

Question 32

saddle joint

Answer 32

The shape of the bones allows for movement in two planes Example - Thumb

Question 33

plane joint

Answer 33

These joints have two flat surfaces against one another. They are able to glide over one another to the limits of the joint capsule. Example - carpal bones, scapula and clavical

Question 34

Condyloid Joints

Answer 34

These bones both have curved surfaces, one convex and the other concave, to fit against each other. They are not perfectly round surfaces so do not allow for rotation, but do allow a modest range of circumduction.

Question 35

Ball and Socket Joints

Answer 35

These joints are the most mobile joints – they allow circumduction and rotation

Question 36

Structure of a General Synovial Joint

Answer 36

Articulating bones with articular cartilage caps (hyaline cartilage) A joint capsule – the fibrous capsule and synovial membrane Fibrous Capsule - made of fibrous connective tissue. (Ligaments are thickenings of this capsule with fibres running in a single direction to provide added stability) Synovial membrane – a layer of cells lining the capsule that produce fluid Synovial fluid – Fills the space within the joint capsule. Maintains some lubrication to the articular surfaces and pushes on the capsule to stop it from getting pinched in the joint space.

Question 37

Bursae

Answer 37

Little sacs of synovial fluid, are another feature of some joints. These are positioned to prevent friction between: 1. bone and ligament or tendon 2. A bone and skin, where a bone inside a join capsule is near the body surface.

Question 38

Keeping synovial joints together

Answer 38

1. There is a fit of the articulating bones. 2. There is the strength of the joint ligaments holding the bones. 3. Tension provided by the muscle around the joints.

Question 39

Flexion and extention

Answer 39

Flexion - Bending, decreasing the angle between the articulating bones. Means that bones come closer together. Extension - Straightening, increases the angle between the articulating bones. Means that bones move further away.

Question 40

Abduction and adducton

Answer 40

abduction - movement away from the midline of the body. adduction - movement towards the midline of the body.

Question 41

Rotation

Answer 41

Movement of bone around the long axis.