W3 - The musculoskeletal system

Question 1

What are the four functions of the skeleton?

Answer 1

1. Movement
2. Support
3. Protection
4. Physiological functions

Question 2

How does the skeleton provide movement?

Answer 2

• Muscle attatchment
• Provide levers

Question 3

How does the skeleton provide support?

Answer 3

It gives the body shape

Question 4

How does the skeleton provide protection?

Answer 4

The bones in the skeleton protect vital organs

Question 5

What are the physiological functions of the skeleton?

Answer 5

• Ca²⁺ regulation
• Endocrine regulation
• Blood cell production (bone marrow)

Question 6

What is a lever?

Answer 6

A lever is a relatively rigid object that may be made to rotate about an axis by the application of force

Question 7

Which par

Which part of the lever system do body parts play?

Answer 7

• Joint = Fulcrum
• Muscle = Effort
• Body part = Load (resistance)

Question 8

What is the order of the components a first class lever?

Answer 8

Effort - Fulcrum - Load

Question 9

What is the order of the components a second class lever?

Answer 9

Effort - Load - Fulcrum

Question 10

What is the order of the components a third class lever?

Answer 10

Fulcrum - Effort - Load

Question 11

What are the three types of musculoskeletal tissue?

Answer 11

Skeletal - Bone and cartilage

Muscular

Question 12

What percentage of bone are made up of organic and inorganic componds?

Answer 12

Inorganic - 65%

Organic - 35%

Question 13

What are the features of the organic component of bone?

Answer 13

Matrix: mostly type 1 collagen (elasticity)

Cells: osteoblasts, lining cells, osteocytes, osteoclasts

Question 14

What are the features of the inorganic component of bone?

Answer 14

Mineral content: hydroxypatite (rigidity)

Question 15

What is hydroxyapatite?

Answer 15

A complex salt of calcium and phosphate

Question 16

What is the general strucure of bone?

Answer 16

• Long bones consist of a diaphyses (shaft) and two epiphyses (knobs at the ends)
• The metaphysis is where the epiphyseal growth plate resides -it lies between the diapyses and epiphyses

See diagram for locations

Question 17

What are the two types of bone?

Answer 17

Compact/ cortical

Cancellous/ spongey/ trabecular

Question 18

What are the features of Compact/ cortical bone?

Answer 18

80% of bone mass

External surface of bone

Walls of diaphyses

Principally mechanical function

Question 19

What is the function of cancellous/ spongey/ trabecular bone?

Answer 19

20% of bone mass

Lattice of fine plates

Epiphyeses of long bones vertebral bodies and flat bones

Spaces filled with bone marrow

Reduces skeletal mass without compromising strength

Question 20

What are the two types of bone growth?

Answer 20

Longitudinal

Circumferential/ radial growth

Question 21

Where does longitudinal growth occur?

Answer 21

Epipheseal plates

Question 22

When does longitudinal growth stop?

Answer 22

18-20 years (epipheseal line)

Question 23

When does circumferential growth occur?

Answer 23

The diameter increases throughout lifespan, most rapud growth occurs before adulthood

Question 24

What is “Wolff’s Law”?

Answer 24

The form of bone will adapt to the load placed upon it

Increasing or decreasing load will cause the bone to remodel, increaing or decreasing mass and density

Question 25

Describe bone remodelling

Answer 25

A balanced integration of osteocyte signalling osteoblast bone formation & and osteoclast bone resorbtion, in response to load

Question 26

What causes hypertrophy of bone?

Answer 26

An increase in bone mass is caused by the predomincance of osteoblast activity This may be a response physical activity The greater habitual load = more bone mineralisation

Question 27

What causes atrophy of the bone?

Answer 27

A decrease in bone mass resulting from a predominance osteoclast activity.

Question 28

What are the effect of bone atrophy?

Answer 28

Decrease in * Bone calcium * Bone mass and strength

Question 29

Where is bone atrophy commonly seen?

Answer 29

Bed ridden patients, sedentry elderly and astronaughts

Question 30

How many bones are in the axial skeleton?

Answer 30

74

Question 31

How many bones are in the appendicular skeleton?

Answer 31

126

Question 32

Which bones don't the appendicular/ axial skeleton include how many are there?

Answer 32

Sesamoid bones 6

Question 33

What are flat bones?

Answer 33

Thin curved bone They serve as points of attatchment for muscle They protect internal organs

Question 34

What are short bones?

Answer 34

Cube-shaped bone that is approximatly equal in length width and thickness Provides limited motion

Question 35

What are long bones?

Answer 35

Cylinder shaped bones that are longer than wide Function as levers

Question 36

What are sesamoid bones

Answer 36

Bones embedded within tendons to protect them from stress

Question 37

What are irregular bones?

Answer 37

Bone of complex shape Protects internal organs from compressive forces

Question 38

What is the function of a joint?

Answer 38

To facilitate movement between bones To transmit force from one bone to another

Question 39

What is the articular surface?

Answer 39

The contact point between 2 skeletal bones

Question 40

Whats is a synathroses joint?

Answer 40

Joints that don't move

Question 41

What is the function of a synarthoses joint?

Answer 41

Shock absorb (attenuate force)

Question 42

What are amphiathroses joint?

Answer 42

Joints that move slightly

Question 43

What is the function of amphiathroses joints?

Answer 43

Attenuate forces and permit some motion between adjacent bones

Question 44

What are the two types of amphiarthosis joints?

Answer 44

Synchrodroses ( think between ribs and sternum) Sympheses e.g. pubic symphyses/ intervertebral discs

Question 45

What is a diarthroses joint?

Answer 45

Joints that freely move (aka synovial)

Question 46

Name the six types of diarthoses joints?

Answer 46

1. Gliding/ plane 2. Hinge 3. Pivot 4. Condyloid 5. Saddle 6. Ball and socket

Question 47

Describe a gliding/ plane joint

Answer 47

Articulating surfaces are flat permitting on non-axial gliding | E.g. joints between the carpals and tarsals

Question 48

Describe a hinge joint | E.g. Interphalangeal joints

Answer 48

One convex and one concave articulating surface. Strong collateral ligaments restrict to single axis hinge-like movement (uni-axial)

Question 49

Describe a pivot joint

Answer 49

Joints where rotation is permitted around one axis (uni-axial) | E.g. proximal and distal radioulnar joints

Question 50

Describe a condyloid joint

Answer 50

An ovoid articular surface allowing movement around two axes (bi-axial) | E.g. Metacarpophalangeal joints; radiocarpel joint

Question 51

Describe a saddle joint

Answer 51

Similar to condyloid but greater range of motion due to saddle shape of both bones (tri-axial) | E.g. carpometacarpal joint of thumb

Question 52

Describe a ball and socket joint

Answer 52

Rotation around three axis (tri-axial) | E.g. Glenohumeral/ hip joints

Question 53

What is articular cartilage?

Answer 53

Protective layer of connective tissue, covering ends of articulating bones

Question 54

What is the function of articular cartilage?

Answer 54

* Reduces stress by distributing force * Reduces friction and wear

Question 55

What is the articular capsule?

Answer 55

Double-layered membrane that surrounds every synovial joint

Question 56

What is the synovial membrane?

Answer 56

Lines the deep surface of the capsule; secretes synovial fluid

Question 57

Define joint stability

Answer 57

The ability of a joint to resist abnormal displacement of the articulating bones

Question 58

What provides joint stability?

Answer 58

* Shape of articulating bone surfaces * Arrangement of ligaments an muscle * Other connective tissues