W3 Lecture 1 6/3

Question 1

How does the human body move?

Answer 1

Via leverage i.e. we are composed of lever systems that facilitate movement

Question 2

What is bone?

Answer 2

A living and dynamic tissue that is continually remodelled by the forces that act on the body.

Question 3

How many bones are in the body? (2 subdivisions?)

Answer 3

206 bones in the body divided into axial skeleton and appendicular skeleton

Question 4

What are the three mechanical functions of the bone?

Answer 4

Support, protection, anchorage

Question 5

What is support?

Answer 5

Bones in lower body support trunk.

Question 6

What is protection?

Answer 6

Vertebrae protect the spinal column.

Question 7

What is anchorage?

Answer 7

For skeletal muscles and ligaments e.g. via bone projections like tubercles.

Question 8

What are the bone tissue categories?

Answer 8

Compact bone & spongy bone

Question 9

What is stress?

Answer 9

Measure of the internal force acting. Compact bone withstands greater stress i.e. withstands larger internal forces

Question 10

What is strain?

Answer 10

Measure of deformation. Spongy bone can withstand greater strain i.e. has more “give” or ability to bend.

Question 11

What are the bone types?

Answer 11

Long, irregular, flat & short

Question 12

Long bones?

Answer 12

The bones that form our limbs (levers)

Question 13

Key structural elements: Diaphysis/shaft

Answer 13

Forms the long axis of the bone. Constructed of compact bone.

Question 14

KES: Epiphyses

Answer 14

Ends of long bones. Constructed of spongy bone.

Question 15

KES: Epiphyseal plate (growth plate)

Answer 15

Site of longitudinal bone growth.

Question 16

KES: Epiphyseal line

Answer 16

Former site of epiphyseal plate

Question 17

Bone Remodelling

Answer 17

Replaces 5-10% of our skeleton through bone resorption and deposition.

Question 18

Bone Resorption

Answer 18

Carried out by osteoclast activity (osteoclast=cell that breaks down bone)

Question 19

Bone Deposition

Answer 19

Carried out by osteoblast activity (osteoblast=cell that forms bone)

Question 20

Common fracture types

Answer 20

Comminuted, compression, spiral, depressed, greenstick

Question 21

Bone fracture treatment

Answer 21

Step 1: Reduction (realignment of bones), S2: Immobilisation

Question 22

Osteoporosis - homeostatic imbalance

Answer 22

Imbalance between resorption & deposition - bone decenty reduced with age due to imbalance

Question 23

3 ways a joint can be injured

Answer 23

Cartilage tears, sprains (3 grades), dislocations

Question 24

Joints/articulations

Answer 24

Where 2 or more bones meet

Question 25

2 fundamental functions of joints

Answer 25

Mobility, hold bones together

Question 26

Degree of mobility influenced by?

Answer 26

The joints stability & an individual's flexibility

Question 27

Joints are classified as being:

Answer 27

1. Immovable joints (fibrous) e.g. skull sutures 2. Slightly movable (cartilaginous) e.g. pubic symphysis 3. Free movable or synovial joints e.g. hip joint

Question 28

6 types of synovial joints

Answer 28

Pivot, hinge, saddle, plane, condylar/condyloid, ball & socket

Question 29

Key elements of synovial joint structure (4)

Answer 29

1. Joint cavity - filled with synovial fluid 2. Articular cartilage - protects bone ends 3. Synovial fluid - reduced friction 4. Reinforcing ligaments - add stability

Question 30

3 factors that impact stability of synovial joints

Answer 30

1. shapes of articulating surfaces - greater contact = greater stability 2. ligaments - more ligaments=stronger joint BUT if ligaments are primary source of stability the joint isn't particularly stable 3. muscle tone - strength/health of tendons that cross joints

Question 31

2 common homeostatic imbalances

Answer 31

fractures & osteoporosis

Question 32

Remodeling is regulated by?

Answer 32

Maintaining adequate calcium levels, ensuring the bone is regularly loaded i.e. exercise