Session 1 Introduction 2

Question 1

Cells at the centre of inter zone region will undergo

Answer 1

Apoptosis to form joint cavity

Question 2

Classes of lever

Answer 2

• Class 1: scissors. Effort applied on opposite side of fulcrum to load
• Class 2: wheelbarrow. Load lifted lies between fulcrum and effort
• Class 3: forceps. Effort applied between fulcrum and load

Question 3

Muscles key principles

Answer 3

• Provide stability and propel body segments
• Can only pull
• Can only act on joints that they or their tendons cross

Question 4

What do neutralisers and fixators do

Answer 4

neutralisers- prevent unwanted actions of a muscle

Fixators- stabilise a joint

Question 5

Muscle contractions can be divided into

Answer 5

Concentric- shortening
Eccentric- lengthening
Isometric- same length

Question 6

What are pennate muscles

Answer 6

One or more aponeuroses running through muscle body from tendon, feather looking, generate greater force as more muscle fibres, less shortening achieved though to less movement

Question 7

What is superficial fascia

Answer 7

Subcutaneous fatty layer found in most regions of the body

Question 8

What is deep fascia

Answer 8

thickened elaboration of epimysium enveloping muscle compartments. Collagen and elastin

Question 9

What do aponeuroses do

Answer 9

Connect muscle to muscle or sometimes to bone

Question 10

what to tendons consist of and what are their main features

Answer 10

Dense regular connective tissue fascicles, anchored to bone by Sharpey’s fibres, low ratio of elastin to collagen, Minimal waste of energy transfer

Poor blood supply and low water content limiting nutrients hence poor healing

Question 11

What are ligaments comprised of

Answer 11

Dense regular bundles of connective tissue, protected by dense irregular connective tissue sheaths

Question 12

What is Hilton’s law

Answer 12

the nerves supplying the muscles moving the joint also supply the joint capsule and skin overlying insertions of these muscles

Question 13

Segmentation is controlled by

Answer 13

Hox genes

Question 14

What are limb buds

Answer 14

First appear as small projections on the lateral body wall during the fourth week of development

Mass of mesenchyme covered by a layer of ectoderm. Tip of bud = apical ectodermal ridge

Elongate by proliferation of mesenchyme

Question 15

The developing upper and lower limbs rotate in

Answer 15

Opposite directions and to different degrees

Question 16

process of intramembranous ossification

Answer 16

• Flat bones such as skull
• Mesenchymal stem cells form cluster
• transform into osteoprogenitor cells and then osteoblasts
• Lay down osteoid (extracellular matrix containing type 1 collagen)
• Mineralises as calcium crystals form
• Osteoid not mineralised forms spongy bone
• Connective tissue differentiates into red bone marrow
• Spongy bone remodelled into thin layer of compact bone on surface of spongy bone

Question 17

Process of endochondral ossification

Answer 17

• Long bones
• Converts cartilage laid down by chondrocytes into bone
• Appearance of primary centres of ossification in middle
• Hyaline cartilage matrix begins to calcify (prevents nutrient diffusion so chondrocytes die)
• Blood vessels invade cavities, osteoblasts and osteoclasts modify calcified cartilage matrix into spongy bone
• Osteoclasts break down some spongy bone to make marrow
• Dense irregular connective tissue forms periosteum which attaches to surroundings
• Bone continues to grow and elongate as cartilage cells at epiphyses divide
• Centres of epiphyses begin to calcify
• Begins by 12th week of embryonic development