Lecture 2 - Skeletons

Question 1

Why have a skeleton?

Answer 1

Support
Muscle attachment
Protection for organs
Permit transmission of force

Question 2

Hydrostatic skeleton

Answer 2

A fluid skeleton in many soft-bodied invertebrates, including annelids, that allows an organism to change shape but not volume.
Pressure generated by muscles

Question 3

Exoskeletons

Answer 3

thick, hard outer coverings that protect and support animals’ bodies

Question 4

Endoskeleton

Answer 4

internal skeleton or supporting framework in an animal

Question 5

Vertebrate skeletons are generally made of?

Answer 5

Cartilage and bone

Question 6

What makes up the axial skeleton?

Answer 6

skull, vertebral column, ribs, sternum

Question 7

What makes up the appendicular skeleton?

Answer 7

Pectoral girdle, arm and hand, pelvic girdle, leg and foot

Question 8

Cartilage skeleton

Answer 8

Cells surrounded by a gel matrix

Question 9

Bone

Answer 9

Dynamic tissue that continually repairs and remodels itself.

Connective tissue hardened by calcium phosphate

Question 10

What is bone made up of?

Answer 10

made up of bone tissue, marrow, cartilage and periosteum

Question 11

Compact bone

Answer 11

Hard, dense bone tissue that is beneath the outer membrane of a bone
Cylinders of tissue around blood vessels

Question 12

Spongy bone

Answer 12

A layer of bone tissue having many small spaces and found just inside the layer of compact bone.
Formed by trabeculae
Strong but light

Question 13

Diaphysis

Answer 13

Cylinder of compact bone

Endosteum cells resorb and deposit

Question 14

Epiphyses

Answer 14

Spongy bone covered with compact bone and cartilage

Question 15

Where do bones grow?

Answer 15

Bones grow between the ends of the diaphysis and the epiphysis

Question 16

How does bone grow?

Answer 16

The ends grow first, then the shaft extends

Bone grows by filling in parts

Question 17

Bone matrix

Answer 17

rigid framework of bone that consists of tough protein fibers and mineral crystals

Question 18

bone restoration

Answer 18

Through the crystallization of ions from plasma and deposited in the bone
Osteoblasts produce collagen fibers that become encrusted with minerals

Question 19

How can bone restoration be reversed?

Answer 19

Can be reversed by low pH and acid phosphate - can lead to osteoporosis

Question 20

How does a bone grow?

Answer 20

The bone first begins as Endochondrial (bone as cartilage)

Then increases in length at ends

Question 21

Where does the bone increase in width?

Answer 21

Increase in width at periphery with centre dissolved

Question 22

How does bone respond to forces?

Answer 22

The growth of certain bones will continue to grow during life in response to what is needed.
E.g., a tennis played having very strong bones in it’s right arm

Question 23

Wolff’s Law

Answer 23

A bone grows or remodels in response to forces or demands placed upon it

Question 24

Simple wolff’s law

Answer 24

Stressed bone is strengthened, unstressed bone is reabsorbed

Question 25

Bone Marrow

Answer 25

A soft tissue inside the bone that produces blood cells

Question 26

Red marrow

Answer 26

Mesh of fibres that produces blood cells

Question 27

Fatty yellow marrow

Answer 27

Stores fat

Question 28

Types of joints

Answer 28

Fibrous Cartilaginous Bony Synovial

Question 29

Fibrous joint

Answer 29

Collagen between bones e.g., sutures of the skull | Immovable and usually strong

Question 30

Cartilaginous joints

Answer 30

allow only slight movement and consist of bones connected entirely by cartilage e.g., sternum Most flexible joint

Question 31

Bony joints

Answer 31

- bones fused by osseous tissue | e. g., mandibles in childhood

Question 32

Synovial joints

Answer 32

bones separated by fluid-filled joint cavity e.g., knee, elbow Tendon attaches muscle to bone, ligament attached bone to bone

Question 33

Synovial joints strength

Answer 33

The strongest joints

Question 34

Examples of Synovial joints

Answer 34

``` Ball and socket e.g., shoulder Hinge e.g., knee, elbow Pivot e.g., radius and ulna Saddle e.g., base of thumb Condyloid e.g., fingers Gliding e.g., wrist ```

Question 35

Ball and socket joint

Answer 35

-smooth hemispherical head fits within a cuplike depression -extensive movement, et less stable (dislocation; shoulder) Multiaxial joint

Question 36

Hinge joint

Answer 36

convex surface of one bone fits into the concave surface of another Monoaxial joint

Question 37

Pivot joints

Answer 37

One bone has a projection that is held in place by a ringlike ligament of another bone The first bone rotates on its longitudinal axis relative to the other Monoaxial joint

Question 38

Condyloid (ellipsoid) joints

Answer 38

Oval convex surface on one bone fits into a similarly shaped depression on the next. e.g., fingers Biaxial joints

Question 39

Gliding (plane) joint

Answer 39

Two flat surfaces that slide over each other to allow movement Non-axial joint

Question 40

Saddle joints

Answer 40

Two planes of movement, with a small amount of rotation | Similar to ellipsoid joint