Human musculoskeletal anatomy ( Component 3 )

Question 1

What are the 3 types of cartilage ?

Answer 1

Hyaline cartilage
Yellow elastic cartilage
White elastic cartilage

Question 2

What is cartilage ?

Answer 2

Smooth, elastic tissue found in many areas of the body ( eg joints ) that provides structural support
Consists of chondrocytes, surrounded by an extracellular matric

Question 3

What are the 4 main properties of cartilage ?

Answer 3

Cartilage is a hard but flexible, compressible and elastic connective tissue consisting of cells (chondrocytes) embedded in a matrix.

Question 4

Describe the distribution of blood vessels in cartilage and therefore describe the movement of nutrients and oxygen

Answer 4

There are no blood vessels within cartilage and so nutrients and oxygen must diffuse through the matrix to the cells

Question 5

Where is hyaline cartilage located ?

Answer 5

at the ends of bones, the nose and in the trachea

Question 6

Describe the structure of hyaline cartilage

Answer 6

Contains a lot of collagen but no nerves or blood cells

Question 7

What is hyaline cartilage at the ends of the long bones know as ?

Answer 7

Articular cartilage - has parallel collagen molecules coated with smooth glycoprotein to resist wear at end of bones

Question 8

Where is yellow elastic cartilage located ?

Answer 8

located in the external ear and epiglottis

Question 9

What does yellow elastic cartilage consist of ?

Answer 9

Yellow elastic fibres

Question 10

Where is white fibrous cartilage located ?

Answer 10

Found in discs between the vertebrae

Question 11

Describe the composition of white fibrous cartilage

Answer 11

made up of cartilaginous tissue with white fibrous tissue and contains many bundles of the protein collagen giving a much greater tensile strength than hyaline cartilage

Question 12

Describe bone formation ( ossification )

Answer 12

1) Cartilage cells flatten and calcium salts are deposited around them
2) Osteoblasts secrete layers of bone matrix around the cartilage
3) Osteoblasts break down the cartilage
4) Ossification begins at the ends and in the middle. The remaining cartilage allows for growth of bones
5) The dense fibrous connective tissue surrounding the bone is called the periosteum

Question 13

Outline the components of a compact bone

Answer 13

A matrix which is 30% organic (mainly the protein collagen) and 70% inorganic (the main component being hydroxyapatite containing calcium and phosphate)

Question 14

How much of a compact bone is organic and what is this made of ?

Answer 14

30% organic (mainly the protein collagen)

Question 15

How much of a compact bone is inorganic and what is this made of ?

Answer 15

70% inorganic (the main component being hydroxyapatite containing calcium and phosphate)

Question 16

What is the function of the organic components of a compact bone ?

Answer 16

help to resist fracture.

Question 17

What is the function of the inorganic components of a compact bone ?

Answer 17

help prevent compression

Question 18

Name two types of specialised bone cells

Answer 18

Osteoblasts
Osteoclasts

Question 19

What are osteoblasts ?

Answer 19

Group of connected cells in the matrix of the bone that lay down new bone during development of the skeleton and remodelling

Question 20

What are osteoclasts ?

Answer 20

Bone cells that break down bone tissue
This is important in the repair and remodelling of the bone

Question 21

What is the functional unit of compact bone ?

Answer 21

Haversian system

Question 22

Describe the structure of Haversian systems

Answer 22

Small cylindrical structures
Consists of layers of bone tissue around a central canal ( Haversian canal ) which contains the blood supply

Question 23

What is the function of Haversian systems ?

Answer 23

Provide a transport system in bone, facilitating the supply of nutrients and oxygen to bone cells

Question 24

What is the role of volkmann canals in compact bone ?

Answer 24

They carry blood vessels from the bone surface through to the Haversian canals in the centre of each system.

Question 25

What does the Haversian canal contain ?

Answer 25

contains an arteriole, a venule, a lymph vessel and a nerve fibre.

Question 26

What are the 4 main structures that make up compact bone ?

Answer 26

Haversian Canal Canaliculi-fine cytoplasmic threads Lamella-concentric rings Lacunae containing Osteocytes

Question 27

What are Haversian canals ( osteons )

Answer 27

Channels through the bone, parallel to its long axis which contain blood vessels, lymph vessels and nerves

Question 28

What are Canaliculi ?

Answer 28

Fine threads of cytoplasm which connect the cells to the Haversian canals for exchange of materials

Question 29

What are Lacunae ?

Answer 29

Spaces where the bone cells are located

Question 30

What are osteocytes ?

Answer 30

Bone cells

Question 31

What are lamella ?

Answer 31

A ring of osteocytes and collagen fibres

Question 32

Is the matrix impermeable and what does this result in ?

Answer 32

The matrix is impermeable, so the living cells cannot get nutrients or lose waste via diffusion. The threads of cytoplasm in the canaliculi allow for the delivery of nutrients to the osteocytes and the removal of waste.

Question 33

Give two examples of bone disorders

Answer 33

Rickets Osteomalacia

Question 34

What deficincies caused rickets and osteomalcia

Answer 34

Calcium and vitamin D deficiency

Question 35

What is rickets caused by ?

Answer 35

defective calcification of bone as a result of a Vitamin D deficiency or a lack of calcium in the diet

Question 36

What are the symptoms of Vitamin D ?

Answer 36

Bowed legs / knocked knees Enlarged joints Stunted growth

Question 37

What is Vitamin D required for ?

Answer 37

the absorption of calcium from the gut.

Question 38

What is Vitamin D ?

Answer 38

Fat soluble vitamin present in a variety of foods Also produced by the body in response to sunlight exposure Required for calcium absorption in the gut

Question 39

Where is Vitamin D found ?

Answer 39

foods such as butter, eggs and fish liver oils.

Question 40

How can Vitamin D be synthesised ?

Answer 40

Can be synthesised in the skin by the action of UV on a precursor in the skin.