Bones

Question 1

Functions of the skeleton (6)

Answer 1

support
protection
movement
mineral storage
blood cell production
fat storage

Question 2

What is the axial skeleton and what does it include?

Answer 2

Central axis

eg. skull, vertebral column, ribs

Question 3

What is the appendicular skeleton and what does it include?

Answer 3

Appendages
upper and lower limbs
include shoulders (pectoral girdles) and pelvis (pelvic girdles)

Question 4

Why do adults have less bones than babies?

Answer 4

bones fuse together as humans grow

Question 5

What are the 5 different types of bones?

Answer 5

long (with bulbous ends)
short
flat (eg. sternum)
irregular (eg. vertebrae)
sesamoid (eg. patella being the only one everyone has)

Question 6

What are the cells, fibres and ECM present in a bone?

Answer 6

osteogenic cells, osteoblast, osteocyte, osteoclast

collagen (organic)

mineral salts (inorganic)

Question 7

Anatomy of a long bone: what is the diaphysis?

Answer 7

shaft, compact bone

Question 8

Anatomy of a long bone: what is the epiphysis?

Answer 8

ends of bone, spongey

Question 9

Anatomy of a long bone: what is the articular cartilage?

Answer 9

covers epiphyses

Question 10

Anatomy of a long bone: what is the medullary cavity?

Answer 10

marrow cavity

Question 11

Anatomy of a long bone: what is the endosteum?

Answer 11

lining of marrow cavity

Question 12

Anatomy of a long bone: what is the periosteum?

Answer 12

tough membrane covering bone but not cartilage

Question 13

Function and location of osteogenic cells?

Answer 13

derived from embryonic fibroblasts
undergo mitosis
located at edge of bone
some become osteoblasts

Question 14

Function and location of osteoblasts?

Answer 14

bone forming
synthesis organic bone matrix
initiate calcification
become osteocytes
located at the edge of bone

Question 15

Function and location of osteocytes?

Answer 15

cytoplasmic ‘fingers’
osteoblasts that have become trapped in the matrix secreted
maintain marrow
located inside cavities in the matrix

Question 16

Function and location of osteoclasts?

Answer 16

bone dissolving
release lysosomal enzymes
multinucleate
large
derived from fusion of bone marrow in monocytes
located at edge of bone in pits

Question 17

What is the inorganic matter in the bone matrix?

Answer 17

calcium phosphate and calcium carbonate salts form crystals (bone is hard)

Question 18

What is the organic matter in the bone matrix?

Answer 18

collagen fibres for strength and flexibilty

Question 19

What is mineralization (calcification)?

Answer 19

hardening of matrix when mineral crystals deposit around collagen fibres

Question 20

What are the two types of bone found within bones?

Answer 20

Compact and spongey

Question 21

What is the function and location of compact bone?

Answer 21

solid layer located at diaphysis and edges of bone

resist stresses from weight and movement

Question 22

What is an osteon or Haversian system (compact bone)?

Answer 22

bone matrix laid down in rings around blood vessels
blood vessels run in Haversian canals
osteons align along lines of stress

Question 23

What is lamellae (compact bone)?

Answer 23

layers of bone
concentric- rings of bone
interstitial- old osteons that have been partially removed

Question 24

Where are osteocytes found in compact bone and how do they communicate?

Answer 24

found in spaces in matrix called lacunae

communicate with each other via canaliculi

Question 25

Structure, function and location of spongey bone

Answer 25

latticework of thin plates (trabeculae) orientated along lines of stress
spaces filled with red marrow
located at epiphyses in flat bone
provide strength with little weight

Question 26

How do osteogenic cells, osteoblasts and osteoclasts receive nutrients?

Answer 26

Near edge of bone near blood vessels

Diffusion

Question 27

How do osteocytes receive nutrients?

Answer 27

Nutrients cannot diffuse through matrix

Join to each other via cell extensions within canaliculi which allow diffusion

Question 28

Function and location of red bone marrow

Answer 28

located medullary cavity and trabeculae spaces

development of blood cells

Question 29

Function and location of yellow bone marrow

Answer 29

located diaphysis medullary cavity

fat storage

Question 30

Functions of cartilage (3)

Answer 30

resist compression
absorb shock
smooth surface to minimize friction

Question 31

What are the three cells in cartilage?

Answer 31

chondroblasts, chondrocytes, matrix

Question 32

What and where are chondroblasts?

Answer 32

secrete cartilage matrix, near edge

Question 33

What and where are chondrocytes?

Answer 33

chondroblasts trapped within matrix secreted, located in lacunae

Question 34

What is the cartilage matrix made from?

Answer 34

chondroitin sulphate (retains water so is rubbery)

Question 35

What are the three different types of cartilage and what characterizes them?

Answer 35

hyaline (articular) cartilage: collagen = elastin
fibrocartilage = more collagen
elastic cartilage = more elastin

Question 36

Location, function and structure of hyaline cartilage

Answer 36

clear, glassy, fine collagen fibres
over ends of bones at moveable joints to prevent friction
holds airways open, eg. trachea

Question 37

Location, function and structure of fibrocartilage

Answer 37

row of chondrocytes in lacunae, parallel bundles of collagen
located intervertebral discs
resist compression, absorb shock

Question 38

Location, function and structure of elastic cartilage

Answer 38

web-like mesh of elastin amongst lacunae
located external ear, epiglottis
flexibility, elastic support, maintain shape