1.1 Bone Tissue and Function

Question 1

Bone remodeling

Answer 1

the building of new bone and the breaking down of old bone tissue

Question 2

What is bone made up of?

Answer 2

different tissues working together, such as:

bone (osseous) tissue, cartilage, dense connective tissue, epithelium, adipose tissue, and nervous tissue

Question 3

Functions of bone

Answer 3

support
protection
assistance in movement
mineral homeostasis
red bone marrow (blood cell production)
yellow bone marrow (triglyceride storage)

Question 4

diaphysis

Answer 4

bone’s shaft or body;

the long, cylindrical, main portion of the bone

Question 5

epiphyses

Answer 5

proximal and distal end s of the bone

Question 6

metaphyses

Answer 6

region between the diaphysis and the epiphyses;
each metaphysis contains an epiphyseal plate
—turns into the epiphyseal line when it stops growing

Question 7

articular cartilage

Answer 7

thin layer of hyaline cartilage covering the part of the epiphyses where the bone forms an articulation joint with another bone

reduces friction; absorbs shock at freely movable joints

lacks a perichondrium; lacks blood vessels, repair of damage is limited

Question 8

periosteum

Answer 8

surrounds the bone surface wherever it is not covered by articular cartilage

also protects the bone
assists fracture repair
helps nourish bone tissue
serves as an attachment point

Question 9

medullary cavity

Answer 9

hollow, cylindrical space that contains fatty yello bone marrow and many blood vessels

minimizes the weight of the bone

Question 10

endosteum

Answer 10

single layer of bone-forming cells

lines the medullary cavity

Question 11

extracellular matrix of bone

Answer 11

15% water, 30% collagen fibers, and 55% crystallised mineral salts

Question 12

calcification

Answer 12

initiated by osteoblasts (bone-building cells)

mineral salts are deposited in the framework formed by collagen fibers of the extracellular matrix, they crystallize and the tissue hardens

Question 13

four types of cells in bone tissue

Answer 13

osteoprogenitor cells
osteoblasts
osteocytes
osteoclasts

Question 14

osteoprogenitor cells

Answer 14

unsepcialized bone stem cells
undergo cell division; results in: osteoblasts
found along inner portion of periosteum, endosteum

Question 15

osteoblasts

Answer 15

boen-building cells
synthesize and secrete collagen fibers and other compounds
initiate calcification
surround themselves with extracellular matrix, and become trapped in their secretions and become osteocytes

Question 16

osteocytes

Answer 16

mature bone cells; main cells in bone tissue
do not undergo cell division
maintains daily metabolism, like exchange of nutrients and wastes with the blood

Question 17

osteoclasts

Answer 17

huge cells derived from the fusion of as many as 50 monocytes (types of White blood cells); concentrated in the endosteum
help regulate blood calcium level

Question 18

compact bone tissue

Answer 18

strongest form of bone tissue
composed of osteons
makes up bulk of diaphyses
provides protection; resists stresses

Question 19

osteons

Answer 19

made up of concentric lamella arranged around an osteonic canal

note: their organisation is not static but changes over time in response to the physical demands placed on the skeleton.

Question 20

concentric lamellae

Answer 20

circular plates of extracellular matrix, surrounding blood vessels and nerves

Question 21

lacunae

Answer 21

small spaces between the concentric lamellae

contains osteocytes

Question 22

canaliculi

Answer 22

slender fingerlike extensions of osteocytes that radiate from the lacunae

Question 23

interstitial lamellae

Answer 23

are fragments of older osteons that have been partially destroyed during bone remodeling/growth

found in areas between neighboring osteons

Question 24

interosteonic canals

Answer 24

how the blood vessels and nerves from the periosteum penetrate the compact bone

Question 25

circumferential lamellae

Answer 25

arranged around the entire outer and inner circumference of the shaft of a long bone

Question 26

spongy bone tissue

Answer 26

also called trabecular or cancellous bone tissue

always located in the interior of the bone, protected by a covering of compact bone

Question 27

trabeculae

Answer 27

lamellae arranged in an irregular pattern of thin columns

Question 28

difference between spongy and compact bone tissue

Answer 28

1) spongy bone tissue is light

2) trabeculae of spongy bone tissue support and protect the red bone marrow

Question 29

periosteal arteries

Answer 29

small arteries accompanied by nerves; enter the diaphysis through interosteonic canals and supply the periosteum and outer part of the compact bone

Question 30

metaphyseal arteries

Answer 30

enter the metaphyses of a long bone and (along with nutrient artery) supply the red bone marrow and bone tissue of the metaphyses

Question 31

Veins that carry blood away from long bone, evident in 3 places:

Answer 31

1) one of two nutrient veins accompany the nutrient artery and exit through the diaphysis
2) many epiphyseal veins and metaphyseal veins exit through the epiphyses and metaphyses, respectively
3) many periosteal veins accompany their respective arteries and exit through the periosteum