Bone Tissue (2 webinars)

Question 1

what makes bone tissue specialized ?

Answer 1

it has a hard and calcified (mineralized) extracellular matrix . calcium salts are deposited in ground substance

Question 2

what is the cell responsible for maintenance of bone ?

Answer 2

osteocytes

Question 3

what are the main functions of the bone?

Answer 3

support and protect

provides levers for muscle ( muscle cannot work without bone )

stores calcium phosphorus minerals

red marrow inside bone is site for formation of blood cells (hematopoeisis )

Question 4

describe the structure of the bone –0——–

Answer 4

the outer layer is covered by periostium

the inside is covered in a very thin layer called endostium

in between we will find the cells
osteocytes are present in the middle while the oseoblast are on the peripheral side of the inside of the cell

Question 5

what is the periosteum ?

Answer 5

the outer cover layer of the bone . it is composed of external fibrous layer and inner vascularized layer ( osteoblasts , also known as osteo-progenitor layer )

Question 6

what cell is responsible for healing fractures in bones?

Answer 6

osteo-progenitor cell

Question 7

What are Sharpey’s fibers ?

Answer 7

the part of any fiber that penetrated the bone and binds to periosteum

Question 8

describe the structure of the endosteum ,

Answer 8

it is the lining of internal surface of the bone .similar in function to periosteum but only 1 layer thick (one cell thick ) and it contains immature cells .

Question 9

what type of collagen is present in bone fibers ?

Answer 9

collagen type 1

Question 10

extra cellular matrix of bones is not fluid it is calcified and mineralized

70% crystalline complex of calcium and phosphorus and 30% collagen

Answer 10

,,

Question 11

what are osteoblasts ?

Answer 11

immature cells responsible for formation of bone

they are always resting on un-minaralized tissue (bone)

Question 12

what is the matrix of oseoblasts made of?

Answer 12

glycoprotein and collagen

Question 13

what are osteocytes ?

Answer 13

mature bone cell responsible for maintaining matrix and health of bone.

they rest on and are surrounded by lacuna ( cytoplasmic extension to communicate with other type of cell)

Question 14

what is the lacunae?

Answer 14

cytoplasmic extension to communicate with other type of cell

Question 15

what are ossteoclasts ?

Answer 15

the cell responsible for resorbing of bone

it is large

has multiple nucli

contains acids

Question 16

where does the embryonic connective tissue originate from ?

Answer 16

mesoderm / mesenchyme

Question 17

what is ossification and what are the 2 types?

Answer 17

it is the formation of bone . the two types are intramembranous ossification and endochondral ossification

Question 18

what is the difference between intramembranous and endochondral ossification ?>

Answer 18

in intramembranous ossification the body draws a membrane in the shape of the desired bone ( by the mesoderm’s ) and then osteoblasts start to differentiates and form the bone inside the membrane . ( no cartilage needed)( flat bones of skull , maxilla)

in endochondral ossification a cartilage grows and the deep layer converts into bone . classification of the bone happens inside cartilage . ( vertebral column , long bones in limbs )

Question 19

what types of ossification does the mandible have ?

Answer 19

both intra membranous(body of mandible) and endochondral ossification (coronoid process and condylar process)

Question 20

which part of the mandible has intramembranous ossification ?

Answer 20

the body of the mandible .

Question 21

what part of the mandible has endochondral ossification ?

Answer 21

the coronoid and the condylar process

Question 22

what is the cartilage in endochondral ossification made of ?

Answer 22

chondroblast

Question 23

what is a lamelar bone

Answer 23

bone arranged in layer

Question 24

what are the 2 types of lamelar bone ?

Answer 24

compact bone and spongy bone

Question 25

describe the structure of compact bone.

Answer 25

has definite structure and is composed of Haversian system

Question 26

describe the structure of Haversian system

Answer 26

lamellae layers, surrounding Haversian canal . osteocytes arranged surrounding the layers of lamellae

Question 27

why and how is the bone vascularized?

Answer 27

inside the Haversian canal there are vessels

Question 28

what are canaliculi ?

Answer 28

branches coming off of the osteocytes

Question 29

what is Volkmann’s canals?

Answer 29

horizontal canal in between Haversian canal , connecting them . this is how the bone cells and blood vessels can be present inside the bone and reach into osteocytes

Question 30

complete drawing of bone under microscope on webinar 2 specialized connective tissue minute 12

Answer 30

lol

Question 31

inter statial laouter circumferential layer and inner circumferential layer . mellae

Answer 31

.

Question 32

outer circumferential layer (up next to the fibers penetrating the bone )

Answer 32

.

Question 33

inner circumferential layer( down)

Answer 33

.

Question 34

inerstacial lamella ( scattered osteocytes and lamella between Haversion system )

Answer 34

.

Question 35

how are compact and spongy bones different ?

Answer 35

lamelea are arranged keeping wide space (unlike compact bone which is compact )that contains bone marrow and is responsible for formation of hemopoietic tissue . i