Physiology: The Skeletal System

Question 1

What structure of bones is the Diaphysis

Answer 1

▪ the long main portion of the bone▪a.k.a. body, shaft

Question 2

What bone structure is the Epiphyses ▪sing. epiphysis, adj. epiphyseal?

Answer 2

▪ the ends of the bone

Question 3

what region of the bone is the Metaphyses▪sing. metaphysis?

Answer 3

the regions between the diaphysis and the epiphyses

▪ contains the epiphyseal growth plate/epiphyseal line

Question 4

What and where is the Epiphyseal Growth Plate?

Answer 4

▪ a cartilagenous area within the metaphysis of a growing bone
▪ once growth stops, what remains is the epiphyseal line

Question 5

A thin layer of hyaline cartilage covering the epiphyses?

Answer 5

Articular Cartilage

Question 6

what is Periosteum?

Answer 6

-a tough CT covering that surrounds bone

▪well vascularized and innervated

Question 7

what does Periosteum do/is for?

Answer 7

▪it protects, nourishes and heals bone
▪it is an attachment for tendons and ligaments
▪outer layer is tough and supportive/protective
▪inner layer has bone forming cells

Question 8

what is bone?

Answer 8

Connective tissue

Question 9

Bone Structure: What is the Medullary Cavity a.k.a. marrow cavity?

Answer 9

▪the space within the diaphysis that contains:

1) red marrow (for blood cell formation)
2) yellow marrow (for fat storage)

Question 10

what is bone made of/matrix?

Answer 10

25% water
25% collagen
50% mineral salts

Question 11

what are osteoblasts?

Answer 11

bone building cells (and differentiate into osteocytes)

Question 12

what are osteoclasts?

Answer 12

bone “eating” cells

Question 13

what are osteocytes?

Answer 13

mature bone cells

Question 14

what is an osteoprogenitor?

Answer 14

• cells that are active during normal growth, healing and cyclical bone replacement
• they differentiate and turn into osteoblasts

Question 15

what are the two bone types?

Answer 15

spongy and compact

Question 16

structure of compact bone contains?

Answer 16

• Osteons a.k.a. Haversian systems
• Central (a.k.a. Haversian) canal
• Concentric Lamellae
• Lacunae, sing. (lacuna)
• Canaliculi
• Volkmann’s Canals a.k.a. transverse perforating canals

Question 17

a hole through the centre of the osteon through which blood and lymphatic vessels run

Answer 17

Central (a.k.a. Haversian) canal

Question 18

rings of hard, calcified bone matrix around the central canal:

Answer 18

Concentric Lamellae

Question 19

what is the Lacunae, sing. (lacuna)?

Answer 19

▪spaces between the rings▪in the lacunae are osteocytes (little “lakes”)

Question 20

what are Canaliculi?

Answer 20

▪small channels sticking out (in all directions) from the lacunae▪filled with extracellular fluid
▪allows osteocytes to communicate

Question 21

Volkmann’s Canals a.k.a. transverse perforating canals?

Answer 21

▪holes which run transversely to connect the inner and outer portions of the bone

Question 22

Spongy bone contains:

Answer 22

trabiculae, which contain osteocytes in lacunae connected by canaliculi

Question 23

periosteal arteries enter the diaphysis at multiple points (Volkmann’s canals) to supply:

Answer 23

the periosteum and outer compact bone