Skeletal Tissue

Question 1

functions of the skeletal system

Answer 1

• support
• protection
• movement
• storage
• hemopoiesis

Question 2

protects the body core (heart, lungs, brain)

Answer 2

protection

Question 3

muscles attach for movement

Answer 3

movement

Question 4

store calcium & phosphate

Answer 4

storage

Question 5

blood cell production (red bone marrow produces all RBC’s for O2, all platelets ~clotting~, and most WBC’s for defense)

Answer 5

hemopoiesis

Question 6

dense, hard outer layer

under periosteum for strength

Answer 6

compact bone

Question 7

porous w/ open spaces (for red marrow) and trabeculae (needles)

Answer 7

spongy bone

Question 8

longer than short bone

examples: humerus, radius, ulna, femur

Answer 8

long bone

Question 9

cube shaped

examples: carpals, tarsals (wrists/ankles)

Answer 9

short bone

Question 10

examples: ribs, scapula

Answer 10

flat bone

Question 11

odd shapes

examples: pelvis, vertebra

Answer 11

irregular bones

Question 12

examples: knee cap (patella)

Answer 12

sesamoid bones

Question 13

main shaft or “tube” composed of compact/dense bone; hollow cylinder that functions as support

Answer 13

diaphysis

Question 14

• found on both ends or long bone
• bulbous area (rounded) is space for muscle attachment
• made of spongy bone filled w/ red marrow

Answer 14

epiphysis

Question 15

• fibrous outside layer of long bone (everywhere except where there is articular-cartilage)
• fibers penetrate bone & hold it
• fibers interlace w/ muscle fibers to hold on muscle
• BV from ______ penetrate into bone

Answer 15

periosteum

Question 16

cartilage that covers joint surfaces

functions to cushion bone from jarring

Answer 16

articular cartilage

Question 17

space in the middle of the diaphysis

filled w/ yellow marrow

Answer 17

medullary cavity

Question 18

in adults, rich in fat, no hematopoiesis

Answer 18

yellow marrow

Question 19

connective tissue located at the ends of long bones, flat bones skull, sternum, and ribs (adult)
-hematopoiesis (blood cell formation) occurs here

Answer 19

red marrow

Question 20

contains many needlelike bony spicules called trabeculae

Answer 20

spongy bone

Question 21

thin epithelial membrane that lines medullary cavity and covers Trabeculae of spongy bone

Answer 21

endosteum

Question 22

main supply of nutrients to bone, brings oxygen to living bone tissue

Answer 22

nutrient artery

Question 23

layer of cartilage that separates diaphysis from epiphysis, where longitudinal growth occurs during youth, growth stops when all epiphyseal cartilage is transformed into bone

Answer 23

epiphysial plate

Question 24

bone remnant of growth plate

Answer 24

epiphyseal line

Question 25

bone building cells (store calcium, become osteocytes)

Answer 25

osteoblasts

Question 26

bone absorbing cells (break down bone, releasing calcium)

Answer 26

osteoclasts

Question 27

mature bone cell

Answer 27

osteocyte

Question 28

the "structural unit" is the Osteon or Haversian Canal system

Answer 28

compact bone

Question 29

secrete, or "spit out" matrix material and collagen fibers | they spit out so much of these fibers that it is now "trapped" in a prison chamber of it's own making

Answer 29

osteoblasts

Question 30

chamber or space for bone cells

Answer 30

lacuna

Question 31

- concentric circles that osteocytes arrange themselves in, around a central canal - "thin plate" in Latin

Answer 31

lamellae

Question 32

the central/vertical canals, inside are blood vessels that nourish the bone

Answer 32

Haversian canals

Question 33

- contain slender extensions that connect osteocytes, carrying nutrients and waste (nourishment) - tiny canals that radiate out from the central canal to the lacuna of lamellae to lamellae

Answer 33

Canaliculi

Question 34

a central (haversian) canal and all concentric layers of lamellae are referred to as the ______, or haversian system

Answer 34

osteon

Question 35

- horizontal canals - run into the compact bone/marrow cavity from periosteum - at right angle to the central canal - complete communication pathway (w/ central canals) btw. bone interior and external surface

Answer 35

Volkmann's canals

Question 36

large, multi-nucleated cells that resorb or "eat" bone matrix

Answer 36

osteoclasts

Question 37

How does endochondral ossification occur and where?

Answer 37

WHERE: process used in most bones!!! HOW: cartilage model is laid down and covered by a fibrous periosteum, soon a collar bone appears deposited by the osteoblasts -cartilage cells enlarge and die bc they are basically starved to death (medullary cavity forms) -BV's invade cartilage model (bring osteoblasts and clasts) and work together to carve out medullary cavity -BV's care called primary ossification center -osteoblasts deposit calcium -secondary ossification centers form at each epiphysis -until bone growth complete, epiphyseal plate btw. diaphysis and epiphysis

Question 38

How does intramembranous ossification occur and where?

Answer 38

WHERE: simpler ossification, found in flat bones of skull HOW: 1) groups of cells differentiate into osteoblasts and cluster into centers of ossification 2) osteoblasts secrete collagen fibers 3) calcium salts crystalize around fibers (process=calcification) 4) eventually become trabeculae and spongy bone formed 5) outer areas of spongy bone will be reconstructed to compact/dense bone