chapter 6- skeletal system

Question 1

what are the four components of the skeletal system?

Answer 1

bones, cartilage, tendons, and ligaments

Question 2

what are the functions of the skeletal system ?

Answer 2

framework for the body, protection, allows movement, stores minerals in the bone, stores adipose in bone cavity, red bone marrow, and hematopoesis

Question 3

what is hematopoiesis?

Answer 3

the creation of blood cells

Question 4

what do tendons attach to?

Answer 4

muscles and bones

Question 5

what do ligaments do?

Answer 5

hold bones together

Question 6

what are the three types of cartilage ?

Answer 6

hyaline
elastic
fibrocartilage

Question 7

hyaline cartilage

Answer 7

found on the ends of bones and in the nose
gives rise to the skeleton when developing
glassy appearance
collagen

Question 8

elastic cartilage

Answer 8

elastin
flexible
found in external ear and epiglottis

Question 9

fibrocartilage

Answer 9

collagen fibers
strong
found in pubic symphysis, knee meniscus, and intervertebral discs
maintains height

Question 10

what are the types of cartilage growth?

Answer 10

appositional and interstitial

Question 11

appositional growth

Answer 11

cartilage forming cells secrete new matrix against external face of existing cartilage
adds more to surface

Question 12

interstitial growth

Answer 12

chondrocytes divide and secrete new matrix
expand cartilage from within

Question 13

what is the bone matrix?

Answer 13

“reinforced concrete”

Question 14

what does collagen do?

Answer 14

adds flexible strength
lose=brittle

Question 15

what does minerals do for bones?

Answer 15

(hydroxyapetite)
weight bearing strength
lose= bend

Question 16

what are the bone cells?

Answer 16

osteoblasts, osteocytes, osteoclasts

Question 17

what are the ossification bone types?

Answer 17

woven and lamellar

Question 18

final bone types:

Answer 18

compact and spongey

Question 19

osetoblasts

Answer 19

builds matrix, turns chondrocytes into bone
osteogenesis/ ossification
lay down new bone on the surface (appositional)
arise from stem cells

Question 20

osteocytes

Answer 20

maintain matrix, 90-95% of bone cells
arise from osteoblasts, live up to 25 years
found in lacunae,
communicate via canalicoli
connects 1 cell to another, anchors, attaches, and communicates

Question 21

osteoclasts

Answer 21

breakdown matrix (reabsorption)
calcium in blood
arise from bone marrow

Question 22

when does ossification occur

Answer 22

as a fetus
when growing
when a fracture is repaired

Question 23

woven bone

Answer 23

formed first by osteoblasts, weak due to random placement of collagen, osteoclasts break down woven bone

Question 24

lamellar bone

Answer 24

formed by osteblasts to build stringer, more permanent bone
arranged in concentric sheets/layers=lamellae
parallel arrangement= strong
more consistent= more strength

Question 25

spongey bone

Answer 25

appears porous with more space
consists of trabecular= interconnected roots
thin, found along mechanical stress lines

Question 26

compact bone

Answer 26

more bone matrix
dense, solid outer layer
osteoblasts/ haversian system= unit
concentric rings of lamellae
shaft of bone, vascular

Question 27

what are the types of bone?

Answer 27

long bone
flat bone
short and irregular bone

Question 28

what is long bone made up of ?

Answer 28

compact bone with a medullary cavity in the center

Question 29

diaphysis

Answer 29

the main shaft of the long bone

Question 30

epiphysis

Answer 30

the ends of the long bones, mostly made out if spongey bone
covered in articular cartilage

Question 31

epiphyseal plate

Answer 31

“growth plate”
between two parts
occurs on both ends
becomes the epiphyseal line when growth is complete

Question 32

red bone marrow

Answer 32

gives rise to blood cells in the epiphyses

Question 33

yellow bone marrow

Answer 33

adipose in the diaphysis

Question 34

what are the layers of the long bone?

Answer 34

periosteum and the endosteum

Question 35

periosteum

Answer 35

the outer surface
made of dense irregular tissue

Question 36

endosteum

Answer 36

inner surface= bone

Question 37

sharpens fibers

Answer 37

perforating
attachment and strengthens area for ligaments/ tendons

Question 38

flat bone

Answer 38

“spongey bone sandwich”
compact, spongey, compact

Question 39

short and irregular bones

Answer 39

no diaphysis
small growth plates

Question 40

types of fetal ossification

Answer 40

intramembraneous and endochondral

Question 41

intramembraneous

Answer 41

starts with mesenchymal, embryonic connective tissue (fibrous) = flat (cranium)
emery at 8 weeks= 2 years old

Question 42

endochondral

Answer 42

hyaline cartilage- long bone

Question 43

what areas use endochondral fetal ossification ?

Answer 43

base of the skull, mandible area, clavicle epiphyses, rest of skeleton
embryo t 8 weeks in some areas
other areas start at 18-20 years old

Question 44

intramembraneous ossification

Answer 44

begins at ossification centers, expands to form bone slowly.
centers have the oldest bone and the edges are the youngest

Question 45

fontanels

Answer 45

soft spots, covered by membranes, bone fuse to cover, allows for brain growth
complete after aprox. 22 months
frontal is the largest

Question 46

what is the process of intramembraneous ossification ?

Answer 46

1. osteoblast formation
2. spongey bone formation
3. compact bone formation

Question 47

what happens during osteoblast formation?

Answer 47

step 1, mesenchymal cells (give rise to everything)
osteochondral progenitor cells (bone or cartilage cells), osteoblasts (lay down bone matrix) and become osteocytes
trabecular join together to form spongey bone

Question 48

what happens during spongey bone formation?

Answer 48

step 2, osteoblasts present on trabecular surface, causing it to become larger and longer
trabecular join together to form spongey bone

Question 49

what happens during compact bone formation?

Answer 49

red bone marrow forms as well as the periosteum.
osteoblasts from periosteum lay down bone matrix to form compact bone
creates spongey bone sandwich