Presentation 5: Skeletal System

Question 1

Connective Tissue

Answer 1

cartilage, bone, and adipose
all have extracellular fibers + proteins
provide support for organs and movement

Question 2

Extracellular fibers (proteins)

Answer 2

Collagen (found in skin), Elastin(found in tips of nose/ears), and Keratin(found in nails, beaks, etc.)
all imbedded in a matrix of muccopolysaccharides

Question 3

Matrix of Muccopolysaccharides

Answer 3

Cartilage - glycoproteins
Bone - hydroxyapatite

Question 4

Cartilage Types

Answer 4

Hyaline Cartilage (replacement bones)
Fibrocartilage (not flexible, provides strength, bundles of collagen)
Elastic cartilage (bundles of elastin fibers)

(all avascular aka no blood supply)

Question 5

Cartilage Development

Answer 5

1. Mesenchymal cells secrete mucopolysacharide matrix
2. Inner layer of perichondrium contains matrix secreating mesenchymal that continue to deposit cartilage
3. Once chondroblasts are surrounded by matrix, they stop secreting matrix and become a chondrocyte

Question 6

Mesenchymal cells

Answer 6

secrete fibrous mucopolysaccharide matrix (i.e. fibroblast) during cartilage development

Question 7

Perichondrium

Answer 7

Membrane surrounding cartilage, the inner layer of which contain mesencymal cells

Question 8

Chondroblast

Answer 8

Mesenchymal cells that differentiate into cartilage secreting cells

Question 9

Condrocyte

Answer 9

What chondroblasts become ones fully surrounded by matrix and stopping matrix secretion

Question 10

Lacunae

Answer 10

where chondrocytes are located

Question 11

Bone Types

Answer 11

Endochondral (required cartilaginous precursor)
Membranous (deposits directly in skin aka dermal bone)

Question 12

Bone Development

Answer 12

1. Cartilage impregnated w/ hydroxyapatite and Chondrocytes die
2. Perichondrium proliferate and blood vessels invade cartilage
3. Bone matrix secreted along disintegrating cartilage fiber axes
4. Perichondrium -> periosteum and secretes layers of bone matrix that form outer covering of bone

Question 13

Periosteum

Answer 13

What the perichondrium becomes during bone development to form layers of bone matrix to surround bone

Question 14

Osteon

Answer 14

harvesian system of blood vessels + osteocytes

Question 15

Osteocytes

Answer 15

In concentric layers of lamellae of bone, adult cells of osteoblasts interconnected by Canaliculi

Question 16

Osteoclast

Answer 16

reabsorb bone during remodeling (i.e. if you break your bone)

Question 17

Funtional Units of the Skeleton

Answer 17

1. Head skeleton (cartilaginous brain case, visceral skeleton, dermal skeleton)
2. Axial Skeleton (vertebral column, sternum and ribs)
3. Appendicular Skeleton (pectoral and pelvic girdles and limbs)

Question 18

Head Skeleton

Answer 18

Protects sense organs and brain
- Cartilaginous brain case aka Chondrocranium (endochondral bone)
- Visceral Skeleton aka Splachnocranium (embryonic jaws and gill arches
- Dermal Skeleton aka Dermatocranium (membrane bones)

Question 19

Components of Head Skeleton

Answer 19

1. Notochord - most ant. part
2. Parachordal cartilages - 1 pair form basal plate (floor)
3. Trabeculae - 1 pair fuse at ethmoid plate
4. Occipital Cartilages - set of cartilages fuse at occipital arch
5. Orbital Cartilages - 1 pair, behind the eyes descend to form side of brain case
6. Sensory capsules - olfactory, optic, and otic

Question 20

Foramina

Answer 20

Holes in the cartilage which allow nerves or blood vessels to pass through (ex. Foramina magnum = hole for spinal chord)

Question 21

Parachordal cartilages

Answer 21

form the basal plate

Question 22

Trabeculae

Answer 22

fuse together at ethmoid plate

Question 23

Occipital cartilages

Answer 23

set of cartilages fuse at occipital arch

Question 24

orbital cartilage

Answer 24

behind the eyes form side of brain case