Block 2 - Skeletal Tissue

Question 1

Where is cartilage found?

Cartilage is the template for what?

Answer 1

articular surfaces:

smooth / low friction

template for bone formation

Question 2

The strength of cartilage is due to ________.

The resilience of cartilage is due to _________.

Answer 2

collagen fibers

chondroitin sulfate

Question 3

What is the term for mature cartilage cells and where are they found?

Where are these derived from?

Answer 3

chondrocytes / lacunae

chondroblasts

Question 4

Cartilage is a dense network of what two substances embedded in a ground substance of what compound?

Answer 4

Collagen and elastic fibers

chondoitin sulfate

Question 5

The dense, irregular connective tissue that covers cartilage is called?

Once this area is vascularized, it becomes the periosteum.

Answer 5

the perichondrium

Question 6

Cartilage has no blood vessels.

It also has no nerves except for in one area.

What area is this?

Answer 6

the perichondrium

Question 7

What are the three types of cartilage?

Answer 7

hyaline

fibrocartilage

elastic

Question 8

What type of cartilage is the most abundant type of cartilage and covers the ends of long bones and parts of the ribs, nose, trachea, bronchi, and larynx?

Answer 8

hyaline

Question 9

Where can hyaline cartilage be found?

Answer 9

Covers the ends of long bones and parts of the ribs, nose, trachea, bronchi, and larynx

Question 10

What cartilage consists of thick bundles of collagen fibers and is a very strong, tough cartilage?

Where can this type be found?

Answer 10

fibrocartilage

Typically occurs as disc-shaped segment of cartilage between bones.

Question 11

What type of cartilage consists of chondrocytes located in threadlike network of elastic fibers?

Where are two locations this cartilage could be found?

Answer 11

elastic cartilage

malleable part of the external ear

&

epiglottis

Question 12

What two minerals are involved in bone mineral homeostasis?

What is produced and what is stored within bone?

Answer 12

calcium and phosphorous

blood cell production

triglyceride storage

Question 13

Give the term for each description:

1. shaft or body
2. distal and proximal ends
3. where the diaphysis and epiphyses meet
4. at the metaphysis of a growing bone
5. hyaline cartilage covering the epiphyses
6. dense irregular connective tissue that covers the bone (except for the articular cartilage)
7. space inside the diaphysis
8. membrane lining the marrow cavity

Answer 13

1. diaphysis
2. epiphsyses
3. metaphyses
4. epiphseal plate
5. articular cartilage
6. periosteum
7. marrow cavity
8. endosteum

Question 14

Bone matrix is made up of what percentage of

water, collagen, and hydroxapatite?

Answer 14

25% / 25% / 50%

Question 15

All bone tissues come from what?

Give the term for the description:

stem cells that can divide and differentiate into osteoblasts

secrete bone matrix and become osteocytes

mature bone cells; regulate the composition of the bone matrix

release enzymes that digest bone matrix for remodeling of bone

Answer 15

the mesenchyme

osteogenic cells

osteoblasts

osteocytes

osteoclasts

Question 16

The regions of the bone have two sub-types:

what are those two sub-types?

Most of the skeleton is what type

Can both sub-types be present in the same bone?

Answer 16

compact bone

spongy bone

compact bone

Yes.

Question 17

What are the units that are within the compact bone?

Where are these units/systems formed?

What exists between left over fragments of older osteons?

Answer 17

osteons (Haversian systems)

Formed from concentric lamellae (rings of calcified matrix)

interstitial lamellae

Question 18

What encircles the bone beneath the periosteum?

What encircles the medullary cavity?

Answer 18

outer circumferential lamellae

inner circumferential lamellae

Question 19

What are the small spaces between the lamellae which house osteocytes?

What are the small channels filled with extracellular fluid connecting the lacunae?

Answer 19

lacunae

canaliculi (like a canal)

Question 20

Within the bone tissue, where are the blood and lymphatic vessels found?

What allows transit of these vessels to the outer cortex of the bone?

Answer 20

in the osteon’s central canal

The perforating (Volkmann’s) canals

Question 21

What does spongy bone lack?

Since spongy bone lacks this particular portion, what replaces (it is a lattice of thin columns of trabeculae)?

Answer 21

osteons

lamellae

Question 22

What is the scientific term for blood cell production that occurs in spongy bone?

What is the function of the trabeculae of spongy bone?

Answer 22

hematopoiesis

supports and protects the red bone marrow

is oriented along lines of stress

Question 23

What exist within the trabeculae of spongy bone?

What is the process of forming new bone?

When does bone formation occur?

Answer 23

lacunae

ossification / osteogenesis

1. Formation of boen in an embryo
2. Growth of bones until adulthood
3. Remodeling of bone
4. Repair of fractures

Question 24

Beginning about the 6th week of embryonic development,

what are the two ossifications?

Answer 24

intra-membranous ossification

endochondral ossification

Question 25

What occurs in intra-membranous ossification? What occurs in the endochondral ossification?

Answer 25

produces spongy bone (this bone may subsequently be remodeled to form compact bone) cartilage is replaced by bone and forms both compact and spongy bone

Question 26

The forming of flat bones of the skull, mandible and clavicle can be attributed to what ossification process? Within the above process of ossification, bone forms from ____________ cells that develop with a \_\_\_\_\_\_\_\_\_\_\_-without going hrough a cartilage stage.

Answer 26

intra-membraneous mesenchymal / membrane

Question 27

This process is particularly common in the formation of most bones and especially long bones.

Answer 27

endochondral ossification

Question 28

Within bone remodeling, what are the two types?

Answer 28

**bone resoprtion:** removal of minerals and collagen fibers from bone by osteoclasts (clast = "crush") **bone deposition (deposit):** addition of minerals and collagen fibers to bone by osteoblasts (blast = "build")

Question 29

When there is a imbalance between the actions of osteoblasts and osteoclasts, abnormalities occur such as: 1. **too much new tissue formed-bones become thick and heavy** 2. **excessive loss of calcium weakens the bones and creates "pores" in the bone structure** 3. **bone structure can become "soft" - i.e. "rickets"**

Answer 29

acromegaly osteoporosis osteomalacia

Question 30

**Within bone fracture and repair**, What forms within the first 6-8 hours after injury? What causes this formation?

Answer 30

formation of a fracture hematoma blood vessels breaking in the periosteum and osteons

Question 31

Within fracture repair, the ssecond and third steps involve the formation of what? What is the role of phagocytes and fibroblasts?

Answer 31

the callus phagocytes remove cellular debris fibroblasts deposit collagen to form a fibro-cartilaginous callus osteoblasts form a bony callus of spongy bone

Question 32

What occurs in the final step of fracture and repair?

Answer 32

spongy bone is replaced by compact bone

Question 33

What are three things Calcium is used in? 99% of the body's calcium can be found where?

Answer 33

synaptic transmission / muscle contraction / blood clotting in the bone

Question 34

**Name the vitamin involved in each process:** 1. Stimulates activity of osteoblasts 2. Needed for synthesis of collagen 3. Essential to healthy bones because it promotes the absorption of calcium from foods in the gastrointestinal tract into the blood 4. Needed for synthesis of bone proteins

Answer 34

Vitamin A Vitamin C Vitamin D Vitamin K and B₁₂

Question 35

**What substance has these functions:** 1. Promotes resorption of bone matrix 2. Prevents loss of calcium in the urine 3. Promotes vitamin D (calcitriol) formation

Answer 35

Parathyroid hormone

Question 36

What substance promotes the intestinal absorption of calcium? What substance is produced by parafollicular cells of the thyroid gland and lowers blood calcium levels by inhibiting bone resorption?

Answer 36

calcitriol calcitonin

Question 37

Blood calcium can be increased by two different negative feedback systems. What are the two ways?

Answer 37

release of Calcium from bone matrix retention of calcium by the kidneys

Question 38

A joint can be described as a point of contact between two bones, between bone and cartilage, or between ________ and a \_\_\_\_\_\_\_.

Answer 38

bone and a tooth

Question 39

**Within fibrous joints, what is the term for these descriptions**: 1. thin layer of fibrous connective tissue 2. more space than a suture; more fibrous connective tissue 3. teeth in sockets of upper and lower jaw

Answer 39

sutures syndesmoses gomphoses

Question 40

Within cartilaginous joints, joint components are connected by what two types of cartilage? What are the two types of cartilaginous joints?

Answer 40

fibrocartilage and hyaline cartilage 1. Synchondroses 2. Symphyses

Question 41

**Describe the two types of cartilaginous joints**: Synchondroses Symphyses Which is primary? Which is secondary?

Answer 41

**Synchondroses**: *primary* cartilaginous joints that has hyaline connecting bones **Symphyses**: *secondary* cartilaginous joints that has fibrocartilage connecting bones

Question 42

**Within the synovial joints, what is the term for each description**: 1. Dense irregular and regular connective tissue 2. Lines the capsule; secretes synovial fluid 3. Viscous, clear fluid; lubricates, allows diffusion of nutrient and wastes 4. Covers epiphyses of bone; not covered by synovial membrane 5. Contain articular discs

Answer 42

1. articular capsule 2. synovial membrane 3. synovial fluid 4. articular cartilage 5. also called menisci