Exam 2 Study Guide: Ossification

Question 1

Main functions of bone (5)

Answer 1

• support (framework)
• protection
• movement
• storage (minerals, especially calcium + phosphorous)
• blood cell production

Question 2

Hematoporesis

Answer 2

Blood cell production

Question 3

What minerals does the skeletal system mainly produce? (2)

Answer 3

Calcium
Phosphorous

Question 4

What tissues are found in bone? (5)

Answer 4

Areolar
Dense irregular
Dense regular
Bone marrow
Osseous tissues

Question 5

What are the bone cell types (3)

Answer 5

Osteoblasts
Osteocytes
Osteoclasts

Question 6

Osteoblast Function

Answer 6

Bone formation (“form new bones and add growth to existing bone tissue” - Cleveland Clinic)
(Then turn into osteocytes or die)

Question 7

Osteocyte Function

Answer 7

Maintain mineral concentration of matrix (“responsible for the balance of bone formation/resorption” -Study.com)
(They monitor + respond to things)

Question 8

Osteoclast Function

Answer 8

Bone resorption (dissolve and break down old/damaged bones, making space for osteoblasts)

Question 9

Osteon definition

Answer 9

Structural unit of bones

Question 10

Osteon components (4)

Answer 10

• lacunae
• lamellae
• haversian/central canal
• canaliculi

Question 11

Lacunae

Answer 11

open pockets where osteocytes reside

Question 12

Haversian/Central Canal

Answer 12

Central canal containing blood vessels, nerves, and lymphatics vessels

Question 13

Lamellae

Answer 13

concentric rings of calcified matrix

Question 14

Canaliculi

Answer 14

Small channels that connect connecting lacunae allowing nutrients + waste to move

Question 15

Parts of a typical long bone (9) (Recommend labelling them or using quizlet)

Answer 15

• diaphysis
• epiphysis
• growth plate
• articular cartilage
• medullary canal
• periosteum
• endosteum
• spongy bone
• compact bone

Question 16

Diaphysis

Answer 16

tubular shaft that runs between proximal and distal ends of the bone

Question 17

Epiphysis (2)

Answer 17

• wider section at ends of the bone
• enlarged to strengthen joint + attatch ligaments

Question 18

Articular cartilage

Answer 18

Acts like a shock absorber + reduces friction

Question 19

Periosteum

Answer 19

outer fibrous layer of collagen

Question 20

What are the blood supply locations in bone? (3)

Answer 20

Haversian Canal
Volkmann’s Canal
Canaliculi

Question 21

Volkmann’s Canal

Answer 21

Moves blood between osteons

Question 22

Parts of a flat bone (3)

Answer 22

• periosteum (around compact bone)
• compact bone
• spongy bone

Question 23

Spongy bone structure (AKA trabeculae) (4)

Answer 23

• helps resist stress
• NO osteons
• irregularly arranged lamellae + osteocytes connected by canaliculi
• gets nutrients from capillaries in endosteum

Question 24

Structures/characteristics of flat bone

Answer 24

• bone plates sandwiched between connective tissue membranes
• no shaft/epiphyses
• bone marrow throughout spongy bone (no marrow cavity)
• hyaline cartilage covers articular surfaces

Question 25

Intramembranous ossification description

Answer 25

bone DEVELOPS from fibrous membrane (skull)

Question 26

Endochondral ossification description

Answer 26

bone forms by REPLACING hyaline cartilage (long/short bones, growth plate stuff)

Question 27

What hormones are responsible for bone growth? (4)

Answer 27

- growth hormone - estrogen - testosterone - thyroxine

Question 28

Growth hormone (2)

Answer 28

- Increases bone length (triggers chondrocyte increase in epiphyseal plates) - increases calcium retention

Question 29

Thyroxine

Answer 29

- promotes osteobast activity + bone matrix synthesis

Question 30

Testosterone + Estrogen (3)

Answer 30

- promotes osteoblast activity + bone matrix production - responsible for growth spurt - also end growth by inducing epiphyseal plate closure

Question 31

Parathyroid hormone and Calcium Homeostasis (PTH) (3)

Answer 31

- increases circulating calcium - stimulates osteoclasts so the resorb more bone - kidney tubules resord that calcium (anyways, pretty much breaks down the bone for more calcium)

Question 32

Calcitonin and Calcium Homeostasis (2)

Answer 32

- decreases circulating calcium - inhibits osteoclast activity + increases bone calcium intake (Pretty much builds more bone using the calcium)

Question 33

If calcium too low... (receptor, integrator, and effector)

Answer 33

Receptor = parathyroid gland Integrator = parathyroid hormone Effector = osteoclast cells (break down bone)

Question 34

If calcium too high ... (receptor, integrator, effector)

Answer 34

Receptor = thyroid gland Integrator = calcitonin (stimulates osteoblasts) Effector = osteoblasts (make more bone)

Question 35

What is the role of vitamin D in bone health?

Answer 35

Needed for calcium absorption

Question 36

Transverse fracture

Answer 36

STRAIGHT across long axis

Question 37

Oblique fracture

Answer 37

Occur at angle NOT 90 degrees

Question 38

Spiral fracture

Answer 38

Pulled apart as result of TWISTING (Imagine oblique but rougher)

Question 39

Comminuted Fracture

Answer 39

Crushed! (Several breaks = lotsss of small pieces)

Question 40

Impacted fracture

Answer 40

One fragment driven into another (ouch) - often due to compression

Question 41

Greenstick

Answer 41

Only one side of bone is broken (Crack) (Imagine broken stick just dangling)

Question 42

Open (Compound) (2)

Answer 42

Bone pierces the skin Increases risk of infection

Question 43

Closed (Simple)

Answer 43

Skin remains intact/bone doesn't get through skin