Bi106 Lecture Exam One

Front 1

What makes up the axial skeleton?

Back 1

skull and associated bones (auditory ossicles and hyoid bone), the vertebral column and the thoracic cage (ribs and sternum)

Front 2

What makes up the appendicular skeleton?

Back 2

The Pectoral and Pelvic girdles that supprt and attach the upper and lower limbs to the trunk.

Front 3

What does the skeletal system inlcude?

Back 3

the bones of the skeleton, cartilages, ligaments and other connective tissues that stablize or innterconnect bones;

Front 4

What is the functino of the skeletal system?

Back 4

Structural support, storage of minerals and lipids, blood cell production, protection of delicate tissues, organs and leverage.

Front 5

Structure of Bone:
What is osseous tissue?

Back 5

Bone tissue comprised of supporting CT with specialized cells and a solid, xtracell. matrix of protein fibers and ground substance.

Front 6

Structure of Bone:
Histological Organization of Mature Bone:

Hydroxyapatite

Back 6

Large crystals that make up the majority of the bone matrix; accounts for 2/3 bone weight (1/3 made up of collagen fibers and Ca salts, bone cells and other cell types.

Front 7

Structure of Bone:
Histological Organization of Mature Bone -

What are osteocytes?

Back 7

Mature bone cells that are completely surrounded by hard bone matrix; reside in spaces called lacunae where they are interconnected by small, hollow channels called canaliculi.

Front 8

Structure of Bone:
Histological Organization of Mature Bone:

What is the lacunae?

Back 8

a small space containing an osteocyte in bone; situated between the lamellæ (calcified matrix), and consist of a number of oblong spaces

Front 9

Structure of Bone:
Histological Organization of Mature Bone:

What are Osteoblasts?

Back 9

Immature, bone-forming cells; formed via osteogenesis; sythesize osteoid, the matrix of bone prioir to calcification

Front 10

Structure of Bone:
Histological Organization of Mature Bone:

What are the functions of osteocytes?

Back 10

To maintain and monitor the protein and mineral content of the matrix.

Front 11

Structure of Bone:
Histological Organization of Mature Bone:

What are osteoblasts?

Back 11

Cuboidal cells on the inner and outer surface of bone; secrete osteoid that eventually mineralizes.

Front 12

Structure of Bone:
Histological Organization of Mature Bone:

What is osteogenesis?

Back 12

The production of new bone via the osteoblasts.

Front 13

Structure of Bone:
Histological Organization of Mature Bone:

What happens when an osteoblast is surrounded by matrix?

Back 13

It differentiates into an osteocyte.

Front 14

Structure of Bone:
Histological Organization of Mature Bone:

What are osteoprogenitor cells?

Back 14

Mesenchymal (stem cells) cells found in bone tissue; found in the periosteum and endosteum, lining the marrow cavities; can divide into daughter cells that become osteoblasts, important for bone fractures.

Front 15

Structure of Bone:
Histological Organization of Mature Bone:

What are osteoclasts?

Back 15

Giant cells w/50+ nuclei; secrete acids, causes osteolysis

Front 16

Histological Organization of Mature Bone:
Cells - What is osteolysis?

Back 16

An erosion process in which acids from osteoclasts dissolve the bony matrix and release amino acids and stored calcium and phosphate; this inc the Ca and P032- concen. in body fluids

Front 17

Histological Organization of Mature Bone:
Cells - What determines bone strength?

Back 17

Weak bones form when osteoclasts remove Ca salts faster than osteoblasts deposit the; Strong bones form when osteoblast activity predominates.

Front 18

Histological Organization of Mature Bone:
Bone Tissue:
Compact and Spongy Bone

Back 18

Osseous tissue has 2 types, compact bone and spongy bone; both are present in bones and have same matrix comp.

Front 19

Histological Organization of Mature Bone:
What does compact and spongy form form?

Back 19

Compact: Dense and solid tissue that forms the walls;
Spongy: open network of struts and plates that surround the marrow cavity.

Front 20

Histological Organization of Mature Bone:

What is bone marrow?

Back 20

Loose connective tissue dominated by adipocytes (yellow marrow) or by a mixture of mature and immature red and white blood and stem cells (red marrow).

Front 21

Histological Organization of Mature Bone:

How do spongy and compact bone differ, structurally?

Back 21

In their 3-D arrangement of osteocytes, canaliculi and lamellae.

Front 22

Histological Organization of Mature Bone:
Compact bone - what are osteons?

Back 22

Mature compact bone is called osteon, in it are osteocytes that surround a central canal that contain the blood vessel supply for the osteon.

Front 23

Histological Organization of Mature Bone:
Compact bone - name the three lamellae found in compact bone.

Back 23

Concentric (form rings around central canal), Interstitial (fill spaces b/w osteons) and circumferential (on bone surface)

Front 24

Histological Organization of Mature Bone:
Spongy Bone (SB) - what's the primary diff b/w spongy and compact bone?

Back 24

The parallel lamellae form struts of thin, branching plates (trabeculae) in SB and there aren't any ostens in SB, nutrients delivered via diffusion

Front 25

Histological Organization of Mature Bone:
What the fx diff b/w SB and CB?

Back 25

CB covers bone surfaces, it's thickest where stresses come from limited range of direction. SB in inside bones and found where stresses are few and come in many diff directions.

Front 26

Histological Organization of Mature Bone:
The Periosteum - define

Back 26

Covers the outer bone surface, consists of dense fibrous CT and osteoprogenitor cells.

Front 27

Histological Organization of Mature Bone:
The Periosteum - functions?

Back 27

isolates and protects bone from tissue, provides a route and attachment site for circulatory and nervous supply, participates in bone growth and repair, attaches the bone to the CT network of deep fascia

Front 28

Histological Organization of Mature Bone:
The Periosteum - you won't find it here...

Back 28

around sesamoid bones or at attachment sites for tendons, ligaments or joint capsules, or near articular cartilage of bone

Front 29

Histological Organization of Mature Bone:
The Periosteum - so what happens to it around joints?

Back 29

Becomes continuous w/CT to stablize joint; or becomes part of the joint capsule in fluid filled joints

Front 30

Histological Organization of Mature Bone:
The Endosteum - what is it?

Back 30

Found in the bone, a cellular endosteum lines the marrow cavity, contains osteoprogenitor cells, osteoblasts and osteoclasts, active during growth and repair; usually simple or incomplete epithelium

Front 31

Bone Development and Growth:
When does the skeleton begin to form in utero?

Back 31

6 weeks after fertilization

Front 32

Bone Development and Growth:

What is ossification?

Back 32

during embryonic development, either mesenchyme or cartilage is replaced by bone, this process of replacing other tissues with bone is ossification; two types.

Front 33

Bone Development and Growth:

What is calcification?

Back 33

The process in which calcium salts are deposited into a tissue; any tissue can be calcified, but only ossifcation reults in bone.

Front 34

Bone Development and Growth:

Intramembraneous Ossification (definition)

Back 34

aka dermal ossification: when bone develops from mesenchyme or fibrous CT; begins in deep layers of dermis, when mesenchymal cells differentiate into osteoblasts w/in embryonic of fibrous CT, bones that result are dermal/membrane bones; eg. roofing bones in skull, jaw, clavicle

Front 35

Bone Development and Growth:

Intramembraneous Ossification - Step One of the Process

Back 35

mesenchymal cells differentiate into osteoblasts that cluster and secrete matrix components that mineralizes; location of bone where this happens is the ossification center; as ossification proceeds, it traps some osteoblasts that become osteocytes.

Front 36

Bone Development and Growth:

Intramembraneous Ossification - Step Two of the Process

Back 36

Bone grows outwrd in small struts called spicules, growth accelerates as blood vessels reach b/w the spicules

Front 37

Bone Development and Growth:

Intramembraneous Ossification - Step Three of the Process

Back 37

Overtime, many ossification centers form and newly deposited bone becomes spongy bone. Continued deposition of bone via osteoblasts close to the blood vessels form compact bone.

Front 38

Bone Development and Growth:

Endochondral Ossification: (definition)

Back 38

begins with the formation of hyaline cartilage model, eg. limb bones, the model cont to grow by expansion of the matrix

Front 39

Bone Development and Growth:

Endochondral Ossification:
Step 1 of the Process

Back 39

as the cartilage enlarges, chrondocytes by the shaft grow and the matrix calcifies

Front 40

Bone Development and Growth:

Endochondral Ossification:
Step 2 of the Process

Back 40

Cells differentiate into osteoblasts and the inner osteogenic layer produces a bone collar (a thin layer of bone around the shaft of cartilage)

Front 41

Bone Development and Growth:

Endochondral Ossification:
Step 3 of the Process

Back 41

Blood supply increases, calcified matrix breaks down and is replaced by spongy bone.

Front 42

Bone Development and Growth:

Endochondral Ossification:
Step 4 of the Process

Back 42

Entire diaphysis is filled with spongy bone, as it enlarges a marrow cavity forms

Front 43

Bone Development and Growth:

Endochondral Ossification:
Step 5 of the Process

Back 43

Marks beg of inc length of bone; Center of epiphyses calcify, capillaries and osteoblasts migrate to these areas creating secondary ossification centers

Front 44

Bone Development and Growth:

Endochondral Ossification:
Step 6 of the Process

Back 44

Epiphyses fill with spongy bone, articular cartilage forms, epiphyseal cartilage now sep the epi from the diaphysis

Front 45

Bone Development and Growth:

Endochondral Ossification:
Step 7 of the Process

Back 45

Epiphyseal cartliage production slows and rate osteoblast production accelerates at maturity causing the epiphyseal cartilage to become narrow until it disappears, called epiphyseal closure.

Front 46

Bone Development and Growth:

Endochondral Ossification:
Increasing Bone Diameter

Back 46

Diameter enlarges via appositional growth at the outer surface, where osteoprogenitor cells add bone matrix, thus adding successive layers of circumferential lamellae.

Front 47

Bone Development and Growth:

Endochondral Ossification:
Increasing Bone Diameter Process

Back 47

new bone deposited in ridges by blood vessels @ bone surface, ridges enlarge and grow toward eachother until they meet and fuse, cells differentiate and form new bone; as bone diam. grows, so does the marrow cavity

Front 48

Bone Development and Growth:
Formation of blood and lymphatic supply

Back 48

bones formed thru endochondral ossification have 4 sets of vessels: nutrient, metaphyseal, epipyhseal and periosteal; lymphatic vessels enter osteons via canals

Front 49

Bone Development and Growth:
Bone Innervation-

Back 49

Sensory nerve endings branch the periosteum and sensory nerve penetrate the cortex w/nutirent arteries to innervate the endosteum, marrow cavity and epipyhses.

Front 50

Define epiphysis:

Back 50

The rounded end of a long bone.

Front 51

Bone Development and Growth:

Factora Reg. Bone growth

Back 51

nutrients, parathyroid homone that stimulates osteoclast and blast activity, calcitonin that inhibits osteoclas activity and inc Ca loss, epi. cartilage closure.

Front 52

Bone Maitenance, Repair and Remodeling:
What's the turnover rate for bone?

Back 52

high, each year 1/5 of the adult skeleton is broken sown and rebuilt

Front 53

Bone Maitenance, Repair and Remodeling:

Changes in bone shape:

Back 53

Mineral turnover and recycling allows bone to adapt to new stresses

Front 54

Bone Maitenance, Repair and Remodeling:

Injury and Repair

Back 54

healing of a fracture can occur if portions of the blood supply, endosteum and periosteum remain intact

Front 55

Bone Maitenance, Repair and Remodeling:

Aging

Back 55

as you age, your bones get thinner and weak, osteopenia develps and can progress to osteoporosis.

Front 56

Bone Maitenance, Repair and Remodeling:

remodeling bones

Back 56

involves simultaneous process of adding new bone and removing old bone

Front 57

How are bones classified?

Back 57

By anatomical classifications; they are long, sutural, irregular, short and sesamoid bones.