The skeletal system part I

Question 1

Functions of the skeleton

Answer 1

Support
Protection
Movement
Electrolyte balance-calcium and phosphate ions
acid-base balance- buffers blood against excessive pH changes
Blood formation- red bone marrow produces red blood cells

Question 2

How many named bones are there in the Adult human skeleton?

Answer 2

206 bones, born with 270 but many fuse overtime

Question 3

What sections does the Axial skeleton contain?

Answer 3

Skull- cranium and face
Hyoid
Auditory ossicles
Vertebral column
Thorax- sternum and ribs

Question 4

What sections does the Appendicular skeleton contain?

Answer 4

Pectoral (shoulder) girdle- clavicle and scapula
Upper Limbs- Humerus, Ulna, Radius, Carpals, Metacarpals, Phalanges.
Pelvic (hip) girdle- hip, pelvic, or coxal bone
Lower Limbs- Femur, patella, fibula, tibia, tarsals, metatarsals, phalanges

Question 5

Long bones

Answer 5

longer than wide
rigid levers moved by muscles

Question 6

short bones

Answer 6

equal in length and width
glide across in multiple directions

Question 7

flat bones

Answer 7

protect soft organs
curved but wide and thin

Question 8

irregular bones

Answer 8

elaborate shapes that don’t fit into the other three categories

Question 9

Long bone anatomy

Answer 9

Diaphysis
Epiphysis
Metaphysis- epiphyseal growth plate
Articular cartilage- perforating fibers
Periosteum
Medullary cavity
Endosteum

Question 10

Periosteum

Answer 10

covers majority of the bone
Functions to protect, nourish and attach ligaments and tendons
rich in sensory nerves

Question 11

Outer periosteum

Answer 11

Dense irregular connective tissue

Question 12

Inner periosteum

Answer 12

cells

Question 13

Diaphysis

Answer 13

Bone shaft is made of compact bone
Medullary cavity inside bone shaft is filled with yellow marrow and lined by endosteum (a single layer of cells).

Question 14

Epiphyses

Answer 14

Proximal and distal ends of a long bone
Mostly spongy bone with thin compact bone surrounding to give it shape.
Filled with red marrow for making red blood cells
Capped by articular cartilage (hyaline) instead of periosteum

Question 15

Metaphysis

Answer 15

region between diaphysis or bone shaft and epiphysis (proximal and distal ends)
Epiphyseal plate: hyaline cartilage and growth zone

Question 16

Periosteal arteries

Answer 16

Accompanied by nerves, supply the periosteum and compact bone with blood and nutrients

Question 17

Epiphyseal veins

Answer 17

carry blood away from the long bones

Question 18

Structure of a flat bone

Answer 18

• name for the compact spongy compact pattern in the skull.
  Outer layers of —- are covered by periosteum

Question 19

Diploe

Answer 19

Spongy layer in the cranium
-absorbs shock
-Marrow spaces lined with endosteum

Question 20

Composite Materials of bone

Answer 20

Polymer and ceramic matrix
25% water
25% collagen fibers
50% crystallized mineral salts

Question 21

What is the most abundant mineral salt found in bone at 85%

Answer 21

Calcium phosphate or hydroxyapatite

Question 22

What is the scientific name for brittle bone disease

Answer 22

Osteogenesis imperfecta

Question 23

Osteogenic cells

Answer 23

undergo cell division and produce osteoblasts

Question 24

Osteoblasts

Answer 24

Bone-building cells
Synthesize extracellular matrix of bone tissue

Question 25

Osteocytes

Answer 25

Mature bone cells exchange nutrients and wastes with the blood

Question 26

Osteoclasts

Answer 26

release enzymes that digest mineral compositions of bone matrix (resorption) Regulate blood-calcium level Forms from white blood cells called monocytes so it has multiple nucleii

Question 27

Compact bone

Answer 27

resists caused by movement and weight compact bone is arranged into osteons or haversian systems

Question 28

Osteons (Haversian Systems)

Answer 28

Consist of a central canal with concentrical lamellae, lacunae, osteocytes, and canaliculi

Question 29

Lamellae

Answer 29

Rings of calcified matrix, like rings of a tree trunk

Question 30

Lacunae

Answer 30

small spaces between lamellae and contain osteocytes

Question 31

Canaliculi

Answer 31

radiate from the lacunae and are filled with extracellular fluid for nutrients

Question 32

Spongy Bone

Answer 32

Construction: Lamellae are arranged in a lattice of thin columns called trabeculae Spaces between trabeculae make bone lighter Composes most interior bone tissue

Question 33

Trabeculae

Answer 33

The lattice of thin columns in spongy bone bone support that protects red marrow oriented along lines of stress

Question 34

Ossification

Answer 34

Process that forms bones

Question 35

Four situations of Ossification

Answer 35

1. Formation of bone in an embryo 2. Growth of bones until adulthood 3. remodeling of bone 4. repair fractures

Question 36

Intramembranous ossification

Answer 36

Osseus tissue develops directly within sheet-like layers of mesenchyme Involved in making flat bones notably in the skull and mandible

Question 37

Endochondral ossification

Answer 37

this type of bone formation has bone cells forming inside a pre-existing hyaline cartilage model responsible for most bone construction including long bones.

Question 38

Fontanelle

Answer 38

Newborn skull

Question 39

Steps of Endochondral Ossification

Answer 39

Step 1: The cartilage mold forms Step 2: Cartilage molds grow along with growth of the body Step 3: The primary ossification center forms when the nutrient artery arrives and provides blood. Step 4:As ossification continues forms a medullary cavity Step 5: blood vessel entry into the epiphyses stimulates development of new secondary ossification centers Step 6: as the epiphyses ossifies, residual hyaline cartilage remains on the surface of the bone

Question 40

Bone Growth : Length

Answer 40

1) Growth of epiphyseal cartilage on the growth plate 2) replacement of cartilage with bone tissue in the epiphyseal plate.

Question 41

Achondroplastic Dwarfism

Answer 41

Failure of metaphysical chondrocyte multiplication Homozygous lethal head and trunk develop normally but limbs are stunted

Question 42

Bone Growth: Thickness

Answer 42

grow in thickness at the outer surface

Question 43

Bone growth: remodeling

Answer 43

bone continually forms and resorbs, replacing itself after a certain amount of time balance must exist between actions of osteoclasts and osteoblasts (creation and resorption)

Question 44

Rickets

Answer 44

Calcitrol deficiency (VitD) Stimulates uptake of dietary calcium, increased resorption necessary for normal bone deposition Rickets-occurs in childhood Osteomalacia- occurs in adults