HAP Skeletal System Quiz

Skeletal system

bones, joints, cartilages, ligaments

Axial skeleton

 long axis (skull, vertebral column, rib cage)

What is in the Axial skeleton?

Cranium (skull)

Mandible (jaw)

Vertebral column (spine)

Cervical vertebrae

Thoracic vertebrae

Lumbar vertebrae

Sacrum Coccyx Sternum (breastbone)

Ribs

Appendicular skeleton

limbs and girdles

What is in the Appendicular skeleton?

Clavicle (collarbone)

Scapula (shoulder blade)

Coxal (pelvic girdle)

Humerus (arm)

Radius, ulna (forearm)

Carpals (wrist)

Metacarpals (hand)

Phalanges (fingers, toes)

Femur (thigh)

Tibia, fibula (leg)

Tarsal, metatarsals (foot)

Calcaneus (heel)

Patella (knee)

What are the functions of the bones?

• Support structural support for body and cradle soft organs

• Protect vital organs and soft tissues

• Movement: muscles move bones

• Storage of minerals (calcium salts, phosphorus) & growth factors, and fat (triglycerides) (in yellow marrow)

• Blood cell formation RBC/WBC/other blood elements in red bone marrow

• Leverage - Bones function as levers that change the magnitude and direction of the forces generated by skeletal muscles

How many bones are in the body?

206

How many shapes are there?

6

What are the 6 shapes?

1. long bones

2. flat bones

3. structural bone

4. irregular bones

5. short bones

6. sesamoid bones

What are long bones?

Long and slender

Located in arm, thigh, leg, palms, soles, fingers and toes.

The femur (thigh bone) is largest and heaviest bone in the body

What are flat bones?

Thin, relatively parallel surfaces

Found in roof of skull, sternum, ribs, scapula

Provide protection of underlying tissue

Large surface area for attachment of muscles

What are sutural bones (wormian bones)?

Small, flat, irregularly shaped

Found between flat bones of the skull

What are irregular bones?

Complex shapes with short, flat, notched or ridged surfaces

Vertebrae, pelvis, some skull bones

What are short bones?

Small and boxy; Wrist bones and ankle bones

What are sesamoid bones?

Small, flat, shaped like sesame seed

Kneecaps, some bones in hands and feet

Compact bone?

outer layer – dense & solid

Spongy bone?

inner layer - open spaces, marrow

What are features of the 2 types of bone tissue?

Very hard (calcium salts)

Light weight

Ability to resist tension and forces (collagen fibers)

Diaphysis?

tubular shaft

Epiphysys?

expanded area at each end of the diaphysis

Metaphysis

 thin area that connects the epiphysis to the diaphysis

Compact bone (cortical)?

outer portion of diaphysis Solid, sturdy layer that surrounds the marrow cavity

Spongy bone (cancellous)

Mainly found in the epiphysis of long bones and central regions of skull bones

Open network of struts and plates with a thin covering of compact bone

Marrow is present here, but no marrow cavity

What is bone tissue?

supporting connective tissue

What does bone tissue have?

specialized cells and matirx

what is the matrix?

an environment or medium in which something develops

What are 4 characteristics of bone?

1. Matrix dense and contains calcium salts

2. Matrix contains bone cells (osteocytes), within pockets (lacunae), which are organized around blood vessels

3. Canaliculi, canals from lacunae to the blood vessels, allow for the transfer of materials

4. Except at joints, the outer surface of bone is covered by a periosteum

What is matrix composition?

Calcium phosphate (Ca3(PO4)2) makes up about 2/3 of bone

About 1/3 of bone consists of collagen fibers (protein)

About 2% of bone mass is cells

Calcium phosphate is…?

Very hard, but inflexible and brittle

Can withstand compression, but will shatter when exposed to bending, twisting, or sudden impacts.

Collagen fibers (protein) are…?

When subjected to tension, they are stronger than steel

Easily tolerate bending and twisting (flexible), but when compressed, they just bend out of the way

The mixture of calcium crystals and protein fibers give bone what properties?

Strong, somewhat flexible, resistant to shattering As good as steel reinforced concrete Bone matrix is solid, due to calcium salts around protein fibers

What are the 4 bone cell types?

1. Osteocytes

2. Osteoblasts

3. Osteoprogenitor cells

4. Osteoclasts

What are Osteocytes?

mature bone cells

Most bone cells found in bone

Maintain mineral and protein content of surrounding matrix

Participate in the repair of bone

Occupy a lacuna, between layers of matrix (lamella)

Can NOT divide

Canaliculi connect lacuna to each other and blood vessels providing cells with necessary nutrients

What are Osteoblasts?

make new bone matrix

Process is called osteogenesis

Eventually mature into osteocytes

Can NOT divide

Form directly from stem cells

What are Osteoprogenitor cells?

stem cells that give rise to osteoblasts

What are Osteoclasts?

remove and recycle bone matrix

Process is called osteolysis

Form from up to 50 monocytes

white blood cell origin

that’s why they can digest and dissolve bone by releasing enzymes* and acids* from their folds Ca2+ & P gets back into blood as matrix breaks down … “reabsorption”

Osteon (Haversion System)?

basic functional unit of mature compact bone

Osteocytes are arranged in…

Layers around a central canal (Haversian canal)

Canal contains blood vessels

Canals run parallel to surface of bone

Perforating canals run…

Perpendicular to surface of bone

Contain blood vessels that take blood to deeper osteons and to marrow cavity

Compact bone is the thickest or thinnest?

thickest; stresses arrive from limited directions

Osteons run parallel or perpendicular?

In diaphysis are parallel to long axis b/c shaft doesn’t bend

In spongy bone, lamellae…

Are not arranged like in osteons, but would form struts and plates called trabeculae. This creates an open network

Is there blood supply in spongy bone?

No blood supply in spongy bone; Nutrients come from diffusion through canaliculi

Is bone marrow in spongy bone or compact bone?

spongy

What are the 2 types of bone marrow?

Red and yellow

Red Marrow?

Makes blood cells

Found in greater quantities in juvenile bones; converts to yellow marrow as you age

Yellow marrow?

Made of adipose tissue

Fat storage for energy reserve

Found in greater qty in adult bones

What does periosteum cover?

 superficial layer of compact bone, except at joints

What are the functions of periosteum?

1. Isolates bone from surrounding tissue

2. Provides route for circulatory and nervous supply

3. Actively participates in bone growth and repair

What is Periosteum interwoven with?

the synovial capsules and with tendons

What does Endosteum line?

marrow cavity

When is Endosteum active?

During bone growth, repair and remodeling

What is Endosteum?

Single, incomplete layer of osteoprogenitor cells

Where layer is incomplete, osteoblasts and osteoclasts can remodel bone tissue

Elevations and projections

Process, Ramus

Process

any projection or bump

Ramus

An extension of a bone making an angle with the rest of the structure

Processes formed where tendons or ligaments attach

Trochanter, Tuberosity, Tubercle, Crest, Line Spine

Trochanter

a large, rough projection

Tuberosity

a smaller, rough projection

Tubercle

a small, rounded projection

Crest

a prominent ridge

line

a low ridge

spine

a pointed process

processes formed for articulation with adjacent bones

head, neck, condyle, trochiea, facet

head

the expanded articular end of an epiphysis, separated from the shady by a neck

neck

a narrow connection between the epiphysis and the diaphysis

condyle

a smooth, rounded articular process

trochiea

a smooth, grooved articular process shaped like a pulley

facet

a small, flat articular surface

depressions

fossa, sulcus

fossa

a shallow depression

sulcus

a narrow groove

openings

foramen, canal, fissure, sinus or antrum

foramen

a rounded passageway for blood vessels or nerves

canal

a passageway through the substance of a bone

fissure

an elongated cleft

sinus or antrum

a chamber within a bone, normally filled with air