The skeletal system

Functions of skeletal system:

1. support and shape - support and shapes the body/ endoskeleton (inside)

2. Protection- Protects the organ inside

3. Movement- Helps make movement possible/ contraction of muscles pull on the bone causing movement

4. Storage of minerals and lipids- Moves quickly from blood to bones then moves slowly from bones into body

5. Hemopoiesis- production of red and white blood cells/ Myeloid tissue (red bone marrow) transforms into yellow marrow

VOCAB +

Osseus Tissue

• Contains CT (connective tissue)

• between cell spaces: Hard; have minerals salts in them

• 67% inorganic

• 33% organic

Classification of Bones:

Long	long shaft curved for strength exp: humerus or femur
Short	spongy texture, small and boxy (wide) exp: 16 carpal bones (wrist)
Flat	thin parallel surfaces, broad surface for muscle attachment exp: cranium
Irregular	complex, irregular shape exp: vertebrae or ossicles
Sutural (Wormian)	found in the sutures of the skull, individual variations like size number, and position exp: skull lining (looks like stiches)
Sesamoid	small, flat, develops within the tendons exp: patella at the knee joint

Bone surface features

• Neck- narrow part of the bone (when shaft meets end)

• Ramus- extension of bone that makes an angle

• Head- rounded end of bone that help form a joint/ a smooth surface

• Condyle- knuckle like articular process (will be smooth)

• Trochanter- large projection for a tissue attachment (rough)

• Crest- raised ridge for a CT to a bone (rough + bumpy)

• Spinous process- (spine) sharp and slender process, stick out away from bone.

• Tuberosity- large rough projection for tissue attachment

• Trochlea- smooth, grooved surface, shaped like a pulley

• Tubercle- small, rounded projection (rib tubercles)

• Facet- smooth and flat articular surface

• Sulcus- groove for nerve, blood vessels or tendon

Bone Openings and Depressions

• Foramen- Opening or a hole in the bone for the nerves and blood vessels largest in skull: foramen magnum

• Meatus- tube like canal in the bone, auditory meatus- ear canal

• Fissure- Narrow, irregular slit between parts of a bone

• Fossa- Shallow depression on the bone surface

• Sinus-(antrum) chamber within a bone and usually air filled

Bone structure

• Diaphysis- long shaft

• Epiphysis- articular end

• Metaphysic- middle part

• Medullary cavity-

• Spongy bone-

• Compact Bone- Dense bone

Bone Cells

1. Osteo blast

   ~ Bone that forms cells

   ~forms the bone matrix/ stuff around the cells (osteogenesis)

   ~ To remember: Bone Builders

2. Osteocytes

   ~maintain healthy bone tissue

   ~ To remember: Care takers

3. Osteoprogenitor (osteogenic)

   ~ found lining outside of your bone, marrow cavity, passageways, for blood vessels.

   ~ To remember: PRepairing to build but not there yet

4. Osteoclast

   ~bone that destroys cells

   ~removes and recycles bone matrix

   ~To remember: osteo Crash- to break

Structure of Bone

• Periosteum

  • the outside lining (membrane) surrounding the bone

  • repairs the nutrients of the bone

• Haversion canal

  • Runs length wise (up and down) the central canal

  • forms small blood vessels in bone

• Volkmann’s canal

  • Runs horizontally (left-right)

  • canal for small blood vessels in bone

• Endosteum

  • Membrane that lines the inside marrow cavity and central canals

• Lacuna

  • spaces that contain osteocytes

  • “Little Lakes”

• Canaliculus

  • system of canals

• Lamella

  • concentric rings of hardened bone

Bone Marrow

• Red Marrow- the production the RBC