Unit 7, Lesson 2
Pages 430-443 in textbook
1/9(B) & 1/16(A)
Musculoskeletal System
Bones & Cartilage
 Types of connective tissue
o Bone – ________________________________
o _________________________- soft and flexible
Functions of Bones:
1) Serve as site for muscles to attach to move body parts
2) Give body its shape and ___________________________
3) ________________delicate structures such as heart, lungs, spinal cord and brain
4) Serve as storage place for _____________________________________
5) Produce red blood cells, white blood cells and platelets in ______________
Bone structure
1. _______________________________- osteocytes trapped in small cavities in
bone structure
2. Connective tissue fibers - made off protein- __________________
3. Inorganic compounds- calcium and phosphorus
4. Haversian Canal- cavity in bone that contains blood vessels and
nerves that ____________________________________________
5. Periosteum- outer covering of bone that is ___________________
______________________________________ ** muscles attach here too**
Bone is constantly being broken down and rebuilt
o ____________________________ build new cells by secreting collagen protein ,

then ____________________________________ forms on the fibers to
form hard, heavy bone
o Osteoclasts _________________________________________________
 release calcium and phosphorus
Bone tissue types
1. Compact bone- _____________________________________________
2. Spongy Bone- very ________________ (full of holes)- marrow fills holes
Bone Marrow Types
1. __________________________ Found: in spongy bones of vertebrae, ribs, cranium and tips of long bones or
arms and legs
 Function: _______________________________________________ and some
white blood cells
2. Yellow Marrow found in ________________________________________________
 made of fat cells
Cartilage connective tissue that bends easily
 gives support and ________________________________________
_____________________________ and pressure
 Found in:
 Embryos- most of skeleton begins as cartilage then becomes bone
 Ossification_____________________________________________
 Children- more cartilage than adults therefore their bones are more
elastic and not as easily broken
 Adults- ____________________________________________, around
joints
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Skeletal System
Total # of bones: ___________________
2 Main Parts:
____________ skeleton-
 _____________- cranium and facial and jaw bones (mandible)
 _________________- vertebrae with cartilage discs in between to cushion,
ribs and sternum (breastbone)
Appendicular Skeleton –
 _____________________________________
 Pectoral girdle- Shoulder blades (scapula) and collar bones (clavicle)
 ____________________- hip bones
Joints point where ______________________________________
 Held together by __________________________________ (tough fibrous bands of
connective tissue)
Joint Types:
 Immovable- cranium (tightly fitted)
 Movable1. _________________- Back & Forth motion (knee & elbow)
2. Ball & Socket- move in all directions, ball shaped fit into a cuplike
space (shoulder & hip)
3. _____________- side to side & up and down motion (base of skull)
4. Gliding- some bending and twisting movement
(____________________________________)
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MUSCLES
Types:
1) _________________________ Muscle- used in locomotion and in all voluntary
movement
 Cells fuse together to form fibers
o bundles of fibers bind together to form muscles
 ___________________ appearance- striped with light & dark bands, shows
overlapping fibers
 Fibers made up of thin filaments called Actin & Myosin
o Filaments ____________________________________________to contract
(shorten) and relax (lengthen)
 Connected by _______________________________to bones
 Muscles pull bones when they contract (shorten)** cannot push**
 ______________________________________________ to each other:
o As one muscle contracts (shortens) the
___________________________________________ (lengthens)
o Example- Biceps (flexor bends a joint) and triceps (extensor extends or
straightens a joint) in the arm
o
 Unique to Skeletal Muscle:
o __________________________________________________ unlike smooth
muscles
2) Smooth Muscle- ________________________________ muscle
 Found: in ________________________________________________, diaphragm
and some other internal organs
 Appearance:
o Long, overlapping sheets of cells
o ___________________________________________ (no bands)
 Unique to Smooth Muscle: ___________________________________
________________________________________
3) _____________________________ muscle- found in heart only
 Appearance:
 __________________________________________ of muscle cells with a single
nucleus in each
 _____________________________ muscle
 Unique to Cardiac Muscle:
 Built-in ability to contract ___________________________________
 Muscles _________________________________________________ (heartbeat)different than skeletal