1. Skeletal and Muscular System

2. Human Musculoskeletal System
Bones & Cartilage
Types of connective tissue
Bone – hard and inflexible
Cartilage- soft and flexible

3. Functions of bones:
Serve as site for muscles to attach to move body parts
Give body its shape and support
Protect delicate structures such as heart, lungs, spinal cord and brain
Serve as storage place for calcium and phosphorus
Produce red blood cells, white blood cells and platelets in marrow

4. Bone Structure
Living bone cells- osteocytes trapped in small cavities in bone structure
Connective tissue fibers - made of the protein- collagen
Inorganic compounds- calcium and phosphorus
Haversian Canal- cavity in bone that contains blood vessels and nerves that nourish and regulate the osteocytes
Periosteum- outer covering of bone that is responsible for new bone growth and repair ** muscles attach here too**

5. Bone is constantly being broken down and rebuilt
Osteoblasts-
build new cells by secreting collagen protein ,
then calcium phosphate forms on the fibers to form hard, heavy bone
Osteoclasts-
break down old bone
release calcium and phosphorus

6. Bone tissue types: Compact bone- very dense & strong
Spongy Bone- very porous (full of holes)- marrow fills holes

8. Bone Marrow Types: Red marrow- Yellow Marrow-
Found: in spongy bones of vertebrae, ribs, cranium and tips of long bones or arms and legs
Function: makes red blood cells, platelets and some white blood cells
Yellow Marrow-
found in hollow center of long bones
made of fat cells

9. Cartilage connective tissue that bends easily
gives support and cushions joints against impact and pressure
Found in:
Embryos- most of skeleton begins as cartilage then becomes bone
Ossification- change of cartilage into bone
Children- more cartilage than adults therefore their bones are more elastic and not as easily broken
Adults- Ear, nose, ribs, around joints

10. Human Skeleton 2 main parts: Axial skeleton-
Total number of bones: 206
2 main parts:
Axial skeleton-
Skull- cranium and facial and jaw bones (mandible)
Spine- vertebrae with cartilage discs in between to cushion, ribs and sternum (breastbone)

11. Human Skeleton Appendicular Skeleton – Arms and Legs
Pectoral girdle- Shoulder blades (scapula) and collar bones (clavicle)
Pelvic girdle- hip bones

12. Joints point where bones meet
Held together by LIGAMENTS (tough fibrous bands of connective tissue)

13. Joint types: Immovable- cranium (tightly fitted) Movable-
Hinge- Back & Forth motion (knee & elbow)
Ball & Socket- move in all directions, ball shaped fit into a cuplike space (shoulder & hip)
Pivot- side to side & up and down motion (base of skull)
Gliding- some bending and twisting movement (wrist & vertebrae)

17. MUSCLES
Types:
1. Skeletal Muscle- used in locomotion and in all voluntary movement
Cells fuse together to form fibers
bundles of fibers bind together to form muscles
Striated appearance- striped with light & dark bands, shows overlapping fibers

19. Muscle types: Fibers made up of thin filaments called Actin & Myosin
Filaments slide over each other to contract (shorten) and relax (lengthen)
Connected by tendons to bones
Muscles pull bones when they contract (shorten)** cannot push**

22. Muscle types: Work antagonistic to each other:
As one muscle contracts (shortens) the opposite muscle relaxes (lengthens)
Example- Biceps (flexor bends a joint) and triceps (extensor extends or straightens a joint) in the arm
Unique to Skeletal Muscle:
Fast, strong contractions unlike smooth muscles

23. Skeletal muscle is a system of pairs that relax and contract to move a joint.
For example, when front leg muscles contract, the knee extends
(straightens) while back leg muscles relax. Conversely, to flex (bend)
the knee, back leg muscles contract while front leg muscles relax.

24. Muscle types: 2. Smooth Muscle- involuntary muscle
Found: in digestive tract, blood vessels, diaphragm and some other internal organs
Appearance:
Long, overlapping sheets of cells
Non-striated (no bands)
Unique to Smooth Muscle: Long, less intense contractions

26. Muscle types: Cardiac muscle- found in heart only Appearance:
Interlocking network of muscle cells with a single nucleus in each
Striated muscle
Unique to Cardiac Muscle:
Built-in ability to contract on their own
Muscles can contract together (heartbeat)- different than skeletal

27. Muscle and Skeleton Disorders
Osteoporosis- brittle bones due to lack of calcium
Treatment- medication and increased calcium intake in diet

29. Muscle and Skeleton Disorders
Scurvy- caused by a lack of vitamin C (Absorbic Acid) causing wounds to heal poorly, bruising easily, gums bleed, teeth loosen, loss of appetite
Treatment- Vitamin C

30. Caption: Close of the mouth of a person
suffering from scurvy, a disease caused by
a deficiency of vitamin C (ascorbic acid), showing
swollen and bleeding gums. Scurvy results from a diet that is devoid of fresh fruit & vegetables.
Swollen and bleeding gums are initial symptoms
and may be followed by bruising of the skin
(subcutaneous bleeding) and the opening of
previously healed wounds. A prolonged deficiency may cause death. Scurvy responds to treatment with vitamin C.

31. Muscle and Skeleton Disorders
Arthritis- inflammation of the joints can be immune system related
Treatment- anti-inflammatory drugs

32. Muscle and Skeleton Disorders
Scoliosis- curvature of the spine caused by unknown (idiopathic); it can eventually lead to decreased lung capacity and congestive heart failure
Treatment- wearing a spine straightening brace or surgery

34. Muscle and Skeleton Disorders
Muscular Dystrophy- muscles break down and waste away to nothing eventually affects all voluntary muscles, heart and breathing muscles Duchenne’s MD usually only affects boys
Treatment- none currently, physical therapy to help with symptoms

37. Muscle and Skeleton Disorders
ALS or Lou Gehrig’s disease- muscle weakness and wasting, some twitching then paralysis of arms and legs and then all voluntary muscles from motor neuron malfunction
Treatment- none currently, some medication to slow it but physical therapy is needed
Ex. Steve Gleason -Saints