1 The skeletal- muscular systemPart 1: the skeleton

2 The skeleton’s purposeThe skeletal system makes up all the bones and cartilage in the human body. These bones do 5 important tasks for the body.

5 The skeleton’s purpose4. The stem cells in the marrow makes new blood cells. 5. They store calcium and phosphorous used to heal the body, and rebuild bones.

6 The Developing SkeletonThe number of bones change as you age. As a baby, most of your bones are small, separated, and made mostly of cartilage (a rigid, but flexible tissue).

7 The Developing SkeletonAs the body’s skeleton grows, the cartilage changes into bone, making some separate bones in the skull and ribcage fuse together.

8 The Developing Skeleton--A baby has 300 bones in its skeleton --Teenagers have bones --Adults( 25 yrs +)have 206 bones

9 The skeleton’s purposeThroughout your life, your bones are completely replaced slowly over a 6 year-period.

10 The skeleton’s purposeBased on your life-style, the bones’ structure changes. Ex: runners’ shin bones and knee bones get thicker and stronger from the constant pressure your weight being thrown at them.

11 The skeleton’s purposeBody-builders’ bones get thicker at the places where the muscles connect to the bone. Inactive people’s bones get softer and weaker, causing problems later in life.

12 Layers of bone Layer 1—the periosteumA thin, hard, outer layer that contains blood vessels and nerves that feed the bone tissue and alert the brain when they get hurt.

13 Layers of bone--periosteumLayer 1—the periosteum If the bone is broken, the periosteum layer swells, and makes the repairs to the damaged bone.

14 Layers of bone—Compact boneLayer 2—Compact bone—solid bone made with calcium and phosphate deposits. Also, the top of this layer is where the bone cells are.

15 Layers of bone—spongy boneLayer 3—Spongy bone—filled with holes and air that take the weight away from large bones, and absorb trauma.

16 Layers of bone—marrow Layer 4 (center) contains the marrow—there are 2 types of marrow.

18 Joints At the ends of bones, where 2 bones meet, (the joint) is a pad of cartilage. This cartilage pad cushions the bones and protects them from damaging each other by rubbing together.

19 Joints This cartilage pad can split, tear, and rupture with injury, causing a life-time of problems afterwards.

20 Skeleton Parts--head Cranial Bones --AKA: skull--made from 8 bones with immovable joints --most cranial bones share the same name as the lobes of the brain.

21 Skeleton Parts--head 2. Mandible --AKA: jawbone --one of the strongest bones in the body

22 Skeleton Parts--torsoVertebrae: 33 hollow bones that hold and protect the Spinal cord

24 Skeleton Parts--torso4. Scapula—AKA: shoulder blades—attaches arm bones to ribcage

25 Skeleton Parts--torso5. Clavicle—AKA: collar bone. attaches scapula to ribcage.

26 Skeleton Parts--torso6. Pelvis—AKA; hipbones—attaches legs to body, holds and protects reproductive system, and lower digestive system.

27 Skeleton Parts--torso7. Coccyx and Sacrum—AKA: Tailbone. Evolutionary remnant of a human tail?

28 Skeleton Parts—arms Humerus—upper arm bone

29 Skeleton Parts—arms 2. Radius—shorter of the 2 forearm bones

30 Skeleton Parts—arms 3. Ulna—longer of the 2 forearm bones.

31 Skeleton Parts—arms 4. Carpals—bone cluster of the wrist 5. Meta-carpals—bone cluster of the hand 6. Phalanges—AKA finger bones

32 Skeleton legs Femur—AKA thighbone—the largest/strongest bone in the body

33 Skeleton legs 2. Tibia—the larger of the 2 shin bones. 3. Fibula—the smaller of the 2

34 Skeleton legs 4. Tarsals—bone cluster of the ankle 5. Meta-tarsals—bone cluster of the foot 6. Phalanges—toe bones