1. Skeletal & Muscular Systems

2. Skeletal system
The skeletal system provides support, protects internal organs, provides for movement, store mineral reserves, and provides a site for blood cell formation
Composed of types of connective tissue called bones, cartilage, and ligaments

3. Skeletal & Muscular Systems

4. The Skeleton
There are 206 bones in a human adult skeleton
Axial skeleton – supports central body and consists of skull, vertebral column, and rib cage
Appendicular skeleton – consists of bones of arm, legs, pelvis and shoulders
A newborn baby’s skeleton is mostly composed of cartilage, which is replaced by bone during ossification.
In adults, cartilage remains in places that need flexibility, such as the tip of nose, the ears, and where the ribs meet the sternum to allow for movement during breathing

5. Structure of Bones
Mostly made of calcium and phosphorus, but remember: bones are living things!
Solid network of living cells and protein fibers
Surrounded by a tough layer of connective tissue = periosteum
Dense compact bone layer contains a network of tubes = Haversian canals, which have blood vessels and nerves in them
Less dense spongy bone layer adds strength to bones without adding mass
Two types of soft bone marrow within central cavity:
Yellow = made up primarily of fat cells
Red = produces RBCs, some WBCs, and fragments (platelets)

6. Figure 36-3 The Structure of Bone
Section 36-1
Spongy bone
Compact bone
Periosteum
Bone marrow
Haversian canal
Osteocyte
Artery
Vein

7. Joints Joints are places where one bone meets another bone
Immovable joints = “fixed” allow no movement (for example: skull)
Freely movable joints = permit movement in one or more directions
Ball-and-socket: circular movement (shoulder/hip)
Hinge: back and forth motion (elbow/knee)
Pivot: one bone rotates around another (radius and ulna in arm)
Saddle: one bone slides in two directions (carpals and metacarpals in wrist)
Ligaments connect bones to other bones.

8. Figure 36-4 Freely Movable Joints and Their Movements
Section 36-1
Ball-and-Socket Joint
Pivot Joint
Clavicle
Ball-and-socket joint
Scapula
Humerus
Humerus
Radius
Pivot joint
Ulna
Hinge Joint
Saddle Joint
Femur
Patella
Hinge joint
Tibia
Fibula
Metacarpals
Carpals
Saddle joint

9. Muscular system
The muscular system provides the forces that put the body in motion

10. Types of Muscle Tissue There are 3 different types of muscle tissue:
Skeletal: usually attached to bone, responsible for voluntary movements (typing, dancing, winking), appears to have alternating dark and light bands = striated muscle, controlled by CNS
Smooth: not under voluntary control, not striated, do not need nerve stimulation because they are connected by gap junctions that allow electrical impulses to travel from one cell to the next (digestive tract, blood vessels, pupils)
Cardiac: only found in the heart, striated, not under voluntary control

11. Types of Muscle Tissue

12. Muscle Contractions
Occurs when thin muscle filaments slide over thick muscle filaments
Thick have myosin protein
Thin have actin protein
The energy for muscle contractions is supplied by ATP

13. Interactions of Muscles and Bones
Skeletal muscles move bones by contracting, or pulling (muscles can ONLY pull)
Tendons connect muscles to bones
Skeletal muscles work in pairs: one contracts and the other relaxes

14. MASSETER
BICEPS
STERNOCLEIDOMASTOID
TRICEPS
PECTORALIS MAJOR
DELTOID
RECTUS ABDOMINIS
SARTORIUS
RECTUS FEMORIS
GASTROCNEMIUS
TIBIALIS ANTERIOR

15. MUSCLE FUNCTIONS Masseter– moves the mandible
Sternocleidomastoid- flex & rotate the head
Biceps- flex the elbow
Triceps- extend the elbow
Deltoid- raise the arm
Pectoralis Major- pulls arms toward center of body
Rectus abdominis- bends body forward
Sartorius- rotates the thigh
Gastrocnemius- pulls toes down
Rectus femoris- extends lower leg
Tibialis Anterior- pulls toes up