1. Skeletal, Muscular & Integumentary Systems

2. Do Now If you ever knew someone that broke a bone, or pulled/strained a muscle, write down what it was.

3. 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

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. Skull Sternum Ribs Vertebral column Metatarsals Metacarpals Phalanges Clavicle Scapula Humerus Radius Pelvis Ulna Carpals Femur Patella Fibula Tibia Tarsals Phalanges The Skeletal System Section 36-1 Axial Skeleton Appendicular Skeleton

6. 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)

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

8. Joints Joints are places where one bone meets another bone – Immovable joints = “fixed” allow no movement (for example: skull) – Slightly movable joints = permit restricted movement (for example: between 2 bones of lower leg, or between adjacent vertebrae) – 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.

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

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

11. 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

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

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

14. Integumentary system “Integument” = “to cover” in Latin It serves as a barrier against infection and injury, helps to regulate body temperature, removes waste products from the body, and provides some protection against ultraviolet (UV) radiation from the sun. The integumentary system includes: – Skin – Hair – Nails

15. Skin The largest organ of the body Contains several types of sensory receptors that enable us to feel pressure, heat, cold and pain

16. Structure of Skin Skin is made up of 2 main layers: – Epidermis: outer layer of skin, contains melanocytes that produce melanin (pigment) Outer epidermis: dead cells Inner epidermis: rapidly dividing cells – Dermis: inner layer of skin, contains collagen fibers, blood vessels, nerve endings, glands, sense organs, smooth muscles, and hair follicles Glands: sweat and sebaceous (oil) Beneath the skin is a subcutaneous layer (fat)

17. Hair follicle Sweat pore Nerves Hair Epidermis Dermis Subcutaneous layer Muscle Sweat gland Fat Sebaceous gland Figure 36-13 The Structure of Skin Section 36-3

18. Hair & Nails Made up of keratin (tough protein) – Hair: covers body, protects from UV rays, insulates from cold, and prevents dirt from entering the body, produced by hair follicles – Nails: protect tips of fingers and toes, grow from the nail root