Ch 36- Skeletal, Muscular, and Integumentary Systems 36.1 Skeletal System 36.2 Muscular System 36.3 Integumentary System

36-1 Skeletal System  206 bones in your body compose your Skeleton  The bones of your skull, ribs, spine, and sternum form the Axial Skeleton  Appendicular Skeleton is the bones of your arms, legs, scapula, clavicle and pelvis

36-1 Skeletal System  The bone’s surface is covered by a tough membrane called Periosteum  Compact Bone is the layer under the periosteum which is composed of a mineral crystal cylinders called Haversian Canals which contain blood vessels.  In between haversian canals are Osteocytes which are the living bone  A network of connective tissue inside the compact bone is called Spongy Bone. (Hard for support)  Bone Marrow is a soft tissue in the spongy bone that produces red and white blood cells and also stores fat for energy reserve

Cross section of a bone Fig 36-3

36-1 Cont  Fracture is a break or crack in a bone  When cartilage is converted into bone through the depositing of minerals is called Ossification  Bone elongation takes place near the end of long bones in the Epiphyseal Plate.

36-1  The place where two bones meet is a Joint  Movable Joint- Majority of joints in the body in which allows a wide range of movements  Fixed Joint- Prevent movement (Bony plates that compose the Skull)  Semimovable Joints- permits limited movement- Example-Spine  Tough bands of connective tissue, called Ligaments, hold the bones of the joint in place  The term Arthritis is used to describe painful, swollen joints

Questions  Pg 925 (1-5)

36-2 Muscular System  Skeletal muscle tissue is made up of elongated cells called Muscle Fibers  Each fiber has dark and light lines called Striation  Fascicles are the dense bundles of muscle fibers  Voluntary Muscles are consciously controlled  Skeletal Muscles  Because most of its movements cannot be consciously controlled, Smooth and Cardiac muscle is referred to as Involuntary Muscles

 Each muscle fiber consists of Myofibrils  Each myofibrils is composed of two proteins:  Myosin- Thick filaments  Actin-Thin Filaments  Where all of the actin are anchored together is the Z-Line  From z-line to the next is considered a Sarcomere

36-2 Muscular System  Muscle are attached to periosteum by a Tendon  The point where a muscle attaches to a stationary bone is called the Origin  The point where a muscle attaches to a moving bone is called the Insertion  Flexor- Muscle that bends the joint-Bicep  Extensor- Muscle that straightens the joint- Triceps  Neuromuscular junction is to point in which the motor neuron and a skeletal muscle meet  The neurotransmitter released at this junction is Acetylcholine

Questions  Pg 931 (1-6)

36-3 Integumentary System (Skin)  Skin is the body’s largest organ  The outer layer of the skin, Epidermis, is composed of layers of thin Epithelial cells (Dead)  Keratin- A protein in epidermal cells which makes it leathery and waterproof  A color pigment in skin called Melanin, is what absorbed Ultra Violet light to protect us  The inner layer of living skin, Dermis, and has specialized structures such as Sensory Neurons, Blood Vessels, Muscle Fibers, Hair Follicles, and Glands

36-3 Cont..  Hair, which protects and insulates the body is produced in the dermis in pits called Hair Follicles  Exocrine glands- Glands that release secretion through ducts in the skin  Glands that release excess water, salt and Urea are called Sweat Glands  Oil Glands, Which are found in large numbers on the face and scalp produce a fatty substance known as Sebum  Excess amount of Sebum, dead cells and bacteria produces the skin disorder Acne

Book Questions  Pg 936- (1-6)  HW if you don’t finish  Pg 939 (1-20) complete sentences