Do Now From the first class of the term. 1. Write down the number of bones in the body. 2. Tendons connect what? 3. Name the three bones that make up the forearm? Answers: 1. 206 (ish) some people have an extra or one less bone in the their “tailbone.” 2. Tendons connect muscle to bone. Tendonitis (anything itis means inflammation of (aka swelling)). Humerous, ulnar & radius

Homework The Muscular System 928-933 Prepare for finals. Check your notes and understanding of the following: The Muscular System 928-933 Ready for Thursday - The Integumentary System 935 – 939 Ready for Friday - The Circulatory System – 948-953 Your ability to bring in a study aid (aka Cheat Sheet) is based on how well you are prepared for each class. No preparation, no aid during the exam.

New Material Axial Skeleton – maintains the central axis (line) of the body. The Appendicular Skeleton – the bones of the arms, legs & pelvis. The skeleton’s purpose is to give the body structure, protect the body’s internal organs (heart, lungs, brain), assist in movement, stores minerals as well as blood formation (primarily in the long bones such as humerus and femur).

New Material Bone Marrow is the center of the bone where white & red blood cells are made. The bones also serve as levers. Think of a board placed under a rock with a fulcrum (another rock) used to leverage the rock out. For example. Here are examples of the body’s lever system. Write each down. The W = weight, the F = Fulcrum, P = Power

New Material Bones – the outer (rigid) layer of the bone is known as the periosteum. The channels within the bones that allow blood and nerves to run through are known as Haversian Canals. Spongy bones are not as dense as found at the end of long bones (like the femur). Also found in flat bones (clavicle – collar bone), short bones like in the wrist or feet.

New Material Again, within the middle of the bone is bone Marrow. There are two types of bone Marrow: 1. Yellow – the yellow contains fat cells which is why it is yellowish. 2. Red – the red is stem cells that produce red blood cells. This is what they want for bone Marrow transfers. The idea is to allow the new red blood Marrow to replace the cancer ridden Marrow. They typically kill the bone Marrow with chemo-therapy and then bone Marrow donation.

New Material Cartilage is the soft cushion between bones Cartilage does NOT contain blood vessels. It relies on the surrounding tissue for the blood supply. This is partly why when people have a knee injury it can be difficult because the doctor will remove the torn cartilage which means there is less cartilage for protection / cushion.

New Material Cartilage eventually will form (most but not all) hard bone in a process called ossification. Osteoblasts – cells that start off as cartilage and will eventually form bone known as osteocytes. These osteocytes keep the minerals flowing and continue to strengthen the bone.

New Material Bone grow from the middle out. The end of the bones contain the softer cartilage to protect the bones (acting as cushions) and allowing for greater movement. The growth plate is the end of the bones. Around 18 these epiphyseal plates will eventually harden. This is why when punch walls and break bones, doctors are concerned if the fracture will interrupt the growth plate. If interrupted then growth stops. Not good if a young child.

New Material When a person breaks a bone, the bone repairs itself because the bone never stops regenerating. Osteoclasts helps to break down bone minerals so that the bones can make use of the minerals People with osteoporosis which is a weakening of the bone. More common in women. Often the bone becomes brittle enough that they fall and cause a break.

New Material Can someone be double jointed? No. a Joint is where two or more bones form. For example your elbow (aka Olecranon Process). The types of joints found in the human body: Immoveable Joints – No movement allowed for example the skull Slightly moveable – Joints within your spinal column. They have small amount of movement

New Material Finally, free moving joints. Have movement in two or more directions. Structure of joints – made up of muscle, ligaments, & tendons. The inner layer of the joint is known as the synovial cavity. Sometimes there is a fluid filled sac called a bursa. It acts like a wheel on a pulley. The muscle being the rope and the bursa being the wheel.

New Material Types of joints: 1. Hinge joint – like that of a door 2. Ball & socket joint – where the ball fits into a pocket such as the head of the femur into the pelvis / hip. 3. Saddle joint 4. Pivot joint

New Material Why are knee injuries common? The knee supports the entire body and really only has four ligaments to keep it from moving too far forward, backward, inward and outward. When the knee is stretched beyond its limits it will tear. The constant running and pounding of the knee can lead to various conditions such as tendonitis, bursitis,… What is bursitis? Remember itis = inflammation of

New Material Why are knee injuries common? The knee supports the entire body and really only has four ligaments to keep it from moving too far forward, backward, inward and outward. When the knee is stretched beyond its limits it will tear. The constant running and pounding of the knee can lead to various conditions such as tendonitis, bursitis,… What is bursitis? Remember itis = inflammation of

Muscular System Muscles allow movement, but they also allow basic functions to occur. There are three types of muscle: 1. Cardiac – the muscle of the heart is very special. Never rests. 2. Smooth Muscle (aka involuntary muscle) – such as muscles around the rib cage. 3. Skeletal Muscle (aka voluntary muscle) – muscles that you decide to move or control.

Muscular System Skeletal muscles – eventually attach to bones. Skeletal muscle under a microscope will show striation caused by white and dark fibers. Why do chicken legs have dark meat? Darker generally means more blood travels through. More in the legs because the muscle is thicker and used for walking versus the breast which is more white meat.

Muscular System Smooth Muscle – little or no striation. Under the microscope the muscle appears smooth (hence the term). They are called involuntary because you do not have control over these muscles. Other muscles that are smooth – digestive Question – if you are paralyzed will these muscles still function? Depends where the cut to the spinal cord is. Sometimes the impulse will allow the muscle to still function. Skeletal will not

Muscular System Cardiac muscle – is somewhat a combination of smooth & skeletal. Smooth because the person has no control over them. Like skeletal because it is very strong and fibrous (striation). The heart can never stop beating or tire. It has its own impulse to beat known as a pacemaker. Some people have an external pace because their heart does not beat on its own.