THE SKELETAL, MUSCULAR AND INTEGUMENTARY SYSTEMS Chapter 22 Sections

What makes up the skeletal system? Bones, cartilage, and the connective tissue that holds bones together make up your skeletal system.

What does your skeletal system do for you? 3. MOVEMENT- Skeletal muscles pull on bones to produce movement. Without bones you cannot sit, walk or run! 4. BLOOD CELL FORMATION- Some of your bones are full of marrow- this makes blood cells. 1. PROTECTION- Heart & lungs protected by your ribs, your brain is protected by the skull 2. STORAGE- Bones store minerals that help your nerves and muscles. Long bones store fat- that can be used for energy.

HOW ARE YOUR BONES STRUCTURED? A bone is a living organ made of several different tissues. Bone is made of connective tissue and minerals. 2 TYPES OF BONE TISSUE: compact bone- does not have any visible open spaces, rigid and dense spongy bone- Bone tissue that has many open spaces, provides most of the strength and support for a bone

3 TYPE OF JOINTS… JOINT- A PLACE WHERE TWO ORE MORE BONES MEET. Joints are held together by ligaments. Ligaments are strong elastic bands of connective tissue. They connect the bones in a joint.

SKELETAL SYSTEM ISSUES Diseases of the skeletal system: Osteoporosis is a disease that causes bones to become less dense. Bones become weak and break more easily. Parts of the skeletal system can be injured: Bones may be fractured, or broken. Joints can also be injured. A dislocated joint is a joint in which one or more bones have been moved out of place. Another joint injury, called a sprain, happens if a ligament is stretched too far or torn.

THE MUSCULAR SYSTEM Ch. 22 Section 3 (588-591)

Muscles of the Body

WHAT ARE THE THREE TYPES OF MUSCLES? 1.Skeletal muscle - move us around and responsible for most of our behavior; most attached to bones at each end via tendons stimulation or hormones or may be rhythmic; striated and voluntary 2. Cardiac muscle - found in the heart, acts like rhythmic smooth muscle, modulated by neural activity and hormones; which is striated and involuntary 3. Smooth muscle - controlled by the autonomic nervous system; ~may either be generally inactive and then respond to neural ; which is non striated and involuntary

Skeletal muscle cells are elongated or tubular Skeletal muscle cells are elongated or tubular. They have multiple nuclei and these nuclei are located on the periphery of the cell. Skeletal muscle is striated. That is, it has an alternating pattern of light and darks bands that will be described later.

Cardiac muscle cells are not as long as skeletal musclescells and often are branched cells. Cardiac muscle cells may be mono-nucleated or bi-nucleated. In either case the nuclei are located centrally in the cell. Cardiac muscle is also striated. Cardiac muscle contains intercalated discs.

Smooth muscle cell are described as spindle shaped (wide in the middle and narrow to almost a point at both ends.) Smooth muscle cells have a single centrally located nucleus. Smooth muscle cells do not have visible striations. They do contain the same contractile proteins as skeletal and cardiac muscle, these proteins are just laid out in a different pattern.

HOW DO MUSCLES WORK? Muscles Work in Pairs One muscle in the pair bends part of the body. The other muscle straightens part of the body. A muscle that bends part of your body is called a flexor. A muscle that straightens part of your body is an extensor .

HOW MUSCLES WORK CONTINUED… Muscles Attach to Bones Strands of tough connective tissue connect your skeletal muscles to your bones. These strands are called tendons. When a muscle that connects two bones gets shorter, the bones are pulled closer to each other. For example, tendons attach the biceps muscle to a bone in your shoulder and to a bone in your forearm. When the biceps muscle contracts, your forearm bends toward your shoulder.

USE IT OR LOSE IT… ~ Skeletal Muscles can be come weak and small if they are not exercised. ~ Exercised muscles are stronger RESISTANCE EXERCISE: People work against the resistance, or weight, of an object. Some resistance exercises, such as curl-ups, use your own weight for resistance. AEROBIC EXERCISE: Steady, moderately intense activity is called aerobic exercise. Jogging, cycling, skating, swimming, and walking are aerobic exercises. This kind of exercise can increase muscle strength. However, aerobic exercise mostly strengthens the heart and increases endurance.

MUSCLE INJURY A strain is an injury in which a muscle or tendon is overstretched or torn. Strains often happen because a muscle has not been warmed up. Strains also happen when muscles are worked too hard. People who exercise too much can hurt their tendons. The tendon becomes inflamed. This condition is called tendinitis. Often, a long rest is needed for the injured tendon to heal. Some people try to make their muscles stronger by taking anabolic steroids. Anabolic steroids can damage the heart, liver, and kidneys. They can also cause high blood pressure. If taken before the skeleton is mature, anabolic steroids can cause bones to stop growing.

Integumentary System Is made up of the skin, hair, and nails. Function: it protects your body and helps maintain homeostasis.

Skin Four functions Keeps water in the body and keeps foreign particles out of the body. Helps you touch the outside world with nerve endings in the skin. Helps regulate body temperature through sweat glands. Helps get rid of waste.

Layers of Skin Epidermis: the outermost layer of the skin. Dermis: the thicker layer of skin that lines beneath the epidermis.

Hair and Nails Hair: helps protect the skin from ultraviolet light. It also helps keep particles out of your eyes and nose. Nails protect the tips of your fingers and toes.

Skin Injuries Skin cancer: can be caused by damage to the genetic material in skin cells. Skin may also be affected by hormones that cause oil glands to produce too much oil. The oil, dead skin cells, and bacteria can clog the hair follicles.

TODAY IN CLASS WORK ON IAN PG. 4– Ch. 22 Review- QUIZ IS ON TUESDAY! (Remember No school on Monday) WORK ON HUMAN BODY FLIPBOOKS– This will be your last class day to work on it. (DUE THURSDAY 1/23)