Chapter 6: Structure and Movement Section 1 - The Skeletal System Section 2 - The Muscular System Section 3 - The Skin

Section 1 – Skeletal System Before we begin, we are going to play a game: I want you to divide the paper in the middle of the table in half. On one side, I want you to label it Above the Neck and the other side Below the Neck. Number both sides 1 – 5. Now list 5 body parts that have only 3 letters. You should have a total of 10 body parts listed on your paper. You will work with the students at your table only.

Section 1 – Skeletal System Above the Neck Eye Ear Jaw Lip Gum Below the Neck Rib Toe Hip Leg Arm

Section 1 – Skeletal System Are your bones alive? Yes! Bones are made of a mixture of hard stuff that makes them strong and many living cells which help them grow and repair themselves. Like other cells in your body, the bone cells rely on blood to keep them alive. Blood brings them food and oxygen and takes away waste.

Skeletal System Includes ALL the bones in your body The Framework of your body and has Five Major Functions. Gives shape and support to your body Protection of your Internal Organs Major Muscles are attached to bones and help them move Blood Cells are formed in the center of many bones in soft tissue called red marrow Storage of Calcium and Phosphorous compounds, which also makes bones hard. Skeletal System

Bone Structure Periosteum – a tough, tight-fitting membrane that covers the surface of a living bone. Its blood vessels supply nutrients and its nerves signal pain Compact Bone is a hard, strong layer located directly under the periosteum. This layer contains calcium and phosphorous deposits giving the bone its strength, bone cells, and blood vessels. Spongy Bone is located toward the ends of long bones and made up of many small, open spaces that make bones lightweight. In the centers of long bones are large opening called cavities. These cavities and spongy bone contain marrow. Cartilage is a smooth, slippery, thick layer of tissue that covers the ends of bones. Cartilage does not contain blood vessels or minerals. Cartilage is flexible and important in joints because it acts as a shock absorber.

Bone Formation Before birth, your skeleton was made of cartilage. Gradually the cartilage broke down and was replaced with bone. Bone-forming cells called Osteoblasts deposit the minerals calcium and phosphorous in bones, making the bone tissue hard. At birth, your skeleton was made up of more than 300 bones. As you develop, some bones fused, or grew together, so that now you have only 206 bones.

Joints Any place where two or more bones come together. The bones are held in place at these joints by a tough band of tissue called a Ligament. Immovable Joints allows little or no movement. Examples are joints in your skull and pelvis. Movable Joints allows the body to make a wide arrange of motions. Types of Movable Joints – Pivot, Ball and Socket, Hinge, and Gliding

Joint Problems Arthritis is the most common joint problem. The term arthritis describes more than 100 different diseases that can damage the joints. All forms of arthritis begin with the same symptoms: pain, stiffness, and swelling of the joints.

Section 2 – The Muscular System

Section 2 – The Muscular System An organ that can relax, contract, and provide the force to move your body parts Energy is used and Work is done Some muscle are continuously moving Example: Your Heart Beating Movement of the Human Body - Muscles

Muscle Control Voluntary Muscles = Controllable Examples – Hand, Arm, and Leg Muscles Involuntary Muscles = Uncontrollable Examples – Heart Beat and Food moving through your Digestive system

Three Types of Muscles Classification of Muscle Tissue *All muscle tissue in your body in NOT the same* Three Types of Muscles Skeletal Muscles More common Attached to bones by thick bands of tissue called tendons Striated in appearance Cardiac Muscles ONLY in the Heart Contracts about 70 times a minute Smooth Muscles Located in your intestines, bladders, and other internal organs Non-striated in Appearance Involuntary muscles that slowly contract and relax

How do muscle allow you to move your body? Working Muscles Changes in Muscles How do muscle allow you to move your body? One muscle of a pair contracts The other relaxes or returns to its original length Muscles ALWAYS Pull!!! NEVER Push!!! Overtime, muscles can become larger or smaller Activity increases muscle mass Inactivity decreases muscle mass

Energy is needed for muscles to contract and relax How Muscles Move Energy is needed for muscles to contract and relax Muscle contraction releases energy in the form of mechanical energy (MOVEMENT) and thermal energy (HEAT) Heat produced by muscle contractions helps keep your body temperature constant

Section 3 - The Skin

Section 3 – The Skin Skin = Largest Sensory Organ Sensory - conveying nerve impulses from the sense organs to the nerve centers Skin senses touch, pain, warmth, and coldness

Skin Structure Epidermis Dermis Fatty Layer Made up of 3 Layers Outer, thinnest layer of the skin Dead and Water Repellent Thousands rub off New cells continuously made at the base and move up Contains melanin – pigment that protects and gives color Dermis Layer of cells beneath the epidermis Thicker than epidermis Contains many blood vessels, nerves, muscles, oil & sweat glands, and other structures Fatty Layer Below the dermis Insulates the body

Skin Functions 1. Protection 2. Sensory Response - Against injury and disease-causing organisms - Prevention of water loss 2. Sensory Response - Detect and relay information to the brain 3. Vitamin D Formation - Helps absorb Calcium 4. Body Temperature Regulation - Blood vessels help release or hold heat - Perspiration eliminates excess heat by evaporation 5. Waste Elimination through Sweat Glands

Skin Injury and Repair Bruises Cuts Skin Grafts - Occur when tiny blood vessels beneath the skin burst and leak into surrounding tissue Cuts - Scab forms to prevent bacteria from entering your body - Cells from blood vessels fight infections - Skin cells beneath scab grow to fill in gap of torn skin Skin Grafts - Pieces of skin that are cut from another part of a person’s own body and moved to injured area