Chapter 14 Bones, muscle, and skin Sections 1& 2 Mrs. Bailey 7 th grade

Objectives Levels of organization of human body Tissue types Body systems overview Skeletal system overview –4 categories of bone –5 functions –Moveable and immoveable joints –Bone structure Compact vs. spongy bone Marrow red and yellow

Section 1-Body organization The levels of organization in the body consist of cells, tissue, organs, & organ systems Cell-basic building unit of life Tissue-a group of similar cells Organs- a group of different tissue Organ system- a group of organs working together.

Tissue types 4 types of tissue Muscular tissue- makes up the muscles to allow movement Nervous tissue- makes up nerves that send messages Epithelial tissue- make up the skin that covers and protects Connective tissue- make up the bones. Connects and supports parts of the body.

Section 2-Organ systems The human body is made of 11 different systems: Skeletal RespiratoryImmune MuscularExcretory CirculatoryEndocrine NervousReproductive DigestiveCardiovascular

Skeletal system Consists of all the bones in your body. Infants have 350 bones that fuse together as the baby grows. Adults have 206 bones. Smallest bone-stirrup (found in inner ear) Largest bone-femur (found in thigh) Bones consist of living material that grows and repairs itself

How are bones classified 4 categories of bone 1. long bones ( legs and arms) 2. short bones (wrists and ankles) 3. flat bones (ribs, sternum, skull, shoulder) 4. irregular bones (vertebrae and all other bones)

Skeletal system 5 Functions of skeletal system: 1. Shapes and supports the body 2. Helps with movement along with muscle system 3. Protects internal organs (heart, brain) 4. Produces blood cells using marrow 5. stores minerals such as calcium.

How do bones move? Joints, places in the body where two bones meet, allow for bending, twisting, swinging, rotating and sliding. web code cep-4012www.PHSchool.com

Moveable vs Immoveable Joints Immoveable Joints- places where bones are connected but they cannot move Ex. Skull Movable Joints- allow movement between bones –Ligaments-connect bone to bone –Cartilage- strong, flexible, connective tissue found in nose, ears and between joints.

Types of moveable joints 4 types of moveable joints 1.Hinge joint- allows forward and backward motion (knee, elbow) 2. Ball and socket -allows greatest range of circular motion (hip & shoulder) 3. Pivot joint -allows for rotation (side to side) neck 4.Gliding joint -allows bending (wrists & ankles)

Bone structure Bones are complex living structures that undergo growth and development Bones are covered by a thin membrane. Blood vessels and nerves enter and leave through the membrane. Composed of compact and spongy bone.

Bone structure Compact bone – hard and dense but not solid. Spongy bone- Located at the ends of bones. Contains many small spaces Marrow- connective tissue found inside the bone. –Red marrow- produces red blood cells (children) –Yellow marrow- produces and stores fats (teens)

Femur-longest single bone in human body that makes up 25% of a persons height.

Review questions 1. What are two types of bone marrow? 2. How are moveable joints held together? 3. What are the functions of the skeletal system? 4. What is the level of organization of the human body? 5. What is the difference between tissue and organs?