Human Body & Its SystemsChapter 6Sec. 1

Cells• Microscopic structures• Basic unit of life

• Nucleus contains genetic material• Chromosomes (23 pair)• DNA (within the chromosome)• The ‘active’ part of the DNA determine how that cell will

work

Tissues• Groups of cells that perform similar functions

• Tissues perform tasks for the body

• Example = Cells join together to form muscle tissue (which can contract)

Organs• Tissues joined together to perform a function• Within 1 organ, you will have a variety of tissues

• Example = Heart (all work together to pump blood)

•Muscle tissue• Nerve tissue• Connective tissue

Body Systems• Group of organs working together to perform a

function

• Body systems work with other systems

• Example = Skeletal system works with muscular system to provide movement

Skeletal System• Organs = Bones, Cartilage, Tendons

• Provides movement, posture

Muscular System• Organs = Muscles, Ligaments, Tendons

• Allows movement

Nervous System• Organs = Nerves, Spinal cord, Brain

• Sends & receives messages to/from the body

Digestive System• Organs = Mouth, Esophagus, Stomach, Small &

Large Intestine

• Breaks down food for nutrients

Cardiovascular System• Organs = Heart, Blood vessels• Pumps blood to body cells (carries oxygen to cells)

Respiratory System• Lungs, Diaphragm• Delivers oxygen to blood cells

Urinary System• Organs = Kidneys, Ureters, Bladder, Urethra• Pulls waste from blood; balances fluids

Immune System• Organs = Spleen, Lymph nodes, Tonsils• Fight infections

Key Terms (pg. 132 – 135)

1. Homeostasis2. Genes3. DNA4. Nucleus5. Chromosomes