HUMAN BODY SYSTEMS Part 1 Seventh Grade Science

WHAT IS A SYSTEM? A system is a group of organs that work together and provide an organism with an advantage for survival

WHAT IS A SYSTEM? SYSTEM Organs Tissues Cells Organelles

HUMAN BODY SYSTEMS The two systems that you think of most are probably your respiratory system and digestive system We will also learn about: Muscular-Skeletal System Circulatory System Reproductive System Endocrine System Nervous System Excretory System

Respiratory System Includes all organs that aid in getting air into, around, and out of the body

Main Parts of the RESPIRATORY SYSTEM

Lungs contain smaller parts:

Air exchange is from alveoli to blood stream

DISEASES OF RESPIRATORY SYSTEM Common colds Bronchitus Asthma Lung cancer

DIGESTIVE SYSTEM Includes all organs that help prepare food for use by your body

Main Parts of the DIGESTIVE SYSTEM

Epiglottis closes opening to nasal passages

Esophagus moves food from the mouth to the stomach in about 10 seconds

Small (20 ft.)& Large (5 ft.)Intestines

Small Intestine: absorbs nutrients through villi VILLI on walls of small intestine Villus showing absorption mechanism

Large Intestine: contains “friendly” bacteria that aid in digestion of non-nutrient food materials

SKELETAL MUSCULAR SYSTEM Includes all of the bones of the skeleton with their attached muscles

How does your skeleton move your body? Tendons attach muscles to the bones Muscles get signals from nerves leading to the brain Signals from the brain make your body move…no signals, no movement

Diseases of the Muscular System Polio – caused by a virus Tetanus – caused by a bacteria Muscular dystrophy, multiple sclerosis, cerebral palsy – genetic or present at birth