Slideshow Transcript

1. Slide 1: The Nervous and Digestive Systems
2. Slide 2: The Nervous System • your nervous system controls all parts of your body – receives and sends messages • brain is the control center of your nervous system – neurons: nerve cells • brain and all other parts of Click on brain for nervous system made of website neurons
3. Slide 3: • brain gets a lot of info from sense organs in your head – eyes, ears, tongue, and nose • brain gets info from other parts of your body • your body has nerves, that pass along info – nerves: groups of neurons • sense organs in your head have nerves that connect directly to your brain • spinal cord connects the nerves in the rest of your body to your brain – spinal cord: a tube of nerves that runs through your spine • backbone
4. Slide 4: • info from your body goes up your spinal cord to your brain – brain acts on info and sends a message back • playing a baseball game - at bat, your eyes watch the ball; eyes send info to the brain about speed and direction of the ball; in less than a second your brain decides whether or not to swing • if you decide to swing, your brain will send information down your spinal cord to nerves in your arms; the message will tell your arm muscles when and how hard to swing • if you hit the ball your brain will tell your leg muscles to run – the more you practice, the better your brain will get at telling your muscles how to hit the ball
5. Slide 5: The Digestive System • provides nutrients for the whole body – breaks down, digestes, the food you eat into nutrients your body’s cells can use • begins in your mouth – teeth grind up food into smaller pieces – salvia softens food and begins to digest it
6. Slide 6: • after swallowing, food enters esophagus – esophagus: a tube that connects your mouth with your stomach – actions of smooth muscles in your esophagus move the food to your stomach • stomach is a bag made of smooth muscles – muscles squeeze food and mix it with digestive juices • juices digest some parts of the food – food is mixed and squeezed – until it becomes mostly liquid
7. Slide 7: • the liquid food then passes into the small intestine, a long tube of muscle – different digestive juices are added and other parts of food are digested • small intestine does more than any other part of the digestive system – the nutrients from digested food pass through the walls of the small intestine into capillaries • blood carries nutrients to body’s cells
8. Slide 8: • large intestine is the last part of digestive system – most food that reaches the large intestine can’t be broken down any more – large intestine removes water from this food – what is left travels through the large intestine until it passes out of the body
9. Slide 9: Summary • brain sends messages to and from all parts of the body through the spinal cord and nerves • controls the way all other body systems work • the digestive system breaks down food to provide nutrients for all body’s cells • blood carries nutrients to every cell in body