7th Grade Science – Day 26!

Bell Ringer: 1.) Name an organ system, its main organs, and its main function

Daily Objective: Achievers on the ROAD to College will explain the functions of the muscular system and skeletal systems and name the major muscles of the body.

Intro to the Skeletal and Muscular Systems Your bones and joints are arranged so that they can move- but not by themselves. They need muscles. Muscles lie next to bones and you pull them into different positions, so that you can walk, run, or throw a ball.

DID YOU KNOW … The human body has about 650 skeletal muscles KP1: Skeletal muscles are muscles attached to bones, they help with voluntary movement DID YOU KNOW … The largest muscle in the body is the gluteus maximus. You have one in each buttock.

So, why should we study muscles?

1. Why do our muscles ache after exercise 1. Why do our muscles ache after exercise? Famous Jamaican sprinter Usain Bolt Olympic gold metal for 100m in 9.72 sec

2. What are shin splints?

3. Muscles are strong! The jaw muscle, or the masseter, can exert more force than any other muscle in the body. Even though it is small, the pressure of a normal person’s bite can be up to 200 pounds – the same as the weight of a fully grown man.

4. How do muscles work? Every time I press a button on my phone, there is a complicated chain of events inside the body. Your brain, nerves, and muscles work together to make your body move.

5. What happens if our muscles do not function properly 5. What happens if our muscles do not function properly? What are come common muscular disorders?

6. Muscles in space When astronauts come back to Earth after a long trip in space, they find it hard to walk because they have been in zero gravity. On Earth, muscles have to work against gravity to hold you up. Without gravity, they get weaker and weaker or they atrophy

7. Muscles help us communicate The face has about 80 small, precise muscles for moving your mouth and tongue to make different words and make different facial expressions. Smile = 17 facial muscles Frown = 43 facial muscles

KP 2: FOUR FUNCTIONS of the muscular system: 1. Movement 2. Heat production 3. Maintain posture 4. Stabilize joints

KP 3: There are three types of muscles: 1. Skeletal muscles = voluntary movement 2. Smooth muscles = involuntary movement 3. Cardiac muscles = heart (involuntary)

ROAD CHECK: What are the three types of muscle tissue? What do they do in the body?

KP 3: There are three types of muscles: 1. Skeletal muscles = voluntary 2. Smooth muscles = involuntary 3. Cardiac muscles = heart

KP4: Skeletal muscles Muscles you use to move around Muscles that you can control! Mostly attached to your skeleton They make up nearly half of your total body weight

Smooth muscles Involuntary muscles: you can’t control these! Found in bladder, respiratory tract, blood vessels

Cardiac muscles Involuntary muscle in our heart! Heart contractions are controlled by the sinoatrial node (SA node) and atrioventricular node (AV node)

Muscle fuel Just like cars, muscles need a supply of fuel to give them the energy they need to work What is our body’s fuel for energy?

Energy is stored in your muscles as Adenosine triphosphate, or ATP, which the mitochondrion makes from breaking down lipids and carbohydrates! KP 5: Muscle cells have a lot of mitochondria!

Tendons… The end of each muscle narrows into a tough cord called a tendon, which is attached to bone. When the muscle contracts, the tendon pulls the bone.

THE SKELETAL SYSTEM! Our bones hold us up, protect our most valuable insides, and make our blood. Without our skeleton, we would be a shapeless sack of organs.

DID YOU KNOW…? The adult body has 206 bones, but babies are born with up to 270. The smallest bone in the body is the stapes bone in the ear. It’s less than 0.15 of an inch long. The biggest bone in the human body is the femur. In some men, it can grow up to 2 feet long.

1. But why do I need to drink milk?

2. Where does blood come from?

3. What happens when I crack my joints?

4. What are the names of all these bones?

5. How do doctors use X-rays?

6. How do bones heal and how long does it take?

KP6: FIVE FUNCTIONS of the skeletal system: 1. Framework for the body 2. Protection 3. Movement (with muscles) 4. Blood cell formation 5. Store salts (calcium)

KP7: Muscle tissues are attached to skeletal system to make bones move!

Major Axial bones: Cranium Mandible Vertebrae Sternum Ribs (true and false)

Independent Practice Make a q-tip human skeleton using the glue provided. You only need 21 q-tips. (2 points) Write down the organ system and its main functions. (4 points) Write down the names in your group 4. Do not make a mess!

HAVE A GOOD DAY!