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The human body has different systems that work together to help us move, breathe, and live. Here’s how some of them work:

• Skeletal System (Bones):
    - Think of our bones as building blocks. They create a strong structure for our body.
    - The back is made of little pieces called vertebrae. They come in different types:
      - Cervical Vertebrae: These are the small bones in your neck.
      - Thoracic Vertebrae: These bones are in your upper back and connect to your ribs.
      - Lumbar Vertebrae: These are the big, strong bones in your lower back.
    - The sacrum is a set of bones in the back of your hips.
    - The coccyx is the small bone at the very bottom of your spine; some people call it the tailbone!

• Ribs:
    - We have 12 ribs that help protect our heart and lungs.
    - Some ribs connect directly to the middle of the chest, while others don’t directly connect.

• Sternum:
    - This is the bone in the center of your chest that connects the ribs together. It has three parts: the top part called the manubrium, the middle part called the body, and the small bottom part called the xiphoid process.

Muscular System (Muscles)

• Our muscles help us move. They work like rubber bands to help us bend, stretch, and lift things.
    - Trunk Muscles:
      - Rectus Abdominis: This is a muscle in your tummy that helps you bend forward.
      - External Oblique: These muscles are on the sides of your tummy and help you twist and bend sideways.
      - Internal Oblique: These muscles also help twist and bend, but they work on the same side of your body.
      - Transversus Abdominis: This strong muscle helps hold everything in tight.

• Back Muscles:
    - Quadratus Lumborum: This muscle helps you stand up straight and bend to the sides.
    - Erector Spinae: These muscles are super important for keeping your back upright.

Breathing Muscles

• Diaphragm:
    - This is the main muscle we use to breathe. When it moves down, it helps pull air into our lungs.

• Intercostal Muscles:
    - These muscles are between our ribs.
    - Internal Intercostal: They help pull the ribs down to push air out when we exhale.
    - External Intercostal: They assist in raising the ribs to take a deep breath in.

Blood Vascular System (Circulation)

• Arteries and Veins:
    - Our blood brings oxygen and nutrients to our body, and the blood vessels are like tiny highways for it.
    - The aorta is the biggest artery that pumps blood out to the whole body.
    - The inferior vena cava brings blood back from the lower parts of our body, and the superior vena cava brings blood from the upper body.