We give your body support and structure . We also protects your delicate orgains , like your brain, liver, and lungs. We are filled with a substance called marrow. What are we?

Bones of the Skeleton

Explanation:

The bones hard supporting tissues buried within the soft tissue of an animal. The mammalian skeleton is is built from more than 200 bones, some fused together and others connected at joints by ligaments that allows freedom of movement.

 Bones fused together to form skeleton gives shape to the body, they also  protect the various organs of the body such as the skull which protects the brain, the sternum and ribs protect the heart and lungs.

Substances in the bone marrow are also site for red and white blood cells production.

Bones

Explanation: The human skeletal system consists of an arrangement of bone which help protect the vital organs in the body. Eg, the brain is protected by the skull, and the lungs by the ribs. The body is made up of 206 bones in which muscles are attactched to and helps give structure and support to the body. Most of the bones are filled with a spongy tissue called the bone marrow. Some of the bones eg, the hip bone, contains the bone marrows which gives rise to stem cells that produce red blood cells in the body.

altitude, density, pressure

air gets less dense the higher the altitude and also the air pressure is less as altitude rises.