Biology Notebook: 07.04 Muscular, Skeletal, and IntegumentaryObjectives:·0Describe the structure and functions of the skeletal system·1Describe the structure and functions of the muscular system·2Explain how the muscular and skeletal systems work together·3Explain that the largest organ in the body is also body’s first line of defense against pathogensKey Questions and TermsNotesThe Skeletal SystemWhat is the skeletal system made of?living tissueList and describe the functions of the skeletal system.1.Support: The skeleton’s bones give support and shape to the body.2.Protection: Bones protect the internal organs of the body.3.Movement: The skeleton has a system of joints and levers that coordinate with muscles to produce movement.4.Mineral Storage: Bones contain reserves of minerals, such as calcium, that are important to processes in the body. Whenever calcium levels in the blood are low, some of the stored calcium is released from the bones.5.Blood Cell Formation: Blood cells are produced in the soft marrow tissue thatfills the internal cavities of some bones.What is the axial skeleton?The bones that support the central axis of the body, including the skill vertebral column, an rib cage.What is the appendicular skeleton?The bones of hte arms, legs , pelvis, and sholder areas.Bone StructureDescribe the layers of bone:·4Cartilage·5Spongy Bone·6Compact Bone·7Bone Marrow·8Periosteum·11 CartilageCartilage is a dense and fibrous substance that is strong but flexible. It can be found in flexible parts of the body, such as the nose andear, and also in the areas where bones meet. Cartilage also grows near the growth plates at
·9Osteoclast·10 Osteoblasteither end of long bones, such as those in the arms and legs. This cartilage is gradually replaced by bone tissue, making the now longer bone stronger. There are no blood vessels within cartilage like there are within true bone. Instead, cartilage cells receive nutrients through diffusion from the neighboring blood vessels and tissue.·12 Spongy BoneA layer of less dense spongy bone may be found under the outer layer of compact bone. Spongy bone is not soft and squishy like a kitchen sponge. It is actually a strong network of thin fibers that adds strength to the bone without adding much excess weight.·13 Compact BoneBeneath the periosteum is a dense layer of compact bone. Nerves and blood vessels run through this layer in channels.·14 Bone MarrowMany bones have an inner cavity of soft tissuecalled bone marrow. Yellow marrow is made up of cells that store fat, while red marrow contains stem cells that produce most types of blood cells.·15 PeriosteumThe rigid outside of the bone is a tough layer of connective tissue called the periosteum.