Note on Skeletal System

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Bones together form the supporting framework of the body is called skeletal system. An infant has 213 bones in the skeleton but an adult has 206 bones. If a bone is treated with hydrochloric acid for some hours, its calcium dissolves and the bone soften. Such bone is called decalcified bone. Bone is the hardest connective tissue in our body. It is composed of 20% water, 30 to 40% organic material and 40to 50% inorganic material. Organic material are bone cells and matrix and inorganic materials are minerals like calcium, magnesium and phosphorous.

Structure of bones

Bone found in our body are of different shape and siize. The bones which form the vertebral column are irregular bones. All the bones are covered with a thin and delicate membrane called the periosteum which contains blood vessels to nourish the bones. The inner part of a long bone is hollow and it is called medullary cavity. It contains yellow bone marrow. The two ends of a bone are called spongy bone which is also called red bone marrow.

Functions of the skeletal system

  1. It forms the supporting of framework of the body to give its shape and size.
  2. It gives attachments to the muscles and tendons and allows various types of movements.
  3. It provides mechanical protection to internal delicate organs.
  4. The cartilage of larynx helps in speech.
  5. It provides a reservoir of calcium, phosphorous and fat.
  6. It contains red bone marrow in which red blood cell develops.
  7. The ribs and sternum help in breathing movements of the chest.

Types of skeleton

The skeleton present on the outer surface of the body is called exoskeleton. The hard part present beneath the skin is called endoskeleton.

The bone of the skeleton are divided into two major groups: Axial skeleton and appendicular skeleton.

  • All the bones are covered with a thin and delicate membrane called the periosteum which contains blood vessels to nourish the bones.
  • The cartilage of larynx helps in speech.
  • The inner part of a long bone is hollow and it is called medullary cavity.
  • Skeletal system contains red bone marrow in which red blood cell develops.
  • The skeleton present on the outer surface of the body is called exoskeleton.
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Very Short Questions

Skeleton is a group of different types of bones and cartilage, which provides the supporting firework for the muscles and delicate organs.

Its function are as follows:
i) This determines the framework of the body.
ii) The delicate internal organs of human body are protected by the skeleton.
iii) The red blood cells and while blood cells are formed inside the bone called bone marrow.
iv) It helps to store calcium and phosphorous.

The bones of human skeleton can be divided into two main divisions:
a) Axial skeleton
b) Appendicular skeleton.

The basic and central firework of the body is called axial skeleton.
The bones which lie at the sides of the body are called appendicular skeleton.

Axial skeleton Appendicular skeleton
i)It is at the centre of the body. ii)It is on the side of the body.

Vomer: Face
Vertebra: Vertebral column
Sternum: Thorax
Ulna: Forelimbs
Scapula: Pectoral girdle
Femur: Hind limbs

Bone kept in hydrochloric acid becomes soft because HCL reacts with calcium present in bone and destroy it. Hence, it becomes soft.

0%
  • How many bones are there in the average person's body?

    It varies by the individual
    639
    333
    206
  • What is the skeletal system?

    All the bones in the body
    All the bones in the body and the tissues that connect them
    All the body's organs, both soft and hard tissue
    All the muscles and tendons
  • Which bone protects the brain?

    The cerebrum
    Calcium
    The cranium
    none of these
  • What makes bones so strong?

    Cartilage
    Blood and marrow
    Silica
    Calcium and phosphorous
  • Muscles are made of ______

    Blood and marrow
    groups of cells called fibres
    Silica
    Calcium and phosphorous
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DISCUSSIONS ABOUT THIS NOTE

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Forum Time Replies Report
inportant of skeletal system

not about skeletal system


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Modigho Mahfudhigho

Differentiate between exoskeleton and endoskeleton


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Modigho Mahfudhigho

Differentiate between exoskeleton and endoskeleton


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Ask any queries on this note do animal have scapula


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