SUPPORT AND MOVEMENT

SUPPORT AND MOVEMENT

INTRODUCTION:

To retain their shape, all organism need some type of support. In multicellular organisms, this support is provide in the form of skeleton. Arthropods have external exoskeleton and vertebrates is made of bones, cartilage, ligaments and muscles. Bones provide a system of levers which produce movement with the help of muscles.

MOVEMENT:

The ability of changing place or position by entire body of an organism or its body parts is called movement. It can occur at:

i) Cellular level e.g. movement of gametes by flagella.

ii) Organ level e.g. heart beat, movement of limb, shoot and root of a plant.

iii) Movement of the whole organism from one place to another e.g. locomotion of unicellular and multicellular organism.

Movement is clearly visible in most of the animals as compared to the plants.

Organisms need a support for their movement an standing erect on the earth l. In unicellular organism, this support is provide by a thick cell membrane. In multicellular organism, this support is provide by exoskeleton and endoskeleton systems.

TYPE OF MOVEMENT

Movements are of two types:

i) Movement of body parts

ii) Locomotion

(i)MOVEMENT OF BODY PARTS:

The movement of body parts means movement of hand, finger, head and shoulder.

(ii)LOCOMOTION:

The movement of an animal as a whole from one place to another place is called Locomotion.

In humans, skeleton is responsible for support and movement of the body and its parts.

SKELETON:

The hard, bony, supported and rigid framework of the body is called skeleton. It gives physical support, shape, movement and protection to the soft organs of the body. Skeleton also stores minerals and provide a site for blood cell formation. Human skeleton is located in side of the body, and is called Endoskeleton . It consist of 206 bones. These bones can be divided into four groups.

1) Skull...........28 bones

2) Neck...........1 bones

3) Truck..........51 bones

4) Limbs..........126 bones

FUNCTION OF SKELETON

Main function of skeleton are:

(i) Support and Shape

(ii) Movement

(iii) Protection

(iv) Blood Cells

(i) Support and Shape:

The bones of skeleton support soft tissue and provide shape to the body.

(ii) Movement:

Muscles are attached to the bones which help the body to move.

(iii) Protection:

Bones of the skeleton provide protection to the internal organs e.g. brain, spinal cord, heart, lung and reproductive organs.

(iv) Blood cells:

Red blood cells are manufactured in red bone marrow. Red bone marrow is found in sternum, ribs and cranial bone.

Human skeleton is composed of two types of connective tissues

FUNCTION OF SKELETON

1) Bone:

Boon is the rigid or hardest form of connective tissues in the body cells of bone are called osteocyte.

Structure:

The matrix of boon contain a protein called collagen the collagen fibers are hardened by the deposition of minerals e.g. calcium, phosphate and salts. Bone is alive and contains living cells. Food and oxygen is supplied to the bone by blood vessels.

Type:

bones are of two types:

1) Compact bones

2) Spongy Bones

1) Compact bones:

The hardest bone is called compact bone. It makes the outer layer of the bone. It provides an attachment site for muscles. It supports our arms and legs.

2) Spongy bones:

Spongy bone is soft and highly porous. Layer of spongy bone lies below the compact bone. The cavities of spongy bone is contained bone marrow. Where red blood cells, white blood cells and platelets are formed. Spongy bone also contain blood vessels.

Types of bone cells Associated with Bone:

i) Osteoblasts (Bone forming cells)

ii) Osteocyte (Mature bone cells)

iii) Osteoclasts (Bone dissolve cells)

(2) Cartilage:

Cartilage is soft flexible and very strong made from collagen fibers. It is much softer than bone.

Structure:

The living cell of cartilage are called chondrocytes. These cells secrete flexible, elastic, non-living Matrix called collagen. It consist of protein, polysaccharide, collagen fibers but no blood vessels. Collagen fibres give elasticity to the cartilage. Cartilage contains less quantity of minerals than that of bone.

Types of Cartilage

Cartilage is of three types.

1) Hyaline. 2) Elastic. 3) Fibrous

1) Hyaline cartilage:

Hyaline found in the nose, larynx, trachea, bronchial tubes and moveable joints.

2) Elastic Cartilage:

It is elastic due to the elastic fibers and collagen fibers. It is found in epiglottis pinna of external ear.

3) Fibrous Cartilage:

It is very tough but less flexible due to the presence of a large number of collagen fibers. It is found in the intervertebral discs.

Function of cartilage:

It covers the ends of the bone and joint and gives support to the flexible portion such as nose and air. It also help in the moment of body parts.

Function of bone