Muscles are of three types
(i) Striated Muscles
1. These are also called as skeletal muscles or voluntary muscles
2. These are multi nucleated, and unbranched.
3. These are attached to bones.
4. Striated muscles are found in arms, legs, neck.
ii) Non-striated Muscles
1. These are also called as smooth muscles or involuntary muscles.
2. They possess single central nucleus.
3. Non-striated muscles are attached to soft parts of the body like blood vessels, iris, bronchi and the skin.
iii) Cardiac muscles
1. These are branched muscles with 1-3 central nuclei
2. These are involuntary muscles.
3. These muscles are found in Heart.

Streamlined body
(i) A streamlined body is the shape of the body that reduces resistance when moving
(ii) Streamlined bodies often have a teardrop shape.
(iii) Streamline shape reduces the friction of movement to a minimum thus decreasing overall drag
(iv) Streamlined body of birds help the particles of air to move upload them quickly and come together smoothly on the other side. The air does not provide much resistance to the body so that they can fly easily in air spending less energy.
(v) Streanilined body of fishes help them to move smoothly with the flow of water. Its body shape reduces friction while moving in water. It helps in the orientation of the fish movements in a particular direction.

There are three types of movements:
a) Amoeboid movement
It is brought about by pseudopodia which are appendages which move with the movement of protoplasm within a celle
b) Ciliary movement
This movement is brought about by appendages called as cilia which are the hair like extensions of the epithelium. Both these kinds of movements are seen with cells of the lymphatic system
c) Muscular Movement
It is a more complex movement which is brought about by the musculoskeletal system. This type of movement is seen in the higher vertebrates.

Axial Skeleton
The axial skeleton consists of the bones along the axis, or central line, of the human body. The axial skeleton consists of the skull, facial bones, sternum, ribs and vertebral column.
a) Skull

Skull is a hard structure made up of small bonds. It is formed by 22 bones out of which 8 bones are fixed together to form the cranium and 14 bones fuse to form the face. Skull placed on the top of the backbone can be moved up, down and sidewards
b) Vertebral Column

(i) Vertebral column running at the back of the body is also called the backbone. It is in the trunk region to offer support to the upper part of the body.
(ii) Vertebral column is made up individual bones called as vertebrae. Total vertebral column consists, of 7 cervical vertebrae, 12 thoracic and 5 lumnar vertebrae, 5 fused sacral and 3 fused coccygeal vertebrae.
(iii) Vertebral column runs from the base of the Skull to the hip bone forming a tube. Spinal cord passes through this hollow tube. Vertebrae are joined by gliding point which allow the body to be bent back, front or side wards.
c) Sternum or Rib cage

(i) The rib cage occupies the chest region. It is a cone shaped structure tirade up of 12 pairs of ribs. Ribs are attached to vertebrae at the back which curve around to form a cage, 10 pairs of ribs are attached to the breast bone at the front. 2 pairs of lower ribs are free at front. These are called as free-floating ribs; Rib cage is set up in such 4 way that it can contract and expand during the process of breathing.
(ii) Rib cage protects the underlying lungs, heart and some part of Liver.

The different types of joints are as follows: 
(i) Immovable joints - Example: Bones of the skull box .
(ii) Partially movable joints - Example: Joints between the ribs and breast-bone.
(iii) Freely movable joints - Example: Hip joint.
(iv) Gliding joint - Example: Ankle bones.
(v) Pivot joint - Example: Joint between axis vertebrae and atlas.
(vi) Hinge joint - Example: Joint between finger bones and toes.
(v) Ball and socket joint - Example: Shoulder joint.