1. Movement and Locomotion

Movement:

• Movement is the act of changing the place or position by one or more parts of the body. 
• It can either be voluntary or involuntary. 
• A movement takes place at the biological level. 
• Movement requires energy.

 Locomotion: 

• Locomotion is the movement of an organism from one place to another. 
• It is always voluntary. 
• Locomotion takes place at the organism level. 
• Locomotion doesn’t necessarily require energy.

 2. Endoskeleton and Exoskleton

Endoskeleton: 

• It is the skeleton found inside the body. 
• It originals from mesoderm. 
• Example: Human beings. 

Exoskleton: 

• It is the skeleton found on the exterior layer of the body. 
• It originals from embryonic ectoderm or mesoderm. 
• Example: Scales of fish feathers of birds

 3. Pectoral and Pelvic girdle

Pectroal girdle: 

• It is situated in the shoulder region. 
• It gives articulation to forelimbs.
• The shoulder blade and collar bone remain separate. 
• They are comparatively lighter. 

Pelvic girdle: 

• It is situated in the hip region. 
• It gives articulation to legs or hind limb. 
• Three bones (ilium, ischium and pubis) are fused to form a single hip bone. 
• They are strong to take upto lot of stress.

4. Ball and socket Joint and Hinge Joint

Ball and socket Joint: 

• A ball shaped head of one bone articulates with a cup like socket of an adjacent bone. 
• Movement can occur in three planes. This joint allows the greatest range of movement.
• Example: Shoulder, Hip

Hinge Joint: 

• A cylindrical protrusion of one bone articulates with a trough-shaped depression of an adjacent bone. 
• Movement is restricted to one plane. This joint allows bending and straightening only. 
• Example: Elbow Knee Ankle

 5. Voluntary and Involuntary muscle: 

Voluntary muscle: 

• They are striated (Multinucleate muscles and unbranched) muscles.
•   They are attached to bones. 
• Example: found in arms, legs 
• They are used as per our will.

Involuntary muscle: 

• They are non – striated (Single muscle, central nucleus) muscles. 
• They are attached to soft parts of the body like blood vessels, Iris, Skin etc. 
• They are not under our control.