Locomotion and Movement class 11 notes
- Movement is one of the significant features of living beings.
- Animals and plants exhibit a wide range of movements.
- Streaming of protoplasm in the unicellular organisms like Amoeba is a simple form of movement.
- Movement of cilia, flagella and tentacles are shown by many organisms
- Human beings can move limbs, jaws, eyelids, tongue, etc.
- Some of the movements result in a change of place or location.
- Such voluntary movements are called locomotion.
- Walking, running, climbing, flying, swimming are all some forms of locomotory movements.
- Locomotory structures need not be different from those affecting other types of movements.
- For example, in Paramoecium, cilia helps in the movement of food through cytopharynx and in locomotion as well
- Hydra can use its tentacles for capturing its prey and also use them for locomotion.
- We use limbs for changes in body postures and locomotion as well.
- The above observations suggest that movements and locomotion cannot be studied separately.
- The two may be linked by stating that “all locomotions are movements but all movements are not locomotions.”
- Methods of locomotion performed by animals vary with their habitats and the demand of the situation.
- However, locomotion is generally for search of food, shelter, mate, suitable breeding grounds, favourable climatic conditions or to escape from enemies/predators.
TYPES OF MOVEMENT
- Cells of the human body exhibit three main types of movements, namely, amoeboid, ciliary and muscular.
- Some specialised cells in our body like macrophages and leucocytesin blood exhibit amoeboid movement.
- It is effected by pseudopodia formed by the streaming of protoplasm (as in Amoeba).
- Cytoskeletal elements like microfilaments are also involved in amoeboid movement.
- Ciliary movement occurs in most of our internal tubular organs which are lined by ciliated epithelium.
- The coordinated movements of cilia in the trachea help us in removing dust particles and some of the foreign substances inhaled along with the atmospheric air.
- Passage of ova through the female reproductive tract is also facilitated by the ciliary movement.
- Movement of our limbs, jaws, tongue, etc, require muscular movement.
- The contractile property of muscles are effectively used for locomotion and other movements by human beings and majority of multicellular organisms.
- Locomotion requires a perfect coordinated activity of muscular, skeletal and neural systems.
- Muscles make up approximately 40 percent of total weight.
- The heart is the hardest-working muscle in the body. It pumps 5 liter of bloodper minute and 2,000 gallons daily.
- The gluteus maximus is the body’s largest muscle. It is in the buttocks and helps humans maintain an upright posture.
- The ear contains the smallest muscles in the body alongside the smallest bones. These Muscles hold the inner ear together and are connected to the eardrum.
- A muscle called the masseter in the jaw is the strongest muscle by weight. It allows the teeth to close with a force of up to 55 pounds on the incisors or 200 pounds on the molars.