Technology

Part One
The nervous system serves as the control and communications center of the body. Suppose that a person would like to reach an object from a high shelf. Upon seeing the object from above, the sensory cells in the eyes respond. Nerve impulses are carried by the sensory nerves towards the brain. This is received by the forward portion of the frontal lobe which then sends a command to Area 6 which decides which part of the body to move. Area 6 delivers the command to the primary motor cortex which initiates the movement by sending the signal or the message by the help of the neurons in the spinal cord down to the nerves of the legs and feet to move. This decision to reach an object from a high shelf is triggered by an increasing electrical activity in the frontal region of the primary motor cortex. The neurons send signals to the motor cortex to activate the necessary muscle. With the help of the information provided by the visual cortex, the motor cortex determines the ideal way to reach the object on the high shelf. The motor cortex, in return, signals the central grey nuclei and the cerebellum to help coordinate the muscles in sequence.

The motor association cortex, on the other hand, handles the more complex movement which is the necessary amount of hand pressure needed to make sure that the object is not shattered or dropped. Finally, the axons of the neurons of the primary motor cortex move down to the spinal cord to relay the information to the motor neurons. Motor neurons are directly connected to the muscles which activate contraction. The muscle of the feet, legs, arms and hands will then contract to be able to reach the object from the high shelf. During the contraction of the muscles of the legs and the arms, the myosin makes the think filaments hook on to the think filaments towards the center of each sacromere. And as each of the thin filaments slide over the thick ones, the I-bands and the H-zones become narrower  until both disappear at its full contraction.

Part Two
The gluteal muscles or gluteus maximus are used for locomotion such as climbing stairs or stepping up to go to higher ground. It works as an extensor and rotator of the hip joint. When stepping up, bones involved are the patella or kneecap, femur or thighbone and fibula or the rear calfbone.

On the other hand, when reaching for an object, the humerus or the upper arm bone as well as radius and ulna. The elbow joint which connects the humerus with the radius and ulna is also involved.