Related Changes In Balance Ability example essay topic

Background Information What is Balance Balance is a reflex system that allows us to maintain awareness of our special orientation at all times, and to react to it. It is an integral part of all movement activities. The only time balance is not necessary is when the body is completely supported, for example lying flat on an even and horizontal surface or strapped in a wheelchair. Humans are unique in the animal kingdom as we are the only creatures that can always walk upright on two legs.

To keep ourselves upright we rely heavily on a highly developed sense of balance. Balance is commonly subdivided into two main types, static and dynamic. Static Balance is the ability to maintain a desired body posture or position when the body is stationary. Dynamic balance is also an ability to maintain a desired body posture or position when the body is moving.

Both static and dynamic balance is used in many movement activities. The bodies balancing system is in the ear. The ear is not just used for hearing; it contains delicate organs of balance in the innermost part of the ear, called the inner ear. Each ear contains a vestibular apparatus, which detects the position of the head and signals any change in position or movement. Each apparatus consists of a chamber, the utricle, and three semi-lunar canals. The balancing system in the ear works with the visual, nervous and skeletal systems to maintain orientation of balance.

The Balancing System in the Ear The utricle and saccule are concerned with detecting the position and acceleration of the head. Each of these two cavities contains a pad of cells, covered by a jelly lie substance called endolymph, embedded in small granules of chalk, called otoliths. When the body is upright, gravity causes the otoliths to press against the sensitive hairs in the jelly. The hairs then transmit nerve signals t the brain to say 'upright'.

When the head moves forward, backwards or sideways the otolith push against the hairs, forcing them to bend in different ways. A new message is then sent to the brain, which can then if necessary send out instructions to the muscles to adjust the position of the body so it will be in balance. The otolith responds sharply to sudden changes, and if they are over stimulated then motion sickness or dizziness may occur. The utricle is also in action when the body moves forwards or backwards. If for example a child starts to run then the otolith are pushed back against the hairs as though the child were falling backwards. As soon as the brain receives this information it sends signals to the muscles, which make the body lean forwards, restoring its balance.

The signals from the otoliths in the saccule and the utricle compliment each other and give us an integrated signal about our movement. Jutting out, just above the utricle of the ear are three fluid filled semi-circular canals. Two of the semi-circular canals are vertical and at right angles to each other, whole the third is on a horizontal plane Semi circular canals are sensitive to movements of the head, particularly turning and rotation. At the base of each canal is a mass of jelly called endolymph; in which tips of sensitive are encased in a fragile membrane called the capulla. When you move your head, the fluid in the ampulla lags behind, pushing the am pulls, which causes the hairs to bend. The bending hairs stimulate the hair cells, which in turn trigger sensory impulses in the vestibular nerve going to the brain, which pass on information of the movement.

Hair cells are extremely sensitive; the brain detects for example a capulla movement of even a thousandth of an inch. He there canals react separately and in combination with each other to detect different types of head movement. For example they detect when we nod in an up and down motion, (pitch), when we tilt our head down towards our shoulder (roll) and when we shake our head in a down to down motion like we are saying no (yaw). Control Centre The part of the brain most responsible for detecting the action of the muscles in keeping the body balanced is the cerebellum. The nerve fibres from the vestibular portion of the auditory nerve run to the cerebellum, the centre of balance in the brain. It is known as a large mass of nervous tissue.

As well as taking in messages from balancing organs in the ears, messages from all over the body including the neck, eyes, spine and limbs are coordinated in the cerebellum. The brain interprets the messages transmitted from the ear, utricle and semi-circular canals and then sends reflex information to the muscles in the body. Like breathing it all happen automatically at a sub-conscious level. Do Eyes Help you Balance?

Eyes also play a role in sense of balance as they provide vital information about the body's relation to its surroundings. As we move and see how objects around us are changing, our brains calculate our body's relationship to those objects. Eyes also have an important link with the semi-circular canals. When the head begins to move to the left for example the movement in the semi-circular canals causes the eyes to move to the right.

Balance mechanisms then cause them to move left to adjust to the same position as the head. Balance changes with Age? Older adults experience a decline in their ability to balance. Age related changes in balance ability could be related to a variety of changes in the body's system, especially the nervous system.

Vision also changes as people age, which sometimes has an effect on a persons balance.