The Respiratory System

The function of the respiratory system is to move air in and out of the lungs in a process known as ventilation, respiration, or breathing. The exchange of oxygen and carbon dioxide in the lungs is called external respiration. The same exchange within the hemoglobin of red blood cells is internal respiration. The larynx contains the vocal cords, which stretch between the thyroid and cricoids cartilages. The muscles of the lower vocal cords stretch and relax to produce different sounds which allow you to sing. The lungs contain connective tissue, the bronchial tree, nerves, lymphatic vessels and blood vessels. The left lung consist of two lobes, upper and lower and the right lung consist of three lobes, upper, middle, and lower. Within each lung are the primary, secondary, and tertiary branches of the bronchi, the bronchioles, and the alveoli.  The lungs are covered by, and the chest cavity is line with the pleura. The outer membrane is the parietal pleura and the inner membrane is the visceral pleura.

During inspiration, the diaphragm contracts and the intercostals muscles raise the ribs, increasing the space in the thoracic cavity. This decreases the pressure within the cavity so that the air outside the body passively flows into the thoracic cavity. During expiration, the diaphragm relaxes, pushing up into the thoracic cavity, and the intercostals muscles lower the rib, forcing the air flow out of the body.  Breathing is controlled by the respiratory center of the brain, located in the pons and medulla oblongate. 

Thoracic- chest cavity 

The Ear

Everyone knows the function of ears are, and that's to hear, but do you know what parts make up the ear?

There are three parts to the ear. The external ear includes the auricle or pinna and the external auditory canal to the tympanic membrance. The middle ear begins at the typanic membrance and ends at the oval window and includes the ear ossicles. The inner ear is composed of the labyrinth and contains the organ of Corti as well as perilymph and edolymph, the fluids of hearing. The semicircular canals are vestibule in the inner ear function in the equilibrium and balance of the body, sending impulses to the vestibular nerves, which brings information to the cerebrum (to your brain)  for interpretation. The outer ear collects sounds waves and channels then to the tympanic membrance, which then vibrates. The vibrations are amplified by the ear ossicles and enter the inner ear and cochlea. The movements of the hairs in the cochlea trigger nerve impulses that are transmitted by the auditory never to the brain. 

Aging causes the eardrum to shrink. The joints between the ossicles degenerate so there is less freedom of movement, which decrease in hearing acuity.

The types of hearing loss are conductive hearing lost which is the result of sound wave transmission interruption as with cerumen impaction and tumors or infections.

Another type is sensorineural hearing loss which is the result of nerve damage so that the brain cannot perceive sound waves as sounds. Also there is tinnitus, which is an abnormal constant ringing in your ears, suggests damage to the auditory nerve.