Question

Course Name: Introduction to Anatomy and physiology

Please Don't copy and past,

Please Avoid Plagiarism ,

Don't use handwriting. Please before Due date :28 March

Choose "only one system" of the human body and prepare a response to the following questions in 1-2 pages:

e.x. "The Integumentary or The Endocrine System "

1. Introduction(Explain the system with the components)
2. Body(Explain how the system relates to achieve homeostasis in human body)
3. Conclusion( Choose any disease common and explain how and which part of the system is affected)

again Please Don't COPY and PAST, Please Avoid Plagiarism,

Answer 1

THE RESPIRATORY SYSTEM

Respiratory system consists of the upper respiratory tract and the lower respiratory tract.Upper respiratory tract includes the nasal passages while lower respiratory tract includes the bronchi, bronchioles, alveolar ducts and alveoli.The primary function of the respiratory system is gas exchange. Oxygen (which we need for our cells to function) from the external environment is transferred into our bloodstream while carbon dioxide (a waste product of cellular function) is expelled into the outside air.The exchange of gases takes place at the alveoli, where oxygen (O₂) diffuses into the lung capillaries in exchange for carbon dioxide (CO₂).

• The trachea – the tube connecting the throat to the bronchi.
• The bronchi – the trachea divides into two bronchi. One leads to the left lung, the other to the right lung. Inside the lungs each of the bronchi divides into smaller bronchi.
• The broncheoli - the bronchi branches off into smaller tubes called bronchioles which end in the pulmonary alveolus.
• Pulmonary alveoli – tiny sacs (air sacs) delineated by a single-layer membrane with blood capillaries at the other end.The exchange of gases takes place through the membrane of the pulmonary alveolus, which always contains air: oxygen (O2) is absorbed from the air into the blood capillaries and the action of the heart circulates it through all the tissues in the body. At the same time, carbon dioxide (CO2) is transmitted from the blood capillaries into the alveoli and then expelled through the bronchi and the upper respiratory tract.
• The lungs – a pair of organs found in all vertebrates.The structure of the lungs includes the bronchial tree – air tubes branching off from the bronchi into smaller and smaller air tubes, each one ending in a pulmonary alveolus.

How the respiratory system achieves homeostasis?

Homeostasis is achieved by the respiratory system mainly by gas exchange and the regulation of the blood pH. Blood within the pulmonary artery is oxygen-poor and contains a large concentration of carbon dioxide. As blood passes through the capillaries surrounding the alveoli, oxygen diffuses into blood and carbon dioxide diffuses out of blood into the alveoli. Thereafter, carbon dioxide is exhaled by moving from the alveoli to the nose. Since the blood within the pulmonary vein is oxygen-rich and contains a small concentration of carbon dioxide, it is clear that carbon dioxide has been replaced for oxygen as blood passes through the lungs. The respiratory center, located in the medulla oblongata automatically discharges nerve impulses to the diaphragm and the muscles of the rib cage. In its relaxed state, the diaphragm is dome-shaped, but upon stimulation, it contracts and lowers. Also the rib cage moves upward and outward. As the thoracic cavity increases in size, air pressure within the expanded lungs lowers and is immediately balanced by air rushing in through the nose. This is why it can be said that humans breathe by negative pressure. When the respiratory center stops sending out stimulatory nerve impulses the diaphragm and rib cage resume their original positions and exhalation occurs.
There are chemoreceptors adjacent to the respiratory center in the medulla oblongata that are sensitive to the carbon dioxide content of the blood, and chemoreceptors in aorta and carotid arteries that are sensitive to both the carbon dioxide content and the pH of the blood. When the carbon dioxide concentration rises or when the pH lowers the respiratory center is stimulated and the breathing rate increases. It is interesting to observe that the oxygen content of the blood does not directly affect the activity of the respiratory center.

Disease affecting the respiratory system

There are many diseases that can affect the respiratory system.One of the most common disease that affects this system is Chronic Obstructive Pulmonary Disease(COPD).

This is preventable and treatable disease characterised by persistent airflow limitation that is usually progressive, and is associated with enhanced chronic inflammatory response in the airways and lungs to noxious particles or gases.Related diagnosis include chronic bronchitis(cough and sputum on most days for 3 months) in each of 2 consecutive years) and presence of emphysema, which is characterised abnormal permanent enlargement of airspaces.This disease mainly occurs in smokers, and other risk factors include infections, reduced lung growth, low birth weight etc.

Generally, the airflow limitation and premature airway closure leads to gas trapping and hyperinflation, reducing pulmonary and chest wall compliance.This causes flattening of diaphragmatic muscles and an increasingly horizontal alignment of the intercostal muscles causing mechanical disadvantage.So, the work of breathing increases and gradually the patient might have severe respiratory distress.

COPD can be managed by:-

• Reducing the exposure to noxious particles or gases
• Bronchodialators
• Corticosteroids
• Pulmonary rehabilitation
• Oxygen therapy
• Surgical methods
• Treatment of the underlying causes