THE ROLE OF THE RESPIRATORY AND THE CIRCULATORY SYSTEMS IN THE PROVISION OF OXYGEN AND

THE ROLE OF THE RESPIRATORY AND THE CIRCULATORY SYSTEMS IN THE PROVISION OF OXYGEN AND REMOVAL OF CARBON DIOXIDE FROM THE BODY.

Name of student

Name of instructor

Course

Name of institution

Date

Introduction

The respiratory system is the human body’s system that is responsible for breathing, both mechanical through the chest wall; and physiological, through the alveoli. The circulatory system assists in gaseous exchange, in the alveoli, and circulation of oxygen to all parts of the body, as well as, removal of carbon dioxide from the parts of the body. The two systems work together to facilitate gaseous exchange. This paper seeks to the role played by the two systems in gaseous exchange and transportation to and from the body tissues. To effectively discuss the relation of the systems and their role, the paper is divided into sections, each discussing a particular aspect.

• Structure of the Respiratory System:

The respiratory system is divided into the upper and the lower respiratory tract. The part that is upper respiratory tube is composed of the structures that pick up air and direct it into the lower structures. These include: the nose, the mouth and a section that has the beginning of the trachea.

The lower respiratory tract includes the trachea, the two bronchi, the branches of the bronchi called bronchioles, and the lungs. The lungs are two in number; one lung is on the left; the  other on the right. The chest cavity holds the structures of the lower respiratory tract. Sternum, chest muscles and the rib cage offers mechanical protection to them.

Trachea is a tube that starts from a point below the nose, and divides into two branches called bronchi. The division of the bronchi into smaller branches gives out bronchioles. These divide further when they get into the alveoli lungs. The lungs consist of the alveoli-small air sacs where gaseous exchange takes place. The alveoli are rich in blood vessels to facilitate gaseous exchange. The walls making up the alveoli are only one cell thick to give the molecules entering and leaving them a short distance to travel. To ensure that the rate of exchange is maximum, the alveoli are supplied with a rich blood supply. The alveoli are also very many, in millions, to give a large surface area for gaseous exchange.

• Mechanism of breathing and gaseous exchange:

Breathing involves two steps; inhalation (breathing in) and exhalation-breathing out. The process is aided by two sets of muscles (diaphragm and rib cage) which contract and relax to decrease and increase the volume of the chest cavity.

Inhalation –the muscles are contracted, it flattens causing the chest cavity to increase in volume. Contraction of the rib cage causes it to rise. This creates low pressure in the lungs. Air enters the lungs from the high pressure outside.

Exhalation happens with the muscles relaxed. The diaphragm rises and becomes dome-shaped. The rib cage moves inwards. Volume in chest decreases and pressure increases. This makes the air with more carbon dioxide to be expelled out of the atmosphere.

Gaseous exchange is a function that is aided by a concentration gradient. Air entering the alveoli of the lungs is more concentrated in oxygen. The air in the alveoli is more concentrated in carbon dioxide. The countercurrent flow system of the alveoli also helps increase the concentration gradient. Because of the gradient, air with more oxygen crosses the epithelial lining of the cells of the alveoli into the blood vessels. While this happens, carbon dioxide comes out of the capillaries where it is more concentrated to the alveolar space where it is less concentrated. It is expelled out through the process of exhalation.

• Regulation of breathing:

It is vital to note that; the main purpose of the respiratory system is to distribute oxygen to the tissues as per the demand, and to remove carbon dioxide as it is produced by tissues. The body has a mechanism of regulating breathing through sensing the levels of carbon dioxide (Holmgren and Nilsson 1994 P.59). Carbon dioxide dissolves in water to produce hydrogen ions and hydrogen carbonate ions. The brain has central chemoreceptors, which sense rising levels of hydrogen carbonate ions. When the levels of carbon dioxide rise, it initiates a response through breathing. The peripheral chemoreceptors located at the base of the aorta sense the rising levels of hydrogen ions. They send messages to the brain to stimulate breathing. When the levels of these ions are low, less stimulation is initiated.

• (A). Asthma

Asthma is considered a chronic disease of the respiratory system whose main symptom is difficulty in breathing (WHO 2008). a patient suffering from asthma experiences attacks of breathlessness referred to as Asthmatic attacks.

Among the causes of asthma are allergens like dust and pollen, chemical irritants, tobacco smoke and air pollution.

The main symptoms during the attack are breathlessness, fatigue, and reduced activity levels.

Curing asthma is difficult. Management involves controlling the disease and symptomatic management. Medications that are short term are used to relieve the symptoms and also to reduce exacerbations. Preventing the patient from allergens is a very effective method of management. It is one disease condition that leads to chronic obstructive pulmonary disease. Failing to take the medications can lead to death (WHO 2008).

(B) Emphysema

Emphysema is a respiratory system disorder that results from the destruction of the air sacs. It also constitutes the chronic obstructive pulmonary disease. Among the main causes are marijuana smoke, tobacco smoke, air pollution and silica (WHO 2008).

The main symptom of emphysema is a difficulty in breathing that start slowly. This is also accompanied by fatigue, mental alertness, fast heart rate and cyanosis (Mayo Clinic 2014).

Treatment for emphysema involves oxygen supplementation and pulmonary rehabilitation. Medications are also used. Such medications include antibiotics, pulmonary steroids, bronchodilators, and smoking cessation drugs like Chantix. Counselling people to leave a lifestyle that increases risks is also a rationale used in the management of the disease.

Emphysema can also bring complications to the body. These complications include a collapsed lung which is referred to as a pneumothorax, heart problems like purmonale, and giant bullae that refers to having empty spaces in the lungs (WHO 2008).

2.1. Composition and Functions of Blood Cells:

The blood, which is the liquid part of the body, consists of the plasma and the blood cells. The blood cells consist of three types; the red blood cells also known as the erythrocytes; the white blood cells which are also called leucocytes; and the platelets also known as the thrombocytes (Reiss and Givens 2002).

The red blood cells have no nucleus inside the cell. They contain a component known as the hemoglobin that gives them the red color. The cells are biconcave shaped as an adaptation to carry maximum oxygen. One cell is capable of carrying four molecules of oxygen. Their function is to carry oxygen in the body.

The white blood cells are many per milliliter of blood, and their function is to fight diseases from attacking the body. They are of two types: the phagocytes and the lymphocytes. The phagocytes provide protection by ingesting micro-organisms. The lymphocytes provide protection by the production of antibodies against the a.............