GAS EXCHANGE- Gas exchange is the transferring process of oxygen from the lungs to our bloodstream, and getting rid of carbon dioxide within the bloodstream to the lungs and out of our body. Gas exchange occurs within the alveoli which are tiny air sacs located at the end of each bronchiole. WHY DO WE NEED A LARGE SURFACE AREA FOR GAS EXCHANGE TO OCCUR WITHIN THE ALVEOLI? In general, a large surface area increases the rate of diffusion. Therefore, the purpose of the large surface area the alveoli have is to increase the rate at which oxygen is diffused.
When we inhale, the oxygen enters through our nose or mouth then it gathers it in the Pharynx (throat) then it is passed down in the trachea then it flows down your bronchioles and finally down the alveoli. Our alveoli are surrounded by many blood vessels called capillaries. Oxygen diffuses through the alveoli into the blood stream through the capillary and then up to the heart to be pumped around the body. Due to the thinness of the capillaries, this allows for a greater diffusion rate, due to the gases being able to diffuse quickly in short distances. Our diaphragm contracts (or tightens) when we inhale.
This is very important as this allows osmosis occurs in our bodies. Plasma is forced out of the capillaries under high hydrostatic pressure to form tissue fluid. Some of the tissue fluid is return in capillary ends and some is returned to the blood by the lymphatic system. Plasma carries glucose, ions, waste product, respiratory gases and hormones around the body. Small molecules such as oxygen and carbon dioxide can diffuse in and out of the cells through the phospholipid bilayer; ions and glucose molecules enter and leave the cell via the channel proteins.
More nutrients are used and body temperature rises. To perform as efficiently as possible the cardiovascular system must regulate these changes and meet the body’s increasing demands. The respiratory system has different affects to exercising. When you exercise, your body has an increased need for oxygen. The muscles working in your body need oxygen in order to function, as the heart responses by pumping out more oxygenated blood to your muscles, the respiratory system also makes adjustments to help meet the demands of the body during exercise.
INTRODUCTION Respiration is the sequence that results in the exchange of oxygen and carbon dioxide between the air and the bodys cells. Nerve impulses stimulate the breathing process which moves air through a series of passages in and out of the lungs. Then external respiration takes places this is where an exchange of gases between the lungs and blood take place. Then internal respiration is where the gases exchange between the blood and tissue cells. Then the final step of respiration occurs, this is where the cells utilise the oxygen for what the body requires them to do, this is known as cellular respiration.
This is what is generally referred to as breathing. Internal Respiration This is the exchange of gases between the circulatory system and the tissues of the body. Cellular respiration describes the chemical processes (such as oxidisation) involved when individual molecules use oxygen, creating carbon dioxide as a waste product. The Passage of Oxygen from Nose to Lungs During external respiration or breathing, air is drawn in through the nose, where it is warmed, filtered and moistened. It then passes through the pharynx, larynx and trachea and into the thoracic cavity containing the lungs.
| | | Lesson 6 - The Cardio-Respiratory System DefinitionsThe cardio-respiratory system consists of the cardio vascular system (heart and blood vessels) together with respiratory system (lungs and air ways). These systems work to transport oxygen to the muscles and organs of the body and remove waste products including carbon dioxide. The HeartThe heart is a double pump. "Oxygen-poor" blood enters the heart from the vena cava to the right atrium, and flows down to the right ventricle. The first pump pumps "oxygen poor" blood to the lungs from the right ventricle of the heart via the pulmonary artery where it returns as "oxygen rich blood" via the pulmonary vein to the left atrium.
The Atrial reflex: The atria have in their walls stretch receptors called low-pressure receptors These low-pressure receptors play an important role, especially in minimizing arterial pressure changes in response to changes in blood volume. They do detect simultaneous increases in pressure in the low-pressure areas of the circulation caused by an increase in volume, and elicit reflexes parallel to the baroreceptor reflexes to make the total reflex system more potent for control of arterial pressure. b) Long term mechanism for control of blood pressure: Is determined by the balance between the fluid intake and output. 1. The Renin-Angiotensin System Renin is synthesized and stored in an inactive form called prorenin in the juxtaglomerular cells of the kidneys.
The oxygen rich air works its way to the alveoli and then diffuses across the thin membrane to the capillary network that surrounds each one, this distance is between 0.5-2.5µm. As the diffusion gradient changes, carbon dioxide diffuses into the lungs and is then expelled via exhalation. This is tidal ventilation as the flow of air is bi-directional through the lungs. This system has a
HIGHER EDUCATION FOUNDATION COURSE Human Biology The effect of moderate exercise on heart and breathing rates Assignment unit 2 1. Introduction By measuring the heart and breathing rate, the effect of exercise on the circulatory and respiratory system was shown. 2. Hypothesis As exercise causes the muscle cells in the body to use up more oxygen and produce more Carbon dioxide, the ventilation and the heart rate of a human will increase. 3.