MEDSCHOOL TV

Respiratory Physiology Mechanics of Breathing The processes of inspiration (breathing in) and expiration (breathing out) are vital for providing oxygen to tissues and removing carbon dioxide from the body. Inspiration occurs via active contraction of muscles – such as the diaphragm – whereas expiration tends to be passive, unless it is forced. Now, let's look at the physiology of ventilation – the process of inspiration and expiration, how this differs between quiet and forced breathing. The Lungs and Breathing The space between the outer surface of the lungs and inner thoracic wall is known as the pleural space. This is usually filled with pleural fluid, forming a seal which holds the lungs against the thoracic wall by the force of surface tension. This seal ensures that when the thoracic cavity expands or reduces, the lungs undergo expansion or reduction in size accordingly. During breathing, the contraction and relaxation of muscles acts to change the volume of the thoracic cavi...

 What is blood pressure? Blood pressure is the pressure of blood pushing against the walls of your arteries. Arteries carry blood from your heart to other parts of your body. Your blood pressure normally rises and falls throughout the day. It also increases during exercise or during house work. What do blood pressure numbers mean? Blood pressure is measured using two numbers: the first number, called systolic blood pressure, measures the pressure in your arteries when your heart beats. The second number, called diastolic blood pressure, measures the pressure in your arteries when your heart rests between beats. If the measurement reads 120 systolic and 80 diastolic, you would say, “120 over 80,” or write, “120/80 mmHg.” HIGH BLOOD PRESSURE High blood pressure (hypertension) is a common condition in which the long-term force of the blood against your artery walls is high enough that it may eventually cause health problems, such as heart disease. Blood pressure is determined both by ...