Mammalian Respiratory System

• The nasal cavity makes up the main external opening of the mammalian respiratory system. The nasal cavity is lined with a mucous membrane composed of stratified squamous epithelium tissue. As air gets into the nasal cavity, hairs filter out any impurities or sticks to the mucous membrane. The mucous membrane cells secrete almost 1 liter per day, which moistens the air that is inspired. This mucous membrane is affluent in blood vessels; they warm the air when it goes into the nasal cavity.
• The pharynx is a passageway for not only air but also food. It is commonly called the throat. Through the pharynx, food is delivered into the esophagus and air into the lungs. The mucous lining in the pharynx filters out any contaminated air. It accommodates …show more content…
They divide off the thoracic vertebra before entering the lungs. The right bronchus is more vertical, wider and shorter that the left. It enters the lung at the fifth thoracic vertebra and has three subdivisions. These three subdivisions deliver air to the three lobes in the right lung. The right bronchus is two to three centimeters long compared to the left, which is about five centimeters. The left bronchus enters the lung at the sixth thoracic vertebra and divides into two branches. These subdivide further and further into even smaller bronchioles. The bronchi walls are hyaline cartilage material forming the D shaped walls and this holds them open. They are passages for air to get into the …show more content…
The walls of the heart have three layers of tissue: endocardium which is a single layer of epithelial cells, myocardium this is cardiac tissue, and epicardium which is serious membrane and epithelial tissue. They are surrounded by a pericardium layer that is connective tissue and serious membrane. Blood that is deoxygenated flows through the right ventricle into the pulmonary artery, which takes the blood to the lungs to become oxygenated when it goes through the capillaries in the lungs. When it returns to the heart through the pulmonary vein, there is a rise in pressure to pump the blood from the left ventricle into the aorta. From here, blood flows through aorta to body tissues to provide them with oxygen. The superior vena cava transports blood around the upper body and the blood in the inferior vena cava travels around the lower body. This blood returns to the right atrium to repeat the