BIO 241 1st Edition Lecture 13 Test 3Outline of Current Lecture II. RespirationIII. Respiratory OrgansIV. Nose AnatomyV. Nose PhysiologyVI. PharynxVII. LarynxVIII. TracheaIX. Bronchial TreeX. Anatomical ChangesCurrent LectureII. Respiration is the exchange of gases between the atmosphere, blood, and body cells. The main function of the respiratory system is gas exchange. The respiratory system also contains receptors which are important for smell. It filters, warms, and moistens incoming air (lungs don’t like dirty, cold, or dry air). It is also responsible for producing sound which is known as phonation. Lastly, it eliminates wastes other than just CO2. There are three basic processes: pulmonary ventilation (gas exchange between the atmosphere and lungs), external respiration (gas exchange between blood of lungs and air of lungs), and internal respiration (gas exchange between systemic blood and body cells). III. The respiratory organs can be grouped using two categories. The first is upper vs lower respiratory tract. The upper tract consists of external nose, nasal cavity, and pharynx. The lower tract consists of the larynx down. It is commonly described as the upper tract is vocal cords and up and lower tract is vocal cords and down. The other way to group the respiratory organs is by conducting vs respiring. The tube-like structures such as the trachea are part of the conducting tract. The lung level (alveoli) where gas exchange is occurring is the respiring tract. IV. There are four main parts of nose anatomy. There is the external nose which is composed of 4 plates of cartilage (name not important), 2 nasal bones, and the skin over the nostril. The internal nose is anything that appears on a skeleton (non-cartilage parts). The nasal cavity is a mucosa membrane that consists of the vestibule (where your finger can fit; has thick, large hairs), nasal septum (sheet that divides the nostrils), and nasal conchae/turbinate bones (have great blood supply; three ones; spins air around to better filter and humidify). The fourth part is the paranasal air sinuses which are tiny tubes that open into the nose and are located in the forehead, maxilla, ethmoid, and sphenoid.V. Air is filtered, warmed, and moistened so readily due to the turbinate bones. The nose is responsible for olfaction (smell) also. It contains receptors that are sent to the brain and interpreted almost instantly. It also contains resonating chambers that increase the sound of voice. An example is the paranasal air sinuses because it is filled with air. VI. The pharynx is basically a muscular tube. Its location is shown below. It contains constrictor muscles that ensure air and food go downward in one direction. There are three divisions of thepharynx known as the nasopharynx, oropharynx, and the laryngopharynx also shown below.VII. The larynx is composed of 9 cartilages. The three you need to know is the thyroid cartilage (forms what is known as the adam’s apple), the epiglottis (leaf-like structure that control air or food intake), and the cricoid cartilage which is just posterior to the thryoid cartilage. The term laryngospasm, commonly known as choking, happens when something triggers the very sensitive receptors and forces the epiglottis to cover the larynx. It also has a mucous membrane.This membrane has the vestibular fold (false vocal cords) and the vocal folds (true vocal cords) which help with sound. The larynx is the main organ in voice production.VIII. The trachea is posterior to the larynx, behind the heart. It also has a mucous membrane and a submucous membrane which coat the inside. Unique to the trachea, mucociliary act as escalators to move mucous upward so that it can be swallowed and digested. It has 18-20 cartilage rings which are contracted by the trachealis (muscle down the back of the trachea. IX. Now we will take a look down the bronchial tree. The primary bronchi branch into the right and left lungs. The secondary (lobar) bronchi have 3 branches in the right lung and 2 in the leftlung. They go into each lobe of each lung (3 lobes in the right lung). The tertiary (segmental) bronchi have 10 branches in the right lung and 8 branches in the left lung. These branch into bronchioles (similar to the way arterioles branch from arteries) which branch into terminal bronchioles. Everything listed above is responsible for the conduction of air. These terminal bronchioles branch further into respiratory bronchioles which go to alveolar ducts and sacs which finally end at the alveoli. The alveoli have a lot of surface area which helps with gas exchange. The last three mentioned help with actual respiration.X. There are some anatomical changes as we go down in the bronchial tree. The trachea has a huge C-shaped cartilage ring, the bronchi have irregular plates of cartilage, and the bronchioles completely lack cartilage. Therefore, as we move down the tree, smooth muscle increases and cartilage decreases. Because of this, the bronchioles are allowed to bronchodilate or bronchoconstrict given the need, whereas the trachea cannot (this is a good thing because we need to ensure air gets through it). Also as it goes descends, the epithelium changes in this order. Ciliated pseudostratified + goblet cells → ciliated simple columnar + goblet cells → ciliated simple cuboidal + goblet cells → ciliated simple cuboidal → simple cuboidal → simple squamous. Goblets cells are less important than cilia so they are lost