To find the differences among mammals in Club cells Plopper and colleagues performed three research studies to quantitatively and qualitative assess Club cells among mammals used in lung research [1-4]. In the first study researchers examined lung tissue from adult male rabbits, guinea pigs, rats and hamsters. Lung tissue from four male rabbits, four male guinea pigs, six male rats and eight male hamsters was used. Each animal was sedated with pentobarbital, had trachea cannulated, and thoracic contents removed all together. Before processing lung tissues by a selective embedding technique, airways were fixated by airway infusion at constant pressure and bronchioles were examined by electron microscopy [1]. The lungs were fixed by airway infusion of paraformaldehyde and glutaraldehyde in a cacodylate buffer. Parts of fixed left lower lobes were post-fixed for 2 hours in 1% osmium tetroxide. The blocks of lung tissues were embedded by processes, which allow selection of specific areas from large tissue in either a mixture of Epon 812 and Araldite 6005 or Araldite 502 resin alone. One-micron (1μm) thick sections were produced with glass blades on Sorvall JB4. Thin sections of about 300 to 500 Ångström (Å) were produced with diamond knives on a Sorvall MT2 ultramicrotome. The thin sections were then stained with uranyl acetate and lead citrate, followed up with an examination with a Philips 300 electron microscope (EM) at 80-kilovoltage (KV) [1]. The difference in granules and assessment of organelles was addressed as follows. First, only the most distal non-alveolarized bronchioles were lined because of the direct continuation into one or more alveolar ducts [1]. Club cells were evaluated only if the plane of section passed throu...
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...an with comparison of 15 mammalian species. Experimental Lung Research;1(2):171-80
4 Plopper, CG., Mariassy, AT., Wilson, JL., Alley, SJ., Nishio, SJ., Nettesheim, P. (1983).Comparison of nonciliated tracheal epithelial cells in six mammalian species: ultrastructure and population densities. Experimental Lung Research; 5: 281-294
5 Cortese, K., Diaspro, A., & Tacchetti, C. (2009). Advanced correlative light/electron microscopy: Current methods and new developments using tokuyasu cryosections. Journal of Histochemistry & Cytochemistry, 57(12), 1103-1112.
6 Sjollema, K. A., Schnell, U., Kulpers, J., Kalicharan, R., & Giepmans, B. N. (2012). Correlated light microscopy and electron microscopy. Methods in Cell Biology, 111, 157-73.
7 Harvard Medical School .How is EM different from light microscopy?. (2014, March 24). Retrieved from http://bsp.med.harvard.edu/node/222
Biology 2A03 Lab 4 Respiratory Gas Exchange in a Mouse Lab Manual. Winter Term 2014 (2014). Biology Department. McMaster University.
In the lungs gas exchange occurs to re-oxidize the blood. Air travels through the respiratory tract to reach the lungs and back up to be exhaled into the environment. At the termination point of the respiratory tract lays the alveoli. The alveoli have a sac-like structure. In biological systems, the structure and functions of components are related. The alveoli have a structure specialized for efficient gaseous exchange. In the structure of the alveoli (alveolus), it looks as if it has the form of a hollow cavity that is paired with elastic fibers...
Each lung is actually a composition of 150 million alveoli. There are two types of alveolar cells; squamous (Type I) and great (type II). Squamous alveolar cells cover 95% of the surface area of an alveolus while great alveolar cells only cover 5%. However great alveolar cells are more numerous than squamous alveolar cells. Squamous cells are responsible for the rapid diffusion of gases between the air and blood. Great cells repair alveolar tissues and secrete a substance to coat alveoli and bronchioles.
Person, A. & Mintz, M., (2006), Anatomy and Physiology of the Respiratory Tract, Disorders of the Respiratory Tract, pp. 11-17, New Jersey: Human Press Inc.
Simple epithelia: Epithelia tissue can have cell shapes these are the Columnar, Cuboidal, and Squamous Cell Shapes. All this cells shapes are part of a type of an epithelia tissue which is the simple Epithelia. There are columnar cells, which means column-like cells and squamous cells, which are flattened and scale-like cells, simple squamous epithelia is found in walls of lung alveoli, blood capillaries and bowman’s
...er with adjacent cells to form a large, multinucleated cell creating large masses of cells” (Cooper, Banasiak, & Allen, 2003). In other words, the virus spreads along the epithelial cells of the respiratory tract through cell-to-cell transfer. The “bronchiole mucosa ultimately begins to swell, and the lumina fill with mucus and exudate. Inflammatory cells infiltrate the area resulting in the shedding of dead epithelial cells” (Cooper, Banasiak, & Allen, 2003). The dead epithelial cells then obstruct the small airway passages. The bronchiole cells normally dilate during inhalation and narrow on exhalation, however since the mucosa is inflamed the there is not good movement of air. With the obstruction of the bronchioles “air trapping, poor exchange of gases, increased work of breathing, and a characteristic expiratory wheeze” occur (Cooper, Banasiak, & Allen, 2003).
Healthy lung tissue is predominately soft, elastic connective tissue, designed to slide easily over the thorax with each breath. The lungs are covered with visceral pleura which glide fluidly over the parietal pleura of the thoracic cavity thanks to the serous secretion of pleural fluid (Marieb, 2006, p. 430). During inhalation, the lungs expand with air, similar to filling a balloon. The pliable latex of the balloon allows it to expand, just as the pliability of lungs and their components allows for expansion. During exhalation, the volume of air decrease causing a deflation, similar to letting air out of the balloon. However, unlike a balloon, the paired lungs are not filled with empty spaces; the bronchi enter the lungs and subdivide progressively smaller into bronchioles, a network of conducting passageways leading to the alveoli (Marieb, 2006, p. 433). Alveoli are small air sacs in the respiratory zone. The respiratory zone also consists of bronchioles and alveolar ducts, and is responsible for the exchange of oxygen and carbon dioxide (Marieb, 2006, p. 433).
The larynx prevents food and liquids from traveling down the air path ways which could result in choking. From the larynx, Bronchi trachea splits into two bronchi each leading to a lung, each lung is divided into lobes. The right lung has three lobes and the left has two lobes. The right lung is slightly larger than the left lung. The two lungs are mainly made of up connective tissue, which gives them their soft and spongy texture. The bronchi branch are smaller and are called bronchioles which are divided many more times in the lungs. The lungs is made up of connective tissue, blood, lymphatic tissue, air pathways and alveoli are at the end of the branches inside of the lungs. The alveoli sends oxygen and removes carbon dioxide. This is a basic view of how the respiratory system functions and if the respiratory system doesn’t do its job then this could lead to infectious diseases of the respiratory
Aim: The aim of this assignment will be to research the basic structure and function of Human Lungs and the respiratory condition known as asthma, and how its effects on the human lungs, looking at the causes and treatments used to prevent and treat the illness.
Chronic bronchitis is a disorder that causes inflammation to the airway, mainly the bronchial tubules. It produces a chronic cough that lasts three consecutive months for more than two successive years (Vijayan,2013). Chronic Bronchitis is a member of the COPD family and is prominently seen in cigarette smokers. Other factors such as air pollutants, Asbestos, and working in coal mines contributes to inflammation. Once the irritant comes in contact with the mucosa of the bronchi it alters the composition causing hyperplasia of the glands and producing excessive sputum (Viayan,2013). Goblet cells also enlarge to contribute to the excessive secretion of sputum. This effects the cilia that carry out the mechanism of trapping foreign bodies to allow it to be expelled in the sputum, which are now damaged by the irritant making it impossible for the person to clear their airway. Since the mechanism of airway clearance is ineffective, the secretion builds up a thickened wall of the bronchioles causing constriction and increasing the work of breathing. The excessive build up of mucous could set up pneumonia. The alveoli are also damaged enabling the macrophages to eliminate bacteria putting the patient at risk for acquiring an infection.
Tissues are groups of similar cells which have a similar structure and function. All of these cells work together to complete various tasks. There are four different types of tissue in the human body; connective, epithelium, muscle and nervous.
The electron microscope can magnify objects that are as small as the length of an atom to one million times larger. They are usually used to examine cells and molecules. This is done by increasing the electron’s penetration in a vacuum until their wavelength is exceedingly fast. When this happens, rays of light from the electrons are focused on the cell on the stage, creating a duplicate projection on an electron- sensitive plate.
Histopathological samples are examined in vivo where the relationship between the cells is maintained and observable. These can be cross sections of small organs or slices of larger ones. This results in a large number of cells being available and their cell-to-cell interactions apparent for examination.
The light microscope, also called compound microscope is a machine that enables you to see tiny objects and creatures in a more extended size (things can be magnified more than 1000%). Its function is similar to a refracting telescope, except that in a microscope, the object is very close to the objective lens. In comparison to a telescope, a microscope must gather light from a tiny area of a thin, well-illuminated specimen that is close-by. Therefore, the microscope does not need a large objective lens. Instead, the objective lens of a microscope is just small and spherical, which means that it has a much shorter focal length on either side. It brings the image of the o...
...th the different parts and uses of the microscope. I conclude that compound light microscopes give inverted images of the object because of the reflected light; and that the passage of this light is controlled by the iris diaphragm. I also conclude that each part of the microscope is significant for it to function properly and effectively.