Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Lower Respiratory Tract:
Trachea:
Trachea or windpipe is 12 cm long, 2.5 cm in diameter lying in front of the esophagus and ends opposite the fourth dorsal vertebrae where it divides into main bronchi. It consists of a number of c-shaped rings of cartilage connected byfibrous tissues and having the opening of the C posteriorly. The hnction of the rings of cartilage is to keep trachea open and prevent the collapse of the wall like those of the esophagus. It is lined with ciliated columnar epithelium and cells which secrete mucus.
Bronchi and Bronchioles:
Trachea ends by bifurcating into right and left bronchi at the carina, the level of fourth dorsal vertebra. Each bronchus passes to the corresponding lung. From each main bronchus smaller bronchi are given off, like branches of a tree, and the smallest bronchi is called bronchioles. The structure of the bronchi is similar to that of the bronchi, but they contain no cartilaginous loops, instead there are more muscle fibers. Mucus is secreted by goblet cells interspersed between the ciliated cells and by sub-mucosal mucus-secreting glands.
Each bronchioles terminate in an alveolar sac made up of number of air pockets wihc are lined with delicate layer of flattened epithelial cells and are surrounded by network of capillaries through the walls of which interchange of gasses takes place. Blood in the capillaries is brought by the pulmonary artery from the right ventricle and drained into the left atrium through the pulmonary veins. Alveoli which number 300 millions in adults are minute sacs that arise from the walls of the respiratory bronchioles and alveolar ducts. The alveolus is composed of a single layer of squamous epithelium and elastic basement membrane. These two layers together with the interstitium and the endothelial and basement layers of the adjacent capillary, from the alveolar-capillary membrane or interface. It is across this membrane diffusion of carbon dioxide and oxygen occurs. The structure of millions alveoli provides a large surface area for gaseous diffusion to occur. In addition to this respiratory hnction the alveoli prevent lung collapse by producting surfactant, a phospholipid that decreases surface tension and prevents intersititial fluid from transferring into the lung space.
Toxic agents present in food which interfere with thyroxine synthesis lead to the development of: 1. toxic goitre 2. cretinism 3. simple goitre 4. thyrotoxicosis si
Types of Metamorphic Changes The process of metamorphosis includes reactivation of the morphogenetic processes. The morphogenetic changes also the mode of causation of these
What volume of 4x protein sample buffer do you need to add to 15 ml of a cell extract in order to load it on a gel?
Q. Principal categories in classification? First of all there is a need to know what classification is? Let us define in simple term. Classification is placing of a plant (or g
Q. What do ypu know about Conduction Disturabances? During exercise there is an increase in the sympathetic drive and a withdrawal of vagal tone. Sympathetic enhancement of con
Define the Etiology and Clinical Features of alzheimer's disease? The probable risk factors include a genetic basis, head injury, low education level, Down syndrome and mother
Q. What is the difference between fat-soluble and water-soluble vitamins? Why can fat-soluble vitamins cause harm when ingested in excess? Water-soluble vitamins are those vita
(a) What are the immediate effects of exercise on the functions of (i) the heart, (ii) the lungs, (iii) the liver? (b) How do these changes help to meet the needs of exercise
Name the most important allosteric effector of glycolysis in the liver. Fructose-2,6-bisphosphate is the most important allosteric effector of glycolysis in the liver
Classic Procedure: The approach is the same as described earlier for open mitral valvotomy. The excision starts with an anterior incision on the anterior leaflet at 12o'clock p
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd