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.
Q. What is the intermediate host of Schistosoma mansoni? Where does that host live? The intermediate host of a schistosome is a gastropod mollusc, Biomphalaria genus and a snai
define alimentary canal
Name two possible why the number of live bacteria cell have reached the stationary growth by 60hrs and start to die off after 12hrs?
This species is an ornamental tree in China, and has yielded the clinically active agents topotecan, irinotecan, and 9 -aminocamptothecin, which are semisynthetically derived from
Mounting boxes for insect collections Wood or cardboard cigar boxes make very useful and suitable housings for insect collections. After the insect has been separate from the s
Define Functions of Manganese? Like other micro minerals, Mn also functions in mammalian enzyme systems. It can function both as an integral part of metalloenzymes and as an en
Lymphatic Vessels The function of lymphatic vessels is to aid in the return of interstitial fluid to intra-vascular volume. They assist with transport of lipids from th
Water Absorption and Transpiration The rate of water absorption is controlled by the rate of transpiration. A high water potential in the atmosphere would reduce water loss fr
Pathphysiology Streptococcal upper respiratory infection leads to production of antibodies. An abnormal immunological response to the upper respiratory infection with Beta- h
Mention where the following are located in the human brain, and give single function of each: a) Temporal lobe b) Cerebellum c) Corpus callosum
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