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.
Is crossing over important for the diversity of biological evolution? The Sexual reproduction and the recombination of linked genes (crossing over) are, along with mutations, t
A glycogen molecule having entirely of glucose units, many of that are linked in long chains through α1-4 bonds. Furthermore, every 10 units or so, the chain is branched
Explain the Precautions for Sub-Culturing of a Culture 1. Sterilization of inoculating wire before and after the transfer is a must. Sterilized wire should not be kept on labor
Define the Management of Obesity? Management of obesity should be taken up with a clear understanding of the harsh realities of the problem and its outcome. It may be a frustra
What is panspermia? The Panspermia is a hypothesis that describes life on earth as not originated from the planet. The thought is that the first living beings that colonized th
Group specificity Some enzymes prefer a specific functional group to be present\%on the substrate molecules. Example:- alcohol dehydrogenase acts on alcohols having -OH gr
Q. What are the main human degenerative diseases? The major human degenerative diseases are divided into three groups, neoplastic diseases and degenerative diseases of the nerv
Explain the Riboflavin content of RBC - Riboflavin? The erythrocyte glutathione reductase assay, with an activity coe cient (AC) expressing the ratio of activities in the prese
what is the responding variable in catalyst to change oil molecules
Why can crossing of an individual that manifests dominant phenotype with another that manifests recessive phenotype (for the same trait) determine whether the dominant individual i
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