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!
Pharynx:
Pharynx is a funnel shaped tube about 13cm long that starts at the internal nares and extends to the level of the cricoid cartilage. It lies posterior to the nasal and oral cavities, superior to larynx and just anterior to the cervical vertebrae. Its walls are composed of skeletal muscles and lined by mucous membrane. Three parts of pharynx are nasopharynx, oropharynx and laryngopharynx. The nasopharynx is posterior to nasal cavity. The two internal nares, to eustachian tubes and the oropharynx are the openings of nasopharynx. Oropharynx lies posterior to oral cavity, extends from the soft palate inferiorly to the level of hyoid bone, lined with non-keratinized stratified squamous epithelium. Two pairs of tonsil are found in oropharynx. Laryngopharyx begins at the layer of hyoid bone, lined by non-keratinized stratified squamous epithelium, opens into oesophagus posteriorly and the larynx anteriorly. Pharynx serves as a passage way for air, food and drink, and provides resonating chamber for speech sounds.
Larynx:
Larynx or voice box is a short passage way that connects the laryngopharynx with trachea. It lies in the midline of the neck anterior to oesophagus and corresponds with the levels of cervical 4 to 6 vertebrae. Its wall is composed of nine pieces of cartilage-3 single-thyroid, epiglottis and cricoid and 3 in pairs- arytenoid, cuneiform and comiculate cartilages. Arytenoid influencerhe positions and tensions of vocal folds. Thyroid cartilage, two fused plates of hyaline cartilage to form the anterior wall of the larynx giving a triangular shape. Epiglottis is large, leaf shaped having a stem which is attached to the anterior rim of the thyroid cartilage and hyoid bone and a broad superior 'leaf' portion unattached and free to move up and down. During swallowing epiglottis moves down and forms a lid over glottis closing the entrance to larynx to prevent the entry of food or drink. When small particles of food, drink or dust enter the larynx a cough reflex occurs to expel the material.
Arytenoid cartilages are two small structures situated on the upper surface of the expanded signet portion of the cricoids cartilage. They give attachment to the posterior ends of the true vocal cords. The true vocal cords are fibro elastic bands extending from the posterior aspects of the thyroid cartilage in front to the arytenoids cartilage behind. The false vocal cords are two loose folds of mucous membrane situated above the true cords. Larynx is lined by mucous membrane which, except over the vocal cords, is covered with ciliated columnar epithelium.
Classification of Living Organisms The world of living organisms is extremely diverse. Biologists call these diverse forms 'species'. It is estimated that over fifteen lakh (1
Approximate Composition of Human Tissue Table gives the approximate composition of human tissue. We all know that carbon, oxygen, hydrogen are present in water and other organ
In terms of western medicines, over 3000 antibiotics - including penicillin and tetracycline - are obtained from micro-organisms. Another product of micro-organisms i.e. cyclospori
Why Deficiency of Folate take place? If there is inadequate dietary folate, the activity of both the DNA and the methylation cycles, described above, will be reduced. A decrea
Coevolutionary relationships between parasites and their hosts can be more complicated than between predators and their prey. As in the case of prey-predator relationship, one can
Q. What is the ecological role of earthworms? Earthworms have an important ecological role as they eat decomposing organic material. They also dig tunnels in the subsoil allowi
Q. Asymptomatic or Mildly Symptomatic Patients? The treatment is controversial. Some give them betablockers/or calcium channel blockers like verapamil, in the hope of preventin
cellis basic unit of life
How plants use the pattern of changes in day/night length to solve the paradox that day length is equal twice a year. Plants possess the ability to balance the daily changes in
General Characteristics of Protozoans The protozoans, are eukaryotes that form a group of about 80,000 single-celled organisms under the kingdom Protista. The unicellular leve
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