Ask Question, Ask an Expert

+61-413 786 465

info@mywordsolution.com

Ask Biology Expert

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.  

Biology, Academics

  • Category:- Biology
  • Reference No.:- M9514097

Have any Question?


Related Questions in Biology

Title titer mtl what do you mean when you refer to the

Title Titer MTL: what do you mean when you refer to the burst size of a phage? How will burst size affect your Titer?

A filamentous organism has been isolated from decomposing

A filamentous organism has been isolated from decomposing organic matter. This organism has a cell wall but no chloroplast. why would you classify this organism into "domain eukarya, kingdom of fungi"

A doctor is testing the effectiveness of a new antibiotic

A doctor is testing the effectiveness of a new antibiotic. He gives the first group of patients a placebo, a second group receives antibiotic A while the third group receives antibiotic B. Which of the groups is consider ...

What problems does this traditional classification scheme

What problems does this traditional classification scheme of protists create in our understanding of the evolutionary relationships that exist between protists?

John is a 53-year old contraction worker who has come into

John is a 53-year old contractIon worker who has come into your office complaining of a sore knee joint. You see a buildup fluid close to the patella (kneecap) but deep to the skin and suspect the soreness is due to burs ...

Why biologically is evolved resistance to crop pests

Why, biologically, is evolved resistance to crop pests inevitable?

Chosen dr jan nolta- stem cell researcher head of uc davis

Chosen Dr. Jan Nolta- Stem Cell Researcher Head of UC Davis Stem Cell Program Director Topic Background: early Stem cells have the ability to develop into many different types of cells. Stem Cell Research is not without ...

Question - a pure strain of mendels peas dominant for all

Question - A pure strain of mendel's peas, dominant for all seven of his independently assorting genes, was testcrossed. How many different kinds of gametes could the F1 PRODUCE?

Question this is the final project of the case

Question: This is the final project of the case study 1. Identify the specific case study you chose and the tool(s) you would employ to analyze the healthcare environment. 2. Provide an explanation of how the selected to ...

Select two of the mechanisms of evolutionary change

Select two of the mechanisms of evolutionary change (mutation, gene flow, genetic drift or non-random breeding) and explain what each is and how each can lead to evolutionary change(change in genetic compositions within ...

  • 4,153,160 Questions Asked
  • 13,132 Experts
  • 2,558,936 Questions Answered

Ask Experts for help!!

Looking for Assignment Help?

Start excelling in your Courses, Get help with Assignment

Write us your full requirement for evaluation and you will receive response within 20 minutes turnaround time.

Ask Now Help with Problems, Get a Best Answer

Why might a bank avoid the use of interest rate swaps even

Why might a bank avoid the use of interest rate swaps, even when the institution is exposed to significant interest rate

Describe the difference between zero coupon bonds and

Describe the difference between zero coupon bonds and coupon bonds. Under what conditions will a coupon bond sell at a p

Compute the present value of an annuity of 880 per year

Compute the present value of an annuity of $ 880 per year for 16 years, given a discount rate of 6 percent per annum. As

Compute the present value of an 1150 payment made in ten

Compute the present value of an $1,150 payment made in ten years when the discount rate is 12 percent. (Do not round int

Compute the present value of an annuity of 699 per year

Compute the present value of an annuity of $ 699 per year for 19 years, given a discount rate of 6 percent per annum. As