Digestive System

Pharynx

Our Respiratory system

1) nostril, 2) nose, 3) nasal cavity, 4) superior nasal

concha, 5) middle nasal

concha, 6) inferior nasal

concha, 7) nasopharynx, 8) oropharynx, 9) laryngopharynx 10) larynx, 11) trachea, 12) bronchus, 13) lung, 14) thyroid cartilage

pharynx

Where is the pharynx located ?

The cavity at the back of the mouth. Is cone-shaped and has an average length of 76mm.Lined with mucous membranePart of the digestive system and repiratory system of many organisms.A flap of connective tissue called the epiglottis closes over the trachea when food is swallowed to prevent choking or aspiration. In humans, the pharynx is important in vocalization.

More about Mucous membrane

The mucous membranes are linings of mostly, which are involved in absorption and secretion.It is found at several places continuous with skin: at the nostrils, the lips, the ears, the genital area, and the anus and the pharynx.

FUNCTION of the pharynx

Facilitate the passage of the food bolus into Facilitate the passage of the food bolus into the esophagus. Pharynx is designed to the esophagus. Pharynx is designed to directdirect the food bolus in this direction. the food bolus in this direction.

Second phase of swallowing takes place at the Second phase of swallowing takes place at the pharynx. The moistened food bolus is moved pharynx. The moistened food bolus is moved to the back of the mouth by the tongue to the back of the mouth by the tongue

An involuntary swallowing reflex is triggered An involuntary swallowing reflex is triggered which prevents food from entering the which prevents food from entering the respiratory tract. respiratory tract.

The tongue closes off the mouth, the soft The tongue closes off the mouth, the soft palate blocks the nose, and the larynx rises palate blocks the nose, and the larynx rises such that the epiglottis closes off the trachea.such that the epiglottis closes off the trachea.

Food then moves from the pharynx into the Food then moves from the pharynx into the esophagus.esophagus.

Thus no digestion and absorption takes place.

Reason for absence of absorption: The food haven’t been digested

Reason for absence of digestion: there is no presence of enzymes

Structure of pharynx

Pharynx• Starts at the internal nostrils

and extends partway down the neck

• The wall of the pharynx is made up of skeletal muscles and lined with a mucous membrane

• 2 functions: a passageway for air and food, and• a resonating chamber (amplifying sounds) for speech sounds

• Consist of 3 divisionsFigure 1-4. The nose.

The pharynx Look carefully... ...

Never mind if you still don't know……

Real live organ

Now I bet you will know

The structure of pharynx (I)

Pharynx describes the part of the throat that begins from behind the nose to the beginning of the voice box and the oesophagus.

Divisions IN PHARYNX

Divisions Nasopharynx-Specifically related

to the respiratory system.Location: above the soft

palate, 2 nostrils lead into nasopharynx.The auditory tubes open into the nasopharynx. connect it with the middle ears to equalize

the surrounding & body pressure Tonsils (adenoids) are located in the upper wall of the nasopharynx.

Soft palate

Floor of the nasopharynx

Closes off the upper respiratory passageways during swallowing.

Divisionsoropharynx-related to digestive

systemLocation:

below the soft palate and above the upper edge of the epiglottis.

The epiglottis is the flap that prevents food from entering the larynx during swallowing.

Divisionslaryngopharynx-common to

respiratory & digestive system.

Location:

below the edge of the epiglottis

The digestive and respiratory systems lead into this part from above and lead off from it below.

Structure of pharynx (i)

• The muscles of the pharynx consists of three pharyngeal constrictors:

• superior • middle • inferior • stylopharyngeus

and palatopharyngeus muscles

Structure of Pharynx (ii)

Front of nasal part of pharynx, as seen with the laryngoscope

Structure of Pharynx (iii)

• Muscles of the pharynx, viewed from behind, together with the associated vessels and nerves. (Modified after Testut.)

• pharyngeal cancer • cause is unknown• common among heavy smokers

and people who drink large amounts of alcohol.

• 7 times more common in men than women and generally occurs after age 50.

• Untreated cancer often spreads throughout the throat area to the lymph nodes and into the bloodstream, where the cancer is carried to other parts of the body.

• If no treatment, it will continue to spread and become life-threatening.

• symptoms• no symptoms• If symptoms are present,

similar to those of upper respiratory infections such as colds and other viruses.

• cancer : • slight sore throat that lasts

for over 2 weeks• hoarseness or a change in

your voice so that your voice sounds muffled

• trouble with swallowing or feeling of incomplete swallowing

• earache or blocked ear• bloody phlegm coughed up• swollen lymph node in the

neck• hard lump in the throat or

in the neck lymph node.• Large tumor block the

throat, cutting off the air supply, possibly causing you to pass out or suffocate.

If pharynx is damaged and not functioning

properly due to certain diseases, genetic birth

defects or injuries...

• Treatment

• Radiation therapy to shrink the malignant tumor.

• Surgery to remove the tumor. Tissue removed from another part of your body would be used to replace a part of the pharynx.

• Chemotherapy with or without radiation treatments and with or without an operation if the tumor is large and has spread. Side effects or complications from radiation or chemotherapy happens such as: nausea.Your health care provider may suggest medicines for nausea and vomiting. Your provider may prescribe corticosteroid drugs to help with possible side effects of cancer-fighting treatments.

• If early stage: these treatments may result in complete cure.

Do you think we can still survive without the pharynx ?

Any failure or missing of the pharynx can cause breathing, swallowing and voice problems.

Without the pharynx, it WILL cause choking or aspiration as food when swallowed may enter the windpipe by accident. When that happens, the person will be suffocated.

Aspiration occurs when some kind of material -particulate (food, foreign body) or fluid (gastric contents, blood, or saliva)-enters from the pharynx into the trachea

With all these RISKS of having these problems choking , aspiration , DO YOU THINK ONE CAN STILL SURVIVE IN A CONDITION WITHOUT A VITAL ORGAN????

glossary•aspiration is the entry of

secretions or foreign material into the tracheatrachea and lungslungs . The patient may either inhaleinhale the material, or it may be blown into the lungs during positive positive pressure ventilationpressure ventilation or CPR.

Koh Shi Hui (06)Lim Swee Ling (09)

Lim Zihuan (10)Niew Yan Ling (14)

Tee Hui Yi (17)3T2

Websites :

http:// www.hopkins-gi.org/multimedia/database/intro_250_swallow.swf http://www.sghhealth4u.com.sg/Health4U/otolaryngology/the_throat.htm

Let’s have a short quiz ,shall we ?

What happens as a food bolus is pushed back by the tongue

into the pharynx?

The nose chamber is

sealed by the soft

palate/palate so the food

doesn't enter the nose.

Why do we cough or simply why does a cough occur ?

A cough is a sign that nerves in the

pharynx (upper throat), larynx

(throat), trachea (main breathing tube) or large

bronchi (breathing tubes in the lungs)

are irritated.

Little bird, tell me where is the position of the pharynx ?

It is located at the back of the mouth.