Unit 1 (Lesson 1)
The human digestive system
· the human body is made up of a number of systems:
Example:
1. Digestive system: digests and absorbs food
2. the respiratory system: carries out the process of breathing
3. the circulatory system: distributes the digested food and oxygen all over the body cell
4. the urinary system : helps the body get rid of harmful substances
5. the nervous system : lets us have the ability to feel , hear , smell , and taste
6. the reproductive system :
makes us give birth for new individuals who look like us
The human digestive system
Digestion: changing the food from complex form into a simple to let the body get benefited
Digestive system consists of:
(A) Digestive canal:
Its length (9- 10) meter this canal
Starts with mouth
And ends in the anus
THE STRUCTURE OF
DIGESTIVE CANAL:
1- Mouth 2- Pharynx
3- Esophagus 4- Stomach
5- Small intestine
6- Large intestine
7- Rectum 8- Anus
(B)-Three types of glands:
are connected with digestive canal
1- Salivary glands:
They are three pairs of glands Secrete
Saliva that digests starches into sugar
2- Liver:
Secretes bile that digests fat
into fatty emulsion
3- Pancreas : secretes pancreatic juice
Digest= يهضم digestion=هضم digestive system جهاز هضم=digested food =غذاء مهضوم
Respire = يتنفس , respiration =breathing تنفس= respiratory system=جهاز تنفسي
Distribute= يوزع circulatory system=الجهاز الدوري urinary system = الجهاز البولي get rid=يتخلص من Nervous system =الجهاز العصبي reproductive system=الجهاز التناسلي new individuals=افراد جديدة pharynx=البلعوم esophagus = المرئ small intestine =الامعاء الدقيقة
Large intestine =الامعاء الغليظة rectum= المستقيم anus = فتحة الشرج = فتحة الاست liver =الكبد salivary gland= الغدد اللعابية secrete =يفرز saliva= اللعاب bile juice = العصارة الصفراوية fat = دهون fatty = دهني emulsion=مستحلب function= وظيفة organ=عضو
The function of each organ of the digestive system:
(1) mouth الفم: is a cavity in where teeth and tongue are existed and salivary glands open to it
Teeth:الاسنان
· the teeth number in an adult are 32
· each jaw has 16 teeth divided into:
(4 incisors, 2 canines, 10 molars)
Incisor القواطع and canine الانياب:
They Cut and tear food into small pieces
Molars الضروس
Grind the food to ease its swallowing process
Tongue اللسان
* It mixes food with saliva to help in food swallowing
* it responsible for المسئول عن tasting food
* it changes the sound coming from larynxالحنجرة into understandable word
( it is the speech organ)
(2) pharynx : is a common cavity leads to the esophagus and trachea
(3) Esophagus : allows food to pass from mouth to stomach
(4) Stomach : is a muscular sac , it secretes gastric juiceالعصارة المعدية that makes incomplete digestion of protein
(5) Small intestine : its length is about 7 meter
And it coilsيلتف inside the abdominal cavity
Small intestine consists of:
a- Duodenum الاثني عشر
b- ileum اللفائفي: in which intestinal juiceالعصارة المعوية is poured
Function of duodenum:
There are two juices pouring in it, which are:
1- pancreatic juiceالعصارة البنكرياسية : that is secreted by pancreas
2- Bile juiceالعصارةالصفراوية : that is secreted by liver
Function of bile juice: it changes fat into fatty emulsion
Absorption processعملية الامتصاص: it is a process of transferringنقل the digested food from the small intestine to the blood
(6) large intestine: it is a tube that starts from the end of small intestine and ends with anus
Function of large intestine:
It stores wastes (food remains) and ejects them out side the body through anus
Function of rectum: it absorbs the water from the wastes
How can you keep digestive system healthy? :
· chew the food well
· don't eat much food contains large amount of fat
· avoid having food that contains flavour additives
· don’t buy food from street sellers to avoid the infectious diseases
· practice sports regularly
Notes:
(1) the digestive canal starts with mouth and ends with anus
(2) starches digestion starts by the saliva in mouth
(3) protein digestion starts by gastric juice in stomach
(4) fat digestion starts by bile juice in small intestine
(5) digested food is absorbed in small intestine
(6) proteins are digested in stomach and small intestine
(7) undigested foodالطعام غير المهضوم is assembledيتجمع in the large intestine
(8) saliva اللعابis secreted by salivary gland
(9) bile juice is secreted by liver
(10) gastric juice العصارة المعديةis secreted by stomach
(11) pancreatic juiceالعصارة البنكرياسية is secreted by pancreas
(12) intestinal juice is secreted by ileum
( small intestine )
Glossary
Common cavity تجويف مشترك
Jaw فك
Abdominal cavity تجويف بطني
Wastes فضلات
Thoracic cavity = chest cavity تجويف صدري
chew يمضغ
complete كامل
Avoid يتجنب
incomplete غير كامل
Skip يبتعد
muscle عضلة
Additive مكسبات
Muscular sac كيس عضلي
Keep يحافظ
allow يسمح
eject يطرد
