DIGESTIVE SYSTEM GRADE 9

2. 1. Ingest Food
2. Break it down into small
Molecules that can cross
Plasma membranes.
3. Eliminate Non-digestive
wastes

3. As of Action
1. Mechanical Digestion
- food is converted into small pieces by
physical means such as mastication by the
teeth
2. Chemical Digestion
- food is converted into simpler forms by the
action of enzymes.

4. As to Location
1. Intracellular Digestion
- inside the cell particularly in the
lysosomes, characteristics of unicellular
organisms.
2. Extracellular Digestion
- outside the cell
- inside the digestive tube

5. - Also called as Alimentary canal
- over 30ft, long in human, beginning
In the mouth and ending in the anus.

6.  Organs that secrete juices
Containing enzymes for the
Digestion of food
 Salivary glands, gastric gland,
Pacreas,intestinal gland and
The liver.

7.  Includes structures that help in the digestion
of food
 Tongue and teeth

9.  Anterior opening
 Guarded by upper and lower
lips
 Site of mastication and
lubrication of food

10. a. Parotid Glands
- located in front
of and below the
ears

11. b. Sublingual Glands
- Lie beneath the tongue
proper and their ducts
open into the floor of
the oral cavity

12. c. Submandibular Gland
- lie in the posterior floor
of the oral cavity beneath
the base of the tongue

13.  Produce about 1 liter of saliva a day
 Saliva contains mucus and a digestive
enzyme called salivary amylase.
 Teeth carry on mastication.
 Mastication breaks down food into smaller
portions.
 The tongue forms the chewed food into a
small mass called bolus for swallowing.

14.  Narrow space behind the oral cavity
 Common passageway of food and air
 Swallow occurs in the pharynx
 Breathing does not occur when swallowing

15.  Narrow muscular organ between the pharynx
and the stomach
 Peristalsis movement

16.  The largest and highly muscular part of the
digestive tube.
 Maximum capacity of 2.5 pints
 Food stays about 3 to 5 hours
 Churning movement

17. Cardiac Sphincter
- Anterior end
- prevents backward
movement of food
to the esophagus.

18. Fundus
-most expanded part
of the stomach.

19. Pyloric Sphincter
- posterior end
- regulates the
movement of food
to the small intestine

20.  The largest part of the digestive system.
 Site of final digestion and absorption
 About 52ft. Long
 Food stays 4-5 hours

21. Duodenum
-anterior end
- uncoiled

22. Jejunum
- middle division
-coiled

23. Ileum
- posterior end

24.  Posterior part of the digestive system
 Joined to the small intestine by the vermiform
appendix
 Food stay in the large intestine for 5-25
hours
 Absorption of water

25.  Caecum
-anterior portion
- appendix is located

26. Colon
- middle portion
- divided into ascending colon, transverse
colon, descending colon and sigmoid colon.

27. Rectum
- posterior portion
- temporary storage of undigested food

28.  Posterior opening of the digestive tube
 Exit of fecal matter
 Regulated by the axial sphincter

30.  Found in the oral cavity, esophagus and small
intestine and large intestine.
 Secrete mucin for lubrication of food.

31.  Found in the rugne of the stomach
 Secrete gastric juices
 Controlled by the medulla of the brain and by
the hormone gastrin.

32. Mucin- lubrication of food
HCl- coverts pepsinogen into pepsin
Pepsinogen- converted into pepsin by
HCl; digest protein into polypeptide
chains
Lipase- digests fat into fatty and
glycerol

33.  Found in the intestine
 Secrete intestinal juices

34. Mucin- lubrication of food
Enterokinase- activates trypsinogen to
trypsin
Nucleases- break nucleotides into
nitrogen bases, phosphoric acids and
pentoses.

35.  Found along the peripheral surface of the
duodenum
 Secretes pancreatic juice to the duodenum
through the pancreatic duct.
 The pancreas makes pancreatic juices and
hormones, including insulin.
 The pancreatic juices are enzymes that help
digest food in the small intestine.
 Insulin controls the amount of sugar in the
blood.

37.  Secrete bile that is store in the gall bladder
 The largest gland in the body
 Storage of glycogen
 Production of Fibrinogen for blood clothing
 Site of protein synthesis
 Detoxification of nitrogenous waste by
changing them into urea.
 Destruction of worn out RBC
 Formation and storage of vitamin A and D

39.  The primary function of the GI tract is to
move nutrients, water and electrolytes from
the external environment into the body’s
internal environment.
 The body meets physiological challenges by
coordinating the four basic processes of the
digestive system.

40. THE GI tract
- muscular alimentary canal
 Mouth
 Pharynx
 Esophagus
 Stomach
 Small intestine
 Large intestine
 Anus

41. The accessory digestive organs
-Supply secretions contributing to the
breakdown of food
 Teeth and tongue
 Liver
 Pancreas
 Gall Bladder
 Salivary Glands

42. 1. Digestive
- the chemical and mechanical breakdown of
foods into smaller units that can be taken
across the internal epithelium unto the body.
2. Absorption
- The transfer of substances from the GI
tract to the extracellular fluid.

43. 3. Motility
- movement of materials in the GI tract as
a result of muscle contraction
4. Secretion
- both the transepithelial transfer of water
and ions from extracellular fluid flood to the
digestive tract lumen and the release of
substances synthesized by GI cells.