2. DIGESTION – is the process of reducing food
into smaller particles or molecules
that will be absorb by the body.
FUNCTIONS:
1. To break up big pieces of food into tiny particles.
2. To break the tiny particles of food molecules that
will dissolve in the body fluids
and pass through the cell walls to be used by the
cells.
3. 3 PHASES OF DIGESTION3 PHASES OF DIGESTION
1. INGESTION – process of getting food1. INGESTION – process of getting food
2. DIGESTION PROCESS2. DIGESTION PROCESS
2 STAGES2 STAGES
A. MECHANICAL PHASE – process by which food isA. MECHANICAL PHASE – process by which food is
acted upon physically.acted upon physically.
B. CHEMICAL PHASE - process of converting foodB. CHEMICAL PHASE - process of converting food
from complex molecules into its simplest form.from complex molecules into its simplest form.
3. EGESTION / DEFECATION – process of3. EGESTION / DEFECATION – process of
eliminating the undigested food from the in theeliminating the undigested food from the in the
form of feces.form of feces.
8. DIGESTION IN THE MOUTHDIGESTION IN THE MOUTH
-Upon entering the mouth the food will be physically
broken down into pieces by the Teeth with the help of
the tongue and the buccinator muscle.
MUCUS – comes from the lining of the mouth which
moisten the food facilitates swallowing
SALIVA - another secretion from the glands located at
the different areas of the mouth which lubricates the
food
9.
10.
11.
12.
13. 3 KINDS OF SALIVARY GLANDS3 KINDS OF SALIVARY GLANDS
PAROTID GLANDS - the largest among the 3PAROTID GLANDS - the largest among the 3
glands which are located on each side of theglands which are located on each side of the
face , in front of the ears.face , in front of the ears.
SUBMAXILLARY GLANDS – lies with inSUBMAXILLARY GLANDS – lies with in
the angle of the lower jaw.the angle of the lower jaw.
SUBLINGUAL GLANDS – found under theSUBLINGUAL GLANDS – found under the
tonguetongue
14. TONGUE – acts as the organ of taste using taste
buds
- it pushes the food towards the teeth
- helps in swallowing the food
•SWEET TASTE – sensed at the tip of the
tongue.
•SOUR TASTE - sensed at the lateral part of the
tongue
•BITTER TASTE – sensed at the back part of the
tongue
16. DIGESTION IN THE ESOPHAGUSDIGESTION IN THE ESOPHAGUS
ESOPHAGUS- a long tube which carries theESOPHAGUS- a long tube which carries the
food from the mouth to the stomachfood from the mouth to the stomach
PHARYNX- serves as the passage way forPHARYNX- serves as the passage way for
both air and foodboth air and food
EPIGLOTTIS – covers the glottis to preventEPIGLOTTIS – covers the glottis to prevent
the food from entering the respiratory tractthe food from entering the respiratory tract
* PERISTALSIS- a rhythmic wave like mascular* PERISTALSIS- a rhythmic wave like mascular
action that pushes the food further down theaction that pushes the food further down the
alimentary canalalimentary canal
17.
18.
19.
20. DIGESTION IN THE STOMACHDIGESTION IN THE STOMACH
CARDIAC SPHINCTER – closes and opensCARDIAC SPHINCTER – closes and opens
to allow the flow of food from the esophagusto allow the flow of food from the esophagus
to the stomachto the stomach
STOMACH – large, J – shaped bag likeSTOMACH – large, J – shaped bag like
structure which is located at the end of thestructure which is located at the end of the
esophagusesophagus
- the lining is thick wrinkled membrane ith- the lining is thick wrinkled membrane ith
gastric glands, the walls of each gland aregastric glands, the walls of each gland are
lined with secretory cells.lined with secretory cells.
21.
22. SECRETORY CELLSSECRETORY CELLS
SECRETES:SECRETES:
1.1. ENZYMES –ENZYMES –
- Proteases which break down proteinsProteases which break down proteins
- Pepsin breaks down protein into peptonePepsin breaks down protein into peptone
- Rennin acts on milk protein allowing the milk toRennin acts on milk protein allowing the milk to
clotclot
2. HYDROCHLORIC ACID- helps break up connective2. HYDROCHLORIC ACID- helps break up connective
tissues and cell membranes in food, it also helps intissues and cell membranes in food, it also helps in
destroying the bacteria in the systemdestroying the bacteria in the system
3. MUCUS3. MUCUS
23. PERISTALTIC MOVEMENT- the squeezing action
of the stomach which churn and mix the food together
with the gastric juices
PYROLIC VALVE- the valve that opens and closes
several times letting the food from the stomach enter
the small intestine
24.
25.
26. PANCREASPANCREAS
Secretes hormones that regulate the balance ofSecretes hormones that regulate the balance of
the blood glucosethe blood glucose
Secretes pancreatic juices which is emptiedSecretes pancreatic juices which is emptied
into the duodenuminto the duodenum
EMULSIFICATION- is the process ofEMULSIFICATION- is the process of
breaking down fats into tiny droplets.breaking down fats into tiny droplets.
27.
28.
29.
30. LIVERLIVER
Is the largest gland in the body; it hasIs the largest gland in the body; it has
a gallbladder which produce a bilea gallbladder which produce a bile
Bile- serves as the emulsifier of fatsBile- serves as the emulsifier of fats
31.
32.
33.
34.
35. DIGESTION IN THE SMALLDIGESTION IN THE SMALL
INTESTINEINTESTINE
- IT IS WHERE THE FINAL DIGESTION- IT IS WHERE THE FINAL DIGESTION
AND ABSORPTION TAKES PLACEAND ABSORPTION TAKES PLACE
36. SMALL INTESTINESMALL INTESTINE
3 MAJOR PARTS3 MAJOR PARTS
1.1. DUODENUM- the upper 20cm long tubeDUODENUM- the upper 20cm long tube
connected to the stomachconnected to the stomach
2.2. JEJUNUM-2.5cm longJEJUNUM-2.5cm long
3.3. ILEUM-longest half coiled through theILEUM-longest half coiled through the
abdominal cavityabdominal cavity
40. GLANDS IN THE SMALLGLANDS IN THE SMALL
INTESTINEINTESTINE
1.1. Erepsin- change peptone to amino acidsErepsin- change peptone to amino acids
2.2. Maltose- acts on dextrin and maltoseMaltose- acts on dextrin and maltose
3.3. Sucrase- acts on sucroseSucrase- acts on sucrose
4.4. Lactose acts on LactoseLactose acts on Lactose
Villi-are tiny fingerlike projections coming outVilli-are tiny fingerlike projections coming out
of the folds of the mucosa or membranousof the folds of the mucosa or membranous
lininglining
-it increases the area for absorption-it increases the area for absorption
41. THE LARGE NTESTINE/COLONTHE LARGE NTESTINE/COLON
Shorter than the small intestine but larger inShorter than the small intestine but larger in
diameter(7cm)diameter(7cm)
It absorb water from the undigested foodIt absorb water from the undigested food
materialsmaterials
45. RectumRectum- last 20-30cm of the colon- last 20-30cm of the colon
AnusAnus- forms the end of the digestive tract- forms the end of the digestive tract
FecesFeces-remaining food that is being-remaining food that is being
eliminated through the anuseliminated through the anus
AppendixAppendix-fingerlike structure found-fingerlike structure found
between the large & small intestinebetween the large & small intestine
46.
47.
48. AILMENTS OF THE DIGESTIVEAILMENTS OF THE DIGESTIVE
SYSTEMSYSTEM
Appendicitis,Appendicitis,
- acute inflammation of the- acute inflammation of the vermiformvermiform
(wormlike) appendix, a blind tube projecting(wormlike) appendix, a blind tube projecting
from thefrom the cecum,cecum,—the beginning of the large—the beginning of the large
intestine. The appendix, located in the lowerintestine. The appendix, located in the lower
right side of the abdomen, is an organ with noright side of the abdomen, is an organ with no
known function in humans. If the appendixknown function in humans. If the appendix
wall ruptures, infection may spread to thewall ruptures, infection may spread to the
abdominal cavity, causing peritonitis.abdominal cavity, causing peritonitis.
49. Symptoms of appendicitis include pain andSymptoms of appendicitis include pain and
cramps in the area between the right hip bonecramps in the area between the right hip bone
and the navel, fever, nausea and vomiting,and the navel, fever, nausea and vomiting,
constipation, and diarrhea. The treatment isconstipation, and diarrhea. The treatment is
surgical removal of the appendixsurgical removal of the appendix
(appendectomy). Although the frequency of(appendectomy). Although the frequency of
appendicitis is highest among young adults,appendicitis is highest among young adults,
the ailment can affect persons of any age.the ailment can affect persons of any age.
50. Peptic ulcers are ulcers of the stomachPeptic ulcers are ulcers of the stomach
(gastric) or small intestine (duodenal). In(gastric) or small intestine (duodenal). In
addition to the pain caused by the ulcer itself,addition to the pain caused by the ulcer itself,
peptic ulcers give rise to such complications aspeptic ulcers give rise to such complications as
hemorrhage from the erosion of a major bloodhemorrhage from the erosion of a major blood
vesselvessel
51. ConstipationConstipation
- occurs when the large intestine absorbs too- occurs when the large intestine absorbs too
much water because food residues are movingmuch water because food residues are moving
slowly. As a result, the feces become hard andslowly. As a result, the feces become hard and
dry, which may make elimination difficult.dry, which may make elimination difficult.
52. Anorexia NervosaAnorexia Nervosa
- mental illness in which a person has an- mental illness in which a person has an
intense fear of gaining weight and a distortedintense fear of gaining weight and a distorted
perception of their weight and body shape.perception of their weight and body shape.
People with this illness believe themselves toPeople with this illness believe themselves to
be fat even when their weight is so low thatbe fat even when their weight is so low that
their health is in danger. A person withtheir health is in danger. A person with
anorexia nervosa severely restricts food intakeanorexia nervosa severely restricts food intake
and usually becomes extremely thin.and usually becomes extremely thin.
53. Bulimia, an eating disorder in which persistentBulimia, an eating disorder in which persistent
overconcern with body weight and shape leadsoverconcern with body weight and shape leads
to repeated episodes of binging (consumingto repeated episodes of binging (consuming
large amounts of food in a short time)large amounts of food in a short time)
associated with induced vomiting, use ofassociated with induced vomiting, use of
laxatives, fasting, and/or excessive exercise tolaxatives, fasting, and/or excessive exercise to
control weight. Bulimia was classified as acontrol weight. Bulimia was classified as a
distinct disorder by the American Psychiatricdistinct disorder by the American Psychiatric
Association in 1980; the name was changed toAssociation in 1980; the name was changed to
bulimia nervosa in 1987.bulimia nervosa in 1987.