Transcript sistim pencernakan

SISTIM PENCERNAKAN
Zaenal M. SOFRO
Bagian Ilmu Faal FK.UGM
What is Homeostasis?
Homeostasis – a steady state of bodily
functioning and equilibrium
What does “environment” mean?
External to Internal environment
..a hint of integration?
- John Hughlings Jackson (1835-1911)
Father of English Neurology
Quoted by Stephen Porges 11/01
Social
Sympathetic
Parasympathetic
Freeze
The Human Nervous System
Cardiovascular
system
Central
Nervous
System
Autonomic
Nervous
System
Immune
system
Urogenital
tract
Homeostasis
Gastrointestinal tract
PARASYMPATHETIC
CRANIAL OUTFLOW
SYMPATHETIC
THORACOLUMBAR
OUTFLOW
SACRAL OUTFLOW
Tongue
Teeth
Sublingual gland
Trachea
Liver
Gall bladder
Parotid gland
Pharynx
Submaxillary gland
Larynx
Esophagus
Spleen
Stomach
Duodenum
Ascending colon
Cecum
Appendix
Rectum
Pancreas
Transverse colon
Descending Colon
Ileum
Sigmoid colon
Anus
Prehospital Emergency Care
The Human Body
4-71
5 basic processes: 1. Ingestion
2. Movement of food
3. Digestion
4. Absorption
5. Defecation
Mechanical Digestion: movement of food that reduces
the size of the food particles
Chemical Digestion: breaks proteins, carbohydrates,
and lipids into simple molecules
Digestive System: made of the gastrointestinal tract and
accessory structures (teeth, tongue,
salivary glands, liver, gall bladder, and
pancreas)
1. Mouth (oral or buccal cavity)
A. lips - keep food between the teeth and assist in
speech
B. tongue - maneuvers food for chewing; pushes
food to back of mouth for swallowing;
important for speech
C. teeth - 1) incisors - cut food
2) cuspids - tear and shred food
3) premolars - crush and grind food
4) molars - crush and grind food
2. Salivary Glands
Secrete saliva which is primarily water with the
enzyme salivary amylase
a. water dissolves food
b. mucus lubricates food
c. lysozyme destroys bacteria
Mechanical: mastication (chewing) breaks food down
and mixes it with saliva reducing it into a
soft bolus
Chemical: 1) salivary amylase begins digestion of
starches into simpler sugars until
stomach acid inactivates it
2) lingual lipase from glands on tongue
reduces some triglycgerides into fatty
acids and monoglycerides
3. Pharynx - oropharynx and laryngopharynx
contract to move food into the esophagus
4. Esophagus - transports food to the stomach and
secretes mucus
3 Stages of Swallowing
1) voluntary stage: bolus is moved into the
oropharynx
2) pharyngeal stage: involuntary movement
from pharynx into the esophagus;
epiglottis blocks glottis
3) esophageal stage: involuntary movement
through the esophagus to the stomach
through rhythmic contractions called
peristalsis
5. Stomach
A. has 4 areas
1) cardia: surrounds upper opening
2) fundus: curve above and to the left of the cardia
3) body central portion 4) pylorus: narrow, lower region
B. pyloric sphincter: controls opening between the stomach
and duodenum
C. rugae: folds in empty stomach
D. gastric glands: in stomach lining, contain 4 types of
secreting cells
1) chief cells: secrete pepsinogen
2) parietal cells: secrete HCl and intrinsic factor which,
with pepsinogen, make up gastric juice
3) mucous cells: secrete mucus which is also part of
gastric juice
4) G cells: secrete the hormone gastrin
Mechanical: peristaltic waves mix food with gastric
juices and change it into a thin liquid
called chyme
Chemical: protein digestion begins in stomach
Pepsinogen secreted by chief cells is changed
into the active form pepsin by HCl. Pepsin
breaks proteins into peptides.
Gastric lipase aids in the breakdown of large
lipids.
Absorption: The stomach absorbs some water,
electrolytes, some drugs, and alcohol
6. Pancreas
A. exocrine glands produce pancreatic juice which
is made of water, some salts, sodium
hydrogen carbonate (NaHCO3), and enzymes
B. NaHCO3 increases the pH of chyme to 7.1 - 8.2
stopping the action of pepsin.
C. The enzymes that are present breakdown
carbohydrates, proteins, lipids, and nucleic
acids.
7. Liver: secretes bile which causes the emulsification
of fats into a suspension of small droplets.
Other Liver Functions - page 424
8. Gall Bladder: concentrates and stores bile which is
emptied into the duodenum through the common
bile duct.
9. Small Intestine
A. made of 3 sections: duodenum - shortest
jejunum - middle portion
ileum - longest, final part; joins the large
intestine at the ileocecal sphincter
B. Intestinal glands in the lining secrete intestinal juice
with a pH of 7.6
C. Duodenal glands secrete alkaline mucus
D. Inner lining contains villi, microvilli, and circular
folds which provide more surface area for
digestion and absorption
Mechanical: segmentation moves food back and forth;
peristalsis mixes chyme through the
small intestine
Chemical:
Carbohydrates - Pancreatic amylase produces the
disaccharides maltose, sucrose, and lactose.
Sucrase breaks sucrose into glucose and fructose.
Maltase breaks malatose into 2 glucose molecules.
Lactase breaks lactose into glucose and galactose.
More chemical digestion in the small intestine.
Proteins: Pancreatic enzymes break peptide bonds
making small peptides.
Peptidase that is made by the small intestine
completes the digestion into amino acids
Lipids: Most digestion of lipids occurs in the small
intestine.
Bile emulsifies fats into tiny droplets.
Pancreatic lipase breaks triglycerides into 2
fatty acids and a monoglyceride.
Nucleic Acids: Ribonuclease (RNA) and
deoxyribonuclease (DNA) convert nucleic
acids into nucleotides
Monosaccharides, amino acids, glycerol,
monoglycerides, water, electrolytes, and
vitamins are absorbed in the small intestine.
Vitamin B12 requires intrinsic factor to be
absorbed.
10. Large Intestine
Sections:
A. cecum - pouch below the ileocecal sphincter
B. appendix - attached to the cecum
C. colon - above the cecum - 6 parts
1) ascending colon - up right side of abdomen
2) transverse colon - across top of abdomen
3) descending colon - down left side of the abdomen
4) sigmoid colon - curved portion between the
descending colon and rectum
5) rectum - lower portion
6) anus - opening to the outside with internal and
external sphincter
Bacterial digestion breaks down remaining
carbohydrates and proteins and is responsible for the
production of some B vitamins and vitamin K.
Vitamins, electrolytes, and most water is absorbed
in the large intestine.
Remaining substances make up feces which is
eliminated.
Maintaining a Healthy Weight is a Balancing Act
Calories In = Calories Out
How long will you have to walk in order
to burn those extra 305 calories?*
*Based on 130-pound person