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The Digestive System: Lizbet Reyes-Salgado Period 6 - Coggle Diagram
The Digestive System
: Lizbet Reyes-Salgado Period 6
Mouth
Propulsion
is initiated by swallowing
Mechanical
digestion begins
Food is ingested
Salvia
mixture of mucosa and serous fluid
forms a food bolu
contains salivary amylase
Chemical
breakdown of starch begins
The
pharynx and oesophagus
is the passageway for food
Defecation Process
Mass movements force feces into rectum and
stretch wall
to signal the
defecation relflex
Internal sphincter
relax (involuntary)
External sphincter-
remains closed (voluntary)
Rectum is typically empty
Digestive organs
GI tract/ Alimentary canal
Stomach
Small intestine
Esophagus
Large intestine
Pharynx
Rectum
Mouth
Anus
Accessory digestive organs
Teeth
Pancreas
Tongue
Liver
Salivary gland
Gall bladder
Structure
Submocosa-
blood supply and nerves
Musculares externa-
smooth muscle (circular and longitudinal)
Mucosa-
innermost and moist/mucus membrane
Serosa-
anchors organs
Large intestine
No digestive enzymes produced but bacteria digests remaining nutrients
Remaining materials are
eliminated
= feces
Propulsion:
Mass movement
Presence of faces
in the rectum causes a
defection reflex
Small intestine
Jejunum
lleum
Duodenum-
bile duct empties secretions into the small intestine
Peristalsis-
moving of food
Segmentation-
mix of chyme and juices
Esophagus
4 layers within the wall
Peristalsis
Runs from pharynx to stomach
Digestion
Mechanical
Churning of food in the
stomach
Segmentation (mixing) in the
small intestine
Mastication/chewing- grinding and mixing food in the
mouth
by teeth and tongue
Chemical
Carbohydrates-
are broken down into simple sugars
Proteins-
broken to simple sugars
Enzyme break down food molecules into smaller units
Fats-
broken to fatty acids and glycerol
Process
Absorption:
end products of digestion are absorbed into blood or lymph
Defecation:
elimination of indigestible substances as feces
Ingestion-
voluntary movement of food into mouth
Liver
Largest gland:
in the body
Produces bile-
emulsifies fat
to aid enzymatic breakdown
Stomach
Function
Peristalsis
occurs-movement
Pylorus
lets out
chyme
into
small intestine
Food breaks down into smaller fragments-
chyme
Rugae-
folds of the mucosa
Food empties into
small intestine
at the
pyloric sphincter
Food enters at the
cardioesophageal sphincter
Storage tank- Volume of 50ml to 4L
Mucosa
Mucus surface layer traps a
bicarbonate fluid
beneath it.
Gastric pits
Mucous neck cells-
secrete mucus
Parietal cells-
secrete HCI and intrinsic factor
Chief cells-
produce pepsinogen and is activated by HCI in the stomach
Goblet cells
produce alkaline mucus
Pancreas
Control
blood glucose levels-
insulin and glucagon
Produces
digestive enzymes
to break down food and secreted into duodenum