Digestive System Flashcards
(49 cards)
What is the digestive system often called?
Alimentary canal (lumen/ opening inside)
What is the order of the digestive system
Oral cavity- mouth
Throat- pharynx- space
Oesophagus- muscular tube
Stomach
Small intestines 7Metres
SUB DIVIDED
Duodenum top- always
connected to the stomach
Jejunum - quite a lot of it
Ilium- border to the large intestines
In-between small and large
Diverticulum - appendix
Large Intestine/Colon Bigger diameter
¯ Rectum- feces stored
Anus- sphincter
What are the 4 stages of food processing?
INGESTION
DIGESTION
a. Mechanical breaking down food with teeth
b. Chemical- chemical hydrolysis- enzymes
ABSORBTION into circulatory system
ELIMINATION - undigested food feces
1.
Ingestion is
2.Digestion
What are the two types of digestion:
Explain them
is the process of taking in food
is the process of breaking down food –
Ø Mechanical
Ø Chemical
Mechanical
Oral cavity mouth
Stomach- helps to mechanically break down
Chemical- enzymes that break down macromolecules
Proteins— amino acids
Lipids- Fats into glycerol and fatty acids
Carbohydrates- Starch into Maltose- glucose
- Absorption
is the process of:
Where? - Elimination
is the process of:
Where?
Absorption of nutrients in the small intestines.
Food absorbed from sm int into the circulatory system
Removal of undigested material
Anus- sphincter
Where are the steps that food passes through the digestive system in the Alimentary canal?
- oral cavity- tongue
- pharynx
- Esophagus
- Stomach
- Small Intestine
6 Large Intestine- Colon
- Anus
Name the accessary organs (4)
What are their functions?
- Salivary Glands
- Liver
- Gall Bladder
- Pancreas
Accessory Organs- food doesn’t pass through.
Help with process of digestion
Function produce secretions
Helps with chemical digestions
Released via ducts
What are the 3 salivary glands?
SALIVARY GLANDS
1. Parotid Gland- Biggest- ducts carry saliva into oral cavity, Sits in cheek muscle under skin- located in between the corner of your mouth and your ear.
not compact, dispersed.
Made of lobules- Lobular Structure
2. Submandibular Gland
Duct that leads to the oral cavity sits under mandible/ jaw bone
3. Sublingual Gland sits under tongue (tongue is a lingur)
Where is the pancreas found?
What is the pancreas for?
Pancreas is always found in the 1st part of small intestine the
duodenum (U shaped loop.)
Produce secretions that will go into the duodenum
Mouth
what is a Dental formula
Why do we have different teeth?
How to record teeth
One side of body- # of teeth and types
Canine Incisors premolar Molar
C i P M
top 2 1 2 3
bottom 2 1 2 3
These types of teeth as we are omnivores- molars flat- grinding, incisors and canines ripping meat
What are the 3 steps of digestion for the mouth?
- Once food is moistened it becomes a bolus (a ball food moistened with saliva, from SALIVARY GLANDS). This bolus swells and goes into your oesophagus
- Start mechanical digestion- grinds food with teeth and tongue (powerful muscle that helps with mechanical digestion.
3.Chemical Digestion of carbohydrates starts at the level of the mouth
Where does the breakdown of starch begin?
CHEMICAL DIGESTION
IN THE MOUTH
STARCH ——–MALTOSE
SALIVARY AMYLASE
(enzyme produced by salivary glands-
parotid gland, sublingual gland, submandibular gland)
- Mouth
Starch, big carb- many glucoses,
Breaking down starch into maltose,
a polysaccharides into a disaccharide
- Second stage, DIGESTION OF STARCH is in the small intestine to break down the disaccharide, maltose, into glucose.
- What is the pharynx?
Pharynx is a cavity that is a common space for both respiratory system and Digestive System
What are the structures of the esophagus and the wind pipe/trachea?
Esophagus- a muscular tube no cartilage
Wind Pipe/ Trachea-Can feel the rings of cartilage- keep it open because the gases go through the trachea and the gases are not powerful enough to force the tube open
Trachea is like the hose of a vacuum cleaner
Describe an epiglottis and how it works
Epiglottis- is like a door, made of Cartlidge DOOR LIKE STRUCTURE
Epiglottis is lifted up when we breath in so O2 can go into the trachea
Location: Entrance to your windpipe
Epiglottis is down (trachea is closed) during swallowing so food doesn’t go into the wrong pipe- the trachea.
The food can go go to the esophagus
What is the esophagus?
How does it work?
How long is it?
What type of tissue is it made from?
Esophagus
Ø Muscular tube that carries
food to the stomach
Ø Peristalsis
-Smooth muscles contract
and relax, forming a ‘wave’
Peristalsis: contractions of the muscles in mainly the esophagus
(small intestines are also contracting too!)
WAVY APPEARANCE
Short tube 25cm length
Muscular tube- smooth tissue
What does the stomachs function during digestion?
What is the pH in the stomach?
What type of chemical digestion begins here?
What enzyme is produced here?
Ø Stores materials
Ø Produces
digestive enzymes and HCl (hydrochloric acid) (gastric juice)
Ø pH of HCl is low(2)
Ø Protein digestion begins here
-Produces pepsin (enzyme)
What is the stomach made of?
What how much can it hold?
Muscular pouch made from 3 layers of smooth muscles, arranged longitudinally and circularly
Up to 4 liters
What are the digestive enzymes in the stomach mainly used for?
When HCI creeps up into the esophagus, what is this?
What type of PH does HCI create?
the digestion of proteins
Heartburn
PH is LOW 2- very acidic
Where does protein digestion begin
How many stages of protein digestion are there and where do they occur?
What helps the digestion of proteins in the stomach ?
In the stomach
2
- stomach: LONG PROTEINS/ POLYPEPTIDES-
long chains broken down into smaller chains - Small intestine:smaller chains of amino acids are broken down into single amino acids
Enzyme Pepsin
What does the interior surface of the stomach wall look like?
What type of digestion chemical or mechanical, does the structure of the stomach contribute to?
Highly folded with small depressions/pits leads into the tubular gastric glands
Mechanical- powerful muscle. Inner wall is folded and uneven. The ropes of muscles help give power.
What are the gastric glands in the stomach for?
What 3 types of cells, in the gastric glands are responsible for secreting different parts of the gastric juice?
What type of tissue lines the gastric gland?
To secrete different parts of the gastric juice
Mucus cells- lubricates living of stomach to prevent erosion of stomach wall
Chief cells- secrete pepsinogen (immature, INACTIVE form of the enzyme pepsin)
Parietal Cells-secrete HCL
Epithelium - lining and covering (also on the outside of the stomach to line it)
What 3 steps cause proteins to be broken down into smaller protein chains in the stomach? (1st stage of protein digestion)
1 Pepsinogen and HCl are secreted into the stomach
2 HCl converts pepsinogen to
pepsin
- Pepsin then activates more pepsinogen into pepsin
ØStarts a chain reaction
Q
How many sphincters are in the stomach?
What are their names?
What are their functions?
A
2
- Top, cardiac sphincter- its near the heart)
- Bottom, Pyloric Sphincter- on the boarder between the stomach and the duodenum (small intestine)
Cardiac sphincter- controls the flow into and out of the stomach
Pyloric- Regulates the entry of food into the small intestine (the amount)
