Digestive System Flashcards
What are the 5 processes which food undergoes
Ingestion Digestion Assimilation Absorption Egestion
What are the two types of digestion
Mechanical and Chemical
Where does mechanical digestion take place
Mouth
Esophagus
Stomach
Small intestines
Define mechanical digestion
When food is eaten, large pieces are physically broken down
Where does chemical digestion take place
Mouth
stomach
Small intestine
Define chemical digestion
Digestive juices break down the food into soluble molecules
What is Ingestion
Taking in food and chewing
What is Digestion
Ingested food is broken down
What is Absorption
Soluble food molecules are taken up the bloodstream
What is Assimilation
Absorbed food is used to provide energy
What is Egestion
Undigested food is excreted
What does the mouth do
Receives food and begins the process of mechanical digestion
What do the lips do
Serve as an opening for food intake and assists in articulation of sound and speech
What is a Rubonant animal
Has more than 1 stomach
What do teeth do
Mechanically break down food into smaller pieces
Name the four types of teeth
Incisor
Canine
Molars
Premolars
What does the tongue do (4)
Aids in chewing
Mixes food with saliva
Enables speech
Differentiates flavours
What do the salivary glands do
Produce and secrete saliva
Contains salivary amylase which breaks down starch
What does the Pharynx do
Connects nasal and oral cavities
Aids in swallowing and serves as a pathway for food from the mouth to esophagus
What does the Larynx do
Voice box - Contains vocal cords
What is the Epiglottis
Flap of cartilage that prevents food from entering the trachea
What is the Esophagus
Hollow muscular tube that connects the Pharynx to the stomach
Located behind trachea
Two functions of Esophagus
Secretes mucus
Moves food from throat to stomach using peristalsis
What happens if stomach acid reaches the Esophagus
Heartburn
What is the Uvula
Soft palate which closes the opening to the nasal cavity
Two characteristics of the stomach
Wall is thick and Muscular
Stores all food
What mechanical digestion occurs in the stomach
Muscular wall causes churning movements that ensure the food is mixed with the stomach juices
What chemical digestion occurs in the stomach
Enzymes are secreted that break down the proteins and lipids
Hydrochloric acid kills the bacteria
Digestion turns food into an acidic liquid called…
Chyme
How long are the small intestines
6.5m
What are the three parts of the small intestine and their roles
Duodenum - Digestion of carbs and fats
Jejunum - Absorption
Heum - Absorption
What are the projections on the lining of the intestine and what is their purpose
Villi - Increase surface area to increase absoprtion
What are villi covered in
Microvilli - Further increase surface area
How long does it take food to pass through the small intestine
1-6hr
What are the dimensions of the large intestine
1.5m long
6cm diameter
How long does food stay in the large intestine
8hrs - a few days
What does the large intestine absorb
Water
Mineral Salt
Vitamins
What makes up the large intestine
Ascending colon
Descending colon
Traverse colon
Rectum and anus
Role of the anus
Egestion of undigested food
Defaecation of faecal matter
Where is the appendix located
Beginning of ascending colon
What does the Gallbladder do
Stores Bile
What is Bile
Substance produced by the liver that breaks down fats
What does the liver do
Converts excess glucose to glycogen for storage
Detoxifies / neutralises and absorbs certain toxins
What does the Pancreas do
Secretes Pancreatic juice with enzymes that play a role in digestion
Secretes the hormones - Insulin and Glucagon which control the blood glucose levels in the body
Which raises blood glucose levels
Which lowers blood glucose levels
Glucagon - Raises
Insulin - Lowers
How does the small intestine absorb the nutrients
Nutrients from food pass into the bloodstream through the walls of the small intestine
What does the small intestine absorb
80% ingested water Vitamins Minerals Carbohydrates Proteins Lipids/Fats
