The Human Digestive System Flashcards
Herbivores e.g.
Animals that feed only on plants e.g. rabbit
Carnivores e.g.
Animals that feed on other animals e.g. fox
Omnivores e.g.
Animals that feed on plants and animals e.g. badger
Why is there a need for digestion?
To break down large food particles until they are small enough to pass into body cells.
Why is there a need for a digestive system?
Food can be digested in a single location. Individual cells do not have to contain a full range of digestive enzymes.
Ingestion
Food is taken into the alimentary canal
Digestion
The physical and chemical breakdown of food into soluble particles small enough to pass into body cells.
Absorption
The movement of digested material from the alimentary canal into the blood system.
Egestion
Removal of unabsorbed material as faeces.
Nutrition
The way an organism obtains and uses it’s food.
Autotrophic
A type of nutrition where organism make its own food.
Heterotrophic
A type of nutrition where organism cannot make its own food.
What is the human dental formula?
The number of each type of tooth in the upper jaw one side of the mouth.
Where do symbiotic bacteria function?
The large intestine
What types of mechanical digestion are used to breakdown food?
- Teeth 2. Contractions in the stomach wall 3. Peristalsis
Peristalsis
Rhythmic muscular contraction and relaxation in the wall of the alimentary canal causing the food to move along the canal
Name the different types of teeth
Incisors, Canines, Pre molars, Molars
Incisors
Cutting
Canines
Tearing
Pre molars
Crushing and grinding
Molars
Crushing and grinding
Give the human dental formula
i 2/2 c 1/1 pm 2/2 m 3/3
Name the parts of the human digestive system
Mouth, Salivary Gland, Pharynx, Oesophagus, Liver, Stomach, Gall bladder, Pancreas, Bile duct, Small intestine (Duodenum, Ileum), Large intestine (Colon, Caecum, Appendix, Rectum, Anus)
What is the oesophagus?
A muscular tube 25cm long that connects the pharynx to the stomach that food moves down by peristalsis.
What connects the pharynx to the stomach?
The oesophagus
How does food move down the oesophagus?
Peristalsis
What is the stomach?
A J-shaped muscular bag which stores and digests food for about four hours and churns and mixes food with gastric juice forming Chyme.
What is the shape of the stomach?
J-shaped
What is the function of the stomach?
It stores and digests food for about four hours and churns and mixes food with gastric juice forming Chyme.
What does the stomach mix with food and what does this create?
gastric juice, Chyme
What are the two types of digestion in the stomach?
Mechanical and Chemical digestion
How does mechanical digestion occur in the stomach?
Peristalsis physically breaks up food particles
How does chemical digestion occur in the stomach?
Chemical digestion occurs using gastric juice containing mucus, HCl and pepsinogen.
What does gastric juice contain?
Mucus, HCl and pepsinogen
What are the functions of gastric juice?
Mucus lines and protects the stomach wall, HCl kills bacteria and activates pepsinogen and pepsinogen is converted to the active enzyme Pepsin by HCl. Pepsin digests protein to peptides.
What is Pepsin and what does it do?
Pepsin in an active enzyme that digests protein to peptides.
What and where is the cardiac sphincter muscle?
A circular muscle which contracts to close entry from the oesophagus to the stomach.