Digestive System Flashcards
What are the different nutrient groups?
- Proteins
- Carbohydrates
- Lipids (fats)
- Vitamins
- Minerals
- Fibre
- Water
What are the stages of bird digestion?
- Tongue
- Crop
- Proventriculus
- Ventriculus (the gizzard)
- Ceca
- Cloaca
What are the stages of monogastric digestion?
- Mouth (teeth and tongue= mechanical digestion) (saliva = chemical digestion)
- Stomach (hydrochloric acid and enzymes =chyme)
- Small intestine (duodenum, jejunum and ileum)
- Liver
- Pancreas
6.Large intestine (colon, caecum and rectum)
7.Anus
What are the stages of ruminant digestion?
1.rumen (fermentation)
2. Peristalsis (undigested feed=cud)
3.Reticulum (filters food)
4.Omasum (absorbs water and salt)
5.Abomasum (digestive enzymes and acid are added)
What is mechanical digestion and chemical digestion?
- Mechanical digestion is where food is physically broken down into smaller pieces (chewing/mastication- oral cavity churning- stomach/rumenbile- duodemungrinding-gizzard)
- Chemical digestion is where food is broken down by enzymes, acid and bile (intestines)
Define autotroph
- An autotroph is able to synthesis ‘food’ from it’s surroundings using light or chemical energy e.g photosynthesis
Define heterotrophic
- Heterotrophic species cannot synthesise energy from their environment and therefore rely on others such as plants or animals for nutrition
Define maxillary and mandibular
- Top layer of teeth (maxillary)
- Bottom layer of teeth (mandibular)
What is the function of the liver?
- Stores vitamin A, D,E,k & B12
- Mineral storage (copper&iron)
- Carbohydrate storage
- Bile production
What is the function of the pancreas?
- Detects blood glucose concentration, releases hormones that alter the amount of glucose in the body
- Secretes glucagon and insulin to control levels
How is the regulation of blood glucose performed?
- Blood glucose is regulated by the pancreas in a homeostatic process
- Pancreases detect levels, then releases hormones to regulate
What happens when Hyperglycaemia occurs?
- Pancreas detects high blood glucose levels
- Insulin is secreted (by beta cells)
- Glucagon secretion decreases
- Insulin travels via the blood to the target organ (liver&muscles)
- Excess glucose is converted to glycogen by the liver and stored in the muscles - used to make energy
What happens when hypoglycaemia occurs?
- Pancreas detects low blood glucose levels
- Glucagon is secreted (by alpha cells)
3 Insulin secretion decreases - Glucagon travels via the blood to the target organ (liver and muscles)
- Glycogen is converted back into glucose by the liver and muscles - released back into blood
What are the roles of insulin?
- Released from pancreas
- Converts glucose to glycogen
- Insulin secreted when blood sugar levels are high
- Insulin lowers blood glucose/ removes glucose from the blood
- Involved in regulating blood glucose/homeostasis
What are the roles of glucagon
- Glucagon is released from the pancreas/liver
- Glucagon converts glycogen to glucose
- Glucagon is secreted when low levels of sugar/glucose
- Glucagon raises blood glucose/ releases glucose into the blood
- Involved in regulating blood glucose/homeostasis
What are the different types of nutrient groups and their functions?
- Carbohydrates- (for energy)
- Fibre- (bulk movement through digestive tract)
- Protein- (for amino acids to make body proteins such as cells, tissues, enzymes, hormones, muscles and hair)
- Lipids/fats- (stored for energy and used for insulation and protection of organs)
- Vitamins- (for specific chemical reactions in cells)
- Minerals- (for bones and teeth, osmoregulation, nerve transmission and muscle contraction)
- Water- (involved in chemical reactions, transporting chemicals and regulating body temperature)
Mechanical and chemical digestion within ruminant digestion
- Rumen- chemical digestion
- Reticulum - mechanical digestion
- Omasum - filters food
- Abomasum - chemical digestion
Mechanical and physical digestion within bird digestion
- Crop- storage
- Proventriculus - chemical digestion
- Ventriculus / the gizzard -mechanical digestion
Explain the role of protein in the diet of a pregnant dog
- Repair and maintenance of body tissue
- Puppies growing and developing new tissues
- Protein needed for milk production
Explain a feature of the dental structure for a herbivore
- Flat teeth - designed to grind
- Hard dental pad -for crushing
Explain a feature of the dental structure for a carnivore
- Canines -used to rip meat
Explain two reasons why carbohydrates are important in the diet of an animal
- Provide energy - essential for brain/movement of muscles
- Excess carbohydrates stored as fat- for keeping warm/storing energy
Explain two functions of the liver
- Production of bile to emulsify fats
- Regulating blood glucose by storing and releasing glucose
State one cause and one symptom of ruminant bloat
- Cause - incorrect diet
- Symptom- distress
Explain the role of water in a cats diet
- Prevents dehydration- so cells/organs can function effectively
- Improves the effectiveness of digestion- increasing nutrient absorption
Explain how intestinal villi are adapted to absorb biological molecules
- Large surface area / many microvilli - so more molecules can be absorbed
- Good blood supply to allow increased diffusion of molecules
- Thin walls efficient for diffusion
Explain two ways a cow’s mouth is adapted to eat grass
- Dental pad- grip grass
- Flat teeth- allow side to side chewing
Explain one way birds break down their food without having teeth
- They have a gizzard - to grind food with stones from grit they have swallowed
- They have a beak to tear/crack food to reduce size
Explain two ways birds’ beaks are adapted to feed
- Strong hard- to break nuts
- Sharp pointed - to pick up small pieces of food or spear fish
- Sharp hooked beaks - to tear meat
Give three examples of mechanical digestion
- Churning stomach /reticulum
- Ventriculus / the gizzard - grinding
- Teeth- chewing
Explain one way intestinal villi help the absorption of nutrients
- Finger like projection which increase surface area
- Network of capillaries- to allow efficient diffusion/ absorption of molecules
Compare the roles of the hormones insulin and glucagon
- Insulin is secreted when blood sugar levels are too high
- Insulin is released from the pancreas
- Insulin converts glucose to glycogen
- Insulin is involved in regulating blood glucose
- Glucagon is released from the pancreas
- Glucagon converts glycogen to glucose
- Glucagon is involved in regulating blood glucose
- Glucagon is secreted when blood sugar levels are low
Organs and functions of a bird’s digestion system
- Crop - stores food
- Proventriculus- chemical digestion/enzyme action/hydrochloric acid
- Ventriculus/The Gizzard - mechanical digestion/ grinding food
- Cloaca - eliminate waste
What are the edible faeces rabbits produce called?
- Caecotropes
What is the function of the caecum in hindgut fermenters?
- Where large numbers of microbes ferment the food
What is the key difference in hindgut fermenters
- They do most of their digesting after their stomach
Where does chemical and mechanical digestion take place within a hindgut fermenter?
- Mechanical digestion: Mouth-teeth-grinding, Stomach- churning
- Chemical digestion: Liver-bile production, Pancreas- production of digestive enzymes, Caecum- fermentation/microbes/enzymes
Where does mechanical and chemical digestion occur within a ruminant?
- Mechanical digestion: teeth-grinding plant material, reticulum- filters food
- Chemical digestion: Mouth-saliva- amylase, Rumen- fermentation/microbes, Abomasum (true stomach) digestive enzymes/acids
Where does mechanical and chemical digestion take place within a monogastric digestion system?
Mechanical digestion: Mouth-teeth-chewing, Oesophagus-peristalsis, Stomach-grinding
Chemical digestion: Mouth-saliva-amylase, Stomach- hydrochloric acid/enzymes, Duodenum-enzymes
How are carnivores adapted to eat meat?
- Canines- hold prey, pierce skin and rip meat
- Carnassial teeth- shear meat
How are herbivores adapted to eat plant material?
- Incisors- cut plant material
- Molars- continually grow and worn down by silica in plants
How are omnivores adapted to eat plant material and meat?
- Incisors and canines are used to cut meat
- Flat molars are used to grind plant material
Explain two reasons why carbohydrates are important in the diet of an animal
- Carbohydrates are the main source of energy, essential for brain/movement of muscles
- Simple carbohydrate/sugar short-term store, to provide quick energy
What are three functions of the liver?
- Production of bile to emulsify fats
- Involved in regulation of blood sugar by storing and releasing glucose
- Removing toxins from the blood
Discuss how blood sugar levels are maintained in animals
- Blood glucose levels are maintained primarily by the actions of insulin and glucagon in a negative feedback loop
- As blood glucose levels increase the pancreas responds by secreting insulin
- Insulin stimulates in the liver and and skeletal muscle cells to the form glycogen from glucose
- Insulin stimulates liver cells and adipose tissue to synthesis fat from glucose
- As blood glucose levels decrease glucagon (hormone) is produced
- Glucagon stimulates the liver and skeletal muscle cells to breakdown glycogen to glucose
What is the function of incisors?
- Fine nibbling/cutting/delicate grooming
What is the function of canines?
- Holding prey and tearing meat
What is the function of premolars?
- Shearing flesh, grinding food
What is the function of molars?
- Shearing and grinding
What is the function of canines?
- Hold prey, pierce skin and rip meat
What is the function of carnassial teeth?
- Allow shearing of meat
