Chapter 41 Animal Nutrition Flashcards
What do herbivores mainly eat?
Eat mainly plants and algae
What do carnivores mainly eat?
Eat other animals
What do omnivores mainly eat?
Regularly eat animals as well as plants or algae
What must an animal’s diet provide? (3)
Must provide:
- chemical energy for cellular processes
- Organic building blocks for macromolecules
- Essential nutrients
What are essential nutrients?
Materials that an animal can’t assemble from simpler organic molecules
What are the 4 classes of the essential nutrients?
- essential amino acids
- essential fatty acids
- vitamins
- minerals
What is balanced food?
Food that has all 4 essential nutrients
How many amino acids do animals require?
20 amino acids
What are the 3 complete proteins that contain all the essential amino acids?
- meat
- eggs
- cheese
What is incomplete protein?
Proteins that do not contain all essential amino acids
What should individuals that only consume plant proteins do?
They should consume specific plant combinations to get all the essential amino acids
What must essential fatty acids be obtained from?
Must be obtained from the diet, and include certain unsaturated fatty acids
What are the 2 types of fatty acids?
- unsaturated fatty acid (good fat)
- saturated fatty acid (bad fat)
What is the chemical structure of fatty acids?
They have one or more double bonds
What are vitamins?
Organic molecules required in the diet in very small amounts
How many vitamins are essential for humans? What are the two categories of vitamins?
13 vitamins
Categories:
- Fat soluble
- Water soluble
Which vitamins are water soluble?
Vitamin B complex and Vitamin C
Which vitamins are fat soluble? (4)
- Vitamin A
- Vitamin D
- Vitamin E
- Vitamin K
What are minerals?
Simple inorganic nutrients, usually required in small amounts
What is malnutrition?
Failure to obtain adequate nutrition
What can deficiencies in essential nutrients causes? (3)
Can cause:
- deformities
- disease
- death
How does undernutrition happen?
When a diet doesn’t provide enough chemical energy
What are the 5 consequences of an undernourished individual?
- Use up stored fat and carbohydrates
- Break down its own proteins
- Lose muscle mass
- Suffer protein deficiency of the brain
- Die or suffer irreversible damage
What is epidemiology?
Study of human health and disease in populations
A deficiency in folic acid in pregnant mothers caused what?
Caused neural tube defects
What are the 4 stages of food processing?
- Ingestion
- Digestion
- Absorption
- Elimination
What is ingestion?
The act of eating or feeding
What are suspension feeders?
Aquatic animals that sift small food particles from the water
What are substrate feeders?
Animals that live in or on their food source
What do fluid feeders do?
They suck nutrient-rich fluid from a living host
What do bulk feeders do?
Bulk feeders eat relatively large pieces of food
What is digestion?
Process of breaking food down into molecules small enough to absorb
What does mechnical digestion do?
Increases the surface area of food
also known as chewing
What does chemical digestion do?
Splits food into small molecules that can pass thru molecules ;
used to build larger molecules
What is the process of enzymatic hydrolysis?
The splitting of bonds in molecules with the addition of water
What is absorption?
Uptake of nutrients by body cells
What is elimination?
The passage of undigested material out of the digestive system
What does the digestive compartments help reduce the risk of what?
Reduces the risk of an animal digesting its own cells and tissues
What is intracellular digestion?
Food particles are engulfed by phagocytosis
or
Food vacuoles are fused with lysosomes containing hydrolytic enzomes
What is extracellular digestion?
The breakdown of food particles outside of the animal’s body.
What do animals with a simple body plan have?
Gastrovascular cavity
What is the alimentary canal?
Digestive tube with two openings, mouth and anus
What does the mammalian digestive system consist of?
Alimentary canal and accessory glands that secrete digestive juices thru ducts
What are the mammalian accessory glands? (4)
- salivary glands
- pancreas
- liver
- gallbladder
What is the peristalsis?
Rhythmic contractions of muscles in the wall of the canal; pushes food along
What are sphincters?
Valves that regulate the movement of material between compartments
What is the oral cavity?
Location of where the first stage of digestion is mechanical
What does salivary glands do?
Deliver saliva to lubricate food
What does salivary amylase do?
Initiates breakdown of glucose polymers
What is mucus?
Viscous mixture of water, salts, cells, and glycoproteins
What is bolus?
Food that shaped into a round mass by the tongue
What is pharynx?
Also known as the throat, is the junction that opens to both the esophagus and the trachea
What does the esophagus do?
Also known as food pipe, connects to the stomach
What does tongue do?
- shapes food into bolus
- helps with swallowing
What are the steps that happen b/w the trachea and esophagus? (3)
- Esophagus conducts food from pharynx to the stomach via peristalsis
- Swallowing the food causes for the epiglottis to block entry of the trachea (trachea goes to lung).
- With the trahea blocked, the food is able to properly go down the esophagus to the stomach
What does the stomach do?
Stores food and begins digestion of proteins
What does stomach secrete? What does this secretion do?
Secretes gastric juices, which converts a meal into chyme
What is gastric juice made up of?
Made up of hydrochloric acid and pepsin
What is pepsin?
A protease, protein-digesting enzyme, that cleaves proteins into smaller peptides
What is pepsinogen?
An inactive form of pepsin that becomes activated when mixed with hydrochloric acid
Where does most digestion and absorption occur in the body
Most digestion and absorption occurs at the small intestine
What are the steps in the production of gastric juices? (3)
- Pepsinogen and HCI secreted into lumen
- HCl converts pepsinogen to pepsin
- Pepsin activates more pepsinogen starting a chain reaction
What is the longest compartment of the alimentary canal?
Small intestine
What is duodenum do?
Location of where chyme from the stomach mixes with digestive juices from the pancreas, liver, gallbladder, and the small intestine itself
What does pancreas produce?
produces proteases trypsin and chymotrypsin that are activated in the lumen of the duodenum
What does the pancreatic solution do to the chyme?
It neutralizes the acidic chyme
What does bile do?
Aid in digestion and absorption of fats
Where is bile made and stored?
Made in liver
Stored in gallbladder
What are the 3 portions of the small intestine?
- duodenum
- jejunum
- ileum
What are the lacteals?
Lymphatic vessels in each villus?
What does microvilli help with in the small intestine?
- Greatly increases the rate of nutrient absorption by creating a bush border
What does the hepatic portal vein do?
Carries nutrient rich blood from the capillaries of villi to liver to heart
What are the functions of the liver? (3)
- Regulate nutrient distribution
- Interconverts organic molecules
- Detoxifies organic molecules
What are chylomicrons?
Water soluble components that’s formed from proteins, cholesterol, phospholipids, and fatty acids
What does cecum aid in?
Fermentation of plant material and connects where small and large intestines meet
Where are feces stored?
Stored in the rectum until it’s released via the anus
What is dentition?
Anima’s assortment of teeth
- an example of structural variation reflecting diet
Stomach and intestinal adaptations for carnivores, herbivores, and omnivores
- Carnivores have bigger and more expanded stomachs
- Herbivores and omnivores have longer alimentary canals for vegetation digestion
How does endocrine and enteric division of nervous system help with digestion?
Endocrine: Regulates digestion by releasing and transporting hormones
Enteric Division: Regulates digestive processes
What facilitates the breakdown of glycogen into glucose?
Hormones insulin and glucagon
What is the site for glucose homeostasis?
Liver
How is the synthesis of glycogen triggered?
After eating a carbohydrate rich meal that increases insulin levels?
What stimulates glycogen breakdown and release of glucose?
Low blood sugar that causes glucagon to initiate the first breakdown of glycogen
What do alpha cells make?
What do beta cells make?
Alpha cells - Glucagon
Beta cells - Insulin
What is diabetes mellitus?
A diseases caused by deficiency of insulin or a decreased response to insulin in target tissues
Type 1 vs Type 2 Diabetes
Type 1: Autoimmune disorder where immune system destroys beta cells (lower insulin) –> Appears during childhood
Type 2: Cells do not respond normally to insulin (high glucose levels) –> Appears after age 40 but can appear earlier; increased body weight and lack of exercise
What is Ghrelin?
Hormone secreted by the stomach wall, triggers feelings of hunger before meals
What is Insulin and PYY?
hormone secreted by the small intestine after meals, both suppress appetite
What is leptin? (3)
- produced by adipose (fat) tissue
- also suppresses appetite
- plays a role in regulating body fat levels
