CH 41 Flashcards
Food is taken in, taken apart, and taken up in the process of animal _______
nutrition
What type of feeders are most animals?
Opportunistic feeders
(Herbivores, Carnivores, Omnivores)
What are essential nutrients?
Required materials that an animal cannot assemble from simpler organic materials
Must be obtained from the animal’s diet
What are the 4 classes of essential nutrients?
1) Essential amino acids
2) Essential fatty acids
3) Vitamins
4) Minerals
Animals require ___ amino acids and can synthesize about _______ from molecules in their diet
20; half
Where do essential amino acids come from?
Obtained from food
What are fatty acids used for? What is the special one in mammals?
Membranes, signaling, storage fats
(Mammals- linoleic acid)
where can you get fatty acids from?
East seeds, grains, vegetables
What are vitamins? How many are essential for humans? What are the 2 types?
1) Organic molecules required in the diet in very small amounts
2) 13 are essential for humans
3) Two categories: fat soluble and water soluble
What are minerals?
Simple inorganic nutrients, required in small amounts
What is malnutrition?
Failure to obtain adequate nutrition
Causes deformities, disease, death
What is underourishment?
Diet does not provide enough chemical energy
What happens to undernourished individual (5)
1) Used up stored fat and Carbs
2) Break down its own proteins
3) Lose muscle mass
4) Suffer protein deficiency of the brain
5) Die or suffer irreversible damage
Epidemiology
Study of human health and disease in population
What causes neural tube defects in babies
Deficiency in folic acid in pregnant mothers
What is ingestion?
The act of eating or feeding
4 types of ingestion?
Filter Feeders
Substrate feeders
Fluid feeders
Bulk feeders
What is digestion?
The process of breaking food down into molecules small enough to absorb
2 types of digestion
Mechanical digestion: Chewing/grinding, increases surface area of food
Chemical Digestion: Splits food into small molecules that can pass through membranes; these are used to build larger molecules
What is enzymatic hydrolysis?
to split bonds with the addition of water (Used in chemical digestion)
What is absorption?
Is uptake of small molecules by body cells
What is elimination?
The passage of undigested material out of the digestive system
What does having digestive compartments do?
Reduces the risk of an animal digesting its own cells and tissues
What is phagocytosis?
Food particles that get engulfed
What is pinocytosis?
Liquid particles that get engulfed
Explain the digestion of a food particle by a single cell (4)
1) food particle is engulfed by phagocytosis
2) Food vacuole is formed
3) lysosomes fuse with food vacuole
4) Digestive enzymes in lysosome digest food
What is extracellular digestion?
The breakdown of food particles outside of cells
Occurs in compartments that are continuous with the outside of the animals body
What is an alimentary canal?
complete digestive tract: mouth and anus
What are accessory glands?
Secrete digestive juices into alimentary canal
Mammals have salivary glands, the pancreas, the liver, and the gall balder
Where does food processing begin?
Oral Cavity
What does salivary glands do?
Deliver saliva to lubricate food
What does saliva contain?
contains mucus and amylase
What does tongue movement cause?
It creates bolus and helps with swallowing
What does the pharynx do?
Junction that opens to the esophagus and trachea
What is the esophagus?
Connects to stomach
What is trachea?
Leads to lungs (windpipe)
What does the epiglottis do?
Blocks entry to trachea
What does the larynx do?
Guides bolus
What pushes food from the pharynx to the stomach?
Peristalsis: rhythmic contractions of muscles in the wall of the canal
What are sphincters?
Valves that regulate movement of materials between compartments
What does the stomach do?
Stores food and processes it into liquid suspension
Secretes gastric juice which makes chyme
What is chyme?
Mixture of food and gastric juice
What are the traits of gastric juice?
Low ph, 2, kills bacteria and denatures proteins
Made up of HCL and pepsin
What is pepsin?
Is a protease that breaks peptide bonds to cleave proteins
What do parietal cells do?
Secrete hydrogen and chloride ions into the lumen of the stomach
What are chief cells?
Secretes inactive pepsinogen, which activates to pepsin when HCL reacts with it
How are ulcers formed?
Caused by bacterium: heliocobacter pylori
What is the small intestine?
Longest compartment of the alimentary canal
Most enzymatic hydrolysis happens here
What is the duodenum?
The first part of the small intestine
Chyme from the stomach mixes with digestive juices, from the pancreas, liver, gallbladder, and the small intestine itself
What does the pancreas do?
Produce trypsinogen and chymotrypsinogen
This solution is alkaline and neutralizes the acidic chyme
release bicarbonate and digestive enzymes into small intestine
Where is bile made? What are its functions?
Made in liver and stored in gallbladder.
Bile salts facilitate digestion of fats
Destroys nonfunctional red blood cells
Why does the small intestine have a huge surface area?
Due to villi and microvilli
Microvilli create brush border that increases rate of nutrient absorption
Is transport across the epithelial cell passive or active?
It can be both depending on the nutrient
What does the hepatic portal vein do?
Carries nutrient rich blood from capillaries of the villi to the liver, then to the heart
What is the purpose of the liver? (2)
It regulates nutrient distribution
detoxifies many organic molecules
What do epithelial cells in the small intestine do?
Absorb fatty acids and monoglycerides and turn them into triglycerides
What are chylomicrons?
Fats covered in phospholipids, chloesterol, and proteins
What are lacteal?
Lymphatic vessel in each villus
Deliver chylomicron-containing lymph to large veins that return blood to heart
What is the cecum?
Aids in the fermentation of plant of plant materials and is located where the small and large intestines meet
What is the colon?
Leads to rectum and anus
What is the appendix?
Extension to the cecum that plays minor role in immunity
What completes the recovery of water?
Colon
What are feces
The wastes of the digestive system and stored in the rectum and is eliminated through the anus
Stomach adaptations for carnivores
Large, expandable stomachs
Herbivores and omnivores stomach adaptations
Longer alimentary canals due to longer digestion time
What do intestinal bacteria do?
1) Produce vitamins
2) Regulate the development of the intestinal epithelium
3) Regulate the function of the innate immune system
What are fermentation chambers?
Where mutualistic microorganism digest cellulose
Most elaborate adaptations of an herbivorous diet?
Ruminants
What helps regulate the digestive process?
The enteric division of the nervous system
What also regulates digestion through the release and transport of hormones
Endocrine system
Slide 68
Where is energy stored in humans?
It is stored in the liver and muscle cells in the poylmer glycogen
Where is excess energy stored?
In fat in adipose cells
What happens when fewer calories are taken in then expended?
The human expends liver glycogen, then muscle, then fat
What is central to maintaining metabolic balance?
Synthesis and breakdown of glycogen
The liver is the site for?
Glucose homeostasis
What raises insulin levels?
A Carb rich meal which triggers synthesis of glycogen
What does low blood sugar cause?
Causes glucagon to stimulate the breakdown of glycogen and release glucose
How is brain cells an exception when in comes to insulin?
They can take up glucose whether insulin is present or not
Where are glucagon and insulin produced
Islets of the pancreas, by alpha and beta cells
Alpha cells produce?
glucagon
Beta cells produce?
insulin
What is diabetes mellitus?
1) Deficiency of insulin or decreased response to insulin in target tissues
2) Cells are unable to take up enough glucose to meet metabolic needs
3) The levels of glucose may exceed capacity of kidneys
How to test for diabetes?
Sugar in urine
What is type 1 diabetes?
Autoimmune disease which the immune system destroys the beta cells of pancreas
Appears in child hood
Requires insulin injections
What is type 2 diabetes?
Non insulin dependent diabetes, caused by failure of target cells to respond normally to insulin
Excess body weight and lack of exercise increase the chances
Happens usually after age of 40
What regulates long term and short term appetite
Hormones by affecting a satiety center in brain
What is ghrelin
Hormone secreted by stomach wall, triggers feeling of hunger
What hormones secreted by small intestine suppress appetite?
Insulin and PYY
What is Leptin
Produced by adipose and suppresses appetite and regulates body fat
