Digestion and Metabolism Flashcards
define chemical and mechanical digestion
- mechanical: breaking up of food into smaller pieces
- chemical: further breaking up of larger molecules of food into smaller molecules by action of digestive enzymes
define pancreatic lipase; know effect on fat
-degrades fat
define body weight
-determined by body’s energy balance
incomplete vs complete digestive systems and examples of each
- incomplete: single opening for ingestion of food (no anus); invertebrates
- complete: digestive tube with 2 openings (mouth and anus); vertebrates, nematodes, mollusks, annelids, echinoderms
absorption and where it happens
-simple sugars and protein are absorbed into inner lining of small intestine
leptin vs insulin and effect on appetite
- leptin: secreted by by adipocytes; informs brain on how much fat we have; larger effect on appetite than insulin
- insulin: secreted by pancreatic beta cells; stimulates glucose and amino acid uptake; promotes glycogen and fat synthesis; has receptors in brain and functions like leptin, as index of body’s fat stores; weaker effect on appetite
monosaccharides vs disaccharides
- monosaccharides: 1 sugar; glucose, fructose, galactose
- disaccharides: 2 sugars; sucrose, maltose, lactose
define ingestion
-process of taking food into the digestive system so that it may be hydrolyzed or digested
define nutrition
- process of taking in and using food
- the starting point and basis for all human form and function; source of fuel that provides energy for all biological
define nutrients
-substances in food that are used as energy sources to run the body (what you get from food you digest)
define digestion
-the breakdown of food (chemically or mechanically) in order to utilize nutrients
define amylase
-enzyme that breaks down starch
macronutrients vs micronutrients (types of each)
- macronutrients: must be consumed in relatively large quantities; protein, carbs, lipids
- micronutrients: small quantities required; vitamins, minerals
define bolus, how it’s made, and the activity of peristalsis
- bolus: ball of food formed by saliva after chewing, goes to back of mouth and throat, gets swallowed
- peristalsis: involuntary muscles contractions that move food down esophagus after swallowing, until reaches stomach
aerobic (cellular) respiration (also known as balanced equation)
C6H12O6 + 6 CO2 –> 6 CO2 + 6 H2O
glucose (from food) + oxygen (from plants) go in system and exhale as carbon dioxide and water
-transfers energy from glucose to ATP
define thermoregulation, evaporation, and convection
- thermoregulation: balance between heat production and loss
- evaporation: lose heat to air
- convection: heat in body follows air outside
define cutaneous vasodilation
-increase blood flow close to body’s surface and promotes heat loss; if necessary, triggers sweating and inhibits heat promoting center
define vestigial organ (examples)
-organ that we have but don’t use; appendix
HDL vs LDL (good vs bad, correct ratio, and origin)
- HDL: high density lipoproteins; production in liver; removes excess cholesterol; good to have high number of HDLs
- LDL: low density lipoproteins; hold cholesterol to be released for intercellular use; high LDL is bad bc stores cholesterol in body and liver is not transporting as it’s supposed to; correlates with high cholesterol
organs of digestive system and their function/job
- mouth: chemical and mechanical digestion; breaks up food
- pharynx: back of throat; hallway of food
- esophagus: canal attached to stomach; peristalsis
- stomach: food temporarily stored here; gastric juices secreted; chemical and mechanical digestion; disinfect food
- small intestine: most of chemical digestion; simple sugars and proteins absorbed into inner lining; chemical digestion and absorption
- large intestine: reabsorbs water; solid materials pass through
- rectum: eliminates feces
what causes one to sweat/ shiver? where is this heat promoting center located
- heat promoting center located in hypothalamus;
- vasoconstriction leads to shivering
- vasodilation leads to sweating
accessory glands of digestive system
- salivary glands: release amylase to breakdown starch, saliva to lubricate, and mucinin to glide
- pancreas: secretes exocrine (digestive enzyme) and endocrine (hormone)
- gallbladder: stores bile
- liver: produces bile
job/ role of liver and relationship with gall bladder
-liver produces bile; gallbladder stores it
pathway for digestion (order in which food moves through system)
- food processing begins in mouth
- food is swallowed and moved through pharynx to esophagus
- food is chemically and mechanically digested in stomach
- liver secretes bile
- pancreas secretes digestive enzyme into stomach to break down food
- most enzymatic digestion happens in small intestine
- nutrients are digested as the move through digestive tract
- nerves and hormones regulate digestion
- absorption takes place
negative nitrogen balance
- not brining enough needed nitrogen into body (excretion exceeds ingestion of protein)
- body proteins being broken down for fuel; carb and fat intake is insufficient to meet body energy needs
- atrophy
chief cells vs parietal cells
- parietal: in gastic glands; secrete HCl and intrinsic factor
- chief cells: secrete pepsinogen, when pepsinogen comes in contact with gastric juices it becomes pepsin (main digestive enzyme of stomach); pepsin breaks down protien
- both only work in acidic enviro
pathway for digestion (order in which food moves through system)
- food processing begins in mouth
- food is swallowed and moved through pharynx to esophagus
- food is chemically and mechanically digested in stomach
- liver secretes bile
- pancreas secretes digestive enzyme into stomach to break down food
- most enzymatic digestion happens in small intestine
- nutrients are digested as the move through digestive tract
- nerves and hormones regulate digestion
- absorption takes place
mainly through villi and microvilli of small intestine - large intestine eliminates waste leading to the opening for the elimination of wastes (rectum, anus)
