HNF150 - Week 3 (topic 2)

what are  the 2 systems that transport nutrients and wastes in the body?

the circulatory system (blood) + the lymphatic system (lymph)

how is hunger regulated in the brain?

hypothalamus + pituitary gland control food intake using physiological and behavioral signals

Hormones:

chemical messengers, released into the blood by glands (regulate conditions in the body)

Glands:

organs that monitor a condition and produce one or more hormones to regulate that condition

Identify the 3 organs involved in storage of energy

liver (stores carbs) + muscles (store carbs) + fat cells (adipose tissues - store lipids)

what tissue stores fat in the body?

adipose tissue

Identify the 4 organs involved in excretion:

lungs, liver, kidneys, skin

general processes involved in excretion of wastes - lungs:

release carbon dioxide

general processes involved in excretion of waste - liver:

filters blood + sends waste to SI through bile duct to be excreted as feces, or to kidneys to be excreted as urine

general processes involved in excretion of waste - kidneys:

remove toxins from the body + need good supply of water, strong heart/cardiovascular system + sufficient energy + adequate nutrition

general processes involved in excretion of waste - skin:

maintains body temp through excretion of water and salts

Recognize the fight- or-flight reaction or stress response and the body’s response to stress by the: 1) nerves, 2) hormonal system,3) metabolism, 4)digestive system, 5) liver, and 6) fat cells.

nerves (release neurotransmitters); glands (release epinephrine/norepinephrine); metabolism (speeds up); digestive system (shuts down); liver (releases glucose); fat cells (release fat)

3 functions of the immune system:

barrier defense (skin, urine, gastric juice, saliva - part of innate immunity) + innate immunity (non-specific immunity/natural immunity) + adaptive immunity (acquired immunity/antigen-specific immunity)

relationship between immunity + nutrition

good nutrition supports the immune system and helps the body resist threats and prevent immune related diseases

difference between acute and chronic inflammation

inflammation only for a short period of time; inflammation you have at all times

List the order of the components of the digestive tract and the main digestive actions taking place in each.

Mouth (chewing, swallowing, saliva begins starch digestion) → esophagus (peristalsis transports food to stomach) → stomach (churning/mixing - food becomes chyme; HCI and enzymes digest food) → SI (peristalsis/segmentation; major site of chemical digestion + nutrient absorption) → LI (absorbs water, minerals, fiber fragments; bacteria ferment fiber; forms feces) → rectum/anus (stores/excretes feces)

Mechanical digestion:

Physically breaks food into smaller pieces

mechanical digestion process

mouth (chewing); stomach (churning/mixing); SI (peristalsis/segmentation); large intestine (peristalsis and mass movement)

Chemical digestion:

Uses enzymes and secretions to break down nutrients.

chemical digestion - process

mouth (saliva begins carbohydrate digestion); stomach (HCl and enzymes digest primarily protein); si (enzymes break down carbohydrates, proteins, and fats)

secretions of digestive system - secretions:

saliva, mucus, enzymes (amylases, lipases, proteases), hydrochloric acid, bile, bicarbonate, hormones

basics of digestion and absorption for carbohydrates

broken into simple sugars → absorbed by small intestinal cells → blood → liver

basics of digestion and absorption for protein

broken into smaller units by enzymes → absorbed by small intestinal cells → blood → liver

basics of digestion and absorption - fat

broken into smaller units → bile emulsifies → absorbed; small fats and some vitamins go through lymph → blood/liver

basics of digestion and absorption for water

mostly reabsorbed in the digestive tract, especially the large intestine

secretion - saliva, where it’s made?

mouth

secretion - mucus, where it’s made?

mouth, stomach, SI, and LI

secretion - enzymes (amylases, lipases, proteases), where it’s made?

mouth, stomach, SI, pancreas

secretion - hydrochloric acid, where it’s made?

stomach

secretion - bile, where it’s made?

liver (stored in gallbladder)

secretion - bicarbonate, where it’s made?

pancreas, SI

secretion - hormones, where it’s made?

stomach, SI, pancreas

secretion - mucus, role?

protects lining of the GI tract, lubrication

secretion - saliva, role?

begins with starch digestion, lubrication, aids with swallowing

secretion - enzymes (amylases, lipases, proteases), role?

break down carbs, fats, and proteins so body can absorb them

secretion - hydrochloric acid, role?

unwinds protein chains so enzymes can act, kills microorganisms, stops carb digestion

secretion - bile, role?

emulsifies fat, necessary for fat digestion

secretion - bicarbonate, role?

neutralizes stomach acid in SI

secretion - hormones, role?

regulates digestion + absorption

how are microbiome, prebiotic, probiotics related to eachother?

prebiotics feed beneficial bacteria; probiotics are the living microbes; together they affect the gut microbiome

prebiotics come ____ probiotics

before

prebiotics are the food for ____ which are the bacteria

probiotics

examples of prebiotics

fiber, inulin, oligofructose, nondigestible carbs

probiotics - example

yogurt, fermented foods (kimchi, sauerkraut, kombucha, apple cider vinegar), human milk

How does food affect your gut?

feeds healthy bacteria (dietary fiber/resistant starches from whole plant foods) + support diversity (eating variety of plant foods) + lower diversity processed foods and diets low in whole plant carbohydrates/fiber)

Which foods feed the “healthy” bacteria?

fiber

Which foods lower the diversity of the “healthy” bacteria?

ultra-processed foods (or foods low in fiber)

What are the food preservation and health benefits of fermentation?

preserves food without refrigeration + increases nutrient bioavailability, supports digestive health, and protects food from harmful bacteria + enhances flavor

constipation - causes

low fiber, ignoring urges, slowed peristalsis, stress, some antacids/calcium/iron supplements

constipation - treatments

increase whole plant foods/fiber and water

Diverticulosis/Diverticulitis - causes

low whole plant food/fiber diet

Diverticulosis/Diverticulitis - treatment

high-fiber diet; medical treatment if severe

diarrhea - causes

intestinal infection, food intolerances, medications, poorly absorbed substances

diarrhea - treatments

revent dehydration with fluids, electrolytes, and glucose

heartburn/GERD - causes

acid reflux; GERD when it occurs more than 2× per week

heartburn/GERD - treatment

smaller meals, avoid offending foods/fatty meals, don't lie down after eating, stop smoking, limit alcohol

IBS - causes

unknown (stress and diet may play a role)

IBS - treatment

work with a doctor/dietitian to identify problem foods

Ulcers - treatment

avoid foods causing discomfort, relaxation, antibiotics if caused by bacteria

ulcers - causes

Helicobacter pylori or heavy aspirin/ibuprofen use

ulcerative colitis - cause

over-active immune/inflammatory response; genetic link and possible diet link (affects LI)

ulcerative colitis - treatment

doctor/dietician and medical treatment

crohn’s disease - cause

over-active immune/inflammatory response; genetic link and possible diet link (affects entire GI tract, usually last part of the colon)

crohn’s disease - treatment

doctor/dietitian, immune-suppressive drugs, antibiotics, and sometimes surgery

reasons green leafy vegetables are viewed as “superstars”

high amounts of vitamins, minerals, antioxidants + low calorie count

green leafy vegetable - examples

spinach, kale, arugula, bok choy, cabbage, collard greens

circulatory system

transports energy, oxygen, nutrients and waste through the blood

circulatory system - example

blood carries glucose to cells

lympathic system

transports lymph and helps move nutrients and wastes

lympathic system - example

lymph carries absorbed small fats and some vitamins

hormonal system

uses hormones released by glands to regulate conditions in the body

hormonal system - example

insulin regulates blood sugar

nervous sytem - example

nerves help control food intake

nervous sytem

controls body functions using nerve signals and neurotransmitters

immune system

controls body functions using nerve signals and neurotransmitters

immune system - example

immune cells respond to an antigen

digestive system

breaks down and absorbs food

digestive system - example

the small intestine digests and absorbs nutrients

excretory system - example

kidneys remove toxins through urine

excretory system

removes waste materials from the body

storage systems

organs/tissues that store energy for the body

storage systems - example

liver stores carbohydrates; fat cells store lipids

chewing

crushing and grinding food with the teeth

chewing - example

chewing bread into smaller pieces

peristalsis

one-way, rhythmic movement that moves food through the digestive tract

peristalsis - example

moves food through the esophagus.

segmentation

two-way mixing movement in the digestive tract

mass movement

short-duration movement in the LI (occurring 3-4 times/day)

mass movement - example

moving feces through the colon

stomach muscles - example

mix food and liquid into chyme

stomach muscles

3 crisscrossed muscle layers that create churning and mixing motions

sphincters/valves

control the flow of chyme between parts of the digestive tract

sphincters/valves - example

the pyloric sphincter releases chyme into the SI

cell - example

a small intestinal cell absorbs nutrients

cell

smallest unit of life

tissue

group of cells that work together

tissue - example

muscle tissue

organ - example

the stomach

organ

body structure made of tissues that performs a function