Nutrition exam 1

macronutrients

the essential nutrients your body needs in large amounts to provide energy, support growth and run daily functions. carbs, proteins and fats

micronutrients

essential vitamins and minerals that your body needs in small amounts to support normal growth development and overall health

essential nutrients

chemical compounds that your body needs to work properly but cannot make on its own or enough so you get them from food. 6 major classes: carbs, proteins, fats, water, vitamins, and minerals

nonessential nutrients

compounds that the human body can make on its own in enough quantities. ex) amino acids, fatty acids

conditionally essential nutrients

a compound that your body normally makes in enough quantity but must get from food during times of illness stress or rapid growth

how many kcal/g does a carbohydrate have?

4 kcal/g

how many kcal/g does a protein have

4 kcal/g

how many kcal/g does a lipid (fat) have?

9 kcal/g

how many kcal.g does alcohol have?

7 kcal/g

energy density

refers to the amount of energy provides per given weight of food

neutral energy balance

caloric intake equals caloric output weight remains stable

positive energy balance

caloric intake is greater than caloric output. the extra energy is stored in body

negative energy balance

caloric intake is less than caloric output. the body uses stored energy to make up the difference

AMDR- the acceptable macronutrient distribution range

ranges of carbs, fat and protein intakes that provide adequate amounts of nutrients

AMDR for proteins

10-35% of total kcal

AMDR for Fat (lipids)

20-35% of total kcal

AMDR for carbohydrates

45-65% of total kcal

TUI Tolerable Upper Intake Level

the highest average amounts of a nutrient that is unlikely to harm most people when the amount is consumed daily

which nutrients provide energy

carbohydrates, lipids, and proteins

nonorganic nutrients

nutrients that do not have carbon minerals and water

enriched nutrients

vitamins and minerals added back to food products after they were lost during the manufacturing or milling process

fortified nutrients

vitamins minerals and micronutrients deliberately added to foods during processing to improve their nutritional quality and prevent deficiencies

organic nutrients

refers to compounds that contain carbon carbohydrates proteins and vitamins

nutrient requirement

smallest amount of a nutrient that maintains a defined level of nutritional health

(EAR) estimated average requirement

amount of nutrient that meets the needs of 50% of healthy people who are in a particular group

physiological marker must be identified

(EER) estimated energy requirement

average daily energy intake that meets the needs of healthy people who are maintaining weight

takes into account physical activity level, height, weight, gender, life stage

dietary guidelines for americans 2025-2030

a food guide that translates the DRIs and evidence based information concerning the effects of certain foods and food components on health into dietary requirements

(RDA) recommended dietary allowances

standards for recommended daily intakes of several nutrients

97-98% of healthy individuals in a group

digestion

the process of breaking fown large molecules into nutrients that the body can use

absorption

the process of nutrient uptake from the GI tract for transport through the circulatory and lymphatic systems

nutrient density

measures the amount of beneficial vitamins minerals and other health promoting compounds in a food relative to its calorie or empty content

food groups

fruits vegetables grains proteins and dairy

absorption location

small intestine (main)

stomach (minor)

large intestine (minor)

digestion locations

mouth

stomach

small intestine

accessory organs of digestive system

assist functioning of GI tract

teeth, tongue, salivary glands, liver, gallbladder and pancreas

components of GI tract

mouth esophagus pancreas liver stomach gallbladder small intestine large intestine rectum and anus

mucosa

intermost layer of GI tract surrounds the lumen and contains cells that secrete mucus

lumen

the hollow space through which food and fluids can pass

sphincters

thickened regions of circular muscle that control the flow of contents at various points in GI tract

help control rates of digestion

salivary glands

structure that produces saliva and secretes the fluid into the oral cavity

lysozome

enzyme in saliva that can destroy some bacteria that are in food or the mouth secreted from salivary glands into the oral cavity

saliva

the watery fluid that contains mucus and a few enzymes

salivary amylase

enzyme in saliva that begins starch digestion

lingual lipase

enzyme secreted into saliva that begins fat digestion

esophagus

transfers bolus into stomach

muscular tube that extends 10 in from the pharynx to the upper portion of the stomach

peristalsis

waves of muscular contractions that help move material through most of the digestive tract

upper esophageal sphincter

section of the pharynx that opens to allow a mass of food to enter the esophagus

lower esophageal sphincter

located at the bottom of the esophagus

controls flow of material into the upper part of the stomach

stomach

a muscular sac that stores and mixes food

gastric glands

located in the stomach and synthesizes and secretes gastric juice

gastric juice

collection of stomach secretions that includes mucus hydrochloric acid intrinsic factor and digestive enzymes

mucin

secreted by mucous

carbohydrate rich substance that forms when combined with water

mucous cell

secrets mucus

protects stomach mucosa from HCl and enzymes

parietal cell

secretes components that from HCl and intrinsic factor

activates pepsinogen, destroys many food borne microbes, facilitates the absorption of vitamin B-12

chief cells

secretes pepsinogen and gastric lipase

digests protein after conversion to pepsin and digests small amounts of fat

G cell

secretes gastrin

stimulates stomach motility and gastric gland activity

intrinsic factor

substance necessary for the absorption of vitamin B-12

gastrin

primarily released from the stomach

secreted in response to food entering the stomach

triggers parietal cells to release HCl and chief cells to release pepsinogen

stimulates stomach and small intestinal motility

zymogen (pepsinogen)

the inactive form of a digestive enzyme stored in cells until use

secretin

primarily released from the small intestine by cells in the mucosa of duodenum and jejunem

secreted in response to acidic chyme entering the duodenum and first part of jejunum

stimulates the release of a bicarbonate rich solution from the liver and pancreas

Cholecystokinin (CCK)

primarily released from the small intestine by cells in the mucosa

secreted in response to fat and breakdown products of proteins (peptides) entering the small intestine

stimulates release of bile from the gallbladder into the small intestine and stimulates the release of pancreatic enzymes decreasing stomach secretion and slows stomach motility

gastric lipase

digests small amounts of fat

lower portion of the stomach

mixing food with gastric juice to form chyme

pyloric sphincter

a circular muscle that regulates the flow of chyme into small intestine

what occurs when food enters the stomach

peristalsis — food mixes with gastric juice and some protein and fat in chyme are broken down

few substances absorbed

small intestine

the primary site for nutrient digestion and absorption

3 sections duodenum (1st) jejunem(2nd) ileum(3rd)

ileocecal sphincter

circular muscle that controls the rate of emptying undigested material into large intestine

liver

processes and stores many nutrients synthesizes cholesterol makes bile

bile

greenish - yellow fluid stored in the gallbladder until it is needed for fat digestion

gallbladder

stores and concentrates bile

pancreas

produces and secretes digestive enzymes and bicarbonate ions to neutraliuze the highly acidic chyme coming in from the stomach

place chemical and mechanical digestion occur

small intestine

pancreatic amylase

source pancreas

digests starch

pancreatic lipase

source- pancreas

digests fat

tyrpsin

chymotrypsin

source pancreas

partially digests proteins

carboxypeptidase

source pancreas

breaks down certain partially digested proteins

nuclease

source pancreas

digests DNA and RNA into nucleotides

peptidase

source small intestine

breaks down certain partially digested proteins

sucrase, maltase, and lactase

source small intestine

breaks down certain sugars into simpler sugars

intestinal lipase

source small intestine

digests fat

villi

tiny fingerlike projections of the small intestinal mucosa that are involved in nutrient digestion

enterocytes

outer layer of absorptive cells on each villus

microvilli

part of the enterocyte exposed to chyme

tiny hairlike projections that form the brush border

core of the villus

arteriole- tiny arteriole

blood capillary network

venule (a vein)

lacteal- vessel of lymphatic system

nutrients from chyme transportation

absorbed into either the capillary network or the lacteal

water soluble and certain fat transportation

absorbed into the capillary network and travel to the liver via the heptic portal vein

parts of the large intestine

cecum, descending colon, transverse colon, sigmoid colon, rectum, anus

functions of large intestine

little absorption

water is absorbed forming semisolid feces

internal anal sphincter

circular muscle that allows feces to be moved from the sigmoid colon into the rectum

defecation

expulsion of fecal matter from the body occurng through the external anal sphincter

probiotics

live beneficial microbes that promote good health for their human hosts that contain such microbes

prebiotics

substances in food that promote the growth of beneficial microbes

flow of food through the gi tract

mouth → esophagus → stomach → small intestine→ large intestine → rectum →anus