Nutrition Chapter 5 Digestion, Absorption, & Metabolism

treat galactosemia

A strict galactose-free diet

Glycogen storage disease ( GSD) (genetic defect)

Absence of enzymes required for synthesis or breakdown of gylcogen

Macronutrients and micronutrients

Absorbs through the lymph or blood

What allows for the distribution, use, and storage of nutrients throughout the body ?

Absorption,transport, and metabolism

With proper treatment of PKU

Affected children grow normally and healthy lives

Amount of nutrients absorbed depends on bioavailability?

Amount of nutrient present, competition between nutrients for absorption sites, form in which nutrient is present

The lower part of the stomach is called

Antrum

Phenylketonuria (PKU) (genetic defect)

Are enzymes response for metabolizing essential amino acid phenylalanine is missing

When gylcogen reserves are full, excess energy is stored where ?

As fat via lipogenesis in adipose tissue (fat)

Von ebners glands are located where ?

At the back of the tongue and it secretes lingual lipase

Treatment of GSD is ?

Avoidance of hypoglycemia

Catabolism

Breaking down of larger substances into smaller units

Anabolism

Building up of larger substances from smaller units

If galactosemia is left untreated

Can cause brain and liver damage

pancreatic enzymes

Carbohydrates, proteins, and fats

water and electrolytes

Carey and circulate the products of digestion through the tract and into the tissues

active transport

Carriers partner moves particles across a membrane

lymphatic system

Carries non-water soluble fatty materials, lymph vessels in villi carry fat molecules, route to larger lymph vessels, eventually to bloodstream through thoracic duct

dietary fiber

Contributes bulk to help form feces

What 3 functions does the intramural nerve plexus have ?

Controls muscle tone in wall, regulate rate and intensity of contractions, and coordinate various movements .

disaccharidases

Converts disaccharides into monosaccharides

pancreatic lipase

Converts fat to glycerine and fatty acids

pancreatic amylase

Converts starch to maltose and sucrose

Lactose tolerance

Deficiency of any of the disaccharides in small intestine

All lactose sources must be eliminated from what ?

Diet

4 main steps in preparing food for bodies use:

Digestion, absorption, transport, and metabolism

Bile

Emulsifies fat into smaller pieces to assist fat enzymes

Galactosemia screening and treatment can do what ?

Enable normal life

metabolic processes

Ensure that the body has energy in the form of adesosine triphosphate (ATP)

What does muscle tone (tonic contraction) do ?

Ensures the continuous passage of the food mass and valve control alone the way

Galactosemia (genetic defect)

Enzyme responsible for converting galactose to glucose is missing

Gylcogen storage disease (GSD) depends on what ?

Enzymes missing and tissue affected

Surface villi motions stir and mix chyme which does what ?

Exposes nutrients for absorption

The upper part of the stomach is called

Fundus

Food travels through what system until it is absorbed and delivered to cells or excreted ?

GI System

What at the stomach entrance relaxes, allowing food to enter, then constricts to relation to retain food ?

Gastroesophageal sphincter

Mechanical digestion is also called ?

Gastrointestinal Motility

Chemical Digestion is also called

Gastrointestinal Secretions

They body prefers to use what as its primary source of energy ?

Glucose

Glucose is converted into what ?

Glycogen via glycogenesis, stored in liver or muscles

There are 5 types of GI secretions

Hydrochloric acid and buffer ions, enzymes, mucus, water and electrolytes, and bile

Three types of acid secretions :

Hydrochloric acid, Mucus, & Enzymes

Allergies

Inappropriate immune response , not necessarily a problem with the digestive system

Symptoms of lactose tolerance

Insufficient lactase to break down milk and abdominal cramping and diarrhea . Products containing lactose must be avoided

Metabolism

Is all of the chemical changes in the cell that produce materials for energy, tissue building, and metabolic controls

Peristalsis

Is muscle tone ( tonic contraction) & period muscle contraction

Transport

Is the movement of nutrients through the circulatory system from one area of the body to another

Absorption

Is the taking in of nutrients into cells that line the GI tract

What has to happen for food to become ready to use ?

It has to be changed into simpler substances for absorption and even simpler for constituents that cells can use to sustain life

Protein can be an energy source but :

It is relatively inefficient and results in nitrogen waste

By the time the food mass reaches the lower portion of the stomach what is it ?

It's a semiliquid acid/food mix called chyme

What does the stomach muscles do ?

Knead, mix, store, and propel food mass forward

Pinocytosis

Larger materials are engulfed by a cell

During mechanical digestion what rolls food into a spiral motion, mixing it and exposing it for absorption?

Longitudinal rotation

mucus

Lubricates and protects the GI tract tissues and helps mix the food mass

During metabolism

Macronutrients have been broken down, absorbed into bloodstream or lymphatic system, next nutrients can be converted into energy or stored

At mechanical digestion what begins to break down the food ?

Mastication ( biting & chewing )

What changes must food undergo to be delivered to cell ?

Mechanical and chemical

What two actions makes up the digestive system ?

Mechanical and chemical digestion

Side affects of PKU

Mental retardation and CNS damage

Three absorbing structures

Mucosal folds, villi, & microvilli ( these three structures make the inner intestinal surface area 600 times greater the the outer surface of the intestinal wall

The mucus protects what lining

Mucosal lining

Excess protein/amino acids converted to glucose via gluconeogenesis or converted to fat for storage but they are NOT stored as what ?

Muscle

What are the two general types of movement in the GI wall ?

Muscle tone (tonic contraction) & periodic muscle contraction and relaxation

intramural nerve plexus

Network of nerves in the walls of the intestine that control muscle action and secretions for digestion and absorption. ( extends from the esophagus to the anus)

Intolerance or Allergies aren't what ?

Not genetically inborn errors of metabolism

What does not come ready to use and are packed in foods in a variety of forms ?

Nutrients

simple diffusion

Particles move outward in all directions toward ares of lesser contraction

What types of movements stir chyme ?

Pendulum movements

Enzymes

Pepsinogen is secreted by stomach cells and is activated by HCI to become pepsin. A protein splitting enzyme

What waves pushes food forward during mechanical digestion ?

Peristaltic waves

Three examples of genetic defects are:

Phenylalanine (PKU), galactosemia, and glycogen storage disease

Muscles and nerves work together to do what ?

Produce constant motility ( movement)

Hydrochloric acid and buffer ions

Produces the correct pH necessary for enzyme activity

Which valve slowly releases chyme into the first section of the small intestine ( duodenum)

Pyloric valve

Carboxypeptidase

Removes end amino acids from peptide chains

Salivary glands secrete saliva containing what ?

Salivary amylase or ptyalin

What glands also secrete a mucous material to lubricate and bind food particles, facilitating the swallowing of the food bolus ?

Salivary glands

What from the mucous glands in the esophagus help move food toward the stomach ?

Secretions

mucus

Secretions protect the stomach lining from erosive effect of the acid and also bind and mix food mass and help move it along

What rings chop food mass into lumps ?

Segmentation

Enzymes

Specific digestive proteins for breaking down nutrients

The food enters the upper part of the stomach (fundus) under what control ?

Sphincter control

Trypsin and chymotrypsin

Split large protein molecules into small peptide fragments and eventually into small amino acids ( protein)

Energy that is not need at present is

Stored

Special organ structures and functions accomplish these task through the successive parts of what system ?

The GI System

hydrochloric acid

The hormone gastrin stimulates parietal cells in the stomach lining to secrete acid

Where does mechanical digestion begins ?

The mouth

Digestion

The process by which food is broken down in the GI tract to release nutrients in forms that the body can absorb

Muscles at what base facilitates the swallowing process ?

The tongue

What are periodic muscle contraction and relaxation

They are the rhythmic waves that mix the food mass and movie it forward

facilitate diffusion

Uses a protein channel for carrier-assisted movement of larger particles

Vascular system are :

Veins and arteries, they carry water soluble nutrients, oxygen, other vital substances, transport waste, portal circulation (intestines to liver) first carry nutrients to liver for cell enzymes work

What nutrient does not require digestion and it easily absorbs into the general circulation?

Water

The large intestines main process is to absorb what ?

Water. Small amounts of it remains for the feces

Mitochondria

Where metabolism takes place

What kinds of food must be broken down into smaller substances for absorption and metabolism to meet the body's needs ?

Whole food

metabolism of glucose

Yields less energy than metabolism of fat, but glucose is the body's primary source of energy

Micronutrients are

carbs, protein, fats, water

Two forms of metabolism

catabolism and anabolism

What is chemical and mechanical digestion ?

its when food is broken down into smaller substances and the nutrients are then avaible for biological use