NUSCTX 103 Exam 1 - GI & CHO Questions and Answers With Verified Solutions
2025
component of food deemed to be essential for life and physiological functions.
- Energy
- certain fatty acids and amino acids
- vitamins
- minerals - ✔✔essential nutrients
physiological dysfunction, impaired growth, impaired reproduction and/or organismal demise - ✔✔diets
inadequate in or devoid of essential nutrients result in...
All of the chemical reactions that occur within an organism. "the chemistry of life" - ✔✔metabolism
some influence physiology & health
some may be inert, toxins - ✔✔non-essential nutrients
2 high energy phosphate bonds that can be hydrolyzed, releasing energy to fuel chemical reactions and
perform work - ✔✔ATP contains...
○ Lipids
○ Proteins
○ Nucleic Acids
○ Carbohydrates
We cannot synthesize these macromolecules from nothing. food/nutrition provides the raw materials
then our cells/organs can biotransform compounds found in foods to other molecules needed by the
cell/body
,■ e.g. proteins that are in animal and plant foods are broken down to provide theraw amino acids,
nitrogen, and carbon skeletons needed to maintain the bodiespool of amino acids for protein synthesis
and non-protein functions - ✔✔macromolecules
synthesize at all or cannot synthesize enough - ✔✔our body cannot ...... certain essential fatty acids,
amino acids
for use as cofactors and substrates in metabolic reactions, act as important signaling molecules, and
influence cellular homeostasis through several mechanisms - ✔✔why does the body require additional
accessory factors (vitamins, minerals)?
compounds that we consume that can be absorbed and metabolized, exert influence on physiology, be
unabsorbed or potentially interact with gut microbiota - ✔✔Foods contain 1000s of...
- needed by the plant or animal cell
- most stable/palatable added during product formulation
● Our digestive tracts have to be able to break down the food components into their minimally
absorbable forms to be absorbed and used by our cells - ✔✔The nutrients within food are rarely in an
immediately absorbable form. They are in the form...
difficulty swallowing - ✔✔dysphagia
physical & chemical -> reduce size of molecules& repackage to facilitate absorption - ✔✔Digestion
movement from GI tract to blood or lymph - ✔✔absorption
movement into lumen of GI tract - ✔✔secretion
muscles mix & move contents via peristalsis - ✔✔motility
,1. Mucosa
2. Submucosa
3. Muscularis
4. Adventitia (esophagus) or Serosa (stomach,intestine) Inner (facing lumen) to outer - ✔✔GI tract layers
Goal = Food bolus
Functions
● Chewing (mastication)
● Initiate digestion
● Swallowing - ✔✔oral cavity
Goal = Food bolus
Functions
● Chewing
● Initiate digestion
● Swallowing
The interior of the mouth is covered in a mucous membrane that contains many minor salivary glands
that produce ~7% of saliva - ✔✔salivary glands
● Produce around 500mL/day
○ Water in saliva moistens food
○ Glycoproteins (mucin) in saliva lubricate and prevent abrasion
○ Salivary amylase initiates digestion of starch
○ Antimicrobial agents reduce risk of infection
○ Acts as a pH buffer (protein, phosphate and bicarbonate buffering systems) - ✔✔saliva
Dry mouth from inadequate saliva production
, Causes discomfort, can dramatically impact swallowing capacity
Common causes:
■ Numerous medications
■ Autoimmune diseases (e.g. Sjogren's)
■ Radiation exposure
■ Nerve damage - ✔✔xerostomia
smooth muscle cells rhythmically contract to generate peristaltic waves
○ contraction is controlled by input from mechanical, chemical and electrical (entericnervous system)
stimuli - ✔✔peristalsis
congenital absence of part of the esophagus. Food cannot pass from the baby's mouth to the stomach
● Continuity of the esophagus and its connection to the stomach is essential to facilitate digestion
○ esophageal function can be disrupted in structural (e.g.hernias, diverticula, tumors) as well as
congenital disorders
● various types of EA that lead to the esophagus not reaching the stomach, resulting from fusion failures
between the proximal and distal esophagus in development
● can be diagnosed in the intrauterine period or shortly after birth: excess salivation, gagging, vomiting,
inability to swallow
● Can be corrected surgically in the first days of life - ✔✔esophageal atresia
Form chyme (food + secretions)
○ accept bolus of food from lower esophageal sphincter
○ accommodate (relax gastric wall to prevent excessivepressure)
○ sense the presence of food with mechanoreceptors (stretching)
○ mix - facilitated by weak peristaltic waves in the upper stomach stomach, mucus secretion
2025
component of food deemed to be essential for life and physiological functions.
- Energy
- certain fatty acids and amino acids
- vitamins
- minerals - ✔✔essential nutrients
physiological dysfunction, impaired growth, impaired reproduction and/or organismal demise - ✔✔diets
inadequate in or devoid of essential nutrients result in...
All of the chemical reactions that occur within an organism. "the chemistry of life" - ✔✔metabolism
some influence physiology & health
some may be inert, toxins - ✔✔non-essential nutrients
2 high energy phosphate bonds that can be hydrolyzed, releasing energy to fuel chemical reactions and
perform work - ✔✔ATP contains...
○ Lipids
○ Proteins
○ Nucleic Acids
○ Carbohydrates
We cannot synthesize these macromolecules from nothing. food/nutrition provides the raw materials
then our cells/organs can biotransform compounds found in foods to other molecules needed by the
cell/body
,■ e.g. proteins that are in animal and plant foods are broken down to provide theraw amino acids,
nitrogen, and carbon skeletons needed to maintain the bodiespool of amino acids for protein synthesis
and non-protein functions - ✔✔macromolecules
synthesize at all or cannot synthesize enough - ✔✔our body cannot ...... certain essential fatty acids,
amino acids
for use as cofactors and substrates in metabolic reactions, act as important signaling molecules, and
influence cellular homeostasis through several mechanisms - ✔✔why does the body require additional
accessory factors (vitamins, minerals)?
compounds that we consume that can be absorbed and metabolized, exert influence on physiology, be
unabsorbed or potentially interact with gut microbiota - ✔✔Foods contain 1000s of...
- needed by the plant or animal cell
- most stable/palatable added during product formulation
● Our digestive tracts have to be able to break down the food components into their minimally
absorbable forms to be absorbed and used by our cells - ✔✔The nutrients within food are rarely in an
immediately absorbable form. They are in the form...
difficulty swallowing - ✔✔dysphagia
physical & chemical -> reduce size of molecules& repackage to facilitate absorption - ✔✔Digestion
movement from GI tract to blood or lymph - ✔✔absorption
movement into lumen of GI tract - ✔✔secretion
muscles mix & move contents via peristalsis - ✔✔motility
,1. Mucosa
2. Submucosa
3. Muscularis
4. Adventitia (esophagus) or Serosa (stomach,intestine) Inner (facing lumen) to outer - ✔✔GI tract layers
Goal = Food bolus
Functions
● Chewing (mastication)
● Initiate digestion
● Swallowing - ✔✔oral cavity
Goal = Food bolus
Functions
● Chewing
● Initiate digestion
● Swallowing
The interior of the mouth is covered in a mucous membrane that contains many minor salivary glands
that produce ~7% of saliva - ✔✔salivary glands
● Produce around 500mL/day
○ Water in saliva moistens food
○ Glycoproteins (mucin) in saliva lubricate and prevent abrasion
○ Salivary amylase initiates digestion of starch
○ Antimicrobial agents reduce risk of infection
○ Acts as a pH buffer (protein, phosphate and bicarbonate buffering systems) - ✔✔saliva
Dry mouth from inadequate saliva production
, Causes discomfort, can dramatically impact swallowing capacity
Common causes:
■ Numerous medications
■ Autoimmune diseases (e.g. Sjogren's)
■ Radiation exposure
■ Nerve damage - ✔✔xerostomia
smooth muscle cells rhythmically contract to generate peristaltic waves
○ contraction is controlled by input from mechanical, chemical and electrical (entericnervous system)
stimuli - ✔✔peristalsis
congenital absence of part of the esophagus. Food cannot pass from the baby's mouth to the stomach
● Continuity of the esophagus and its connection to the stomach is essential to facilitate digestion
○ esophageal function can be disrupted in structural (e.g.hernias, diverticula, tumors) as well as
congenital disorders
● various types of EA that lead to the esophagus not reaching the stomach, resulting from fusion failures
between the proximal and distal esophagus in development
● can be diagnosed in the intrauterine period or shortly after birth: excess salivation, gagging, vomiting,
inability to swallow
● Can be corrected surgically in the first days of life - ✔✔esophageal atresia
Form chyme (food + secretions)
○ accept bolus of food from lower esophageal sphincter
○ accommodate (relax gastric wall to prevent excessivepressure)
○ sense the presence of food with mechanoreceptors (stretching)
○ mix - facilitated by weak peristaltic waves in the upper stomach stomach, mucus secretion
