The Science of Nutrition: The GI tract Flashcards
What is in the food we eat?
Macronutrients Micronutrients Phytonutrients, Myconutrients, Zoonutrients Water Other: Alchohol etc.
Enteric nervous system
A branch of the autonomic nervous system that governs the gastrointestinal tract
Gut microbiome
ecosystem of bacteria that live in the GI tract
Functions of the digestive system
-processes nutrients
-provides a barrier to pathogens
-detoxifies harmful substances
-contains the enteric nervous system
-secretes and processes hormones
-regulates immune system
-It’s innervated by nerves also involved in social
engagement and emotion, giving us important signals
about the world and how we feel.
-home to our microbiome
Where does digestion start?
The brain and is organized by the nervous system
What role does the brain play in digestion?
When the brain receives hunger cues, it stimulates and directs our efforts to find food. The brain also tells the rest of the body to prepare for eating, by stimulating salivation and stomach acid production.
Autonomic nervous system
A branch of the nervous system that regulates digestion and internal organs outside of our conscious control
Sympathetic nervous system
A branch of the autonomic nervious system that controls the flight and fight response
Parasympathetic nervous system
A branch of the autonomic nervous system taht controls the rest, digest and repair function
What effect does the SNS have on digestion?
Tends to shut down digestion and appetite. Our mouth goes dry, we stop wanting food, our GI tract stops moving food through the system, and we may get butterflies in our stomach or experience nausea, vomiting, or diarrhea.
What activates the SNS?
intense activity, stress or stimulation
What effect does teh PNS have on digestion?
tends to regulated digestion and movement through the GI tract, so that things proceed steadily and calmy
What activates the PNS?
Rest and relaxation
What are the 3 levels of the “Eat slowly” exercise
Level one: Eat slowly and put your utensils down between bites
Level two: Eat slowly, without distractions (phone, tv etc)
Level three: Eat slowly, without distractions and with full presence and attention, noticing the taste, texture, and experience of each bite”
What are the benefits of the “Eat slowly” exercise?
- helps clients recognize their physiological hunger and fullness cues
- eat less, but feel more satisfied, because it gives our GI tract time to send satiety signals to the brain.
- Experience their food more fully
- digest their food better
What role does olfaction play in the digestive process?
Olfaction, especially retronasal olfaction is imortant for satiety. It tells our brains that we are getting enough nutrients and it increases our satisfaction with our food.
Retronasal olfaction
Sensing odors from food that’s traveled through the backof our through and to our nasal passages as we chew and swallow
Papillae
Tiny bumps on the tongue that increase the surface area and help move food around the mouth
What does salivae consist out of?
95% water mucus enzymes (amylase, lipase) glycoproteins, antimicrobials
How much saliva do we produce every day?
approx. 1.5 liters
What is the role of saliva in the mouht?
To break down carbohydrates
To keep mucus membranes of the mouth healthy
To moisten the mouth and food
Where in the mouth do we find the saliva glands?
sublingual -under the tongue
submandibular -along the bottom of the jaw
parotid - in our cheeks alon the baks of our jaws
Which gene regulates amylase production
AMY1 gene
What influences food preferences
genetics
Age and neurological development
health and reproduction
cultural background
How can we help clients explore their food preferences
red-yellow-green food chart
- why does the client feel attached to certain foods?
- what do those foods mean to them?
- What are teh stories behind those foods?
Anorexia of aging
Older people wanting to eat less or becoming less interested in food.
What role does genetics play in food preferences?
It determines the amount and type of food taste receptors in the mouth. Some people have more fat taste receptors and so food with fat might taste too rich for them, other people might be “super” tasters making even ordinary food taste bitter.
What could gum disease be an indication of
untreated diabetes
inflamatory disorders, such as Inflamatory bowerl disease
Colon cancer
Potential heart disease
What can cause bad breath
gum disease
cavities
diabetes
Gerd or acid reflux
Why may older people struggle to chew
missalignment of TMJ
dental work
What could teeth erosion be an indication of
Bulimia
What happens when we swallow?
The epiglottis involuntarily closes to stop food from entering our trachea. The uvula also closes off the nasopharynx, preventing food from entering the nose.
What is the esophagus?
muscular tube, lined with a mucous memebrane, that transports food and water from the mouth to the stomach.
peristalsis
A seiries of wavelike muscular contractions that moves a substance through a tube.
What is the role of the LES(lower esophageal sphincter)?
regulates food entering the stomach from esophagus.
prevents food stomach acid and food from splashing upwards into the esophagus.
TMJ
temporomandibular joint. The joint that connects the jaw to the skull.
Bulimia
A type of disordered eating characterized by chronic self-inflicted purging
Bolus
The small rounded mass of chewed food before swallowing
Pharynx
The cone-shaped passageway connecting the oral and nasal cavities to esophagus and larynx
Epiglottis
The cartilage flap in the throat that keeps food from entering the trachea and the lungs
ubula
little danlgy bit that hangs from the uper palated down the back of the throught
nasopharynx
The upper part of the pharynx, connecting with the nasal cavity above the soft palate
Lower esohageal sphincter
Aka the cardiac sphincter, a ring like muscle at the end of teh esophagus which regulates food’s passage into the stomach.
Gastroesophageal reflux disease (GERD)
A digestive malfunction of food and acidic stomach juices splashing back upwards into the esophagus. Caused by the sphincter opening more often that it should, or opening at the wrong times. Diet can make it worse.
Short chain fatty acids
Fatty acids with less than 6 carbon atoms.
What are the symptoms of GERD
burning in the back of the throat heart burn (especially after eating) persistant cough, hoarseness pressure and pain in the chest bloating and burping tooth erosion
What is the stomach’s capacity?
0.25 to 1.7 liters
which nutrients can be absorbed by the stomach lining and enter general circulation
certain drugs water, some vitamins, alcohol, some short chain fattyacids(acetate, butyrate and propionate)
Chyme
the acidic fluid of gastric juices and partly digested food that passes from the stomach to the samll intestine
Pyloric sphincter
The ring like muscle that lies at the end ot the stomach and controls the passage of chyme into the small intestine
Gastric mucosa
The mucous membrane layer of the stomach that secretes gastric juices and mucus.