Examination 3 Flashcards
What are the six muscular sphincters in the digestive tract?
Upper esophageal sphincter
Lower esophageal sphincter
Pyloric valve
Ileocecal sphincter
Internal anal sphincter
External anal sphincter
Which of the sphincters in the digestive tract are controlled by the somatic nervous system?
Upper esophageal sphincter
External anal sphincter
Which of the sphincters in the digestive tract are controlled by the autonomic nervous system?
Lower esophageal sphincter
Pyloric valve
Ileocecal sphincter
Internal anal sphincter
What is the “second brain”
The enteric nervous system.
What is the somatic nervous system?
Bodily processes that are consciously and willingly controlled by us (chewing and swallowing food).
What are the five basic processes of the digestive system?
Motility
Secretion
Digestion
Absorption
Excretion
What is the autonomic nervous system?
Bodily processes that are not consciously and willingly controlled by us (food moving from the stomach to the small intestine).
Approximately how long is the GI tube?
28 feet
What is the luminal surface area range?
200-400 square metres
How long does digestion take? How much of this time is spent just in the stomach and small intestine?
Digestion takes between 30-80 hours. Of which 5-8 are spent in the stomach and small intestine
What causes diarrhea and vomiting?
When the digestive system senses noxious substances, it seeks to expel them
What is the gut microbiome
Bacteria, archaea and other small eukaryotes. They help protect against pathogens and can interact with the digestive system. It is individually unique from person to person
Function of the mouth in digestion
Start of digestion. Teeth break down food, tongue tastes and positions the food to swallow
Function of the pharynx in digestion
Passageway for food
Aids in swallowing food
Esophagus
Long muscular tube
Brings food from the pharynx to the stomach
Stomach
J-shaped, muscular organ
Secretes gastric juices (HCl and pepsin) and mixes it with food
Stores food
Beginning of protein digestion
Small intestine
Long, muscular tube
Mixes food with bile and enzymes from pancreas and intestines
Digests most nutrients
Absorbs most nutrients and water
Colon
Part of large intestine
Muscular tube
Absorbs water and some nutrients
Stores waste
Cecum
Part of large intestine
Blind pouch between small and large intestine
Rectum
Part of large intestine
Passageway for feces
Stretching of wall stimulates defecation
Anal canal
Part of large intestine
regulates defecation
Anus
Opening at the end of system
Expels feces
Salivary glands
3 pairs of glands
Secrete saliva to help moisten food
Amylase in saliva helps begin starch digestion
Liver
Secretes bile to emulsify fats
Helps to process and store certain nutrients
Gallbladder
Small sac
Stores bile
Releases bile into small intestine
Pancreas
Gland behind stomach
Secretes enzymes to digest major nutrients
Secretes buffers to neutralize HCL
Enzymes secreted into small intestine
Abdominal breathing
Breathing where the abdominal muscles are engaged to fill lungs to maximum capacity
Thoracic breathing
Breathing where the diaphragm and intercostal muscles are engaged to fill lungs. Not max capacity
Peristalsis
Contraction of muscular tube to move contents along it
One way movement
Used in esophagus, stomach and large intestine
Segmentation
Contraction along muscular tube to move or mix contents
Allows movement in both directions
Used by small intestine, stomach and large intestine
Sphincters and valves
Aids in motility and helps prevent backflow
What are four diseases that affect GI motility
GERD - Gastroesophageal reflux disease
Gastroparesis - affects Pyloric valve
SBBOS - Small bowel bacterial overgrowth syndrome - affects
Ileocecal valve
Chronic constipation
Lumen
Single-celled layer of tissue along the GI tract that separates the inside of the GI tract from the outside of the GI tract.
What glands secrete stuff into lumen? What is it they secrete?
Salivary glands - saliva and amylase
Gastric glands - Acid
Exocrine Pancreas - Pancreatic juice
Liver - Bile
What cells in the epithelium secrete stuff into lumen? What do they secrete?
Goblet cells - Mucus
Paneth cells - Defensins
Specialized epithelial cells - Specialized IgA
Should we drink 8 cups a day, or whenever thirsty?
Drinking when thirsty is better because your body is telling you you need water. It is accurate but trying to get about 15% more water would be the most ideal there.
How much blood plasma in the body?
about 2500mL
Where is most water absorbed?
Small intestine
Where is water lost?
Excreted in feces, in urine and as sweat and evaporative water
What are four diseases in secretion?
Cystic fibrosis
Inflammatory and secretory diarrhea
Anchlorhydria - Low acid
Xerostomia - dry mouth
Homeostatic hunger
Hunger driven by need