Lecture 3: Anatomy and Physiology of the Digestive System Part 1, and types of study designs

Question 1

autonomic nervous system

Answer 1

• sympathetic and parasympathetic responses
• responsible for involuntary control
• cardiovascular, respiratory, urinary, digestive, reproductive functions
• adjusts electrolytes, nutrients and gases in body fluids

Question 2

3 phases of digestion

Answer 2

cephalic, gastric and intestinal

Question 3

How does autonomic nervous system work?

Answer 3

signals from the brain are carries to ganglia, which are then sent to peripheral target organs for either parasympathetic or sympathetic response

Question 4

P or S?: heightened alertness

Answer 4

sympathetic response

Question 5

P or S?: increased metabolic rate

Answer 5

sympathetic response

Question 6

P or S?: decreased digestive and urinary functions

Answer 6

sympathetic response

Question 7

P or S?: activation of energy reserves

Answer 7

sympathetic response

Question 8

P or S?: increased respiration (rate and dilation of respiratory pathways)

Answer 8

sympathetic response

Question 9

P or S?: increased heart rate and blood pressure

Answer 9

sympathetic response

Question 10

P or S?: activation of sweat glands

Answer 10

sympathetic response

Question 11

P or S?: decreased metabolic rate

Answer 11

parasympathetic response

Question 12

P or S?: decreased heart rate and blood pressure

Answer 12

parasympathetic response

Question 13

P or S?: increased secretion by salivary and digestive glands

Answer 13

parasympathetic response

Question 14

P or S?: increased motility in the digestive tract

Answer 14

parasympathetic response

Question 15

P or S?: increased blood flow in the digestive tract

Answer 15

parasympathetic response

Question 16

P or S?: norepinephrine

Answer 16

sympathetic

Question 17

P or S?: acetylcholine

Answer 17

parasympathetic

Question 18

P or S?: greater divergence of reach to organs

Answer 18

sympathetic

Question 19

autonomic tone

Answer 19

the background level of activity regulating the body (ie maintaining heart rate)
-parasympathetic dominates in resting conditions, sympathetic kicks into action in an emergency

Question 20

accessory organs

Answer 20

• digestive organs through which food is not moved, like it is moved through the digestive tract.
• salivary glands, liver, pancreas, gall bladder

Question 21

cephalic phase

Answer 21

-starts with anticipation of food and ends with swallowing

Question 22

gastric phase

Answer 22

-the time during which food is in the stomach

Question 23

intestinal phase

Answer 23

• starts when chyme enters the duodenum
• controls the rate of gastric emptying
• coordinates activities of intestinal tract, pancreas, liver and gallbladder

Question 24

saliva

Answer 24

• made of water, glycoprotein (for viscosity), amylase, lipase
• essential for taste perception, antibacterial
• production lowers during sleep

Question 25

amylase

Answer 25

turns starches into simple sugars

Question 26

lipase

Answer 26

turns triglycerides into fatty acids and glycerol

Question 27

dental plaque

Answer 27

a sticky, colorless biofilm that forms when bacteria in the mouth mix with sugars or starches. -bacteria break down the starches, releasing acid, which releases calcium from the teeth causing tooth decay

Question 28

cross-sectional study

Answer 28

- measures exposure/intervention and health outcome in a population at one point in time - strength of association between exposure and health outcome measured using Odds Ratio (OR) - if OR=1, then no association. if OR>1, increased odds of association. if OR<1, reduced odds

Question 29

prospective longitudinal cohort study

Answer 29

-measures exposure and outcome in a population over a period of time

Question 30

randomized controlled trial

Answer 30

- experimental study wherein the exposure in controlled and the health outcome is assessed - participants are randomly assigned to a treatment or control group

Question 31

bolus

Answer 31

chewed food mixed with saliva

Question 32

after the bolus is compressed against the hard palate, where does it go?

Answer 32

the oropharynx (elevation of soft palate seals off nasopharynx so food doesn't go into nose)

Question 33

what is the function of the epiglottis?

Answer 33

it folds down when the bolus comes to town and directs the bolus away from the trachea (so you don't breathe in your food)

Question 34

what is swallowing?

Answer 34

-contraction of pharyngeal muscles to move bolus down out of oropharynx and into esophagus

Question 35

peristalsis

Answer 35

- the involuntary constriction and relaxation of GI tract muscles, makes wave-like movements - pushes bolus from esophagus down into stomach (through the lower esophageal sphincter)

Question 36

achalasia

Answer 36

problem when lower esophageal sphincter doesn't open up, and food can't drop from esophagus into stomach

Question 37

gastroesophageal reflux disease

Answer 37

(acid reflux). problem when lower esophageal sphincter doesn't close properly, and gastric juices and hydrochloric acid and stuff irritate the esophagus

Question 38

describe the movement of food from mouth to stomach.

Answer 38

mastication with teeth and saliva. cephalic phase. this mastication creates a bolus. the bolus is pressed up against the hard palate by the tongue. it then moves to the oropharynx, and elevation of soft palate blocks off the nasopharynx. meanwhile the epiglottis folds down over the trachea to make sure you don't choke. then pharyngeal contractions move bolus from the oropharynx, through the Upper Esophageal Sphincter, into the esophagus. peristaltic waves in the esophagus move the bolus down, though the lower esophageal sphincter, and drops the bolus into the stomach.