Lecture 25 Unit 4

Question 1

what is the function of the mouth

Answer 1

mechanical and chemical breakdown, deglutition

Question 2

what is the function of the pharynx and esophagus

Answer 2

swallowing and avoiding airway

Question 3

what is the function of the stomach

Answer 3

mechanical and chemical breakdown with some absorption

Question 4

what is the function of the small intestine

Answer 4

chemical and mechanical breakdown with major absorption

Question 5

what is the function of the large intestine

Answer 5

absorption of electrolytes and some vitamins

Question 6

what is the function of the rectum and anus

Answer 6

defecation

Question 7

what are the effectors in the somatic nervous system

Answer 7

skeletal muscle

Question 8

what are the effectors in the autonomic nervous system

Answer 8

smooth muscle, cardiac muscle, and glands

Question 9

what are the effectors in the enteric nervous system

Answer 9

smooth muscle, glands, and endocrine cells of GI tract

Question 10

which parts of the PNS are involuntary

Answer 10

enteric and autonomic nervous system

Question 11

what part of the PNS is voluntary

Answer 11

somatic nervous system

Question 12

what plexuses are in the enteric nervous system

Answer 12

myenteric plexus and submucosal plexus

Question 13

where does the motor neuron travel to from longitudinal and circular smooth muscle layers of the muscularis

Answer 13

myenteric plexus

Question 14

where does the motor neuron from mucosal epithelium travel

Answer 14

submucosal plexus

Question 15

how does the motor neuron from mucosal epithelium travel from the submucosal plexus to the myenteric plexus

Answer 15

an interneuron

Question 16

where do sensory neurons from mucosal epithelium travel

Answer 16

to submucosal plexus, myenteric plexus and to ANS and CNS neurons

Question 17

what does simple columnar epithelium do

Answer 17

• secretes enzymes and absorbs nutrients
• specialized cells (goblet) secrete mucous onto cell surfaces
• enteroendrocrine cells secrete hormones controlling organ function

Question 18

what is lamina propria

Answer 18

• thin layer of loose connective tissue

- contains blood vessels and lymphatic tissue

Question 19

what is muscularis mucosae

Answer 19

• thin layer of smooth muscle causes folds to form in mucosal layer
• drives local movements to increase absorption by exposing ingested material to absorptive surfaces

Question 20

what is the submucosa made of

Answer 20

loose connective tissue that contains blood vessels, glands and lymphatic tissue

Question 21

what is the submucosal plexus

Answer 21

• part of the enteric nervous sytem
• receives input from sympathetic and parasympathetic neurons
• regulates blood vessel diameter, secretion from glands and neurosecretory neurons, and local motility caused by msucularis mucosae

Question 22

what does the muscularis layer have control over

Answer 22

deglutition and defecation

Question 23

what is the smooth muscle under involuntary control

Answer 23

inner circular fibers and outer longitudinal fibers

Question 24

what does smooth muscle allow

Answer 24

motility for mixing and propulsion

Question 25

what is the myenteric plexus

Answer 25

- part of the enteric nervous system with some functions shared with submucosal plexus - provides parasympathetic and sympathetic innervation of circular and longitudinal smooth muscle layers

Question 26

what is the serosa layer

Answer 26

- a serous membrane also called visceral peritoneum - secretes serous fluid - consists of areolar connective tissue covered with simple squamous epithelium

Question 27

describe the adventitia

Answer 27

- only in esophagus | - consists of areolar connective tissue without the epithelium

Question 28

what is the peritoneal caity

Answer 28

space containing serous fluid

Question 29

what does visceral peritoneum cover

Answer 29

organs

Question 30

what does parietal peritoneum line

Answer 30

walls of body cavity

Question 31

what happens in mechanical digestion

Answer 31

- breaks food into pieces | - mixes with saliva so that it forms a moist bolus

Question 32

what happens in chemical digestion

Answer 32

- salivary amylase begins starch digestion in the mouth but when the bolus hits the acidic gastric juices digestion stops - lingual lipase is secreted by glands in tongue and begins breakdown of triglycerides into fatty acids and glycerol

Question 33

what increases salivation

Answer 33

sight, smell, sounds, memory of food and tongue stimulation

Question 34

what decreases salivation (dry mouth)

Answer 34

fear and anxiety

Question 35

what is saliva made of

Answer 35

water, bicarbonate, enzymes

Question 36

what is the function of saliva

Answer 36

- moistens food - dissolves food - bicarbonate buffers acidic food - protects mouth from infection with rinsing action - lysozyme helps destroy bacteria

Question 37

what are the stages of swallowing

Answer 37

voluntary and involuntary stages

Question 38

what happens in the voluntary stage

Answer 38

oral cavity or oropharynx

Question 39

what two stages are in the involuntary phase

Answer 39

- pharyngeal stage | - esophageal stage

Question 40

what happens in the pharyngeal stage

Answer 40

pharynx to esophagus

Question 41

where does food pass in the esophageal stage

Answer 41

esophagus to stomach

Question 42

how does the involuntary stage begin

Answer 42

when sensory nerves in the pharynx signal the deglutition center in brainstem

Question 43

what happens in the involuntary stage

Answer 43

- breathing stops - soft palate and uvula rise closing off nasopharynx - vocal cords adduct - larynx rises - epiglottis covers to larynx

Question 44

what happens in the esophageal stage

Answer 44

- upper esophageal sphincter relaxes - peristalsis pushes food down - lower esophageal sphincter relaxes as food approaches

Question 45

what is the travel time in the esophageal phase for solids? liquids?

Answer 45

solids- 4-8 seconds | liquids- 1 second

Question 46

what is GERD

Answer 46

if lower sphincter fails to open or if lower sphincter fails to close

Question 47

what does GERD stand for

Answer 47

gastro-esophageal reflux disease

Question 48

what happens when the lower sphincter fails to open

Answer 48

distension of esophagus feels like chest pain or heart attack

Question 49

what happens when lower esophageal sphincter fails to close

Answer 49

-stomach acid enters esophagus and causes heartburn

Question 50

what makes GERD worse if the lower esophageal sphincter fails to close

Answer 50

- a weak sphincter - laying down after a large meal - smoking and alcohol