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Anatomy II > Digestive System 1 > Flashcards

Digestive System 1 Flashcards

1
Q

main functions of digestive system

A
  • take materials into body
  • tube mouth to anus
  • take stuff from tubes, bring into body, break down
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2
Q

alimentary canal

A

continuous, muscular tube of digestive system

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3
Q

organs (in order) of alimentary canal

A 
mouth
pharynx
esophagus
stomach
small intestine
large intestine
anus
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4
Q

accessory organs of digestive system

A

teeth, tongue, salivary glands

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5
Q

6 actions of digestive system

A 
ingestion
propulsion
chemical digestion
absorption
mechanical digestion
defecation
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6
Q

ingestion

A

bringing food into system

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7
Q

propulsion

A

moving food through system

2 types: deglutition and peristalsis

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8
Q

deglutition

A

swallowing

a voluntary, initial process

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9
Q

peristalsis

A

wave-like smooth muscle contractions

involuntary

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10
Q

chemical digestion

A

enzymatic breakdown of stuff brought into digestive system

begins in mouth, ends in small intestine

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11
Q

absorption

A

absorbing building blocks (monomers) of foods we eat
occurs in distal parts of small intestine out of lumen
reclaim H2O in large intestine

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12
Q

from what do we reclaim water in the large intestine?

A

mucus, gastric juice, and enzymes

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13
Q

mechanical digestion

A

physical breakdown; making food smaller increases its surface area
includes mastication, mixing, and segmentation

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14
Q

mastication

A

chewing

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15
Q

mixing

A

mixing bolus/chyme with saliva

like when stomach is churning

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16
Q

segmentation

A

kneading tube of alimentary canal
mixing and propulsion
back and forth movement

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17
Q

defecation

A

elimination of wastes from large intestine

wastes formed in large intestine exit body through anus

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18
Q

3 ways we control digestive system

A

sensors
nerve plexuses
hormones

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19
Q

how do hormones control digestive system

A

whatever sensors were stimulated can cause release/inhibition of certain hormones

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20
Q

how do sensors control digestive system

A

sensory receptors are deigned to detect stimuli
stimuli include osmolarity, pH, specific nutrients, and stretch
sensory receptors then send nervous impulses through nerve plexuses

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21
Q

stimuli for sensory receptors of digestive system

A

osmolarity
pH
specific nutrients (carbs, proteins, lipids)
stretch (can be on or off switch)

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22
Q

short/intrinsic nerve plexus

A

nervous impulse exchange that occurs entirely within GI tract

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23
Q

long/extrinsic nerve plexus

A

nervous impulse exchange that involves CNS

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24
Q

sensors in GI tract sending signal to brain to activate something other than GI tract is which type of nerve plexus?

A

long/extrinsic

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25
Q

stimulus in part of body other than GI tract that changes activity of GI tract is which type of nerve plexus?

A

long/extrinsic

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26
Q

mesentary

A

specialized peritoneal component in digestive tract

2 sided serous membrane that anchors abdominopelvic organs to back wall of abdominopelvic cavity

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27
Q

peritoneum

A

abdominopelvic serous membrane

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28
Q

“retroperitoneal” means

A

this organ is not anchored by mesentery

because its behind peritoneum

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29
Q

tunics of alimentary canal

A

mucosa
submucosa
muscular externa
serosa

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30
Q

mucosa

A

superficial layer

epithelial tissue

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31
Q

submucosa

A

deep to mucosa
dense irregular connective tissue
where all blood vessels and nerves go
where we get nutrients into circulatory system

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32
Q

muscular externa

A 
deep to submucosa
muscular layer (smooth muscle; involuntary)
2 layers: circular layer, longitudinal layer
^ their combined interaction moves things through digestive system
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33
Q

circular layer of muscular externa

A

fibers run sideways in a ring around lumen
more superficial than longitudinal layer
when it contracts, it changes the diameter (constricts) of lumen

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34
Q

longitudinal layer of muscularis externa

A

fibers run vertically in tube

when it contracts, the tube shortens

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35
Q

serosa

A

deepest layer of alimentary canal

visceral peritoneum

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36
Q

what type of tissue is pharynx made of

A

squamous epithelium

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37
Q

what type of tissue is the organs at esophagus and beyond made of?

A

columnar epithelium

this includes goblet cells

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38
Q

tunics for organs above diaphragm

A

mucosa
submucosa
adventitia (replaces muscular and serosa)

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39
Q

tunics for below diaphragm

A

mucosa
submucosa
muscularis
serosa

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40
Q

goblet cells secrete ____

A

mucus

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41
Q

functions of mucus

A

secretes enzymes
secretes hormones
protects alimentary canal and its blood vessels from abrasive food

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42
Q

where are enzymes usually produced in alimentary canal?

A

produced by glands in submucosa

needs to get into lumen to digest, so it passes through mucosa

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43
Q

where are hormones produced in alimentary canal?

A

produced in submucosal layers

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44
Q

enteric neurons

A

intrinsic nerve plexus nerves found in wall of alimentary canal
submucosal or myenteric

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45
Q

submucosal nerve plexuses

A

sensory receptors in submucosa that detect stretch, chemical composition, or pH
once activated, they send signals to whatever part of digestive system to make that work
function in secretion

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46
Q

why do submucosal nerve plexuses exist

A

because theres no nerve fibers in mucosa

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47
Q

myenteric nerve plexuses

A 
enteric neurons located between 2 layers of muscle in muscular externa
function in motility
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48
Q

motility action of enteric neurons

A

activation of myenteric nerve plexus causes muscle contraction

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49
Q

secretion action of enteric neurons

A

activation of submucosal nerve plexus causes things like secretions of enzymes/hormones (glandular action)

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50
Q

t/f motility and secretion actions of enteric neurons cannot happen at the same time

A

false

they can both happen at same time

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51
Q

oral/buccal cavity

A

entry to alimentary canal
connected to pharynx so we can breathe and eat
involved with ingestion, propulsion, mechanical, and chemical digestion

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52
Q

only part of digestive system involved with ingestion

A

oral/buccal cavity

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53
Q

components (accessory organs) of oral/buccal cavity

A

palate
tongue (papillae)
salivary glands
teeth

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54
Q

palate

A

roof of buccal cavity and floor of nasal cavity

includes uvula

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55
Q

uvula

A

extension off back of soft palate

blocks nasopharynx when swallowing

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56
Q

tongue

A

functions in swallowing (deglutition)
moves food around oral cavity- causes mixing
creates bolus
includes diff types of papillae

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57
Q

bolus

A

foodstuff ball that we swallow

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58
Q

types papillae

A

fungiform
circumvallate
filiform

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59
Q

fungiform papillae

A

contain taste buds

sensory component

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60
Q

circumvallate papillae

A

make V in back of tongue

have some taste buds and chemoceptors

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61
Q

filiform papillae

A

bumps on top

give tongue grip

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62
Q

salivary glands

A

parotid
sublingual
submandibular

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63
Q

parotid salivary gland

A

far back in oral cavity

made of serous cells, which produce enzymes

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64
Q

enzyme-producing salivary gland

A

parotid

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65
Q

sublingual salivary gland

A

under tongue
made of mucous cells (make mucus)
help lubricate

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66
Q

submandibular salivary glands

A

somewhere between parotid and sublingual glands

made of both mucus and serous cells- produces both secretions

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67
Q

how much saliva do we produce per day

A

1-1.5L

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68
Q

actions of saliva

A

cleans mouth
dissolves food to make it biologically active
moistens food- helps form bolus
enzyme in saliva (amylase) starts starch digestion in mouth

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69
Q

pH of saliva

A

slightly acidic (6.75-7)

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70
Q

components of saliva

A 
water 
electrolytes
amylase
mucin
lysosome
IgA
metabolic wastes
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71
Q

salivary amylase

A

enzyme that starts starch breakdown in mouth

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72
Q

mucin

A

protein that gives mucus its slipperiness to help move food

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73
Q

immune components of saliva

A

IgA and lysosome

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74
Q

metabolic wastes in saliva

A

we produce things like urea/uric acid when breaking down proteins
get rid of these wastes through defacation

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75
Q

control of salivation

A

parasympathetic nervous stimulation controls saliva production
chemoreceptors and pressure receptors send signal to ANS to produce saliva

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76
Q

why do we get cottonmouth when nervous

A

sympathetic nervous system shuts off saliva production

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77
Q

teeth are involved in which digestion process?

A

mastication

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78
Q

2 sets of teeth in humans

A

primary teeth

permanent teeth

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79
Q

primary teeth

A

aka vesiduous/baby teeth
20 total- don’t all appear at same time
we have all by 2 years old
they will fall out

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80
Q

we have all primary teeth by how old?

A

2

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81
Q

permanent teeth

A

32 total
replace primary teeth
dont necessarily last whole life- but will not be replaced

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82
Q

types of teeth

A

incisors
cuspid
bicuspid
molars (incl 18 yr molar)

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83
Q

incisors

A

front 4 teeth

“shearing teeth”- allow us to cut/pull things

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84
Q

cuspid

A

one on each side of incisors

“canine/fang tooth”- for piercing/grabbing hold of things

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85
Q

bicuspids/premolars

A

2 on each side of cuspids

for shearing/cutting

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86
Q

molars

A

last 3 teeth on each side
flat teeth
for grinding and breaking up seeds/plants

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87
Q

3rd molar/wisdom tooth/18 yr molar

A

last tooth to come in
in evolution, human jaw has shrunk
often doesn’t emerge at all or emerges not in line with other teeth
often removed

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88
Q

“carnivorous teeth”

A

cuspids and bicuspids

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89
Q

components of tooth structure

A 
crown
root
neck
enamel
dentine
pulp
root canal
cementum
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90
Q

crown of tooth

A

part of tooth above gumline

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91
Q

gingiva

A

gumline

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92
Q

root of tooth

A

part of tooth below gumline

embedded in bone in jaw

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93
Q

neck of tooth

A

transition part between crown and root

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94
Q

enamel

A

hard substance covering crown of tooth

strengthens tooth; only on crown

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95
Q

pulp of tooth

A

soft tissue deep to dentine

contains blood vessels and nerves

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96
Q

root canal

A

pulp that extends into root

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97
Q

dentine

A

substance deep to enamel

in root and crown

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98
Q

cementum

A

connective tissue

glues tooth into socket

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99
Q

digestive function of pharynx

A

propulsion

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100
Q

which parts of pharynx are pathways for food?

A

oropharynx and laryngopharynx

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101
Q

when swallowing, epiglottis is _____

A

down!

covers trachea so food only goes through esophagus

102
Q

esophagus

A

muscular tube involved in propulsion; sits just behind trachea
includes upper esophageal sphincter and gastroesophageal sphincter

103
Q

upper esophageal sphincter and gastroesophageal sphincter

A

prevent food from going wrong way

not true sphincters

104
Q

main steps of deglutition

A
  1. food compacted into bolus
  2. buccal phase (voluntary)
  3. pharyngeal-esophageal phase (involuntary)
105
Q

buccal phase of deglutition

A

voluntary part

  1. tip of tongue placed against hard palate
  2. tongue contracts to force bolus into oropharynx
  3. bolus stimulates tactile receptors
106
Q

t/f you cannot swallow with your tongue against roof of mouth, you need something in between

A

true

that is usually bolus

107
Q

pharyngeal-esophageal phase of deglutition

A

involuntary part
1. tactile receptors stimulate medulla and pons
2. motor impulses (parasympathetic) sent to muscles in pharynx and esophagus
3. peristalsis moves bolus to stomach
(in stomach, bolus is liquified and turned into chyme)

108
Q

digestion events that occur in stomach

A

propulsion
mechanical digestion
chemical digestion of proteins

109
Q

2 types of action that stomach can engage in

A

secreting gastric juice

muscular contraction

110
Q

cardia

A

part of stomach that’s connected to esophagus

111
Q

fundus

A

part of stomach above direct path from esophagus to body

112
Q

pylorus

A

portion where stomach constricts again

113
Q

cardiac sphincter

A

kink in cardia created from distention/bending of stomach when it fills
prevents stuff from going back up
not true valve

114
Q

pyloric sphincter

A

regulates emptying of stomach
true valve
connects to duodenum

115
Q

muscular layers of stomach

A

circular
longitudinal
oblique

116
Q

rugae

A

folds all over lining of stomach to increase surface area

flatten to increase volume of stomach

117
Q

volume of empty/relaxed stomach

A

50 mL

118
Q

volume of stretched stomach

A

~4L

119
Q

stomach cells

A 
goblet cells
mucous neck cells
parietal cells
chief cells
enteroendocrine cells
120
Q

gastric glands are located __

A

at base of gastric pits of stomach

121
Q

goblet cells

A

found in mucosa, which lines gastric pits and stomach wall

produce mucus

122
Q

mucous neck cells

A

first cells of gastric glands

produce slightly acidic mucus

123
Q

parietal cells

A

embedded within mucus neck cells

produce HCl and Intrinsic factor

124
Q

HCl

A

digestive component secretion of parietal cells
pH= 2
activates pepsinogen to become pepsin

125
Q

intrinsic factor

A

glycoprotein required by small intestine to absorb B12

B12 needed to make RBCs and carry O2

126
Q

chief cells

A

cells in stomach that produce pepsinogen (inactive form of pepsin)

127
Q

enteroendocrine cells

A

cells in stomach that release gastrin
gastrin regulates activity of others parts of digestive tract
at way bottom of gastric gland
aka G cells

128
Q

G cells are also known as

A

enteroendocrine cells

129
Q

phases of gastric secretion

A

cephalic (reflex) phase
gastric phase
intestinal phase

130
Q

cephalic (reflex) phase of gastric secretion

A

first thing that can cause stomach to activate
acquired/learned
if we THINK about eating foods we like, stomach starts to activate and secrete
before food arrives to stomach
long reflex arc

131
Q

t/f cephalic reflex phase occurs for any foods, whether we like them or not

A

false

it only happens with foods we like

132
Q

gastric phase of gastric secretion

A

begins once food starts arriving in stomach
several different stimuli occur once food is in stomach
these stimuli stimulate enteroendocrine cells to start producing gastrin
gastrin activates cells in gastric gland to start secreting things

133
Q

stimuli in stomach during gastric phase of secretion

A

stretch, change (elevation) in pH, or presence of proteins

134
Q

stretch stimulus in gastric phase of secretion

A
  1. food causes stretch in wall of stomach
  2. sends signal to ANS
  3. ANS sends parasympathetic impulses back
  4. causes release of acetylcholine
  5. acetylcholine stimulates gastric gland to start secreting
135
Q

pH stimulus in gastric phase of secretion

A

stomach pH is very low (2), saliva pH is closer to 7

body senses this change once saliva reaches stomach

136
Q

feedback loop of gastric phase of gastric secretion

A 
increased pH activates gastrin secretion
gastrin activates gastric gland cells (like parietal cells)
parietal cells produce HCl
HCl makes pH go down
low pH shuts off gastrin secretion
137
Q

intestinal phase of gastric secretion

A

stomach is still active as food leaves stomach entering small intestine
2 parts: excitatory then inhibitory

138
Q

excitatory intestinal phase

A

arrival of some material in small intestine continues to activate stomach
basically stomach “finishing up” its job

139
Q

inhibitory intestinal phase

A

after excitatory part has gone for a while, small intestine says it is time to start slowing down
bc stomach is probably getting pretty empty, so we don’t want to digest the stomach itself

140
Q

contents from stomach trickle into small intestine _____ (vol) at a time

A

3 mL

141
Q

enterogastric reflex

A

small intestine shutting off stomach by inhibiting nervous stimulation
continued stretch on small intestine inhibits parasympathetic activity and activated sympathetic activity
causes pyloric sphincter to squeeze shut

142
Q

what prevents us from digesting our own stomach by HCl and pepsinogen?

A

mucosal barrier

143
Q

mucosal barrier components

A

bicarbonate-rich mucus
tight junctions in mucosal epithelium
HCl-impermeable plasma membranes in gastric gland cells
undifferentiated stem cells at junction of gastric pits and gastric glands

144
Q

bicarbonate-rich mucus of mucosal barrier

A

produced by goblet cells

buffers pH at lining of stomach (not secreting into stomach)

145
Q

how do tight junctions in mucosal epithelium contribute to mucosal barrier

A

impermeable junctions mean no acid can slip in between cells to get into underlying tissue

146
Q

how do HCl-impermeable plasma membranes in gastric gland cells contribute to mucosal barrier

A

so that the acid that gastric gland cells are producing can only go into gastric pit; cannot go to other side

147
Q

how do undifferentiated stem cells at junction of gastric pits/glands contribute to mucosal barrier

A

gastric pits and glands in lining of stomach need to constantly replace cells
entire wall of stomach is replaced every 3-6 days

148
Q

2 types of gastric filling

A

receptive relaxation

adaptive relaxation

149
Q

t/f stomach has ability to change shape when it’s filling

A

true

150
Q

receptive relaxation

A

thinking about food can make stomach start secreting and make it change shape even before food has gotten there
no stretch has occurred yet! increased size is due to rug flattening out

151
Q

adaptive relaxation

A

after food has started arriving in stomach
rug continue to flatten out
stretch starts to occur only after we have ~ 1 L of food in stomach
^ this stretch causes signals to brain to stomach to start secreting

152
Q

gastric contractions are mostly what kind?

A

longitudinal contractions for propulsion

153
Q

interstitial cells of Cajal

A

autorhythmic cells of stomach (pacemaker of stomach)

within longitudinal layer

154
Q

t/f anything that increases production of HCl also increases rate of muscular contractions in stomach

A

true

includes stretch, proteins, and increased pH

155
Q

basic electrical rhythm of gastric contraction

A

longitudinal cells of stomach contain some autorhythmic cells (interstitial cells of Cajal)
creates basic rhythm of contraction, which happens about 3x per minute

156
Q

autorhythmic cells

A

cells that can depolarize because of leaky membranes

157
Q

reasons for slow release of chyme from stomach

A

increases efficiency of digestion

prevents giant wave of low pH from getting into stomach

158
Q

stomach starts to empty about ___ after you’ve had your meal

A

4 hours

159
Q

process of gastric emptying

A
  1. chyme enters duodenum
  2. stretch and chemoreceptors of small intestine activated
  3. enterogastric or enterogastrone reflexes initiated
  4. gastric activity reduced
  5. pyloric contractions reduced
  6. duodenal filling stopped
160
Q

enterogastrone

A

hormone of small intestine that inhibits gastric secretion

161
Q

what happens during gastric emptying? like how is this chyme actually leaving stomach?

A

every time we get contraction, pressure pushing against pyloric sphincter increases
with each contraction, 30 mL of chyme leaves stomach and goes to duodenum
BUT as “squeeze” relaxes, 27 mL goes back into stomach
only 3 mL escape stomach with each muscular contraction

162
Q

t/f vomiting/emesis is reverse peristalsis

A

false!

peristalsis only moves in one direction (down)

163
Q

vomiting/regurgitation/emesis

A

something enters stomach that causes too much stretch or irritation
excessive stress/irritation stimulates abdominal muscles and diaphragm to contract
this contraction puts lots of pressure on stomach- contents are forced up through esophagus
continues as long as there is stretch/irritation

164
Q

projectile vomiting

A

when the pressure on stomach from contraction of abdominal muscles and diaphragm is very intense

165
Q

why do we have dry heaving

A

emesis continues as long as there is stretch/irritation
even with no food left, there may still be irritation
as this continues, contractions can be so hard you pull up bile from small intestine

166
Q

major digestive organ of body

A

small intestine

167
Q

functions of small intestine

A

chemical digestion of every class of macromolecule
absorption once everything is digested
propulsion through alimentary canal

168
Q

length of small intestine

A

8-13 ft

runs from pyloric sphincter to ileocecal valve

169
Q

when we die how long is out small intestine

A

like 20 ft

170
Q

how much intestinal juice does small intestine produce per day

A

1 to 2 liters

171
Q

production of intestinal juice in small intestine stimulated by _______

A

arrival of acidic chyme

172
Q

function of intestinal juice

A

slightly alkaline, so it neutralizes pH and shuts off/denatures pepsin

173
Q

digestion occurs mostly in _____

A

duodenum

174
Q

absorption of nutrients happens mostly in _____

A

jejunum

175
Q

subdivisions of small intestine

A

duodenum
jejunum
ileum

176
Q

duodenum

A

first 10 inches of small intestine

contains hepatopancreatic ampulla

177
Q

jejunum

A

middle 8 ft of small intestine

178
Q

ileum

A

last part of small intestine

ends with ileocecal valve

179
Q

structural modifications of small intestine

A

length
plicae circulares
villi
microvilli

180
Q

structural modification of small intestine: length

A

long length gives small intestine increased surface area

surface area ~ 200 m^2

181
Q

plicae circulares

A

aka spiral valve
folds in mucosa and submucosa of lining of small intestine
make incoming chyme spiral while going through small intestine
–slows liquid down
–increases contact of liquid with wall to increase efficiency

182
Q

villi of small intestine

A

fingerlike projections of mucosa that increase surface area

help increase contact with chyme to break down its contents

183
Q

microvilli of small intestine

A

within modified plasma membrane of epithelial cells of villi
increases surface area further
why lining of small intestine is called brush border

184
Q

brush border

A

lining of small intestine

because of the villi and microvilli

185
Q

chyme leaving small intestine to go into large intestine is ______; what would happen if we let it all go at once?

A

hypertonic; significant water loss

186
Q

factors of small intestine emptying

A

gastroileal reflex
gastrin
pressure

187
Q

gastroileal reflex

A

linkage between activity (action/motility) of stomach and ileocecal valve
signal from stomach tells small intestine to start releasing contents
causes segmentation-like contractions within small intestine

188
Q

contractions caused by gastroileal reflex trigger ____ in small intestine

A

segmentation

189
Q

how does gastrin affect small intestine emptying

A

activates stomach and small intestine

relaxes (opens) ileocecal valve

190
Q

how does pressure affect emptying of small intestine

A

as chyme from small intestine is released into cecum, it starts to accumulate
this causes stretch and back pressure on ileocecal valve to close it

191
Q

largest internal organ in body

A

liver

192
Q

major function of liver

A

process blood (recycle RBCs and turn hemoglobin into bilirubin and amino acids)

193
Q

byproduct of major function of liver

A

bile production!

194
Q

functions of bile

A

acts as emulsifier
breaks big fat globs into smaller fat globs –> increases surface area
basically causes mechanical digestion of fats to occur

195
Q

t/f bile is an enzyme

A

false!

it does not chemically break anything down

196
Q

bile composition

A 
water
bile salts
bile pigments- bilirubin, urobilinogen
cholesterol
neutral fats
phospholipids
electrolytes
197
Q

lobes of liver

A

4: right, left, caudate, quadrate

198
Q

falciform ligament

A

attaches liver to muscular diaphragm and separates R/L lobes

199
Q

bile salts

A

made of salts from breakdown of blood cells and bilirubin/biliverdin
what’s actually doing the emulsifying

200
Q

urobilinogen

A

when bile is secreted into digestive tract, bilirubin is converted into urobilinogen
brown color

201
Q

common hepatic duct

A

from liver to bile duct

right and left hepatic ducts merge to form common hepatic duct

202
Q

cystic duct

A

brings bile from gallbladder to common hepatic duct

203
Q

bile duct

A

from common hepatic duct to hepatopancreatic ampulla

takes bile from liver and gallbladder to small intestine

204
Q

hepatopancreatic ampulla is also known as

A

ampulla of vater

205
Q

pancreatic duct

A

connects to bile duct

brings secretions from pancreas

206
Q

hepatopancreatic duct is only open when?

A

at mealtime

207
Q

functions of gallbladder

A

store bile

concentrate bile

208
Q

how does the gallbladder concentrate bile?

A

bile is mostly water, gallbladder reclaims some of the water

209
Q

gallstones

A

when gallbladder concentrates bile so much that it crystallizes
get stuck in ducts, cause pain and pressure

210
Q

bile storage

A
  1. hepatopancreatic sphincter closed when not digesting
  2. liver continually produces bile
  3. bile backs up cystic duct into gallbladder
211
Q

bile release

A
  1. fatty chyme entering duodenum stimulates intestine to produce cholescystokinin (CCK)
  2. CCK causes parasympathetic nervous impulses to promote gallbladder contraction to squeeze out bile
  3. CCK also relaxes hepatopancreatic sphincter
212
Q

endocrine function of pancreas

A

insulin and glucagon

213
Q

exocrine function of pancreas

A

produce pancreatic juice

goes into pancreatic duct, connects to bile duct, and released at hepatopancreatic ampulla

214
Q

pancreatic juice components

A

water
enzymes
bicarbonate

215
Q

bicarbonate component of pancreatic juice

A

secreted by cells of pancreatic duct
pH > 8
helps neutralize chyme so enzymes can function

216
Q

enzyme component of pancreatic juice

A 
from exocrine cells of pancreas
enzymes for every class of macromolecule
217
Q

protease enzymes of pancreatic juice

A

break down proteins
secreted into duct in inactive form; activated in duodenum
trypsin, carboxypeptidase, and chymotrypsin

218
Q

other enzymes (not proteases) of pancreatic juice

A

secreted in active form

amylase (starches), lipase (lipids), nuclease (nucleic acids)

219
Q

trypsin

A

protease enzyme in pancreatic juice

inactive form trypsinogen is activated by enterokinase (enteropeptase)

220
Q

where is enterokinase produced

A

brush border of SI

221
Q

carboxypeptidase

A

protease enzyme in pancreatic juice

inactive form procarboxypeptidase is activated by trypsin

222
Q

chymotrypsin

A

protease enzyme in pancreatic juice

inactive form chymotrypsinogen is activated by trypsin

223
Q

components of pancreatic secretion control

A

secretin
CCK
parasympathetic impulses

224
Q

how does secretin help control pancreatic secretion

A

stimulates cells of pancreatic duct to start producing bicarbonate

225
Q

how does CCK help control pancreatic secretion

A

opens hepatopancreatic ampulla
stimulates production of enzymes
activates some exocrine cells to start producing/secreting enzymes

226
Q

how do parasympathetic impulses help control pancreatic secretion

A

stimulates exocrine cells or duct cells to start producing/secreting

227
Q

acidic chyme stimulates intestine to produce _____, which stimulates production of bicarbonate and lowers acidity of chyme

A

secretin

228
Q

presence of fats/proteins stimulates wall of intestine to produce ___, which stimulates production of enzymes to break down proteins and fats

A

CCK

229
Q

digestive actions of large intestine

A

absorption (mostly water)
propulsion
elimination

230
Q

length of large intestine

A

9 feet

231
Q

segments of large intestine in order

A 
cecum
ascending colon
transverse colon
descending colon
sigmoid colon
rectum/rectal canal
anus
232
Q

rectal valve

A

“bends” in large intestine
separates solids and gases
allow gases to pass at higher rate than solids

233
Q

internal anal sphincter

A

closest to rectum

smooth muscle; involuntary

234
Q

external anal sphincter

A

outside of internal sphincter
skeletal muscle
voluntary

235
Q

vermiform appendix

A

appendage that hangs off cecum
no longer any function (possibly used to function in cellulose digestion)
harbors microbiota from digestive tract
becomes trap- things we ate plug opening and cause appendicitis

236
Q

appendicitis

A

something plugs opening of appendix
appendix becomes inflamed/swollen and loses blood supply
caused by tiny seeds, or (most common) gum, or (2nd most common) opiates

237
Q

haustra

A

saclike puckering that divide large intestine

238
Q

taenia coli

A

bands of smooth muscle from muscular that wrap around large intestine and create haustra

239
Q

epiploic appendages

A

deposits of adipose tissue accumulated along large intestine

no known function

240
Q

intestinal bacteria functions

A

ferment indigestible carbs
synthesize B vitamins
synthesize K vitamins

241
Q

intestinal bacteria fermentation of indigestible carbs

A

produces gas rich in dimethylsulfide (smelly)

242
Q

intestinal bacteria synthesis of B vitamins

A

we get all the B vitamins we need in diet, bacteria just add a little more
absorbed with water thats being reclaimed

243
Q

intestinal bacteria synthesis of K vitamins

A

we get enough K vitamins from healthy diet, this just adds more
vitamin K used by liver to make clotting protein

244
Q

motility of large intestine

A

haustral contractions

mass movements

245
Q

haustral contractions

A

activated by stretch caused by arrival of chyme in large intestine
one haustra contracts and slowly moves contents to next haustra, etc
every 30 minutes all day
basically a form of segmentation

246
Q

mass movements

A

arrival of food in stomach causes us to push previous meal from large intestine
happens 3-4 times per day; usually triggered by meal

247
Q

defecation reflex

A
  1. mass movements cause stretch on large intestine wall
  2. stretch triggers parasympathetic stimulation of sigmoid colon and rectum, and inhibits anal sphincters
  3. external anal sphincter under voluntary control still (can ‘hold it’)
  4. valsalva’s maneuver assists emptying
248
Q

valsalva’s maneuver

A

“pushing”

contracting diaphragm and intercostal muscles to help poop

249
Q

what makes up feces

A

undigested food residue
sloughed off epithelial cells from ileum and large intestine
bacteria from digestive tract
tiny bit of water

250
Q

constipation

A

if too much water is reclaimed

251
Q

diarrhea

A

if not enough water is reclaimed

Anatomy II (17 decks)

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