final exam Flashcards
1
Q
tube of digestive system
A
mouth
esophagus
stomach
small intestine
large intestine
rectum
about 15 feet long
2
Q
sphincters
A
rings of muscle
regulate passage of substances from one region to next
3
Q
upper and lower esophageal sphincters
A
upper: between pharynx and esophagus
lower: where esophagus meets stomach
4
Q
pyloric sphincter
A
stomach
regulates passage of food out of stomach into small intestine
5
Q
ileoceal sphincter
A
between small intestine and colon (colon is first part of large intestine)
6
Q
internal and external anal sphincters
A
inside rectum
7
Q
salivary glands
A
parotid
sublingual
submandibular
secrete fluid into mouth
8
Q
pancreas
A
secretes enzymes and bicarbonate into small intestine
9
Q
liver and gall bladder
A
secrete bile salts and bicarbonate into small intestine
10
Q
layers of wall of stomach and small intestine
A
mucosal
submucosal
muscle
serosal
11
Q
mucosal layer
A
highly convoluted
structures extend into lumen
- rugae: stomach
- villi: intestine
invaginations away from lumen
- gastric glands: stomach
- crypts: intestine
12
Q
neural networks in digestive system
A
submucosal plexus
myentric plexus
both receive sympathetic and parasympathetic innervation
13
Q
submucosal plexus
A
located in submucosal layer
innervate effector cells within GI system
14
Q
myentric plexus
A
located in muscle layer
innervate muscle
innervate neurons in submucosal plexus
15
Q
electrical activity of GI contraction
A
slow waves
spikes
16
Q
slow waves
A
slow oscillations in membrane potential that occur at different frequencies at different points in the gut
due to changes in activity in Na-K-ATPase
reflect entry of sodium into smooth muscle cell
17
Q
spike potentials
A
occur when voltage gated calcium and sodium channels open
allow calcium to enter smooth muscle cell
induces contraction
18
Q
depolarization of GI smooth muscle induced by
A
muscle stretch
acetylcholine
GI hormones
19
Q
type of GI smooth muscle contractions
A
tonic, sustained
peristaltic
segmental
migrating motor
20
Q
sustained tonic contractions
A
occur in sphincters
only occasionally relax to allow materials through
21
Q
peristaltic contractions
A
move material down digestive tract
muscle contracts behind bolus of food and relaxes in front of bolus
22
Q
segmental contractions
A
occur to mix food
alternate segments contract/relax
23
Q
migrating motor contractions
A
slow wave contraction that moves from stomach through small intestines between meals
24
Q
swallowing (Deglutition) stages
A
voluntary
involuntary pharyngeal stage
esophageal stage
25
mastication
chewing creates softened mass
increases surface area that will be exposed to digestive enzymes
26
voluntary stage of swallowing
moving food into pharynx by actions of tongue
27
involuntary pharyngeal stage of swallowing
1. phaynx receptor stimulate respone with cranial nerves
2. pharygeal muscles contract
3. glottis closes (opening between pharynx and larynx)
4. respiration is inhibited
5. upper esophageal sphincter relaxes
28
esophageal stage of swallowing
primary peristalsis: continuation of swallowing reflex that began in pharynx
secondary peristalsis: initiated by distention of esophagus, triggers reflex contractions
- afferent send axons through vagus nerve, send efferent outflow to esophagus
29
musculature of esophagus
upper third: striated muscle, controlled by vagus nerve, somatic part (not parasympathetic part)
lower 2/3: smooth muscle, controlled by enteric nervous system (influenced by parasympathetic)
30
what happens when food enters stomach
stimulates receptors
vasovagal reflex induces relaxation of stomach wall
vasovagal reflex: includes vagal afferent and efferent nerves
31
stomach contractions
weak
purpose for mixing food with stomach secretions
antrum contractions are more intense (aid with stomach emptying)
influenced by hormonal factors
32
stomach contractions sphincter
each slow wave forces material through pyloric sphincter into duodenum
pyloric sphincter is normally only partially contracted to allow liquid to move
33
small intestine motility
mixing and propulsive contractions occur
not rapid (12/minute), frequency of slow waves
influenced by distension of intestine --> affects excitability of cells of enteric nervous system
34
ileocecal valve
in small intestine
permits one way movement of materials from small intestine into large ingestine
35
large intestine motility
function: absorb water from residual products and store material until elimination
strong propulsive movements in distal part of colon to force feces into rectum
36
defecation
elimination of wasted triggered by material into rectum
afferent signals
37
digestive enzymes secretion
secreted by exocrine cells
exocrine cells are found in salivary glands and pancreas, and epithelial cells in stomach and small intestine
38
digestive enzymes
proteins
packaged by golgi apparatus into secretory vesicles
stored until secreted by exocytosis
some enzymes become mixed with chyme, other attach to microvilli of epithelial cells
39
salivary amylase
secreted by salivary glands
breaks down starch
40
lingual lipase
secreted by salivary glands
breaks down triglycerides
41
pepsin
secreted as pepsinogen (inactive form)
secreted by stomach
braks down protein
42
gastric lipase
secreted by stomach
breaks down triglycerides
43
pancreatic amylase
secreted by pancreas
breaks down starch
44
pancreatic lipase
secreated by pancrease
breaks down triglycerides
45
colipase
secreted as procolipase (inactive form)
breaks down triglycerides
46
phospholipase
secreted as prophospholipase (inactive form)
secreted by pancreas
breaks down phospholipids
47
trypsin
secreted as trypsinogen (inactive form)
secreted by pancreas
breaks down proteins
48
chymotrypsin
secreted as chymotrupsinogen (inactive form)
secreted by pancreas
breaks down proteins
49
enteropeptidase
secreted by small intestine
activates trypsin
50
disaccharides
secreted by small intestine
breaks down sucrose, maltose, lactose
51
enopeptidase/exopepidase
secreted by small intestine
cleaves interior peptide bonds
52
mucus secretion
secreted by specialized cells in stomach and small intestine
stomach: mucus cells
intestine: goblect cells
parasympathetic innervation
53
bile secretion
secreted by liver cells into hepatic ducts that lead into gall bladder
during meal, contraction of gall bladder sends bile into duodenum through common bile duct
54
bile composition
non enzyme solution
bile salts that aid in fat digestion
bile pigments (bilirubin)
cholesterol
55
carbohydrate absorption
amylase breaks starch into disaccharides
maltase, sucrase, lactase, break discaccharides into monosaccharides
glucose crosses useing 2 ATP
rest facilitated diffusion
56
protein absorption and digestion
pepsin and proteases break proteins into amino acids
amino peptidase break small peptides to amino acids
cross using 2 ATP
57
fat digestion and secretion
bile salts emulsify with fat droplets and lipase convert it to miscelles which diffuse directly
in membrane, converted to chylomicron transported into intersitium because it is to big to be absorbed into the capollary so it moves into lymph
58
components of defense system
physical barriers
non specific immune system
aquired immune system
59
leukocytes
white blood cells
effector cells of immune system
derived from bone marrow stem cells
2 classes: myeoblasts and lymphod progeitors
60
leukocytes developed from myeoblasts
monocytes: tissue macrophage
granulocytes: neutrophills, basophills, eosinophills
dendritic cells
61
leukocytes developed from lymphoid cells
lymphocytes:
b-lymphocytes
t-lymphocytes
natural killer cells
62
innate immune system recognition
PAMPs and DAMPs recognize PRR
causes macrophages to release cytokines
63
phagocytic cells: Macrophage
found in tissue at resting stage
cytokine release activates them and increased their phagocytic activity
64
phagocytic cell: neutrophill
migrate from blood stream into tissue at site of infection because they are attracted to cytokines
65
movement of leukocytes (Neutrophills)
margination: accumulate near vessel wall
attachment: attach to vessel wall
diapedesis: goes through wall
chemotaxis: follow chemical gradient out of circulation
66
phagocyte recognition
sometime PAMPs/DAMPs
usually oposnins
67
opsonins
molecules made by body
bind to pathogens and target them for phagocytosis (opsonization)
68
NK cells
punch holes in cell membrane, causing them to break apart (Perforins)
stimulate apoptosis by releasing fragmentins
69
inflammation response
tissue damage releases histamine from mast cells
causes:
arteriol vasodilation --> increases blood flow
increased capillary permeability --> movement of fluid and proteins to interstital space
70
complement protein system
composed of proteins that function together to destroy invading cells
proteins made by liver
71
C3 protein
complement protein
constantly being broken down into fragments
fragments bind to cell surface protein --> promotes formation of membrane attack complex
72
membrane attak complex
pokes holes in cell killing it
73
Decay accelerating factor
accelerates breakdown of membrane bound protein
protectin destorys MAC
way for normal cells not to be destoryed by MAC
74
antibodies
bounded to cells that target cells for destruction by MAC
75
complement protein actions
destroy cells: MACA
opsonins: target pathogens for phagocytosis
chemoattractants: attract other immune system cells to area
pro-inflammatory
76
aquired immunity
directed to specific foreign substance
mediated by lymphocytes
77
cognate antigen/epitope
proteins made by lymphocytes that allow them to respond to only one type of foreign substance
epitope: specific portion of foreing molecule that it binds to
antibody is specific for one particular epitope
different antibodies can recognize same antigen
78
B lymphocytes
make antibodies
mediate humoral immunity
79
T lymphocytes
need direct cell-cell contact
mediate cellular immunity
80
lymphocyte maturation
lymphocyte binds to cognate antigen
lymphocyte begins to divide (Clonal expansion)
divides into effector cells and memory cells
81
effector/memory cells
effector cells: produce immune response
memory cells: produce rapid/larger response after re-exposure to antigen
82
B-lymphocyte and antibodies
B-cell receptor binds to cognate antigen for 1st time: matures into plasma cells (effector) and memory cells
2nd exposure: response is more rapid and profound
83
antibody structure
pair of identical heavy peptide chains
pair of identical light peptide chains
Fc: constant region of heavy chain, specifies general class of antibody
Fab: antigen recognition portion, heavy and light chain
84
antibodies isotypes
IgG: dominant type in circulation, good opsonin
IgA: dominant in mucus linings
IgM: initial form made by b-cells, switches during maturation
IgE: associated with allergies, acts on mast cells
IgD: rare, associated with B cell receptors
85
what do antibodies do
opsonization and NK cell activity (IgG)
complement activation
agglutination: neutralizae bioactive proteins
IgE: release histamine from mast cells
86
T-lymphocytes and immunity
responsible for cell mediated immunity
activated when T cell receptor interacts with antigen
87
T cell recognition
can only recognize antigen if it is bound to MHC
major histocompatibility complex
88
MHC (major histocompatibility complex)
distinct proteins found on cell surfaces
MHC I and MHC II
89
MHC class I
found on the surface of all nucleated cells (all cells except RBC)
present on cell surface of abnormal proteins
90
MHC class II
produced only by macrophages, dendritic cells, and B lymphocytes
phagocytize foreing matter, breakdown products presented back to cell surface
present abnormal proteins found in interstitial space
91
cytoxic T cells (Tc)
attack and destroy cells expressing cognate antigen presented by MHC class I
release molecules that poke holes in cells and induce apoptosis
92
helper T cells (Th)
activated when encoutner antigen presented by MHC class II
activated Th release cytokines
aids
93
bacterial infection response
- complement system (mannose), MAC, opsonization
- phagocytosis
- no cytoxic cells
94
acute phase response
systemic response to infection
energetically demanding, cause feeling sick
95
acute phase proteins
c-reactive protein (CRP): opsonin
serum amyloid A (SAA): protein that recruits immune cells and induces enzymes that breakdown extracellular matrix
96
immune neural endocrine interactions
immune system: release cytokines
endocrine system: release hormones
nervous system: release neurotransmitters
97
allergies
non-pathogenic antigens
involve IgE, break down mast cells and release cytokines (Histamine)
98
autoimmune disease
mistakenly identifies something as foreing
ex: type 1
99
esophagus
secretions and functions
secrete: mucus
function: move food to stomach by persistalsis
100
stomach
secretions anf functions
secrete: HCL, pepsins, mucus
functions: store, mix digest enzymes
101
pancreas
secretions anf functions
secrete: enyzmes and bicarbonate
function: digestion, neutralize HCl that will enter small intestine from the stoamch
102
liver
secretions and functions
secrete: bile salts, bicarbonate
function: neutralize HCl, secrete bile
103
gallbladder
secretions and functions
dont secrete
function: store and concentrate bile between meals
104
small intestine
secretions and functions
secrete: enzymes, salt, water, mucus
function: mix contents
105
large intestine
secretions and functions
secrete: mucus
function: store undigested matter
106
GALT
gut associated lymphoid tissue
found in mucosal layer
107
stomach structure
fundus: top portion, receives and stores chyme
body: secretes mucus, acid, pepsinogen
antrum: distal third part, more intense contractions, aid in stomach emptying, secretes mucus, acid, pepsin
108
regulation of digestive system
enteric nervous sytem
sympathetic/parasympathetic input
hormones
paracrine agents
109
short vs long loop responses
short loop: involve just enteric nervous system
long loop: involve CNS and autonomic input to enteric NS
110
phases of digestion
cephalic
gastric
intestinal
111
cephalic phase
seeing/smelling food --> prepares body to process food (feedforward)
increase parasympathetic activity causes:
- G cells to secrete gasstrin and
- pariteal and chief cells to release acid and pepsinogen
- prepare stomach to receive chyme
- increased vagal nerve actviity to stomach promotes
gastric acid and pepsinogen secretion
112
saliva/secretion
- starts process of digestion (cephalic)
- contains amylase, lysoszyme, salivary lipase, mucins
113
gastric acid secretion
parietal cells
in response fro increased vagal nerve activity to stomach
114
pepsinogen secretion
chief cells
in response to increased vagal nerve activity to stomach
converted to pepsin in acid environemtn in stomach
115
gastric phase
- gastric motility/secretion continues
- initiated when food enters stomach --> stretch
stomach wall
- also initiated by presence of presence and increase
pH
short and long loop
116
gastric secretions
- HCl
- pepsinogen
- mucus
- gastrin
- somatostatin
117
HCl secretion
paritetal cells in stomach by H,K-ATPase on lumenal memmbrane
- HCl reduces stomach pH
- parietal cells have intrinsic factor (protein absorb B12)
118
mucus secretion
by mucus cells
located near mouth of gastric pits
119
gastrin
- hormone, secreted into blood
- stimulated by vagal input to G cells
- stimulates paritetal cells to release acid
- stimulates enterochromaffin cells to release histamine
ACID INHIBITS GASTRIN RELEASE (negativ feedback)
120
stomach motility
empty: volume is 50 ml
- lower esophageal sphincter is closed, and pyloric sphincter is partially closed
when swallowing:
- lower esophageal sphincter opens (allows food in)
- pyloric sphincter closes tighter
121
stomach contraction control
frequency: intrinsic property of muscles
strength: neural and hormonal input
122
intestinal phase
- begins with delivety of acidic chyme to small intestine --> causes duodenum to release secretin
-fat in duednum stimulates ecretion of CCK
123
secretin
hormone secreted into blood (Not intestine)
inhibits gastric acid secretion and motility
stimulates bicarbonate secretion from pancreas to neutralize chyme acid
124
cholecystokinin (CKK)
- secreted because of fat in duodenum
- inhibits gastric acid secretion and motility
- stimulate pancreatic enzyme secretion
- contract gall bladder which releases bile
125
bicarbonate secretion
secreted from pancrease
in response to secretin
neutralizes gastric acid
126
bile secretion
secreted from liver containing bile salts
stored in gall bladder
fat secretes CKK --> CKK contracts gall bladder --> bile secreted into intestine
127
incretins
hormones released by small intestine
stimulate insulin secretion from pancreas
feedforward response
128
glucagon-like peptide 1 (GLP1)
incretin
secreted by intestinal cells in response to nutrients and intestinal stretch
stimulate insulin secretion from pancreas
129
gatric inhibitory polypeptide (GIP)
incretin
released by presence of chyme in small intestin
stimulates insulin secretion
inhibits gastrin release (negative feedback)
130
sphincter of oddi
located in second part of duodenum
CCK and secretin
131
gastric acid and ulcers
gastric acid eat hole in lining of stomach
usually protected by mucus
treatment: proton pump inhibitors
- histamine antagonists
132
absorptive state: glucose
muscle: stored as glycogen
liver: stored ag glycogen, convert glucose to triglycerides, and VLDL
adipocytes: use glucose to form glycerol phosphate and fatty acids, stored as triglycerides
also store fatty acids made in liver
133
lipoprotein lipase
enzyme located in capillaries to fat
break down VLDL
134
absorptive state: amino acids
taken up by new cells for protein synthesis
metabolized to keto acids
converted to fatty acids
135
absorptive state: fats
triglycerides in chylomicrons broken down and stored
136
postabsorptive state
glucose production
- glycogenolysis: breakdown glycogen to glucose
- lipolysis: breakdown lipids
- gluconeogenesis: synthesize glucose
137
switching between states
signals insulin and glucagon secreted from pancreas
secreted by Iselts of Langerhans
138
Islets of Langerhans
- cell clusters in pancreas
- make up 1% of pancreas (rest is exocrine cells)
4 cell types:
beta cells (70%): secrete insulin
alpha cells (20%): secrete glucagon
139
insulin in absorptive state
-promote glucose uptake and storage
- promote aminio acid uptake and protein synthesis
insulin stimulates glucose uptake by increasing insertion of glucose transporters in cell membane
140
control of insulin secretion
- high glucose level detected by beta cells
- increase GLP1 and GIP
- increased para
- decreased symp
- decreased epinephrine secretion
141
glucagon secretion
in response to:
- increased amino acids
- decreased glucose
- increased sympathetic activity
- increased epi secretion
effect n adipose tissue:
- increased lipolysis
- decrease triglyceride synthesis
liver response:
- increased glycogenolysis, glyconeogensis
142
postabsorptive state stimulated by
- sympathetic NS
- adrenall medulla releasing epinephrine
this all stimulates glucose being produced for energy use
- cortisol p
143
cortisol and glucose mobilization
promotes by increasing liver gluconeogensis and adipose tissue lipolysis
promoted protein brakdown in muscle
reduces glucose uptake
- secreted by adrenal gland, regulated by pituitary gland
144
cholesterol types
chylomicrons
VLDL
LDL
HDL
145
chylomicrons
made in intestine
absorbed from GI tract
146
VLDL
made by liver
target transport to adipose tissue
147
LDL
bad cholesterol
transport cholesterol and fat to blood vessel walls
causes atherosclerosis
148
HDL
good cholesterol
transport cholesterol to liver for secretion with bile
149
metabolic rate
rate of energy utilization Kcal/hr
carb and proteins: 4
fat: 9
measured by oxygen consumption, 1L of o2 is 4.8 kcal
150
basal metabolic rate
individual baseline rate of metabolism
measured at fasting
determined by thyroid hormones T3 and T4
151
what causes hunger
- increased glucose
- increased insulin
- leptin
- ghrelin
- stretch receptors
-- increased temp
152
leptin
hormone released by adipose cells
signal abdunant fat stores
153
ghrelin
hormone
released by empty stomach
promot food intake
154
mucus neck cell
secretion
stimulis
function
secrete: mucus
stimuli: tonic secretion
function: physical barrier between lumen and epithelium
secrete: bicarbonate
stimuli: secreted with mucus
function: buffers gastric acid to prevent damage
155
parietal cells
secretion
stimulis
function
secrete: gastric acid (HCl)
function: activates pepsin
secrete: intrinsic factor
function: complexes with B12 to permit absorption
stimuli for both: acetylcholine, gastrin, histamine
156
enterochromaffin cell
secrete: histamine (Paracrine)
stimuli: acetylcholine, gastrin
function: stimulates gastric acid secretion
157
chief cells
secrete: pepsinogen to digest proteins
secrete: gastric lipase to digest fat
stimuli for both: acetylcholine, secretin
158
D cells
secrete: somatostatin (endocrine)
stimuli: acid in stomach
function: inhibit gastric acid secretion
159
G cells
secrete: gastrin (endocrine)
stimuli: Ach, peptides, amino acids
function: stimulate gastric acid secretion
160
gastric acid secretion pathway
1. food initate cephalix reflexes, secretes gastrin, histamin, and acid
2. gastrin stimulates acid secretion by parietal cells
3. acid stimulates short reflex secretion of pepsinogen
4. stomatostatin releases H+ (neg. feedback), releases pepsin
161
gastric acid secretion during digestion phase
1. cephalic:
- sight/smell
- parasympathetic nerves to enteric NS
- increase HCl
2. gastric phase
- increase peptides, decrease H+
- long and short refelxes
- increase HCl
3. intestinal
- increase H+, osmolarity
- long and shortreflexes
- decrease HCl
162
NPY and agouti related protein
increase food intake
co expressed in hypothalamus
