A&P Exam 3 Flashcards
(307 cards)
1
Q
name the 5 functions of the digestive system
A
ingestion, digestion (mechanical- physical and chemical- enzymes), absorption, compaction, and defecation
2
Q
micronutrients
A
can be absorbed directly from ingested food
3
Q
macronutrients
A
broken down into monomers by hydrolysis reactions
4
Q
the 3 layers of the mucosa of the GI tract wall include
A
epithelium, laminate propria, and muscularis mucosa
5
Q
what is between the muscularis mucosae and submucosa layer?
A
the submucosal nerve plexus
6
Q
what is included in the muscularis externa?
A
inner circular layer and outer longitudinal layer
7
Q
what is the serosa layer made of?
A
areolar tissue and mesothelium
8
Q
what is the epithelium of the GI tract wall made up of?
A
mostly simple columnar
9
Q
in what areas is the GI tract wall made up of stratified squamous epithelium?
A
the mouth to the esophagus and lower anal canal
10
Q
what is the lamina propria made up of?
A
loose connective tissue, MALT (lymphoid tissue that helps fight against pathogens)
11
Q
what is the muscularis mucosase made up of?
A
smooth muscle
12
Q
where do nutrients get absorbed into? lipids? lipid-soluble vitamins?
A
nutrients are absorbed into the blood and lipids and the vitamins are absorbed in the lymphatic capillaries
13
Q
what is the submucosa made up of?
A
loose areolar and dense irregular CT
14
Q
define mixing within the GI tract
A
the intestine separates into many different segments so bolus is separated and then pushed together
15
Q
what does the submucosa contain apart from tissue?
A
blood vessels, lymphatic vessels, a nerve plexus, and mucus glands in some areas
16
Q
what is derived from efferent division
A
somatic NS (motor neurons that activate skeletal muscles) and Autonomic NS
17
Q
the autonomic NS divides into 3 sections
A
sympathetic NS, parasympathetic NS, and the enteric NS
18
Q
what does the sympathetic NS and parasympathetic NS affect?
A
smooth and cardiac muscle, exocrine glands, and endocrine glands
19
Q
enteric NS affects the
A
digestive organs only
20
Q
the Enteric NS is located where
A
the submucosal plexus and myenteric plexus
21
Q
the enteric NS coordinates what
A
the mixing and propulsion reflexes in the GI tract
21
Q
what is between the 2 layers of the muscularis mucosae?
A
the myenteric plexus
22
Q
the parasympathetic ___ GI tract activities
A
promotes
23
Q
the ___ and ___ go to the myenteric plexus and stimulate the ____
A
vagus nerve and pelvic splanchnic nerve, smooth muscle and secretory cells respectively
23
the sympathetic ___ GI tract activities
opposes
24
the ___ and ___ go to the submucosal plexus and stimulate the ____
sympathetic ganglia and preganglionic fibers (from thoracic and lumbar spinal cord) and stimulate the postganglionic fibers and blood vessels respectively
25
describe the short reflex pathway (myenteric reflexes)
the stimulus stimulates chemo, mechano, and osmoreceptors to stimulate the enteric NS which either goes directly to the effector cells like smooth muscle or endocrine glands or it goes to the endocrine cells to stimulate hormone release into the blood which stimulates the effector cells and leads to a response
26
describe the long reflex pathway (vagovagal reflexes)
the stimulus stimulates chemo, mechano, and osmoreceptors to stimulate the central nervous system which stimulates the autonomic NS, and then the enteric NS which stimulates the effector cells or the endocrine cells that eventually stimulate said effector cells for the targeted response
27
what can be secreted to regulate the digestive tract?
paracrine secretions
27
what hormones are released to regulate the digestive tract?
gastrin and secretin
28
what cells is the oral cavity mostly made up of?
mostly nonkeratinized stratified squamous epithelium
29
how does mastication help the digestion process?
increases the surface area of the food to allow it to be exposed to digestive enzymes, promotes salivation
29
what parts of the oral cavity are keratinized?
the lips, portions of the tongue, small part of the hard palate
30
what is mastication controlled by?
the nuclei in medulla and pons, also called the mastication center
31
saliva is mostly made up of what?
99.5% water and a mix of solutes, salivary amylase (antibacterial), mucin (antiviral), and lysozyme
32
salivary amylase starts what
the chemical breakdown of starch
33
what are the 2 types of secretory cells within salivary glands
mucuous and serous cells
33
mucous cells secrete what
mucin, forming mucus upon hydration
34
serous cells produce what
watery fluid with electrolytes and salivary amylase
35
intrinsic salivary glands are where
oral cavity
36
extrinsic salivary glands are located where
outside oral cavity
37
between intrinsic and extrinsic, which produce the most saliva?
extrinsic
38
what are the 3 extrinsic salivary glands
parotid, submandibular, and sublingual glands
39
intrinsic salivary glands ____ release secretions independent of food
continuously
39
lingual, labial, palatine, buccal glands are located where? what is the gland type these are considered?
they're unicellular glands, tongue, labial, roof of mouth, inside of cheek
40
what is the enzyme that intrinsic salivary glands release, specifically the lingual glands?
lingual lipase, which begins digestion
41
which of the extrinsic salivary glands hold 20-30% of saliva?
parotid salivary gland, the largest one
42
infection of the parotid glands causes what
mumps
43
which extrinsic gland produces 60-70% of saliva
submandibular salivary gland
44
which extrinsic salivary gland contributes to 3-5% of saliva?
sublingual salivary gland
45
what 3 skeletal muscle pairs form the pharynx?
superior, middle, and inferior pharyngeal constrictors
46
what type of epithelium is the pharynx lined with?
nonkeratinized stratified squamous
47
superior esophageal sphincter closes when
you inhale
48
inferior esophageal sphincter helps
keep stomach contents from regurgitating with the help of diaphragm muscles
49
the esophagus contains ____ in its submucosa, why is this important?
lots of elastic fibers to allow stretching during swallowing
50
an esophagus' muscularis layer has both ____ and ____ muscle
skeletal in the superior 1/3 and smooth in the inferior 1/3, in the middle 1/3, there's both
51
what are the 3 phases of deglutition
oral phase (voluntary), pharyngeal phase (involuntary), esophageal (involuntary)
52
describe the voluntary phase of deglutition
the food is pushed by the tongue against the hard palate and moves to the oropharynx
53
describe the pharyngeal phase of deglutition
as the bolus goes to through the oropharynx, the soft palate and uvula rise and cover the nasopharynx, and the larynx elevates too so the epiglottis closes over the laryngeal inlet
54
describe the esophageal phase of deglutition
the soft palate and uvula return to their original position, superior esophageal sphincter closes, the inferior esophageal sphincter opens and allows bolus to pass through, overall the peristalsis contractions help move the bolus to the stomach
55
how do the tunics of the stomach differ from the "default" tunic pattern?
there's an extra muscularis layer-- the oblique layer and has different types of cells
56
surface mucous cells in the stomach release what
alkaline mucin
57
mucous neck cells in the stomach release what
acidic mucin, alkaline mucin too but not as much as surface cells
58
parietal cells in the stomach release what
HCl and intrinsic factor
59
what are the 7 major functions of stomach acid
sterilize food, digest proteins, activate pepsin, activate intrinsic factor, stimulate bile and enzyme delivery, close the esophageal sphincter, and open the pyloric sphincter
60
How is HCl formed in the parietal cells?
when Cl- is released by red blood cells, the it passes through the cell. CO2 reacts with water to from H2CO3 which divides into HCO3 and H+ to which the H+/K+ pump. The Cl- and H+ react and form HCl while the HCO3 that was produced is taken up by RBCs or traveling throughout the blood
61
what activates intrinsic factor?
vitamin B12 or cobalamin
62
Chief cells in the stomach release what
pepsinogen and gastric lipase
63
What happens when HCl and pepsinogen react?
the peptide is removed and pepsin is produced, activated form of pepsinogen, which can be used to reactivate the reaction or react with dietary proteins, resulting in denatured proteins and then oligopeptides
64
what's the main source of lipase? other sources?
lipase, then lingual gland, gastric gland, lungs, intestinal mucosa, milk, adipose tissue, and leukocytes
65
enteroendocrine cells in the stomach release what
serotonin and histamine (EDL cells) and somatostatin (d cells) and gastrin (G cells)
66
describe the process of enteroendocrine cell products
the enteric neuron releases acetylcholine which stimulates the parietal cell to release HCl, an acid, which decreases pH which stimulates D-cells who secrete somatostatin which inhibit G-cells
67
what does acidic mucin help with?
maintaining acidic conditions in stomach, and protecting the lining from abrasion and injury
67
zymogen
inactive precursor of pepsin
68
how does the mucous layer help the stomach lining?
it protects the lining from ulceration and from gastric enzymes with high acidity
69
what does gastric lipase do?
digest fats
70
what are the functions of HCl in the stomach?
breaks down plant cell walls and animal connective tissue, denatures proteins, converts pepsinogen into active pepsin, and kills most microorganisms entering stomach
71
intrinsic factor is important for what?
it's required for absorption of vitamin B12 in ileum and needed to produce normal erythrocytes
72
contractions of smooth muscle in the stomach wall mix ___ with ___ to form ____
bolus, gastric secretions, chyme
73
peristaltic waves result in ____ that move stomach contents towards the ____
pressure gradients, pyloric region
74
____ in the stomach increases force in pylorus against ___
pressure gradient, pyloric sphincter
75
when the ___ opens, a small volume of ___ enters the duodenum and then it closes which causes ____
pyloric sphincter, chyme, retropulsion
76
what is the stimulus(i) of the cephalic phase? receptors?
thought, smell, sight, or taste of food and the 5 sense are the receptors
77
after the receptor receives the stimulus in the cephalic phase, the sensory input includes
an increase in nerve signals from the cerebral cortex and hypothalamus
78
what is the integration center of the cephalic phase
the medulla oblongata
79
what is the motor output of the cephalic phase? effector?
an increase in nerve signals that are relayed along the vagus nerve to the stomach. the effector is the stomach which increases the force of contraction and release of secretions
80
what is the stimulus and receptor of the gastric phase?
the presence of food in the stomach and the baroreceptors (which detect stretch in the stomach wall) and chemoreceptors (which detect the high protein or high pH in stomach content)-- these are located in the plexus
81
what is the sensory input of the gastric phase and where is it integrated?
increases nerve signals to the medulla oblongata
82
what is the motor output and effector of the gastric phase?
an increase in nerve signals sent along the vagus nerve to the stomach which is stimulated to increase its force of contraction and release of secretions.
83
Histamine and gastrin continue the stimulation of
acid and enzyme secretion
84
what is the stimulus and receptor of the intestinal phase?
the presence of acidic chyme/low pH in duodenum is detected by the chemoreceptors in the wall
85
what is the sensory input and integration center of the intestinal phase?
a decrease in nerve signals to the medulla oblongata
86
what is the motor output and effector of the intestinal phase?
a decrease in nerve signals relayed along vagus nerve to stomach which decreases its force of contraction and secretions released.
87
what hormones are released during intestinal phase?
cholecystokinin (CCK) and secretin
88
the only hormone released during the gastric phase is
gastrin which increases the force of stomach contractions and release of secretions and also contracts the pyloric sphincter.
89
what is an inhibitory event for the cephalic phase?
loss of appetite or depression
90
what is an inhibitory event for the gastric phase?
very low acidity in stomach and emotional stress. the low acidity targets the g cells to decrease gastrin secretion. stress activates the sympathetic NS to override the parasympathetic controls
91
what is an inhibitory event for the intestinal phase?
bloating of duodenum, presence of fatty, acidic, or hypertonic chyme and/or irritants in duodenum, and partially digested food in duodenum, leading tot he enterogastric reflex and release of entergastrones
92
gastric bypass
a surgical treatment for obesity
93
gastric ulcer
erosion of a part of the stomach due to helicobacter pylori
94
vomiting center is stimulated by
odor, smell, taste and is on the right side of the brain
95
chemoreceptor trigger zone for vomiting is triggered by
drugs and toxins, on the left side of brain
96
gastric reflux and reflux esophagitis
inflammation of esophagus due to acidic chyme refluxing into esophagus
97
how long do ingested nutrients reside in the small intestine?
12 hours
98
the small intestine absorbs most ____ and large percentage of ____,____, and_____
nutrients, water, electrolytes, and vitamins
99
the duodenum is receives what
chyme and accessory gland secretions
100
jejunum does what
chemical digestion and nutrient absorption
101
ileum does what
continues the absorption of digested material
102
duodenum is mostly ____ while jejunum and ileum is _____
retroperitoneal (behind peritoneum) intraperitoneal
103
enzymes on the lumen of the small intestines digest what
mono and disaccharides
104
monosaccharides are absorbed into the cell by ____ diffusion or by ____ transport with Na+
facilitated, secondary active
105
absorbed monosaccharides leave the cell by ___ and enter the ___, the ___ distributes the nutrients throughout the body
facilitated, blood, bloodstream
106
circular folds are more numerous in ___ and ____ less in ____
duodenum and jejunum, ileum
107
the circular folds are also called what? and they increase what
place circulares, surface area
108
the ____ increase the surface area by 10x and contain ___ and ____
villi, blood capillaries and lacteals
109
____ increase the surface area by 20x and is on ____ epithelial cells
microvilli, simple columnar, they are extensions of plasma membrane
110
the epithelium of the intestines include
goblet cells and enterocytes (simple columnar w/microvilli)
111
lacteals
lymphatic capillaries within the villi that absorb lipids and lipid-soluble vitamins
112
what do goblet cells produce?
mucin, precursor of mucous
113
what do enteroendocrine cells release?
hormones like cholecystokinin CCK and secretin
114
what do paneth cells produce?
lysozymes and other antimicrobial agents
115
what does the duodenal submucosal (Brunner) gland produce?
alkaline mucus which protects the duodenum from chyme
116
the smooth muscle of the small intestine mixes ___ with ____ and moves it against new areas of ____
chyme, gland secretions, brush border
117
early intestinal phase is
segmentation, the backward and forward motion that mixes chyme with gland secretions and intestinal juice
118
contractions in segmentation is initiated by ___ and spread through muscularis via ____
pacemaker cells, gap junctions
119
late intestinal phase is
peristalsis which repeats until all content is moved to large intestine
120
peristalsis is initiated by ____ which is released from the duodenum
motilin
121
migrating motility complex
successive waves of contractions
122
describe the gastroileal reflex
ileum contracts and the ileocecal sphincter relaxes (CCK causes this), the cecum relaxes and moves contents from ileum to cecum in response to food in stomach, the ileocecal valve contracts to prevent back flow
123
gallbladder
stores, concentrates, and releases bile
124
liver
produces bile
125
bile contains
minerals, cholesterol, neutral fats, phospholipids, bile pigments (bilirubin), and bile salts (lecithin and bile acids)
126
what do bile salts do to fat globules?
they coat the broken up droplets-- emulsification
127
how do gallstones form?
bile becomes excessively concentrated with wastes
128
hepatocytes can
process blood-born nutrients (arrive from gut through the hepatic portal vein), store fat-soluble vitamins, detoxification, recycle erythrocytes, and produce bile
129
cirrhosis
hepatocytes are replaced by fibrous scar tissue
130
what are the effects of cirrhosis
they compress blood vessels and bile ducts in the liver
131
hepatic portal hypertension
compression of blood vessels in the liver
132
what causes cirrhosis
chronic alcoholism, liver disease, drugs, or toxins, and viral infections like hepatitis B or C
133
what are the symptoms of cirrhosis
fatigue, weight loss, nausea, pain in the upper right quadrant, and more severe cases have jaundice, edema, ascites, itching, toxin accumulation, dilated veins of esophagus
134
what causes gallstones?
condensations of cholesterol or calcium and bile salts
135
what are symptoms of gallstones
severe pain, nausea, vomiting, indigestion, bloating, symptoms are worse after a fatty meal
136
what is pancreatic juice made up of?
sodium bicarbonate and enzymes like zymogen proteases and activated amylase, lipase, and nuclease
137
what kinds of zymogen proteases are involved in pancreatic juice
trypsinogen,, chymptrypsinogen, procarboxypeptidase
138
the enzymes in the pancreas need ___ for optimal activity
bile
139
what does sodium bicarbonate add to the digestion system?
neutralize the acidic gastric juice entering the small intestine, adjusts pH to allow the proper function of digestive enzymes
140
how do pancreatic enzymes affect the digestion process
amylase digests sugars, trupsina nd chymotrypsin digest proteins, lipase digests fats, nuclease digest RNA and DNA back into their nucleic acid building blocks
141
what's a hormone released in response to fatty chyme
cholecystokinin CCK
142
what is the role of CCK?
stimulates gallbladder to strongly contract and release bile, pancreas to release pancreatic juice, relax the smooth muscle within the hepatopancreatic ampulla to allow the entry of bile and pancreatic juice into the small intestine, and stops stomach motility and release of gastric secretions (overall stomach movement)
143
what is released in released in response to increased chyme acidity
secretin
144
CCK and secretin are released from
the small intestine
144
how does secretin affect digestion?
stimulates the release of alkaline solution with bicarbonate from liver and pancreas, neutralizes acidic chyme, and inhibits gastric secretions and stomach motility
145
what are the functions of the large intestine?
absorbs water and electrolytes from remaining digested material, watery chyme compacted into feces, stores feces until eliminated through defecation
146
muscularis externa is unusual where
colon
147
the large intestine does not have intestinal ___, but has numerous ____ extending towards the ____ which help to ______
villi, intestinal glands, muscularis mucosa, lubricate undigested material
148
the cecum and colon have 2 layers of smooth muscle in their muscularis
outer longitudinal layer and the discontinuous layer which forms the teniae coli
149
how much water per day is secreted into the lumen of GI tract?
6L which includes saliva, gastric juice, and mucus
150
what is the role of bacterial flora in the large intestine?
synthesize vitamins B and K, ferment indigestible carbohydrates like fiber--cellulose, and release irritating acids and gases which aid in propulsion
151
describe the neural pathway that stimulates defecation
poop stimulates baroreceptors in rectal wall due to stretching, which sends nerve signals from sensory neurons through the spinal cord, which go through cerebral cortex and relays nerve signals along the motor neurons which contract the smooth muscle of the sigmoid colon and rectum, output to the internal anal sphincter decreases, relaxing it. the decision to defecate is controlled by cerebral cortex, using the valsalva maneuver to eliminate the feces
152
haustral churning
relaxed haustrum fills with material, distention stimulates reflex contractions in muscularis, increasing churning and moves materials to more distal haustra
153
mass movements in large intestine
powerful contractions involve the teniae coli which propel the fecal material towards the rectum, 2-3x a day
154
gastrocolic reflex
started by stomach distention which causes a mass movement
155
when is voluntary defecation learned by? what does it entail?
age 3, relaxation of external (voluntary) anal sphincter
156
inflammation bowel disease (IBD) includes
Cohn disease and ulcerative colitis
157
irritable bowel syndrome (IBS)
affects 1 in 5 Americans, abnormal function of colon, more common in women, involves cramps, bloating, constipation, diarrhea, treated with diet, medication, stress reduction
158
Crohn's disease
autoimmune disorder, happens in young adults, intermittent and relapsing episodes of cramping and diarrhea
159
ulcerative colitis
similar to Crohn's but only involves the large intestine
160
galactose + glucose
lactose
161
glucose + glucose
maltose
162
fructose + glucose
sucrose
163
where do plants store their energy? animals?
in starch, glycogen, both using amylase
164
salivary amylase (mouth) and pancreatic amylase use what kind of digestion?
starch reacting with water to form oligosaccharides and maltose, with pancreatic amylase also producing glucose
165
what is the reaction dextrine and glucoamylase from the small intestine use?
oligosaccharides reacting with water to produce maltose and glucose
166
what is the reaction maltase from the small intestine uses?
maltose and water to produce 2 glucose
167
what is the reaction lactase from the small intestine use?
lactose + water to produce glucose and galactose
168
what is the reaction sucrose from the small intestine use?
sucrose + water to make glucose and fructose
169
what is the process of protein absorption by the small intestine
the pancreatic amylase is secreted to the small intestine, continues digestion of starch that was initiated by the mouth with salivary amylase, the brush border enzymes complete the breakdown of starch to individual glucose molecules and are responsible for the digestion of disaccharides
170
pepsin
produced by gastric glands in the stomach and mixes with water to digest the proteins into oligopeptides
171
trypsin, chymotrypsin, and carboxypeptidase react with water to produce what
oligopeptides and peptides, carboxypeptidase reduces them to dipeptides and amino acids, they're made in the pancreas and do their work in small intestines
172
peptidases
work and are produced by the small intestine, they react with water to produce 2 amino acids
173
what is the process of protein digestion in the small intestine?
first, proteolytic enzymes are released from pancreas, then enter peptidase activates trypsinogen to trypsin which then activates other proteolytic enzymes. Then these activates enzymes break proteins down into peptides and amino acids and then brush border peptidases break peptides into single amino acids to be absorbed through epithelial cell and into blood
174
175
what's the process of lipid digestion in the small intestines?
bile salts are released from the liver and gallbladder and emulsify lipid droplets to form micelles, then pancreatic lipase functions within micelles to digest each triglyceride into a monoglyercide and 2 fatty acids, which then enter an epithelial cell while bile salts remain in the intestinal lumen. the triglyceride molecules are reassembled within epithelial cells and lipids are wrapped with protein to form chylomicrons which are packaged within secretory vesicles and exocytosed from cell and absorbed into lacteals
176
lingual lipase and gastric lipase reaction process
turns triglycerides and 2water molecules into diglyceride and 1 fatty acid
177
pancreatic lipase turns ___ into ____
triglycerides and 2 water molecules into monoglycerides and 2 fatty acids
178
why are smaller fat droplets brown down?
since lipases help them form free fatty acids and monoglycerides
179
what forms the lipid core of a micelle?
monoglyceride, fatty acids, cholesterol, and fat-soluble vitamins
180
once micelles are absorbed by intestinal cells, they
resynthesize triglycerides and package them with cholesterol and phospholipids into protein-coated chylomicrons
181
what organelle packages chylomicrons into secretory vesicles?
Golgi complex
182
name some of the functions of the respiratory system that aren't the basic ones
acid-base balance, communication (sound production), blood pressure regulation, blood and lymph flow, platelet production, and expulsion of abdominal contents
183
what are the 4 processes of respiration
pulmonary ventilation (breathing), external respiration (pulmonary gas exchange), gas transport, and internal respiration (gas exchange)
184
what is the trachea wrapped in?
hyaline cartilage
185
what is included in the pleural sac?
parietal, visceral, and pleural cavity
186
where in the bronchial tree is there cartilage? where is it not?
primary to tertiary bronchus and the bronchioles, terminal, and respiratory which are wrapped in smooth muscle
187
what's the purpose of the pleural sac
reduce friction, compartmentalization, creates pressure gradient
188
the squamous alveolar cells allows for
fast exchanges of gases
189
the great alveolar cells secrete
surfactant that reduces surface tension and opposes collapse during expiration
190
dust cells
phagocytosis of microorganisms, the alveolar macrophages
191
what is the respiratory epithelium made up of? Where is this located?
pseudostratified cilitated columnar, most of the conducting zone: nasal cavity, nasopharynx, trachea, bottom of larynx, main bronchi, lobar bronchi... exception is oro and laryngopharynx and upper larynx
192
where in the respiratory is there stratified squamous?
high abrasion areas like the oro and laryngopharynx, vocal cords, and the upper larynx
193
what parts of the respiratory system has simple ciliated columnar epithelium?
segmental bronchi, smaller bronchi, and large bronchioles
194
what parts of the respiratory system has simple ciliated cuboidal epithelium?
terminal and respiratory bronchioles (no cilia)
195
what parts of the respiratory system has simple ciliated squamous epithelium?
alveolar ducts and alveoli
196
quiet respiration is also called what? and involves what?
eupnea, rhythmic breathing at rest, effortless, automatic
197
forced respiration
vigorous breathing, deep, rapid, during exercise
198
what contracts during inspiration?
diaphragm and external intercostals
198
Boyle's gas law
pressure and volume are inversely related
199
when is a pressure gradient formed?
when force is greater in one place than another
200
when there's an increase in altitude, there's a what in pressure?
decrease
201
intrapulmonary pressure
in alveoli: is equal to Patm at the end of inspiration and expiration
202
intrapleural pressure
pressure in the pleural cavity that keeps lungs inflated as it's less than the Patm (756mmHg)
202
transpulmonary pressure equation
intrapulmonary - pleural
202
during quiet inspiration, what increases, what decreases? direction of airflow?
pleural cavity volume and the volume in alveoli **increase** while lung pressure decreases. air flows down pressure gradient and into lungs until intrapulmonary pressure is equal to the Patm
203
during quiet inspiration, what increases, what decreases? direction of airflow?
pleural cavity volume and the volume in alveoli **decrease** while lung pressure increases. air flows down pressure gradient and OUT of lungs until intrapulmonary pressure is equal to the Patm
204
forced breathing causes
a greater change in thoracic cavity volume and intrapulmonary pressure
205
theres a balance between ___ and ____ forces in the respiratory system
pro-collase, anti-collapse
206
recoil of ____ in lungs pulls thoracic cavity inwards until it's equal to the ____ of the chest wall
elastic tissue, outward
206
ventral respiratory group (VRG) is in the
anterior medulla
207
dorsal respiratory group (DRG) is in the
posterior medulla
208
pontine respiratory group (PRG) is in the
pons: pneumotaxic center
209
what does the VRG neurons do?
synapse with lower motor neurons of skeletal muscle in spinal cord
209
axons innervating diaphragm travel in
phrenic nerves
210
axons innervating intercostal muscles travel in
intercostal nerves
211
central chemoreceptors are located where? what do they respond to?
medulla oblongata, changes in pH in cerebral spinal fluid and regulate respiration to maintain stable pH and stable CO2 levels in blood
211
peripheral chemoreceptors are located where? what do they respond to?
blood vessels, carotid and aortic bodies which respond to O2 and CO2 content and pH of blood
211
baroreceptors in the bronchi are located in
the smooth muscle of the bronchi(oles) and visceral pleura, responds to the inflation of lungs
212
proprioreceptors
muscles and joints stimulated by body movements
213
hypothalamus ___ breathing rate if body is warm
increases
214
limbic system alters breathing rate in response to ____
emotions
215
frontol lobe controls
voluntary changes in breathing patterns which can bypass the respiratory center altogether and sitmulate motor neurons directly
215
how does respiratory depth change?
stimulating accessory muscles
216
what happens if there's an increase in arterial CO2 pressure?
there's a drop in the pH of CSF which stimualtes the chemoreceptors which mediate about 70% of the response and peripheral chemoreceptors do 30%. both stimulate the medullary respiratory center to send signals tot he respiratory muscles which increase ventilation and amount of CO2 exhaled and arterial Pco2 and pH become normal
217
compliance in relation to breathing
how easy it is to inflate something, decreased by surface tension
218
distensibility
ability to stretch, pretty high in healthy lungs,
219
F= change in P/R is also
Patm-Palv/R
220
inspiratory capacity
Vt (tidal volume)-IRC
221
expiratory capacity
Vt+ ERV
222
vital capacity
IRV +Vt +ERV
223
Functional Residual capacity
ERV + RV
223
total lung capacity
VC + RV
223
each gas moves ___ down its own ____
independently, partial pressure gradient
223
give the percentages of the gases in the air
78.6% is Nitrogen, 20.9% O2, 0.04 CO2, 0-4% water, 0.17% other gases
224
dalton's law
Patm is the sum of the partial P of each individual gas
225
air is humidified in the lungs by what
mucous membranes
226
____ is 10x higher than inhaled air
alveolar water pressure
226
what is air mixed within the alveoli?
residual air
226
how much is left in the lungs at all times
about 1000mL of air
227
what is the pressure gradient between the alveoli and blood in pulmonary capillaries?
105 vs 40 and will continue to move until partial pressures are equal in both regions
228
what is solubility of a gas dependent on?
partial pressure of the gas in the air and solubility component (Kh)
228
a greater partial pressure means
more solubility in water
229
alveolar gas exchange has blood ___ O2 and ___ CO2, while tissue gas exchange (internal respiration) has blood ___ CO2 and ___ O2
loading, unloading, and loading, unloading
229
what is oxygen, CO2, and Nitrogen's solubility in water?
oxygen isn't very soluble, CO2 is tho, nitrogen is half of O2 so it doesn't dissolve in blood in significant amounts thus solubility goes from CO2>O2>N2
230
to push a gas with a low solubility component to a liquid what is required
larger partial pressure gradient
231
since residual air has gone through _____ a couple of times, it has a ___ O2 and _____ CO2 levels
gas exchange, lower, higher
232
pO2 in the alveoli is ___ more than inspired air, pCO2 is ____ higher than inspired air
65%,130x
233
in alveolar gas exchange, O2 diffuses into ___, CO2 diffuses into ____
blood and alveolus
234
O2 must cross what before diffusing into blood? CO2 before entering air
alveolar fluid
235
alveolar fluid
respiratory membrane covered with thin film with surfactant
236
henry's law
the greater the pressure of O2 in alveolar air, more O2 blood picks up
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in alveolar air exchange, O2 will dissolve into ___ and diffuse into ____. What are the pressure gradient?
alveolar fluid, blood. in alveoli: 104 mmHg, blood: 40 mmHg, so it flows down gradient
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in alveolar air exchange, CO2 will diffuse from ___ and into ____. What are the pressure gradient?
blood, alveolar fluid and air. goes from 46 mmHg in blood to 40mmHg, a smaller gradient than O2
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even though O2 has a steeper gradient, the ___ of CO2 is greater so there's just as much diffusion of CO2 as O2
solubility
240
ventilation-perfusion coupling
(amount of air flow and blood flow reaching the alveoli) both must match each other: good ventilation in alveoli and good perfusion in capillaries
241
when do pulmonary blood vessels change diameter? bronchi?
depends on airflow to lungs, blood flow. in poorly ventilated areas, the BV will vasoconstriction while the bronchi will constrict in poorly perfused areas, reducing the pressure of CO2 in alveoli so that it matches the O2 pressure
242
how is oxygen transported throughout the body?
by hemoglobin or dissolved in plasma
243
what does the body depend on to transport O2
solubility coefficient of O2 being low (so not alot dissolves in plasma) and presence of Hemoglobin (taking up 98% of blood)
244
HbO2 is called ___ HHb is called
oxyhemoglobin (o2 bound) deoxyhemoglobin (O2 not bound)
245
the amount of O2 bound to Hb determines
it's percent saturation of Hb
246
what is O2's utilization constant?
22% of O2 is delivered to tissues by Hb in resting conditions
247
how long does it take for equilibrium to be established in O2 and CO2 concentrations
1/4 of a second
248
a single RBC will spend ___ within alveolar capillaries even during vigorous exercise
1/2 second
249
if the pressure of O2 outside capillary increases, Hb saturation ___
increases
250
where does CO2 go in the body, give percentages
7% goes to alveoli as dissolved gas within plasma, 23% goes to Hb, on an amine group-- HbCO2-- carbaminohemoglobin, 70% is transported as carbonic acid and bicarbonate
250
cooperative binding effect
after the binding of each O2 molecule, a conformational change in Hb makes it so it's progressively easier for additional O2 molecules to bind to an available iron. this results in a sigmoidal curve
251
decrease in oxygen pressure, ___ binding of CO2 to Hb
increased
252
what decreases Hb affinity for CO2
when O2 is bound to Hb, when it's not, there's an increased ability to bind CO2
253
HHB ___ Hb affinity for O2 and stays bound to it
reduces
254
in what conditions is Hb readily willing to give up O2
when the tissues need more O2
255
the reaction of bicarbonate becoming CO2 keeps the partial pressure of CO2 ____ in RBC than plasma, allowing diffusion of CO2 into plasma
relatively high
256
the concentration of CO2 in tissues is ___ than in capillaries
higher
257
in hard working tissues that use more O2, there's a ___ in oxygen pressure and thus there's ___ o2 held by Hb
decrease, less
258
as Cl- comes in after bicarb leaves cell, the concentration of
bicarbonate in cell decreases, allowing for further diss. of carbonic acid to bicarb + H+
259
____ have pO2 about 40 mmhg so 22% of O2 is released by Hb and in____, there's less pO2 resulting in 40% O2 released by Hb
typical systemic tissues, sigmoidal curve
260
what is the loading and unloading of O2 by hemoglobin regulated by?
pO2, temperature, pCO2, blood pH, and BPG
261
in more active tissues, there's an _____ in temp since there's ____ which results in Hb____
increase, more ATP being used and energy is lost as heat, the increased heat makes Hb hold onto O2 more weakly and decrease Hb saturation (O2 is dropped off at the tissues)
262
active tissues result in an ___ in CO2 and ____ in blood pH as ____ forms. The H+ ___ the bond between Hb and O2, making it more likely to release it.
increase, decrease, bicarbonate, weakens
263
blood pH has the most potent effect on
breathing rate
264
acidosis in pH means blood is
lower than 7.35 (too much CO2)
265
blood alkalosis means pH
is higher than 7.45 (too little CO2)
266
hypocapnia
when pCO2 is less than 37 mmHg (alkalosis)
267
pH is detected by
peripheral (blood vessels carotid and aortic-25%) and central chemoreceptors (medulla oblongata-- pH of CSF-- 75% of response)
267
hypercapnia
pCO2 is greater than 43 mmHg (acidosis)
268
CSF receives CO2 when it
diffuses across the blood brain barriers in capillaries
269
CSF doesn't have as many ____ as blood so it drops dramatically when there's a lot of CO2
pH buffers (in blood there's HHb)
270
what's the corrective homeostatic response to acidosis?
hyperventilation as one needs to get rid of excess CO2, pushing the reaction to the left and increase blood pH to normal levels
271
what is the corrective homeostatic response to alkalosis
hypoventilation/slow breathing as CO2 must be retained and accumulate in body fluids, allowing H+ concentration to increase and pH to drop to normal levels
272
give the location, pO2, temp, pCO2, and pH of Oxygen **loading**
lungs, high, cool, low, high
273
what is directly related to the respiratory production of CO2?
the regulation of pH
274
what are the muscles of quiet breathing?
diaphragm and external intercostals
275
which center bears the main responsibility for generating the respiratory rhythm but is influenced by several other centers?
VRG
276
what issues output to the VRG to adjust the respiratory rhythm
DRG
277
output from higher brain centers can bypass both the DRG and VRG and go directly to ___, which controls the accessory muscles of respiration
spinal integration center
278
emotional states are integrated by the ___, which generates an output that creates such respiratory variations as laughing and crying
PRG
279
the amount of air in excess of tidal volume that can be inhaled with maximum effort is the
inspiratory reserve volume
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