Midterm II stuff - Hes III Flashcards
(176 cards)
1
Q
What does the upper resp tract go from and to? Lower?
A
from nasal cavity. to the larynx
from trachea to alveoli
2
Q
Describe the pathway of air
A
Nares - nasal cavity - nasopharynx - osopharynx - laryngopharynx - larynx - trachea - prim bronchii - secindary bronchi - multipel rbanches of bronchi - bronchioles - terminal bronchioles - respiratory bronchioles - alveolar ducts - alveolar sacs
3
Q
what are the three structures of the respiratory zone
A
respiritory bronchioles, alveolar ducts, alveolar sacs
4
Q
What is the end of the conducting zone?
A
Terminal bronchioles
5
Q
what epithelium is found in the nasal/oral areas and then what in the throat?
A
respiratory mucosa w mucous cells then stratified squamous then - respiratory mucosa - cuboidal - simple squamous
6
Q
What does the nasal cavity do?
A
hair and mucosa filter air and rap particcles -
7
Q
What are the three parts of the throat/pharynx? in order
A
nasopharynx -
osopharynx
laryngopharynx
8
Q
function of nasopharynx, osopharynx and laryngopharynx
A
naso - warm, humidify, filter air
oso - passafe for both air and food
laryngo - also passage for air and food
ant opens into larynx post opens into esophagus
9
Q
What does larynx contain and do? what happens during swallowing?
A
contains vocal chords
Passage for keeping food and lquids out of resp tract
During swallowing larynx lifted by surrounding muscles and glottis (opening to larynx) is closed by the epiglottis
10
Q
What does epiglottis do?
A
Close the glottis - preventing food from entering respiratory tract (trachea)
11
Q
what covers anterior and lat surface of trachea? what does posterior opening allow?
A
hyaline cartillage, post pening allows esophagus to expand during swallowing
12
Q
what is the lumen of trachea lines with and what does tracheabranch into?
A
lumen of trachea lined w mucosa (pseudosgart ciliated columan ep cells and goblet cells)
Trachea branches into the right and left primary bronchi
13
Q
what 2 things happen as bronchi become smaller?
A
Cartillage rings become more incomplete , more space betw each ring
smooth muscle lining- small bronchi can change dimater to control airflow into bronchioles and alveoli
14
Q
what are the smallest airways?
A
bronchioles
15
Q
What is the structure of bronchioles? Inner lining =__ outer layer = ___and there is NO ___
Also lined w ____
What occurs here?
A
innner lining = simple cubodial outer = smooth muscle NO hyaline cartillage
also lined w elastic fibres
Bronchoconstiction and bronchodilation
16
Q
what are the two things off of respiratory bronchioles
A
some alveoli bud directly off and some resp bronchioles branch in two or more alveolar ducts
17
Q
what do alveolar ducts end in and what are alveoli lined w
A
alveolar ducts end in alveolar sac and alveoli are lined with elastic fibres
18
Q
what are the three types of alveolar cells?
A
Type I, Type II and alveolar macrophages
19
Q
what are the most common cells in alveoli? what is their function
A
Type I - gases diffuse across -why it is simple squamous
20
Q
what is the rold of type Ii alveolar cells? what type of cells are they
A
They make surfactant - small cubiodal
21
Q
what do alveolar macrophages do?
A
Theya re immune cells that eatt and digest debris that gets into alveolus
22
Q
What would happen if water was the only molecule present on the inner lining of alveoli? How does surfactant prevent this?
A
force created by tension would cause alveoli to collapse - suraactant interrupts H bonds in order to reduce surface tension
23
Q
How many lobes in each lung? what is each lung seperated by?
A
Left - 2
Right - 3
They are seperated by heart and mediastinum
Inferior base on disphragm
found in pleural cavity
24
Q
What are the 2 serous membranes that encase each lung? What do they secrete?
A
Parietal pleura - outer - fused to rib cage and diaphragm
Turns over itself into..
Visceral pleura - inner layer - lung surface and divide into fissures to form lobes
Pleural membranes secrete fluid into pleural cavity - lubrication for lungs during ventilation
25
what is ventilation?
the movement of air down its pressure grad
26
What is Boyles Law?
Pressure and Volume are inversely related:
P α 1/V
27
what does the process of pulm ventialtion involve and what does this create?
The process of pulmonary ventilation onvolves volume changes in the thoracic cavity and lung leading to creation of pressure gradient
28
What are the 2 main pressures and one ohter pressure that determine airflow into and our of lungs?
atmospheric pressue (patm) and intrapulmonary pressure (Ppulm)
Intrapleural pressure
29
when does ppulm=patm
after expiration (step 1) and after inspiration (step 3)
30
when is atmospheric pressure greater than intrapulmonary pressure?
lungs increase in volume, pressure decreases inside so patm>pulm - inspiration
31
What are the pressures doing during expiration
Ppul is greater than patm - lung volume decreases airflow out of lungs
32
what are the skeletal muscles of quiet inspiration? expiration?
IN: diapghragm and ext interostals
Exp: none
33
what are the accessory mucsles of inspiration?
sternocleidomastoids, scalenes, pec minior, serratus ant
34
what are acc muscles of exp?
internal intercost, transversusb thoracis, ext oblique, rectus abdominis, internal oblique
35
What are three factors that influence pulmonary ventilation
1) Airway resistance
2) alveolar surface tension
3) pulmonary compliance and elastance
36
what is airway resistance mostly determined by? how can this be modified?
airway diametre
modified at the bronchioles - bronchodilation - increases diametre. - decreases airway resistance - increases air flow
bronchoconstriction - decreases diametre, increases airway resistance and therefore decreases air flow
37
The higher the surface tension inside the alveoli - the harder it is for___
How is this decreased?
alveoli to expand. Decreased by the presence of surfactant - breaks up bonds of water molecules
38
What is pulmonary compliance and elastance. What are three factors that determine this ?
the ease of the lungs to expand and recoil.
1) degree of alveolar surface tension
2) distensibility and elasticity of elastic tissue gives lungs the ability to stretch during inspiration and recoil during expriation
3) ability of the chest wall to expand during inspiration
39
what happens when compliance decreasees?
lung less able to expand, effectiveness of inspiration decreases
40
what happens when elastane decreases?
lungs less able to recoil and effectiveness of expiration decreases
41
we can measure volume of air exchnage with each breath using a ____
spirometre
42
what is a graph called that allows us to measure lung volumes and capacities?
pulmonary function tests
43
What is tidal volume? What is normal value?
amount of air inspired/expired during ventilation at rest. 500mL
44
What is inspiratory reserve volume? normal value?
the amount of air that can be forcefully inspired after normal inspiration. 1900-3000mL
45
What is expiratory reserve volume?
amount of air that can be forcibly expired after normal expiration. 1000mL
46
What is residual volume?
Cant be measured w spirometre. Air remaining in lungs after max expiration
47
what is minute ventilation? Formula
total volume of air that moves in and out of the lungs per minute - tidal volume x # of breaths per min
48
what is inspiratory capacity? equation?
total amount of air a person can inspire - IC = TV + IRV
49
What is functional Residual capacity? Formula?
Amount of air left in lungs after tidal expiration. FRC= ERV + RV
50
what is Vital capacity? Equation
Total amount of air that you can move in and out of your lungs. VC = TV + IRV + ERV
51
What is Total lung capacity?
Total amount of air that can fill the lungs
TLC = TV + IRV + ERV + RV
52
What is alveolar ventilation? Equation?
total volume of air reaching alveoli per minute. Va = breaths per min (f) x (Vt-VD (anatom dead space))
53
What is anatomic dead space? Equation?
air that never reaches alveoli, remains in conducting portion of lungs. VD = VT x 0.3
54
What are the 4 main parts of respiration
1) pulmonary respiration
2) Pulmonary gas exchange
3) Gas transport
4) Tissue Gas exchange
55
What is gas exhchange?
DIffusion of gases from one medium to another
56
What is Daltons law of partial pressures? Eqaution for atmospheric pressure?
Each gas in a mixture exerts its own pressure (Partial P) the total pressure in a mixture is a sum of all partial pressures. Patm = PN2 + PO2 + PCO2
57
What is Henry's Law?
Degree to which gas dissolves in a liquid is porportional to both partial pressure and solubility in liquid - explains behaviour of gases in air that come in contact w water in body
58
OF the three gases what is the most, least soluble in blood/water
Most soluble = co2, then o2 has low solubility, N2 very low solubility despite high PN2 grad - barely any acc enters lungs
59
What is pulmonary Gas Exchange
DIffusion of O2 and co2 between alveoli and blood - from alveoli to blood in pulm capillaries
60
What has a higer partial pressure grad o2 or co2?
O2 but solubility is lower so its actual amount that diff acris round the same as CO2
61
What are 3 factors that affect PULM gas exchange?
1) surface area of total resp membrane (where gas exchange occurs - very high SA of lungs cause of struture and number of alveoli
2) distance for diffusion of gases - lowest possible distance due to alveoli and capillaries
3) Matching of ventilation and perfusion
- matching the amount of air reaching alveoli with the amount of blood flow
62
what is tissue gas exchange?
DIffusion of O2 and CO2 between systemic capillaries and cells of tissues down parital pressure gradient
63
three factors affecting TISSUE gas exchange?
1) surface area available for gases - depends of capillary density
2) perfusion of tissue - depends on how much blood flow getting to tissues
3) distance of diffusion - depends on type of cells gases need to get across and how close they are to capillary bed
64
What o2 binds to what on hemoglobin?
heme group?
65
How many heme groups on hemoglobin? How much oxygen can hemoglobin hold?
4 and 4
66
what are the 2 reactions when Hb binds to O2?
loading and unloading: Hb and o2 makes oxyhemoglobin
67
What is the oxygen and hemloglobin graph called?
oxygen-hemoglobin dissacitation curve
68
The more o2 the ____ the bond between hemoglpobin and 02
the stronger the bond (higher affinity)
69
in normal resting conditions each Hb molecule remains ___ saturated with o2 even in venous blood
3/4
70
3 factors that affect the affinity of O2-Hb binding what does it cause
decreased pH, increased PCo2, increased temperature> Right shift of disacc curve - o2 unloads more easily at tissues
71
What are the 3 methods of transport of Co2
1) dissolved in the blood plasma (7-10%)
2) bound to hemoglobin: carabminohemoglobin (20%)
3) as HCO3- (bicarbonate) in the blood (70%)
72
What is co2 converted to for transport?
HCO3-
73
CO2 is converted to HCO3- and the reverse reaction using what enzyme?
carbonic anhydrase
74
what does Co2 first get converted to before becoming HCO3-?
H2CO3 - carbonic acid
75
what is one of the main buffers of the body?
HCO3-
76
in normal condition blood pH is between?
7.34 and 7.45
77
if there is excess H+ how does the body buffer it?
H+ combines with HCO3- to produce H2CO3- which then gets broken down into H20 and co2 and leaves the body thru the alveolus
78
What is respiratory alkalosis? What is it caused by?
It is an increase in pH (Low H+) - caused by hyperventilation
79
what is respiratory acidosis? caused by?
A decrease in pH (increase in H+) - hypoventilation
80
what is hyperventialtion caused by? What is hypoventilation caused by?
hyper - more co2 is expired leads to a low blood PCO2, increase in pH (low H+)
Hypo = less CO2 expired leads to high blood co2 and decrease in pH
81
What is eupnea?
normal breathing - unaffected, natural breathing
82
what do central and peripheral chemoreceptores do generally?
detect changes in PCO2, Po2 and H+ in. blood
83
where are central chemoreceptors found and what do they do>
medulla. Monitor levels in cerebrospinal fluid - detect changes in PCO2 and H+ - signal sent to reg rate and depth of breathing in order to return levels to normal
84
what do peripheral chemoreceptors do and where are they locoated?
in aorta and carotid arteries. detect changes in pCO2, H+ and PO2 (<70mmHg) - singal sent ot medulla
85
where does digestion begin?
oral cavity
86
where does most digestion occur?
small intestine
87
where does most nutrient absorption occur?
small intestine
88
what is the primary goal of the digestive system?
break food down in order to get all nutrients into absorbable units - transfer nutrients and water from food into the body
89
what is another name for the alimentary canal?
gastrointestinal tract
90
what are the 4 main functions of the digestive system?
digestion - chem and mechanical breakdown of food into absorbable units,
absorption - Nutrients, water &
electrolytes are moved from the GI
lumen to circulation,
secretion - endocrine and exocrine
glands secrete substances into the
lumen
motility - Movement of material through
the GI tract
91
were are processes of the GI function regualted ?
endocrine and nervous system - ANS and enteric nervous system
92
where do individal nturient monomers/absorbable units go?
small intestine
93
what is the total flyid input into the digestive system - from what?
9.0L. from food and drink, saliva,bile, gastric secreation, poancreatic scretions, intestinal secretaions
94
How much fluid is excreted. A lot or a little
0.1L out of 9L
95
What are the two types of contractions within the GI tract? Which has a net forward movement?
Peristaltic and segmental. Peristaltic - moves forward. circular muscles contract just behind bolus of food
96
what is the mucosa? What is type of tissue/cells?
Inner most lining of GI tract -
simple columnar and goblet cells which secrete mucous
97
what is the submucosa? what type of tissue cells? waht does it icontain
The second layer fo GI tracts- conn tissue. Contains submucosal plexus - nerves
98
what is muscularis externa? what is it made of?
3rd layer of Gi tract - made of smooth muscle - 2 layers - contains myencentric plexus
99
what is the serosa? made of?
outermost layer of GI tract - made of conn tissue
100
what are the 3 phases of regulation of the GI tract
cephalic phase, gastric phase, intestinal phase
101
what does cephallic phase do?
What nerve is it mediated by?
what is it activated in response to?
Stimulates production of?
Mediated by vagus nerve.
It prepares the GI tract in advance for incoming food.
activated in response to sight, smell, taste, though of food
Stimulates prod of saliva, gastric, pancreatic secret, GI hormones
102
what happens to stomach wall in the gastric phase? what does this lead to?
Distention in stomach wall from incr in food stimulates neurons of enteric NS and sensory receptors that stim vagus N
103
What is the intestinal phase triggered by? what comes after it? Inhibtion of__
Entry of partially digested protein in duodenum
Followed by inhibition of HCl secretion via enterogastric reflex
104
What happens during cephalic phase in stomach/stomach acid secretion
directed by CNS-PNS/vagus nerve
Direct stimulation of parietal cells and VIA horomones that trigger HCl secretion (histamine and gastrine)
105
what are the three main fucntions of oral cavity and 2 types of digestion
What happens here?
digestion, secretion, propulsion. Both mechanical and chemical digestion.
Chewing - mechanical
saliva secretion - begin chem dig by softeing and moistening food.
Propulsion form oral cavity - pharynx - esophagus thru swallowing
106
what are the 3 pairs of gland sthat secrete saliva into oral cavity?
parotid glands, submandibular, sublingual
107
what is saliva made of?
water, electrolytes and mucouse
saliary amylase
lysozyme
antibodies
bicarbonate ions
108
what does salivary amylase do in saliva?
starts chem digestion of carbs
109
what does lysozyme do? what do antibodies do? (in saliva)
kills bacteria
Kills pathogens
110
what do bicarbonate ions do in saliva
neutralize acid that may have escaped from stomach
111
what is salivation regulated by?
parasympathetic and sympathetic ns of ANS
112
What is the swallowing reflex? 3 phases
1) vountary pahse - tongue pushes bolus post. to osopharynx
2)pharyngeal phase - bolus enteres osopharynx - soft palate and epiglottis seal off nasopharynx and larynx
3) esophageal phase - peristaltic waves move bolus down esophagus into stomach
113
what are the 2 main functions of the esophagus? what are the two sphincters?
propulsion 9peristalsis) and secretion
upper esophageal sphincter
lower esophageal (gastroesophageal sphincter)
114
what are the 5 anatomical regions of the stomach
cardia, fungus, body, pyloric antum, pylorus( contains pylroric sphincter)
115
what does pyloric sphincter do?
control flow between stomach and small int
116
Are the layers of the stomach wall the same as GI tract? Name them again
yes - mucosa, submucos, musuclaris externa, serosa
117
what does the mucosa of the STOMACH WALL contain? what do they secrete
gastric pits lined with gland cells - secrete gastric juice and mucus into lumen of stomach
118
What does the muscuaris externa ahve in stomach but not GI? What does this do, how is it arranged?
an extra layer of smooth muscle - arranged obliquely
does mixing and churning to produce chyme
119
what is chyme?
acidic fluid in stomach made of gastric juices and partly digested food
120
what are the 3 main digestive functions of the stomach?
Secretion - HCI and intrinsc factor from parietal cells, pepsiongen and gastric lip form chief cells, horomones from neuroendocrine cells
digestion - mechanical thru mixing and churning
chemical of protein by pepsin
chemical of fat by gastric lipase
motility - mixing and churning of contents - mixing all secetions w food bolus to make chyme
121
where are HCl and intrinsic factor secreted from?
parietal cells
122
where are pepsinogen and gastric lipase secreted by?
chief cells
123
what do parietal cells secrete ?
HCl and intrinsic factor
124
what do chief cells secrete
pepsinogen and gastric lipase
125
what do goblets cels and mucous neck cells secrete?
mucous
126
what does HCL do to pepsinogen?
converts it to pepsin and kills organisms we ingest
127
what does intrinsic factor do?
needed for absorption of vitamin B12 in the intestines
128
what are DNES cells and what do they do?
Diffuse neruoendocrinse system cells secrete different hormones taht reg digestive proccesses
129
what 3 horomones do DNES cells secrete? What do these do>
gastrin, histamine and somatostatin
Gastrin and histamine iniate HCl secretion form parietal cells and somatostatin inhibit secretion
130
Why do our cells secrete
an inactive form of
pepsin (pepsinogen)
pepsin secreted as pepsinogen because it pepsin is strong and can damage the stomach and its glands
131
Describe motility of the stomach
recieves the bolus from esophagus by relaxing the gastroeophageal sphincter, fundus and body of stomach
mixing and churning into chyme thru waves of peristalsis and segmental contractions
the chyme is released into small intestine
132
what are the main functions of the small intestine? division?
accesory organs/
secretion, absorption, digestion, propulsion
Duodenum, jejunum, ileam
Pancreas, liver, galbladder
133
Motility of the small intestine? What does peristalsis do? what does segmentational contractions do?
peristalsis - propels chyme to large intestine
Segmental contractions contribute to mechanical digestion and mix chyme w digestive juices
134
what is the point of the folds in the small intestine?
increase surface area for absorption
135
what are the folds in the small intestine.
circular folds - folding of mucosa and submucos
Villi -
microvilli
136
where are the final steps of digestion and all absorption? brush border?
microvilli
137
what does each villus contain?
layer of enterocytes surrounding central core of capillaries and lympahtic vesseks
138
what type fo cells are in the exocrine pancrease? what do these cells secrete?
acinar cells - secretions of pancreatic juice which is water, digestive enzymes and HCO3-
139
what hormones are secreted by endocrine cells lining duodenum?
Cholecystokinin (CCK):
Secretin:
140
what does cholecytsokinin (CCK) do?
stimulated the acinar cells to secrete digestive enzymes into pancreatic duct
141
what does secretin do?
stimulates secretion of HCO3- into pancratic duct - also feeds back to inhibit acid secretion from parietal cells
142
what does the liver produce and what is this needed for?
produces bile - needed for digestion of lipids
143
what does the galbladder do?
stores, concentrates and regulates release of bile via the common bile duct
144
what does the common bile duct join?
the main pancreatic duct and liver and secretes product into the duodenum
145
3 other functions of liver other than rpoducing bile
Metabolism of nutrients
- Detoxification / metabolism of drugs
- Preparation of waste products for excretion
146
explain regulation of bile secretion
1) duodenal cells secrete CCK and secetin into. blood
2) CCK triggers contraction of galbladder whch then releases bile
3) bile salts and secretin trigger release of more bile (pos feeedbak loop). bile secretions continue until duodenum empti3es
147
Explain how bile secretion is reg by a positive feedback loop?
cck and secretin triggeer contraction of the gallbladder which releases bile the bile salts then trigger the release of more bile until the duodenum is empty
148
where does mechanical digestion occur?
mouth, stomach, small intestine
149
whre does chem digestion occur?
stomach, mouth, small int
150
explain how carbs are digested (not incl absorption)
first salivary amylase begins digest polysacharide chains into oligosaccharides
nothing in stomach - no chem digestion
pancreatic amylase continues digestion
the brushborder enzymes finish digestion of oligosaccahrides into monosaccharides
151
what are the brush border enzymes that finish digestion of carbs/
lactase, maltase, sucrase
152
where are carbs absorbed? what are the absorbable units?
in small intestine, glucose, galactose and fructose
153
How are carbs absorbed?
after becoming monosaccarides the na/k pump creates a gradient for Na+ aboroption from fluid in the lumen
the gradient drives sexondary active tranport of glucose and glctose bia na+/glucose cotransporter
fructose absorbed by facilitated diffusion
all 3 monosac cross membrane and diffuse into blood and go to liver via hepatic portal vein for processing
154
what doe Na+/glucose cotransporter do?
secondary active transport of glucose and galactose
155
How is fructose absorbed
by facilataed diffsuion
156
what vein do the monosac take to get to the liver?
hepatic portal vein
157
describe protein digestion (not absorption
no chem digestion in mouth
in stomach pepsin initates digetion into small polypeptides, aligopeptides and amino acids
in small intestine pancreatic enzymes digest peptides into di and tri peptides - Trypsin, chymotrypsin, carboxypeptidase
brush border enzymes finish digestion into free amino acids -Dipeptidase and Tripeptidase
158
what are the di and tri peptides found in the small intestine?
trypsin, chymotrypsin, carboxypeptidase
159
what are the free amino acid that are created in the small intestine?
Dipeptidase and Tripeptidase
160
what are proteins absoably units?
free amino acids
161
what are oligopeptides first broken down into?
free amino acids
162
what is protein absorption catalyzed by?
pancreatic and brush border enzymes
163
How do the amino acids cross the basal enterocyte membrane?
facilitated diffusion
164
what are the three parts of fat in our diet?
triglycerides, cholesterol and phospholipids
165
explain fat digestion not absorption
no chem in mouth
stomach - mixing and churning in stomach break up large lipid globules
gastric lipase initiates chem diges
Small int: bile salts from gallbladder coat lipid droplets forming an emulsion
166
what enzyme intitiates chem digestion of fats? what enzyme works to chemically digest in the small intestine?
gastric lipase. Pancreatic lipase
167
what do lipids become?
monoglycerides and fatty acids- contained in micelles
168
what do micelles contain?
fatty acids, cholesterol, and any fat soluble vitamins from
169
what are the lipid binding proteins called
apoproteins
170
what are chylomicrons?
In fat absorption they contain the triglycerides, cholesterol, phospholipds and lipid binding proteins
171
where are most nutrients taken for initial processing?
to the liver
172
the capillaries of the GI tact pick up _____ whereas the capillaries of the hepatic portal _______
pick up absorbed nutrients and hepatic portal presents nutrients to the liver
173
what maconutrient does not go directly to the liver abd where does it go instead?
packaged into chylomicrons and enters the lymhatic system
174
what are the divisions of the large intestine?
Cecum
* Colon
* Ascending - Transverse -
Descending - Sigmoid
* Rectum - Anal Canal
175
what are the main functions of the large intestine
Absorption of water, electrolytes &
some vitamins
* Secretion (mostly mucus)
* Propulsion & defecation of waste
* Also houses many important bacteria
176
what is the function of bacteria in the small intestine?
Absorption of water, electrolytes &
some vitamins
* Secretion (mostly mucus)
* Propulsion & defecation of waste
* Also houses many important bacteria
