HES 11 Midterm 2 Flashcards
1
Q
Around how Man litres of blood do we have and what percentage of body does it make up
A
5L and 8%
2
Q
what are the three types of cells and cell fragments in the blood?
A
Leukocytes
eryhtrocytes
Platelets
3
Q
Name 5 functions of the blood?
A
Transport - gases, solutes,
Repair- blood clots seal damaged vessels
Body temp reg
PH rege
blood pressure (maintained by blood volume)
4
Q
What is hematopoeisis, where does it take place and from what?
A
It is formation of blood cells - takes place in red bone barrow from hematopoetic stem cells
eryythropeoisis and leukopoiesis
5
Q
what doe erythroctyes lack? what is the cytosol filled with? what is its lifespan and where are they broken down?
A
Eryhtrocyets lack nucleus and other organells, its cytosol is filled with hemoglobin - has a lifespan of 120 days and its broken down in the spleen and liver
6
Q
What is are RBC’s broken up into? What happens to these products?
A
Broken up into heme, iron and amino acids
The heme gets converted to bilirubin which is a waste product - excreted in urine and feces
Iron and amino acids are recycled to make new hemoglobin
7
Q
What is iron required for in transporting oxygen?
A
It is requite for o2 binding to the heme group of hemloglobin
8
Q
what is erythopoeitin?
A
a horomon excreted by kidneys for RBC maturation - help reg negative feedback loop
9
Q
What are the 5 types of leukocytes, what are the most prominent ones
A
Neutrophils (most prom), eosinophils, basophils, lymphocytes, monocyte
10
Q
What are neutrophils?
A
phagocytyes ingest and destroy damaged cells
11
Q
what are eosinophils?
A
phagocytes - mainly involved in allergic rxns
12
Q
what are basophils?
A
the least common WBC - release chemicals that promote inflammation - mainly in allergic reactions
13
Q
what are lymphocytyes?
A
Have T cells - destroy invaders and B cells- secrete antibodies that destroy invaders
14
Q
What are monocytes?
A
phagocytes - turn into macrophages in tissues - eat up the damage
15
Q
what are platelets broken off from? lfiespan of platelets?
A
megakaryocytes. 7-10 days
16
Q
what is an antigen?
A
A unique glycoprotein found on the surface of all cells?
17
Q
what antigen is present in type A, B, AB, O blood? what does the positive and negative indicate?
A
Type A has A antigen
B has B antigen
AB has both
O has none
Positive means rH antigen is present, negative means it isnt.
18
Q
What does the body to against foreign anitgens that are not recognized as self?
A
make antibodies
19
Q
What happens when you recieve a RBC with a foreign antigen?
A
antibodies bind – agglutination pccurs – hemolysis
20
Q
What is the universal donor ?
A
O -, has no surafce antigens
21
Q
What is the universal recipient?
A
AB+ - has all the antigens therefore has no antibodies and can receive from all blood donors
22
Q
what are the 2 main components of the lymphaticc system?
A
lymphatic vessels
lymphatic tissues and organs
23
Q
what are the three main funtions of the lymphatic system?
A
1) part of the immune system
- immune cell prod, maturation and storage
- filtration of foreign pathogens
2) supports dietary fat absorption
3) Regulation of intertititial fluid volume
- pick up excess fluid in the extracellular spaces and deliver it back to CV system
24
Q
What type of tissue is lymphatic? What type of fibers and cells are present in this tissue?
A
Connective tissue
contains reticular fibres - form nets to cathc foreign pathogens and reticular cells - make the reticular fibres
Immune cells - B and T lymphocytes, macrophages, dendritic cells (derived from monocytes )
25
What do lymph nodes do?
filter and trap pathogens
26
How does the lymphatic system reg fluid volume surrounding cells?
fluid leaks from capillaries into intersitital space, increased prssure forces the lymphatic cells apart, fluid enters the lymphatic capillaries
27
What does the upper resp tract go from and to? Lower?
from nasal cavity. to the larynx
from trachea to alveoli
28
Describe the pathway of air
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
29
what are the three structures of the respiratory zone
respiritory bronchioles, alveolar ducts, alveolar sacs
30
What is the end of the conducting zone?
Terminal bronchioles
31
what epithelium is found in the nasal/oral areas and then what in the throat?
respiratory mucosa w mucous cells then stratified squamous then - respiratory mucosa - cuboidal - simple squamous
32
What does the nasal cavity do?
hair and mucosa filter air and rap particcles -
33
What are the three parts of the throat/pharynx? in order
nasopharynx -
osopharynx
laryngopharynx
34
function of nasopharynx, osopharynx and laryngopharynx
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
35
What does larynx contain and do? what happens during swallowing?
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
36
What does epiglottis do?
Close the glottis - preventing food from entering respiratory tract (trachea)
37
what covers anterior and lat surface of trachea? what does posterior opening allow?
hyaline cartillage, post pening allows esophagus to expand during swallowing
38
what is the lumen of trachea lines with and what does tracheabranch into?
lumen of trachea lined w mucosa (pseudosgart ciliated columan ep cells and goblet cells)
Trachea branches into the right and left primary bronchi
39
what 2 things happen as bronchi become smaller?
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
40
what are the smallest airways?
bronchioles
41
What is the structure of bronchioles? Inner lining =__ outer layer = ___and there is NO ___
Also lined w ____
What occurs here?
innner lining = simple cubodial outer = smooth muscle NO hyaline cartillage
also lined w elastic fibres
Bronchoconstiction and bronchodilation
42
what are the two things off of respiratory bronchioles
some alveoli bud directly off and some resp bronchioles branch in two or more alveolar ducts
43
what do alveolar ducts end in and what are alveoli lined w
alveolar ducts end in alveolar sac and alveoli are lined with elastic fibres
44
what are the three types of alveolar cells?
Type I, Type II and alveolar macrophages
45
what are the most common cells in alveoli? what is their function
Type I - gases diffuse across -why it is simple squamous
46
what is the rold of type Ii alveolar cells? what type of cells are they
They make surfactant - small cubiodal
47
what do alveolar macrophages do?
Theya re immune cells that eatt and digest debris that gets into alveolus
48
What would happen if water was the only molecule present on the inner lining of alveoli? How does surfactant prevent this?
force created by tension would cause alveoli to collapse - suraactant interrupts H bonds in order to reduce surface tension
49
How many lobes in each lung? what is each lung seperated by?
Left - 2
Right - 3
They are seperated by heart and mediastinum
Inferior base on disphragm
found in pleural cavity
50
What are the 2 serous membranes that encase each lung? What do they secrete?
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
51
what is ventilation?
the movement of air down its pressure grad
52
What is Boyles Law?
Pressure and Volume are inversely related:
P α 1/V
53
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
54
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
55
when does ppulm=patm
after expiration (step 1) and after inspiration (step 3)
56
when is atmospheric pressure greater than intrapulmonary pressure?
lungs increase in volume, pressure decreases inside so patm>pulm - inspiration
57
What are the pressures doing during expiration
Ppul is greater than patm - lung volume decreases airflow out of lungs
58
what are the skeletal muscles of quiet inspiration? expiration?
IN: diapghragm and ext interostals
Exp: none
59
what are the accessory mucsles of inspiration?
sternocleidomastoids, scalenes, pec minior, serratus ant
60
what are acc muscles of exp?
internal intercost, transversusb thoracis, ext oblique, rectus abdominis, internal oblique
61
What are three factors that influence pulmonary ventilation
1) Airway resistance
2) alveolar surface tension
3) pulmonary compliance and elastance
62
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
63
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
64
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
65
what happens when compliance decreasees?
lung less able to expand, effectiveness of inspiration decreases
66
what happens when elastane decreases?
lungs less able to recoil and effectiveness of expiration decreases
67
we can measure volume of air exchnage with each breath using a ____
spirometre
68
what is a graph called that allows us to measure lung volumes and capacities?
pulmonary function tests
69
What is tidal volume? What is normal value?
amount of air inspired/expired during ventilation at rest. 500mL
70
What is inspiratory reserve volume? normal value?
the amount of air that can be forcefully inspired after normal inspiration. 1900-3000mL
71
What is expiratory reserve volume?
amount of air that can be forcibly expired after normal expiration. 1000mL
72
What is residual volume?
Cant be measured w spirometre. Air remaining in lungs after max expiration
73
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
74
what is inspiratory capacity? equation?
total amount of air a person can inspire - IC = TV + IRV
75
What is functional Residual capacity? Formula?
Amount of air left in lungs after tidal expiration. FRC= ERV + RV
76
what is Vital capacity? Equation
Total amount of air that you can move in and out of your lungs. VC = TV + IRV + ERV
77
What is Total lung capacity?
Total amount of air that can fill the lungs
TLC = TV + IRV + ERV + RV
78
What is alveolar ventilation? Equation?
total volume of air reaching alveoli per minute. Va = breaths per min (f) x (Vt-VD (anatom dead space))
79
What is anatomic dead space? Equation?
air that never reaches alveoli, remains in conducting portion of lungs. VD = VT x 0.3
80
What are the 4 main parts of respiration
1) pulmonary respiration
2) Pulmonary gas exchange
3) Gas transport
4) Tissue Gas exchange
81
What is gas exhchange?
DIffusion of gases from one medium to another
82
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
83
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
84
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
85
What is pulmonary Gas Exchange
DIffusion of O2 and co2 between alveoli and blood - from alveoli to blood in pulm capillaries
86
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
87
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
88
what is tissue gas exchange?
DIffusion of O2 and CO2 between systemic capillaries and cells of tissues down parital pressure gradient
89
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
90
What o2 binds to what on hemoglobin?
heme group?
91
How many heme groups on hemoglobin? How much oxygen can hemoglobin hold?
4 and 4
92
what are the 2 reactions when Hb binds to O2?
loading and unloading: Hb and o2 makes oxyhemoglobin
93
What is the oxygen and hemloglobin graph called?
oxygen-hemoglobin dissacitation curve
94
The more o2 the ____ the bond between hemoglpobin and 02
the stronger the bond (higher affinity)
95
in normal resting conditions each Hb molecule remains ___ saturated with o2 even in venous blood
3/4
96
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
97
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%)
98
What is co2 converted to for transport?
HCO3-
99
CO2 is converted to HCO3- and the reverse reaction using what enzyme?
carbonic anhydrase
100
what does Co2 first get converted to before becoming HCO3-?
H2CO3 - carbonic acid
101
what is one of the main buffers of the body?
HCO3-
102
in normal condition blood pH is between?
7.34 and 7.45
103
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
104
What is respiratory alkalosis? What is it caused by?
It is an increase in pH (Low H+) - caused by hyperventilation
105
what is respiratory acidosis? caused by?
A decrease in pH (increase in H+) - hypoventilation
106
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
107
What is eupnea?
normal breathing - unaffected, natural breathing
108
what do central and peripheral chemoreceptores do generally?
detect changes in PCO2, Po2 and H+ in. blood
109
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
110
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
111
where does digestion begin?
oral cavity
112
where does most digestion occur?
small intestine
113
where does most nutrient absorption occur?
small intestine
114
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
115
what is another name for the alimentary canal?
gastrointestinal tract
116
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
117
were are processes of the GI function regualted ?
endocrine and nervous system - ANS and enteric nervous system
118
where do individal nturient monomers/absorbable units go?
small intestine
119
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
120
How much fluid is excreted. A lot or a little
0.1L out of 9L
121
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
122
what is the mucosa? What is type of tissue/cells?
Inner most lining of GI tract -
simple columnar and goblet cells which secrete mucous
123
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
124
what is muscularis externa? what is it made of?
3rd layer of Gi tract - made of smooth muscle - 2 layers - contains myencentric plexus
125
what is the serosa? made of?
outermost layer of GI tract - made of conn tissue
126
what are the 3 phases of regulation of the GI tract
cephalic phase, gastric phase, intestinal phase
127
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
128
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
129
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
130
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)
131
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
132
what are the 3 pairs of gland sthat secrete saliva into oral cavity?
parotid glands, submandibular, sublingual
133
what is saliva made of?
water, electrolytes and mucouse
saliary amylase
lysozyme
antibodies
bicarbonate ions
134
what does salivary amylase do in saliva?
starts chem digestion of carbs
135
what does lysozyme do? what do antibodies do? (in saliva)
kills bacteria
Kills pathogens
136
what do bicarbonate ions do in saliva
neutralize acid that may have escaped from stomach
137
what is salivation regulated by?
parasympathetic and sympathetic ns of ANS
138
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
139
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)
140
what are the 5 anatomical regions of the stomach
cardia, fungus, body, pyloric antum, pylorus( contains pylroric sphincter)
141
what does pyloric sphincter do?
control flow between stomach and small int
142
Are the layers of the stomach wall the same as GI tract? Name them again
yes - mucosa, submucos, musuclaris externa, serosa
143
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
144
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
145
what is chyme?
acidic fluid in stomach made of gastric juices and partly digested food
146
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
147
where are HCl and intrinsic factor secreted from?
parietal cells
148
where are pepsinogen and gastric lipase secreted by?
chief cells
149
what do parietal cells secrete ?
HCl and intrinsic factor
150
what do chief cells secrete
pepsinogen and gastric lipase
151
what do goblets cels and mucous neck cells secrete?
mucous
152
what does HCL do to pepsinogen?
converts it to pepsin and kills organisms we ingest
153
what does intrinsic factor do?
needed for absorption of vitamin B12 in the intestines
154
what are DNES cells and what do they do?
Diffuse neruoendocrinse system cells secrete different hormones taht reg digestive proccesses
155
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
156
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
157
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
158
what are the main functions of the small intestine? division?
accesory organs/
secretion, absorption, digestion, propulsion
Duodenum, jejunum, ileam
Pancreas, liver, galbladder
159
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
160
what is the point of the folds in the small intestine?
increase surface area for absorption
160
what are the folds in the small intestine.
circular folds - folding of mucosa and submucos
Villi -
microvilli
160
where are the final steps of digestion and all absorption? brush border?
microvilli
161
what does each villus contain?
layer of enterocytes surrounding central core of capillaries and lympahtic vesseks
162
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-
163
what hormones are secreted by endocrine cells lining duodenum?
Cholecystokinin (CCK):
Secretin:
164
what does cholecytsokinin (CCK) do?
stimulated the acinar cells to secrete digestive enzymes into pancreatic duct
165
what does secretin do?
stimulates secretion of HCO3- into pancratic duct - also feeds back to inhibit acid secretion from parietal cells
166
what does the liver produce and what is this needed for?
produces bile - needed for digestion of lipids
167
what does the galbladder do?
stores, concentrates and regulates release of bile via the common bile duct
168
what does the common bile duct join?
the main pancreatic duct and liver and secretes product into the duodenum
169
3 other functions of liver other than rpoducing bile
Metabolism of nutrients
- Detoxification / metabolism of drugs
- Preparation of waste products for excretion
170
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
171
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
172
where does mechanical digestion occur?
mouth, stomach, small intestine
173
whre does chem digestion occur?
stomach, mouth, small int
174
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
175
what are the brush border enzymes that finish digestion of carbs/
lactase, maltase, sucrase
176
where are carbs absorbed? what are the absorbable units?
in small intestine, glucose, galactose and fructose
177
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
178
what doe Na+/glucose cotransporter do?
secondary active transport of glucose and galactose
179
How is fructose absorbed
by facilataed diffsuion
180
what vein do the monosac take to get to the liver?
hepatic portal vein
181
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
182
what are the di and tri peptides found in the small intestine?
trypsin, chymotrypsin, carboxypeptidase
183
what are the free amino acid that are created in the small intestine?
Dipeptidase and Tripeptidase
184
what are proteins absoably units?
free amino acids
185
what are oligopeptides first broken down into?
free amino acids
186
what is protein absorption catalyzed by?
pancreatic and brush border enzymes
187
How do the amino acids cross the basal enterocyte membrane?
facilitated diffusion
188
what are the three parts of fat in our diet?
triglycerides, cholesterol and phospholipids
189
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
190
what enzyme intitiates chem digestion of fats? what enzyme works to chemically digest in the small intestine?
gastric lipase. Pancreatic lipase
191
what do lipids become?
monoglycerides and fatty acids- contained in micelles
192
what do micelles contain?
fatty acids, cholesterol, and any fat soluble vitamins from
193
what are the lipid binding proteins called
apoproteins
194
what are chylomicrons?
In fat absorption they contain the triglycerides, cholesterol, phospholipds and lipid binding proteins
195
where are most nutrients taken for initial processing?
to the liver
196
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
197
what maconutrient does not go directly to the liver abd where does it go instead?
packaged into chylomicrons and enters the lymhatic system
198
what are the divisions of the large intestine?
Cecum
* Colon
* Ascending - Transverse -
Descending - Sigmoid
* Rectum - Anal Canal
199
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
200
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
