Lab Final Flashcards
1
Q
How many populations of cardiac myocytes does the heart have?
A
two
2
Q
What are the populations of cardiac myocytes and what are they known as (include the percentages)
A
-the majority of the cell (~99%) are known as non pacemaker cells, which are regular contractile myocytes
-the remaining 1% are specialized cells known as pacemaker cells
3
Q
What is the unique property of pace maker cells and what does the property do?
A
-they can spontaneously depolarizing and generating action potentials
-the action potentials they initiate trigger action potentials of the nonpacemaker cells
4
Q
what is the stimulus for the non pacemaker cells to contract?
A
the action potentials that are triggered
5
Q
What makes up the cardiac conduction system?
A
-the clusters of pace maker cells that are located in specific areas of the heart
6
Q
Describe the SA node
A
-the SA node is located in the upper right atrium, where it acts as the main pacemaker of the heart
-it depolarizes spontaneously around 100 times per minute (BPM)
7
Q
What do you have to remember about resting heart rate?
A
-the resting heart rate is generally lower than 100 beats per minute (BPM) due to the influence of the autonomic nervous
system
8
Q
Describe the Atrioventricular Node
A
-located in the lower right atrium just medial to the tricuspid valve
-acts as a backup pace maker and is capable of pacing the heart at about 40 beats per minute
-conduction through the Av node is slow, producing what is known as the AV node delay
-this delay allows the atria to depolarize and contract before the ventricles which allows the ventricles to fill with blood
9
Q
Describe the Purkinje system
A
-the impulse are transmitted from the Av node to the ventricles by the group of pacemaker cells collectively called the Purkinje system
-the myocytes of the Purkinje system pace the heart slowly but conduct impulses more rapidly than any part of the conduction system
-the Purkinje system has 3 components
10
Q
What are the 3 components of the Purkinje system and describe them
A
-the atrioventricular (AV) bundle: a small group of fibers in the lower interatrial septum and upper interventricular septum that transmits impulses from the AV node to the ventricles
-Right and left bundle branches: impulses are transmitted from the AV bundle down either side of interventricular septum by the right and left bundle branches
Purkinje fibers: at the end of the interventricular septum, the right and left bundle branches fan out through the myocardium as the Purkinje fibers. these fibers extend about one third of the way into the heart muscle, after which they bend with regular nonpacemaker cardiac myocytes
11
Q
Describe the general pathway of impulse condition through the heart
A
-starts with the cells in the SA node that generate an action potential
-this pacemaker action potential spreads to the non pacemaker cells of the atria and triggers them to have action potentials and contract
-the impulses are carried through the atria until they hit the AV node, where they encounter a delay
-once the Av nodal cells are depolarized this spreads to the Purkinje system and finally to the non pacemaker cardiac myocytes of the ventricles
-these cells are then trigged to depolarize and contract
-as the ventricles are repolarizing the cells of the SA node are slowly depolarizing, which begins the cycle again
-it is this process that allows for blood to be pumped throughout the heart and the body
12
Q
What is important to note about ventricular depolarization and atrial repolarization
A
-while the ventricles are depolarizing the atria are repolarizing
13
Q
Describe Electrocardiography
A
-known as ECG or EKG
-this is the recording of the electrical potential changes produced by depolarization and repolarization of cardiac muscle cells during the cardiac cycle
14
Q
What is important when interpeting ECG
A
-conducting a systematic assessment
-what is the rate
-is this sinus rhythm? If not what is going on?
-are the P- waves normal?
-are the QRS complex’s normal?
-Are the ST segments normal, depressed or elevated? Quantify abnormalities
-Are the T-waves normal?
15
Q
A
16
Q
What are the ECG paper standards
A
-travels at 25 mm/ sec
1mm (small box)=0.04 sec
5mm (large box)=0.02 sec
17
Q
What is the first way that you can determine Heart Rate
A
15mm/ beat * 0.4 sec/mm= 0.6 sec/ beat–> 60 sec/min/ 0.6 sec/ beat= 100 beats/min (BPM)
-in this case the 15mm comes from counting the R-R
18
Q
What is the second way that you can determine Heart Rate
A
-the rule of 300
(300/ # of large boxes R-R)
-#of large boxes= 1, 2, 3, 4, 5, 6,
HR :300, 150, 100, 75, 60, 50
19
Q
what does R-R mean
A
-this value is the peak (R) to the other peak (R)
20
Q
what makes up one complete cycle in the ECG
A
1 cycle is all of the waves
-P wave, QRS complex and the T waves
21
Q
what does circulatiing blood provide
A
-a transportation and communication system between the body’s cells and serves to maintin a relatively stable internal enviornment for optimum cellular activity
22
Q
why does blood circulate( hint closed circuit)
A
because the heart pumps it through closed circuit of blood vessels
23
Q
how does blood flow through the heart (include the direction)
A
-blood flow through the heart and the blood vessels is unidirectional
-flows from the heart from the pulmonary and systemic veins and out of the heart into pulmonary and systemic arteries
24
Q
why is blood flow throughout the heart unidirectional
A
-blood flows through the chambers of the heart unidirectionally because of the action of four valves inside the heart that normally prevent retrograde or backward flow during the cardiac cycle
25
what are the primary pumping chambers
-the left and right ventricles
26
what happens to the AV and semilunar valves during ventricular diastole (relaxation) (what happens to the ventricles)
-AV valves open and semilunar valves close
-the ventricles fill with blood
27
what happens to the valves during ventricular systole (contraction)
-the AV valves close and the Semilunar valves open
this allows the ventricles to eject the blood into the arteries
28
Describe the pressure of the arteries during the cardiac cycle
-it varies
the ventricles will contract to push blood into the arterial system and then relax to fill with blood before pumping once more
-the intermittent ejection of blood into the arteries is balanced by a constant loss of blood from the arterial system through the capillaries
-when the heart pushes blood into the arteries there is a sudden increases in pressure, which slowly declines until the heart contracts again
29
when is BP at it's highest
-immediatly after the ventricles contracts (systolic pressure)
30
when is the BP at it's lowest
-immediately prior to the pumping of blood into the arteries (diastolic pressure)
31
how can systolic and diastolic pressures be measured ( this is the old mway)
-can be measured by inserting a small catheter into an artery and attaching the catheter to a pressure gauge
-this measurement is very accurate but it is invasive and often inconvenit and impractical
32
How is BP traditionally estimated
-you use a stethoscope and a blood pressure cuff that is connected to a mercury sphygmomanometer
-the cuff is placed on the upper arm and inflated to stop the arterial blood flow to the arm from the brachial artery
-the high pressure in the cuff collapses the artery
-the pressure in then released slowly
-when the cuff pressure begins to fall below the systolic pressure in the artery
-blood begins to flow to the arm through the partially collapsed artery
33
what are the Korotkoff sounds created by
-the turbulent flow of the blood because at this point the blood flow is not streamlined
34
when can systolic pressure be heard
-when the blood flow is first heard
35
when can you hear dystolic pressure
-as the cuff pressure continues to decrease and the artery regains it's normal diamter, flow becomes streamlined and the sounds become muffled and then disappear
36
How do you assess blood pressure
-clean the ear pieces and the part that comes in contact with the skin
-let the subject sit for at least 5 minutes with the elbow slightly flexed
-wrap the cuff around the upper arm and support the arm at the level of the heart; align the cuff with the brachial artery
-palpate the brachial artery and place the stethoscope bell below the antecubital space over the brachial artery. place the stethoscope firmly in ears with earpieces facing toward nose
-quickly inflate the cuff pressure to 160 mm Hg or 20 mm Hg above the estimated systolic BP
-slowly release the pressure at a rate equal to 2-3 mm Hg/sec. Note the first Korotkoff sound
-continue releasing the pressure nothing when the sound becomes muffled (4th phase of diastolic BP) and when the sound disappears (5th phase diastolic BP). the 5th Korotkoff sound is the measurement used for diastolic score
-the bp is generally written 120/80 mm Hg, with the systolic score written first. occasionally, the 5th Korotkoff sound never disappears completely or it may finally diminish at a very low pressure. an accepted way to record the BP when the pressure between Korotkoff 4 and 5 is greater than 10 mm Hg is to mark it as SBP/IV-V for example 120/76-20 mm Hg
37
How do you know when you get the diastolic score
the needle ticks and you dont here anything anymore
38
Describe the blood pressure phases and Korotkoff sounds
Phase 1: first appearance of clear tapping sound; marks the SBP
Phase 2: Murmuring or swishing sounds
Phase 3: Crisper sounds increasing in intensity
Phase 4: sounds suddenly become muffled
Phase 5: sounds disappear; marks DBP
39
what is normal bp for adults
120/80 mm Hg
40
what is elevated Bp
120-129 systolic Bp
<80 diastolic
41
what is the stage 1 hypertension bp
130-139 systolic BP
80-89 diastolic BP
42
what is the stage 2 hypertension BP
> or equal to 140 systolic BP
> or equal to 90 diastolic BP
43
Describe the hypertensive crisis BP
>180 systolic BP
>120 diastolic BP
44
what is needed to takes resting BP
a sphygmomanometer and a stethoscope
45
what does a sphygmomanometer consists of
-consists of an inflatable compression bag enclosed in an unyielding covering called the cuff, plus an inflating but, a manometer from which the pressure is read and a controlled exhaust valve to deflate the system
46
what is the stethoscope made of
-rubber tubing attached to a device that amplifies the sounds of blood passing through the blood vessels
47
what happens when the sphygmomanometer is placed around the upper arm of the patient and is inflated to a pressure above the patients systolic blood pressure and why does this happen
-there will be no sound audible
-this happens because the pressure in the cuff is high enough such that it completely occluded the blood flow
48
what happens if the pressure is dropped to a level equal to that of the patients systolic blood pressure
-the first Korotkoff sound will be heard
49
why is some blood still able to pass through the upper arm when the pressure in the artery rises during systole
-as the pressure in the cuff is the same as the pressure produced by the heart
50
what is turbulence the result of
the blood that is still able to pass through the upper arm flows in spurts as the pressure in the artery rises above the pressure in the cuff and then drops back down, resulting in turbulence
51
does turbulence have a sound
yes
52
what happens to the thumping sounds as the pressure of the cuff falls further
they can still be heard as long as the pressure in the cuff is between the systolic and diastolic pressures, as the arterial pressure keeps on rising above and dropping back below the pressure in the cuff
53
what happens to the sound as the pressure of the cuff drops all the way down
-the sounds change in quality then become muted and then disappear altogether
54
what happens when the pressure in the cuff drops below the diastolic blood pressure
-the cuff no longer provides any restriction to blood flow allowing the blood flow turbulence smooth again with no turbulence and thus produce no further audible sound
55
when would you take the BP of a patient
at different points in time and or under different circumstances (at rest vs. after exercise, etc) to see how to bloods pressure changes
56
what is the equation of mean arterial BP
MAP= (systolic)+ 2(diastolic)/ 3
57
equation for pulse pressure
pp= systolic pressure- diastolic pressure
58
what do endocrine glands do
they secret hormones directly into the blood
59
what is the purpose of secreted hormones
- to evoke a specific responses in cells/ tissues/ organs
60
describe negative feedback in the endocrine system and what does this achieve
-activity of the target organ acts back upon the gland and stimulates it
-this maintains homeostasis
61
describe the pituitary gland
-sits at the base of the skull and is often referred to as the master gland because of it's control of the endocrine system
62
describe the hypothalamus
-an area of the brain immediately above the pituitary gland, controls the pituitary gland by secreting releasing hormones for each of the target organs governed by the pituitary gland
63
how do endocrine system diseases and disorders occur
-when one or more of the endocrine glands become dysregulated
64
descriube neoplasms
-these are masses
-these are the most common disease of pituitary and may cause the pituitary gland to be overactive and underactive
65
what can overactivity attributed to
-attributable to the functional adenoma (benign hormone secreting tumor) formed from one of the cell types of which the anterior pituitary is composed
66
what can an adenoma of the anterior pituitary that secretes adrenocorticotropin (ACTH) result in
-the excessive release of cortisol and related hormones from the adrenal cortex
67
what can the affects of increased cortisol concentrations cause
-produce of combination of clinical findings known as Cushing syndrome such as hypertension, obesity, round facial features, diabetes, skin marks, excess body and facial hair and menstrual and mental abnormalities
-in addition to anterior pituitary adenomas excess cortisol and Cushing syndrome can result from a variety of other endocrine abnormalities
68
describe Luteinizing hormone adenomas
-these are fairly common anterior pituitary adenomas comprising ~10% of all anterior pituitary adenomas
-this type of adenoma causes excess LH to be released
69
is is more common for men or women to have Lh adenomas
-they occur most commonly in middle aged men and women and produce very little hormonal effect
70
why do LH adenomas come to attention
-bc of the mass attention effect (i.e. the adenoma presses on adjacent tissues resulting in pain and/ or functional problems)
71
how else can the endocrine system become dysregulated and give an example
-in the absence of adenomas
-neuroendocrine conditions can cause excessive production of endocrine hormones (like in cortisol)
72
describe how cortisol levels changed and what can prolonged effects of this hormone cause
-cortisol is normally found in low levels in the the blood stream but is secreted in high levels during the body's 'fight or flight' response to stress and is responsible for several stress related adaptive changes in the body (like preparing the body for fight or flight)
-prolonged levels of cortisol in the bloodstream like those associated with chronic psychological stress can have negative effects, such as impaired cognitive performance, suppressed thyroid function, blood sugar imbalances such as hyperglycemia, decreased bone density, decreased muscle tissue, high blood pressure, lowered immunity and increased abdominal fat
73
what is Cushing's syndrome
-is a relatively rare hormonal disorder caused by prolonged exposure of the body's tissues to high level of the hormone cortisol
--high levels of cortisol as a result of exposure to chronic stress is also associated with negative health consequences
74
what is ELISA
-this is one of the ways to measure salivary cortisol levels
-a microtiter plate is coated with monoclonal antibodies to cortisol
-cortisol in standard and unknowns competes with cortisol linked to horseradish peroxide for the antibody binding sites
-after incubation, unbound components are washed away
-bound cortisol peroxidase is measured by the reaction of the peroxidase enzyme on the substrate tetramethylbenzidine (TMB)
-this reaction produces a blue color
-a yellow color is formed after stopping the reaction with sulfuric aid
-optical density is read on a standard plate reader at 450 nm
-the amount of cortisol peroxidase detected is inversely proportional to the amount of cortisol present
75
what does LH play an important role with
-plays an important role in regulating reproduction
-once a month the hypothalamus and pituitary result in a LH surge, the dramatic increase in luteinizing hormone that takes place directly before a woman ovulates
-this is the most fertile time of the month for a females
-since the egg must be fertilized within 6-24 hours following ovulating, correctly predicating ovulation can improve chances of conception
76
what do cells need a constant supply of and why and what is the major byproduct of these reactions
-a constant supply of Oxygen for the oxidative reactions of mitochondrial ATP production
-CO2 is the major byproduct
77
what does the resp system exchange
-exchanges O2 and Co2 between the atmosphere and the blood
78
what do the specialized organs/ airway for the resp system do
filter, warm, and moisten the inhaled air before it enters the lungs
79
what happens once the air is in the lungs
-the O2 gas in the air diffuses in the surrounding capillaries to oxygenate the blood
-as the blood takes up oxygen, CO2 gas in the blood diffuses into the lungs and is exhaled
-pulmonary veins return the oxygenated blood to the heart, where it is pumped into the arteries of the systemic circulation
80
what does the respiratory system consist of
the nose, nasal cavity, sinuses, pharynx, larynx, trachea, bronchi, and lungs
81
what does the upper resp syste consist of and what does it do
-nose
-nasal cavity
-sinuses
-pharynx
-these all filter, warm and moisten the air before it enters the lower resp system
82
what does the lower resp system consist of
-larynx
-trachea
-bronchi
-lungs
83
what does the larynx do
-regulates the opening into the lower resp system and producuses speech sounds
84
what do the trachea and bronchi do
-they maintain an open airway to the lungs, where gas exchanges occurs
85
what is respiratory rate
-aka RR
-the number of breaths (inhalation+exhalation) that occur in one minute
86
how do you find the RR
breathe normally and have the recorder count the number of breaths in 30 seconds
one breath= 1 inhalation and 1 exhalation
-you multiply the number of breaths by 2 to calculate the RR in breaths/minute
-you do this three times, and then take the average
-the unite is breathes/ minute
87
what is the measurement of lung capacities
-spirometry is the diagnostic technique used to measure respiratory volume
-measures tidal volume, expiratory reserve volume, inspiratory reserve volume and vital capacity using handheld spirometers
88
what is vital capacity( hint expiration)
-the maximum amount of air a person can expel from the lungs after maximum inspiration
-a reliable diagnostic indicator of the persons pulmonary status
-VC= TV+IRV+ERV
89
what needs to happen to maintain normal homeostasis (hint this is about VC)
-to maintain normal homeostasis a persons vital capacity should be at least 80% of the precited value (based on gender, height, and age)
90
who has VC's near or even greater than their predicted value
-people who exercise regularly
91
who has a lower VC
-people who smoke
-ppl who have asthma
-some chronic obstruction pulmonary disease (COPD)
-restrictive disorder
92
what is the equation for predicting vital capacity in males
VC= 0.052 (H)- 0.022 (A)-3.6
VC = vital capacity in liters (L)
H = height in centimeters (cm) (recall that 1 inch = 2.54 cm; e.g., 60
inches x 2.54 = 152.4 cm)
A = age in years (yrs)
93
what is the equation for predicting vital capacity in females
VC=0.041 (H)- 0.018 (A)-2.69
VC = vital capacity in liters (L)
H = height in centimeters (cm) (recall that 1 inch = 2.54 cm; e.g., 60
inches x 2.54 = 152.4 cm)
A = age in years (yrs)
94
what is the equation of % predicted VC
% Predicted VC= (Average VC/ Predicted VC) x100
95
how do you find the TV
-inspiratory reserve volume
-the volume of air inspired or expired in a single breath during regular breathing
-determine P-P from the bottom to the top of one normal breath
96
IRV
inspiratory reserve volume
-the maximal amount of additional air that can be drawn into the lungs by determined effort after normal inspiration
-determine the Delta from the top of one normal breath to the top of the maximum inhalation
97
ERV
-expiratory reserve volume
-at the end of a normal expiration the quantity of air that can be expelled by forcible expiration
-determine that delta from the bottom of one normal breath to the bottom of the maximum exhalation
-change the sign from a negative value to a positive value
98
MRV
minute respiratory volume
-quantity of air moved into and out of the lungs in one minute
-you calculate it by this equation:
MRV=TV*Respiratory Rate
99
what do we expect from Resiptory rates HINT gasses
they will vary according to the bodies demand for gas exchange
100
what will happen when O2 and CO2 demand increases
-when this happens we have to increase RR rates to delivery more gases
101
why does heart rate vary hint gasses
the gases exchanged in the lungs must be delivered to the body tissues
102
what is post apnea
brathing after holding breath as long as possible
103
what is sitting eupnea
normal breathing
104
what is post hyperventilating
very deep breathing for 2 minutes
105
what does metabolism produce, what is this function called and and what system is responsible for this
-produces waste that must be eliminated from the body
-this excretory function is the job of the renal system (mostly the paired kidneys)
106
what is the functional unit of the kidney and what does it include
-the nephron
-includes:
-the glomerulus,
-proximal convoluted tubule,
- loop of Henle,
-distal convoluted tubule
-collecting duct
107
what is the function of the glomerulus and what happens to the filtrate after the Bowmans capsule
-the site of of blood filtration where all but the blood cells and the largest dissolved proteins are physically filtered into the cavity of Bowman's capsule
-after the Bowman's capsule the filtrate is subjected to reabsorption while it passes through the tubule system and tubular secretion
108
what are the molecules that are up for selective reuptake (reabsorption) while passing through the tubule system
Na+
HCO-3
Ca++
-glucose
-amino acids
109
what is tubular secretion and what are the molecules
-additional of molecules to filtrate
K+
H+
110
what else do kidneys do
-they help maintain acid base balance
111
what happens under normal conditions with bicarbonate
-almost all bicarbonate ions in the filtrate are reabsorbed
112
what happens when a great deal of base is ingested
-plasma pH increases
-the respiratory system responds quickly by decreasing respiration which increases plasma CO2 that is interconverted H+
-the kidney through a slower path, slows the rate of bicarbonate reabsorption, resulting in more bicarbonate slows and increased urine pH
113
what changes does urine go through and what are those changes based on
-the concentration and composition of the urine excreted by the kidneys changes depending on a variety of factors including our diet
114
what is turbidity and what is it caused by
-aka cloudiness
-caused by excessive cellular material or proteins in the urine or may develop crystallization or precipitation of salts upon standing at room temperature or in the refrigerator
115
what can abnormal colors in the urine be caused by
-red or red brown colors
these can be caused by food dye, eating fresh beat, a drug or the precesne of hemoglobin or myoglobin
-if the sample has too many RBC it would be cloudy an red
116
what does normal or fresh urine look like
-pale to dark yellow or amber in color and clear
117
what is normal pH
5-9
118
what is the digestive tract
-a muscular tube that extends from the mouth to the anus
-a tube is formed by the various hallow organs of the digestive system
119
what makes up the digestive system
-the accessory organs outside of the digestive tract plus the digestive tract organs make up the digestive system
120
what are the accessory organs of the digestive system
-salivary glands
-teeth
-liver
-gallbladder
-pancreas
121
what does the pancreas do
-it manufactures enzymes, hormones and other compound and secrete these substances onto the inner lining of digestive tract
122
does food pass through the accessory organs
no
123
what is another word for swallowing
-degluition
124
what is swallowing largely the result of and list the phases that it happens during
-skeletal muscle activity
-happens during 2 phases
phase 1. buccal (mouth)
Phase 2. pharyngeal-esophageal
125
what is the buccal phase controlled by and describe how the food ends in the stomach
-voluntarily controlled and initiated by the tongue
-once the process is started, it continues involuntarily in the pharynx and esophagus through peristalsis resulting in the deliver of the swallowed contents in the stomach
126
list the steps of swallowing
Step 1: Upper esophageal sphincter is contracted. During the buccal phase, the tongue presses against the hard palate, forcing the food bolus into the oropharynx where the involuntary phase begins.
Step 2: The uvula and larynx rise to prevent food from entering respiratory passageways. The tongue blocks off the mouth. The upper esophageal sphincter relaxes, swallowing food
to enter the esophagus.
Step 3: The constrictor muscles of the pharynx contract, forcing food into the esophagus inferiorly. The upper esophageal sphincter contracts (closes) after entry.
127
what movement is more obvious in males and why
-the movement of the larynx is more obvious bc they have a bigger adams apple
128
what should you look out for when observing for digestion (remember the peristaltic wave)
-note the movement of the tongue when you swallow water
-have someone watch the movement of the larynx
-There should be two audible sounds
- The first sound occurs when the water splashes against the gastroesophageal sphincter, a valve to let food/water into the stomach.
-The second sound occurs when the peristaltic wave of the esophagus arrives at the sphincter and the sphincter opens, allowing water to gurgle into the stomach.
129
what is the formula to measure the speed of water
distance/time
130
what is important to remember about carbs and proteins
-that they both travel through the hepatic portal system before they enter the general circulation
131
What does the p-value tell us?
if the p value is less than 0.05 that means that there is a statistical difference
if the p vlaue is more than 0.05 that means that there is a not statistical difference
132
Conversion for kg to pounds and inches to cm and cm to meters
1kg= 2.2lbs
1in=2.54cm
1cm= 0.01m
then convert to mm
133
how do you calculate resting heart rate?
-rest for 5 minutes
-set a 30 second timer and take ur pulse until time is up
-whatever number you get multiply it by 2 and that is ur resting heart beats per minute
134
how do you take your active heart rate
-after working out take ur pulse for 15 seconds and then multiply that by 4
-what u get is ur active heart rate
135
What are we asking when we are performing a correlation/ regression analysis
-between 2 numerical data sets
-we are asking if one variable (y) increases as the other variable (x) does
136
what does a correlation/ regression analysis have
-a scatter plot
-a line of best fit and an R value (correlation coefficient)
137
what is a line of best fit
a line with approximately the same number of points above it and below it
138
what do r values that are approaching 1 mean
-good correlation, this means that the data points are very close or on the best fit line
-REMEBER U ALWAYS TAKE THE SQUARE ROOT OF THE R VALUE
139
what do lower r values mean
-poor correlation between the variables
-the points are far from and widely dispersed relative to the line
-(<.3)
140
what are the different correlation values
0.85-1.0 high
0.60-0.84 moderately high
0.30-0.59 moderate
0.00-0.29 low
141
why does food have to be broken down
-it must be broken down into substances that the body can absorb and use
142
what are digestive enzymes
proteins which speed up chemical digestion
143
what does each enzyme have and what is it very specific about and give an example of this
-Each enzyme has a set of optimal conditions of temperature and pH under which it performs best
-A particular enzyme is very specific about the substrate with which it will bind
-For example, maltose, a disaccharide sugar can bind with the enzyme maltase, but not sucrase
144
what are the 3 major classes of digestive enzymes
-carbohydrases
-proteases
lipases
145
Describe carbohydrases
- series of carbohydrases act on complex carbohydrates to convert them to simple sugars (monosaccharide)
146
Describe salivary amylase and how it breaks starches down
-this is a carbohydrase
-salivary amylase in the mouth breaks starches which are large polysaccharides into smaller one
-If food stays in the mouth long enough, this enzyme can break the polysaccharides all the way down to maltose, a disaccharide
-when the food is in the stomach, the acid soon stops the action of amylase,
-carbohydrate digestion does not start again until the food reaches the duodenum, where pancreatic bicarbonate ions neutralize the acid, and pancreatic amylase continues
the digestive process
-complex carbohydrates become maltose
- maltase, sucrase, lactase (enzymes) are released from the intestinal glands complete the conversion of all digestible carbohydrates to the monosaccharides (glucose, fructose and galactose)
147
what does maltose become
-two glucose molecules
148
what does sucrase action do
changes sucrose to glucose and fructose
149
what does lactase action result in
results in one glucose and one galactose from lactose
150
what does the small intestine absorb and what is the role of the liver
-monosaccharides and they are transported to the liver via the hepatic portal system
-liver stores much of the sugar as glycogen but some of it goes throughout the body as a source of fuel
-If excess sugar is available, it is converted to fat
151
what do proteases do
-they act upon proteins to release amino acids
152
what does pepsin do
breaks the bonds between some of the amino acids, resulting in shorter chains
153
describe pancreatic trypsin, chymotrypsin, and some peptidases
-in the small intestine pancreatic trypsin, chymotrypsin, and some peptidases break more binds, which results in a mixture of short chains and some individual amino acids
154
what do peptidases do
-Peptidases from intestinal glands help finish the job of protein digestion with the result being individual amino acids
-Amino acids are absorbed along with the sugars, and are
taken to the liver and all parts of the body to be used for protein synthesis, or for energy
155
What do lipases do
- act upon fats (lipids) to result in fatty acids and glycerol
156
where does most fat digestion occur
Most fat digestion occurs in the small intestine with the action of bile and lipase
157
what does bile do
Bile is not an enzyme; it emulsifies the fat, but does not cause a chemical change
158
what is lipase
- is the enzyme which breaks the bonds connecting the fatty acids to the glycerol. Once these
bonds are broken, the end products are absorbed, but most of the products do not go via the portal system to the liver
- They are absorbed into the lymph vessels via lacteals in the intestinal villi, and go throughout the body to be used for energy or to be stored
159
what are proteins and what are they made up of
- nutrients found in meat, fish, milk, and eggs
-Proteins are made up of amino acids; each protein molecule is a chain of often thousands of these amino acids
-The proteins of all life are made up of the same 20 amino acids, but the order of the amino acids makes the protein different
- The amino acid molecules are small enough to get into
the blood stream and into the cell, but protein molecules are way too big
160
what happens when you digest a protein molecule
-you break it apart into the amino acids, kind of like breaking up a string of beads
- In your cell's ribosome, your DNA has the code to put the amino acid molecules back together to form your own proteins
-This is called Protein Synthesis
161
The path of blood flow through renal blood vessels
-aorta--> renal a.--> segmental a. --> interlobar a. --> arcuate a. --> arcuate a. --> cortical radiate a. --> afferent arteriole--> glomerulus (capillaries)--> efferent arteriole--> peritubular capillaries and vasa recta--> cortical radiate vein--> arcuate vein--> interlobar vein--> renal vein--> inferior vena cava
162
What enzymes are secreted in the mouth, stomach and small intestine when carbs need to be digested. Make sure to include what the carbs are broken down to and where they are absorbed
Mouth: salivary amylase
Stomach: no enzyme
Small intestine: pancreatic amylase and disaccharidases
Broken down into monosaccharides and it is absorbed into capillaries
163
What enzymes are secreted in the mouth, stomach and small intestine when proteins need to be digested. Make sure to include what the protiens are broken down to and where they are absorbed
Mouth: no enzyme
Stomach: pepsin and HCL
Small intestine: trypsin and dipeptidases
Broken down to amino acids and absorbed into the capillaries
164
What enzymes are secreted in the mouth, stomach and small intestine when fats need to be digested. Make sure to include what the fats are broken down to and where they are absorbed
Mouth: lingual lipase (small extent)
Stomach: no enzyme
Small intestine: bile/ lipase
broken down to glycerol and free fatty acids
absorbed through the lymph lacteals
