Term
| An increase in heart rate can be mediated through ________. |
|
Definition
| a decrease in parasympathetic activity and an increase in sympathetic activity |
|
|
Term
| The term autorhythmicity refers to the heart's ability to ________. |
|
Definition
| generate its own contractile cycle |
|
|
Term
| Which of the following is the correct conduction pathway through the heart? |
|
Definition
| SA node; AV node; bundle of His; bundle branches; Purkinje fibers |
|
|
Term
What is the function of the sodium
-calcium exchanger in cardiac muscle? |
|
Definition
| remove calcium from the cytosol by transporting it to the extracellular fluid |
|
|
Term
| During phase 3 of a contractile cell action potential, ________. |
|
Definition
| only potassium permeability is increased |
|
|
Term
| What is occurring during ventricular ejection? |
|
Definition
| the AV valves are closed and the semilunar valves are open as blood is leaving the ventricles |
|
|
Term
| Opening of which of the following channels contributes to the spontaneous depolarizaton of pacemaker cells? |
|
Definition
| both calcium channels and funny channels |
|
|
Term
| During which phase of the cardiac cycle are all four heart valves open? |
|
Definition
|
|
Term
| Which of the following components of an ECG represents ventricular depolarization? |
|
Definition
|
|
Term
| The rapid depolarization phase of a contractile cell is phase ________. |
|
Definition
|
|
Term
The end
-diastolic volume minus the end-systolic volume is the ________. |
|
Definition
|
|
Term
| ________ provide the pathway for the movement of electrical current between the cells of the conduction pathway and the ventricular myocytes. |
|
Definition
|
|
Term
| During isovolumetric relaxation, _____. |
|
Definition
| the AV and semilunar valves are closed and ventricular pressure is decreasing |
|
|
Term
| A decrease in afterload will lead to a(n) ________. |
|
Definition
|
|
Term
| What causes the rapid depolarization phase of a contractile cell action potential? |
|
Definition
| sodium movement into the cell |
|
|
Term
| Which side of the heart has thicker muscles, and why? |
|
Definition
| The left side, needs thicker muscles for more force to send blood to brain. Left needs more oxygen and blood flow, does more work, needs more blood. |
|
|
Term
|
Definition
| Heart, arteries(away from heart), arterioles(branching of arteries), Capillaries(tissue level), Venules(branching of veins), Veins(carry to the heart) |
|
|
Term
|
Definition
| Relatively large, brancing vessels that conduct blood away from the heart |
|
|
Term
|
Definition
| Small branching vessels with high resistance |
|
|
Term
|
Definition
| Site of exchange between blood and tissues |
|
|
Term
|
Definition
| Vena cavae->right atrium->tricuspid->right ventricle->pulmonary semilunar valve->pulmonary artery->lungs->pulmanary veins->left atrium->bicuspid(mitral)->left ventricle->aortic semilunar valve->aorta->systemic circuit |
|
|
Term
| How many parts do each of the lungs have? |
|
Definition
| Left lung has 2 parts, right lung has 3 parts |
|
|
Term
| What is the inflammation of the pericardium called? |
|
Definition
| Pericarditis==>membranous sac surrounding heart lubricates heart and decreases friction, it becomes inflammed causing Pericarditis |
|
|
Term
| What are the three layers of the heart wall? |
|
Definition
Endocardium(inner)=>layer of endothelial cells(respond to stretch/pumps)
Myocardium(middle)cardiac muscle(muscle of the heart/respond)
Epicardium(outer)external membrane(sets structure) |
|
|
Term
| If actin and myosin are too far apart what will result? |
|
Definition
| If they are too far apart we can't get a good contraction and blood will start to pool in the heart. This will cause a backflow into the lungs causing us to drown in our own blood(fluids). This is called cardiomyopathy. It can cause congestive heart failure and death |
|
|
Term
| Properties of cardiac muscles |
|
Definition
Intercalated disks-gap junctions(allow cells to communicate directly)--cause heart to contract as a unit
Desmosomes(does not fatigue because of this)--resists stress
Atria and ventricles--separate units |
|
|
Term
| Functions of cardiac muscles |
|
Definition
Rhythmic contraction and relaxation generates heart pumping action
Contraction pushes blood out of heart into vasculature
Relaxation allows heart to fill with blood
Must work together, if not we have no blood flow |
|
|
Term
|
Definition
Atrioventricular valves
Right AV valve=tricuspid valve
Left AV valve=bicuspid valve=mitral valve(because it looks like the miter hat(pope hat)(mitro valve prolapse=blook backflow causing light headed)
Papillary muscles and chordae tendinae(keep AV valves from everting) |
|
|
Term
|
Definition
Shaped like a half moon
Aortic valve
Pulmonary valve |
|
|
Term
| Where is the cardiovascular control center? |
|
Definition
|
|
Term
The long
-term regulation of arterial blood pressure involves ________. |
|
Definition
| the control of blood volume by the kidneys |
|
|
Term
| In comparison to the systemic circuit, the pulmonary circuit ________. |
|
Definition
| has lower resistance to blood flow |
|
|
Term
| The ________ is bounded by the interior surface of the chest wall and the exterior surface of the lung. |
|
Definition
|
|
Term
| The transition from the conducting to the respiratory zone in the lungs occurs at the ________. |
|
Definition
|
|
Term
| The pressure gradient for blood flow through the systemic circuit is the mean arterial pressure. |
|
Definition
|
|
Term
| The smallest (and most distal) structures that remain a component of the conducting zone in the respiratory tract are the ________. |
|
Definition
|
|
Term
| Due to their diameter, capillaries have the greatest individual resistance, while the arteriole networks have the greatest total resistance. |
|
Definition
|
|
Term
| ________ are the most common cells that line the surface of the alveoli and are therefore associated with the exchange of gases within the lungs. |
|
Definition
|
|
Term
| Which of the following equations correctly relates flow, pressure, and resistance? |
|
Definition
Pressure
= Flow × Resistance |
|
|
Term
| The upper airway refers to the passageway for air that is located within the head and neck. |
|
Definition
|
|
Term
| An increase in total peripheral resistance, in the absence of any change in cardiac output, would ________. |
|
Definition
| elevate mean arterial pressure |
|
|
Term
| Intrinsic regulation of arteriolar radius regulates mean arterial pressure. |
|
Definition
|
|
Term
| The conducting zone adjusts the temperature and humidity of the air entering the respiratory tract. |
|
Definition
|
|
Term
The difference between intrapleural pressure and intra
-alveolar pressure is ________. |
|
Definition
|
|
Term
| Spread of excitation between cells |
|
Definition
| Atria contract then followed by ventricles. The coordination due to presence of gap junctions and conduction pathways. Gap junctions for electrical coupling. |
|
|
Term
| How many years are deducted from our lives due to lack of physical exercise? |
|
Definition
|
|
Term
| Conduction system of heart |
|
Definition
1. Sinoatrial(SA)node(pacemaker) internodal pathway
2. Atrioventricular(AV)node
3. AV bundle(bundle of His)
4. Right and left bundle branches
5. Purkinje fibers |
|
|
Term
| Control of heart beat by pacemakers(autorhythmic cells) |
|
Definition
Spontaneous depolarization caused by closing K+ channels and opening two types of channels: If(funny) channels(Na+ and K+, net depolarization
Calcium channels(further depolarization)
Depolarization to threshold:
Open fast calcium channels-->action potential
Repolarization:
Open K+ channels |
|
|
Term
| What are the 5 phases of contractile cell action potentials? |
|
Definition
Phase0-->increased permeability to sodium
Phase1-->decreased permeability to sodium
Phase2-->increased permeability to calcium, decreased permeability to potassium
Phase3-->increased permeability to potassium, decreased permeability to calcium
Phase4-->resting membrane potential |
|
|
Term
| Steps of excitation-contraction coupling |
|
Definition
1. Depolarization of cardiac contractile cell to threshold via gap junction
2. Opening of calcium channels in plasma membrane
3. Action potential travels down T tubules
4. Calcium is released from sarcoplasmic reticulum by calcium-induced calcium release
action potentials in T tubules
5. Calcium binds to troponin causing shift in tropomyosin
6. Binding sites for MYOSIN on ACTIN are exposed
7. Crossbridge cycle occurs |
|
|
Term
| Relaxation of cardiac muscle |
|
Definition
Remove calcium from cytosol
Calcium ATPase in sarcoplasmic reticulum and plasma membrane
Na+-Ca2+ exchanger in plasma membrane
Troponin and tropomyosin return to position covering myosin binding sites on actin |
|
|
Term
| What are 2 factors that deal with cardiac output? |
|
Definition
| Sympathetic and parasympathetic nervous system |
|
|
Term
| If Stroke volume goes up, what does afterload do? |
|
Definition
|
|
Term
Starling's Law
An increase in end-diastolic volume causes stroke volume to what? |
|
Definition
|
|
Term
| Intrinsic control-Frank-Starling's law |
|
Definition
| Increase venous return-->Increase strength of contraction-->Increase stroke volume |
|
|
Term
| Principle of Frank-Starling's law |
|
Definition
Increase end-diastolic volume stretches muscle fibers
Fibers closer to optimum lenght
Optimum lenght=greater strength of contraction
Result=increased stroke volume |
|
|
Term
| Factors affecting cardia output: stroke volume |
|
Definition
Ventricular contractility
End-diastolic volume
Afterload
Treppe effect
These 4 factors plus parasympathetic and sympathetic affect heart rate |
|
|
Term
| Effects of parasympathetic activity on heart rate |
|
Definition
| Increased parasympathetic activity(vagus nerve)-->Mucarinic cholinergic receptors in SA node-->Increase open state of K+ channels and closed state of calcium channels-->decreased rate of spontaneous depolarization and hyperpolarize cell-->decrease heart rate |
|
|
Term
| Effects of sypathetic activity on heart rate |
|
Definition
| Increased sympathetic activity(nerves or epinephrine)-->Beta 1 receptors in SA node-->Increased open state of funny and calcium channels-->Increased rate of spontaneous depolarization-->Increase heart rate |
|
|
Term
| How many beats per minute before it is considered sympathetic activity? |
|
Definition
75-100=sympathetic activity
Under 75=parasympathetic activity |
|
|
Term
| Heart rate-determined by SA node firing rate |
|
Definition
SA node intrinsic firing rate=100/min
No extrinsic control on heart, hr=100
SA node under control of ANS and hormones
Rest:parasympathetic dominates, HR=75
Excitement: sympathetic takes over, HR increases |
|
|
Term
|
Definition
Volume of blood pumped by each ventricle per minute
Cadiac output= CO=SV*HR
Average CO=5 liters/min at rest
At rest: untrained=5 liters/min
With exercise training=6 liters/min |
|
|
Term
|
Definition
Fraction of end-diastolic volume ejected during a heartbeat
Ejection fraction=stroke volume/end-diastolic volume
Normal=60-70%
Chronic heart disease could be as low as 6% |
|
|
Term
|
Definition
EDV=end-diastolic volume(volume of blood in ventricle at the end of diastole(relaxation))
ESV=end systolic volume(volume of blood in ventricle at the end of systole(contraction))
SV=stroke volume(volume of blood ejected from ventricle each cycle)
SV=EDV-ESV(how much blood was ejected from heart during heart beat) |
|
|
Term
Ventricular diastole
Isovolumetric ventricular relaxation |
|
Definition
Ventricle muscle relaxes so that pressure is less than aorta
Aortic valve closes
Pressure in ventricle continues dropping until it is less than atrial pressure |
|
|
Term
Ventricular diastole
Ventricular filling |
|
Definition
AV valve opens
Blood moves from atria to ventricle
Passive until atrium contracts |
|
|
Term
Ventricular systole
Isometric ventricular contraction |
|
Definition
AV and aortic valves closed
Ventricular pressure increases until it exceeds atrial pressure |
|
|
Term
Ventricular systole
Ventricular ejection |
|
Definition
Aortic valve opens
Blood moves from ventricle to aorta |
|
|
Term
| Four phases of cardiac cycle |
|
Definition
Phase#1: Ventricular filling-pressure atria>pressure ventricles
AV valves open
Passive phase-no atria or ventricular contraction
Active phase-atria contract
Phase#2: Isometric ventricular contraction-ventricle contracts-increases pressure
AV and semilunar valves closed
No blood entering or exiting ventricle
Phase#3: Ventricular ejection-pressure ventricles>pressure arteries
Semilunar valves open
Phase#4: Isovolumetric ventricular relaxation-ventricle relaxes-decreases pressure
AV and semilunar valves closed
No blood entering or exiting ventricle |
|
|
Term
| Valves open passively due to pressure gradients |
|
Definition
AV valves open when: Pressure atria>pressure ventricles
Semilunar valves open when:
Pressure ventricles>pressure arteries |
|
|
Term
| Two main periods of cadiac cycle(mechanical events) |
|
Definition
Systole(contraction or ejecting of blood) ventricle contraction
Diastole(relaxation or filling of blood) ventricle relaxation |
|
|
Term
|
Definition
|
|
Term
|
Definition
| Ventricular depolarization and atrial repolarization |
|
|
Term
|
Definition
| Ventricular repolarization |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
Pulmonary ventilation(movement of gasses in)
Exchange between lungs and blood
Transportation in blood
Exchange between blood and body tissue |
|
|
Term
|
Definition
| Air passages of the head and neck: nasal cavaties, oral cavaties, pharynx |
|
|
Term
|
Definition
Airways from pharynx to lungs
Larynx(behind pharynx)
Conducting zone(make up 4/5 of lungs)
Respiratory zone(make up 1/5 of lungs)
Conducting zone has nothing to do with gas exchange but everything to do with moving air
Respiratory zone is only at the very bottom of the lungs |
|
|
Term
| Structures of the conducting zone |
|
Definition
Trachea(coated in creacoat cartilage)
Bronchi(left and right)
Second bronchi-->right side(3 lobes of right lung), left side(2 lobes of left lung)
Tertiary bronchi(20-23 orders of branching)
Bronchioles(very small, less than 1mm diameter)
Terminal bronchioles(end of conduction zone) |
|
|
Term
| Functions of the conducting zone |
|
Definition
Air passageway: 150mL volume=dead space volume(no exchange of gas, that air is last in, first out...waisted air)
Increase air temperature of body temperature
Humidify air |
|
|
Term
| Epithelium of the conducting zone |
|
Definition
Goblet cells(secrete mucus that grabs on to particles in the air)
Ciliated cells(cilia move particles towards mouth
Mucus escalator(cough up the mucus) |
|
|
Term
| Structures of the respiratory zone |
|
Definition
Respiratory bronchioles
Alveolar ducts
Alveoli(prime place for gas exchange)
Alveolar sacs |
|
|
Term
| Functions of the respiratory zone |
|
Definition
Exchange gases between air and blood
Mechanism is by diffusion(gases don't require transporter, No ATP is required, it is passive) |
|
|
Term
| Epithelium of the respiratory zone |
|
Definition
Respiratory membrane-->epithelial cells of alveoli
Endothelial cells of capillary
If the membrane is thicker, it is more difficult to diffuse gases into blood |
|
|
Term
|
Definition
Site of gas exchange
300 million alveoli in the lungs(tennis court size)
Rich blood supply(capillaries form sheet over alveoli)
Alveolar pores |
|
|
Term
|
Definition
Make up wall of alveoli(structural cells)
Single layer epithelial cells |
|
|
Term
|
Definition
Secrete surfactant(basically it is soap, only formed 5-10 days before birth)
Alveolar macrophages |
|
|
Term
| What are bronchitis and pneumonia caused by? |
|
Definition
Bronchitis is caused by partial covering of mucus on the alveolar wall
Pneumonia is where the wall is covered completely with mucus |
|
|
Term
|
Definition
| Disease where you were born with more mucus and you are unable to clear the mucus (mucus escalator) |
|
|
Term
| Roles of pressure in pulmonary ventilation |
|
Definition
Air moves in and out of lungs by bulk flow
Pressure gradient drives flow
Air moves from high to low pressure
Inspiration-pressure in lungs less than atmosphere
expiration-pressure in lungs greater than atmosphere |
|
|
Term
|
Definition
Atmospheric pressure=Patm
Intra-alveolar pressure=Palv-->pressure of air in alveoli
intrapleural pressure=Pip-->pressure inside pleural sac
Transpulmonary pressure=Palv-Pip-->distending pressure across the lung wall |
|
|
Term
|
Definition
760 mm Hg at sea level
Decreases as altitude increases
Increase unde water
Other lung pressures given relative to atmospheric(set Patm=0mm Hg) |
|
|
Term
|
Definition
Pressure of air in alveoli
Given relative to atmospheric pressure
Varies with phase of respiration-->during inspiration=negative(less than atomspheric)
During expiration=positive(more than atmospheric)
Difference between Palv and Patm drives ventilation |
|
|
Term
|
Definition
Pressure inside pleural sac
Always negative under normal conditions
Always less than Palv
Varies with phase of respiration
At rest, -4m Hg
Negative pressure due to elasticity in lungs and chest wall
Lungs recoil inward
Chest wall recoils outward
Opposing pulls on intrapleural space
Surface tension of intrapleural fluid hold wall and lungs together.
Surface tension is dictated by surfactin |
|
|
Term
|
Definition
Transpulmonary pressure=Palv-Pip
Distending pressure across the lung wall
Increase in transpulmonary pressure
Increase distending pressure across lungs
Lungs(alveoli)expand, increasing volume |
|
|
Term
|
Definition
|
|
Term
|
Definition
Pressure=force exerted by blood
Flow occurs from high pressure to low pressure
Flow=P/R
R=P/F
P=R*F
Resistance goes up flow goes down |
|
|
Term
|
Definition
Pressure=force exerted by blood
Flow occurs from high pressure to low pressure
Flow=P/R
R=P/F
P=R*F
Resistance goes up flow goes down |
|
|
Term
| Pressure gradient in the cardiovascular system |
|
Definition
High flow=high pressure
Pressure gradient drive flow from high pressure to low pressure
Flow due to pressure gradient=bulk flow
Heart creates pressure gradient for bulk flow of blood
A gradient must exist throughout circulatory system to maintain blood flow |
|
|
Term
| Pressures of the pulmonary and systemic circuit |
|
Definition
Pulmonary circuit has no pressure
Systemic circuit around 75mm Hg |
|
|
Term
| Resistance in the cardiovascular system |
|
Definition
Pressure gradient in systemic circuit much greater than for pulmonary circuit
Flow through both circuits equal
Flow=P/R
Resistance through pulmonary circuit much less than through systemic circuit |
|
|
Term
| Factors affecting resistance to flow |
|
Definition
Radius of vessel(largest factor)
In arterioles(and small arteries) can regulate radius
Lenght of vessel(same throughout body)
Viscosity of fluid(slipage)=n
Blood viscosity dependent on amount of RBC's and proteins
Higher # of RBC's the more chance of blood clot(no slipage) |
|
|
Term
|
Definition
R=8nL/R(to the 4th power)
Flow=P/R=Pr(to the 4th power)/8nL
Lenght goes up, flow goes down
Any change in radius of vessel changes resistance by 4 times |
|
|
Term
| The effect of arteriole radius on blood flow |
|
Definition
Regulation of radius of arterioles(and small arteries)
Vasoconstriction(sympathetic mediated, epi, norepi)
Decrease radius->increase resistance
Vasodilation(parasympathetic)
Increase radius->decrease resistance
Pulmonary circuit less resistance than systemic
Lower pressure gradient required for blood flow |
|
|
Term
| Total peripheral resistance |
|
Definition
Combined resistance of all blood vessels within the systemic circuit
Resistance across a network of blood vessels depends on resistance of all vessels
Flow through network varies with resistance
Vasoconstriction in network->increase resistance->decrease flow
Vasodilation in network->decrease resistance->increase flow
If we vasoconstrict organs we can flood muscles with blood(exercise) and vice versa |
|
|
Term
| Relating pressure gradients and resistance in the systemic circulation |
|
Definition
Flow=P/R
Flow=Cardiac output(CO)
P=Mean arterial pressure(MAP)
R=Total peripheral resistance(TPR)
CO=MAP/TPR
CO=HR*SV |
|
|
Term
| Determinants of Mean Arterial Pressure |
|
Definition
Determined by:
Heart rate
Stroke volume
Total peripheral resistance
MAP=CO*TPR
CO=HR*SV
Therefore: MAP=HR*SV*TPR |
|
|
Term
| Extrinsic control of arteriole radius |
|
Definition
MAP regulated through control of heart(CO) and arterioles and veins(TPR)
Neural control
Hormonal control |
|
|
Term
| What are the 6 ways to change heart rate |
|
Definition
| Afterload, preload, treppe, contractility, sympathetic, parasympathetic |
|
|
Term
| Mean arterial pressure(MAP) |
|
Definition
MAP=driving force of blood flow
F=P/R
Regulating MAP critical to normal function
MAPhypotension(stand up too quickly and get dizzy)
Inadequate blood flow to tissues
MAP>normal
Hypertension
Stressor for heart and blood vessels
Faiting due to hypotension is good because you fall to the ground and with no gravity to fight with you can get blood back to the brain.
Cardiogenic shock is when your heart beats so fast to try to get the blood to brain that your heart explodes in your chest |
|
|
Term
| Short-term regulation of MAP |
|
Definition
Seconds to minutes
Regulate cardiac output and total peripheral resistance
Involve heart and blood vessels
Primary neural control |
|
|
Term
| Long-term regulation of MAP |
|
Definition
Minutes to days
Regulate blood volume
Involve kidneys
Primary hormonal control |
|
|
Term
| Cardiovascular control center |
|
Definition
Medulla oblongata
Integration center for blood pressure regulation
Input
Arterial baroreceptors(found in aorta and carotid arteries)
Low pressure baroreceptors(found in right atrea)
Chemoreceptors
Proprioceptors(where body is located in space)
Higher brain centers
Outputs
Sympathetic
Parasympathetic |
|
|
Term
| Autonomic output to cardiovascular effectors |
|
Definition
Parasympathetic input to
-SA node(decrease HR)
-AV node
Sympathetic input to
-SA node(increase HR)
-AV node
-Ventricular myocardium(increase contractility)
-Arterioles(increase resistance)
-Veins(increase venomotor tone) |
|
|
Term
|
Definition
Movement of air in and out of lungs due to pressure gradient.
Mechanics of breathing describes mechanisms for creating pressure gradient
Pressure dictates volume |
|
|
Term
|
Definition
Boyle's Law: pressure is inversely related to volume
Pressure goes up, volume goes down
Thus, can change alveolar pressure by changing its volume
R=resistance
Resistance related to radius of airways and mucus |
|
|
Term
| Determinants of intra-alveolar pressure |
|
Definition
Factors determining intra-alveolar pressure
Quantity of air in alveoli
Volume of alveoli
Lungs expand-alveolar volume increases-->Palv decreases
Pressure gradient drives air into lungs
Lungs recoil-alveolar volume decreases->Palv increases
Pressure gradient drives air out of lungs |
|
|
Term
|
Definition
Inspiratory muscles increase volume of thoracic cavity
Diaphram, external intercostals
Expiratory muscles decrease volume of thoracic cavity
Internal intercostals, abdominal muscles |
|
|
Term
| Pleural pressure is always positive or negative? |
|
Definition
|
|
Term
| Pressure gradient for ventilation |
|
Definition
|
|
Term
|
Definition
|
|
Term
| Factors affecting lung compliance |
|
Definition
Elasticity-->more elastic-->less compliant
Surface tension of lungs-->greater tension-->less compliant
Emphysema is when you lungs are not elastic. You have to work your muscles for each breath. |
|
|
Term
|
Definition
Thin layer fluid lines alveoli
Surface tension due to attractions between water molecules
Surface tension=force for alveoli to collapse or resist expansion |
|
|
Term
| To overcome surface tension |
|
Definition
Surfactant secreted by type II alveoli cells
Surfactant=detergent that decreases surface tension
Surfactant increases lung compliance
Makes inspiration easier |
|
|
Term
|
Definition
As airways get smaller in diameter they increase in number, keeping overall resistance low
Pressure gradient needed for air flow thus low-->~1mm Hg
An increase in resistance makes it harder to breath
Pressure gradient needed for air flow >1mm Hg |
|
|
Term
| When climbing a mountain, is there less oxygen with elevation? |
|
Definition
No, the air is composed of the same percentage of oxygen as at sea level. The difference is the pressure. As elevation increases, pressure decreases making it harder for you to breath.
Mt. Everest climbers lost about 10% in their IQ due to an extended period of time without oxygen.
18,000 feet is what they call "dead zone" where pressure is very little and very hard to breath which can lead to hypoxic or lack of oxygen |
|
|
Term
| Extrinsic control of bronchiole radius |
|
Definition
Autonomic nervous system-->sympathetic
Relaxation of smooth muscle
Bronchodilation
Parasympathetic
Contraction of smooth muscle
Bronchoconstriction
Hormonal control-epinephrine
Relaxation of smooth muscle
Bronchodialation |
|
|
Term
| Intrinsic control of bronchiole radius |
|
Definition
Histamine(causes more secretion)bronchoconstriction
Released during asthma and allergies
Also includes mucus secretion
Carbon dioxide-bronchodilation |
|
|
Term
|
Definition
79% Nitrogen
21% Oxygen
Trace amounts of carbon dioxide, helium, argon, etc.
Water can be a factor depending on humidity |
|
|
Term
| Solubility of gases in liquids |
|
Definition
Gas molecules can exist in gas form or dissolve in liquid
Ability to dissolve depends on properties of gas and properties of liquid
Both vaporized and dissolved gases exert partial pressures
The partial pressure of a gas affects the amount of gas that goes into solution
Partial pressure of vaporized and dissolved gases will be equal at equilibrium |
|
|
Term
| Exchange of oxygen and carbon dioxide |
|
Definition
Gas exchange in the lungs
Gas exchange in respiring tissue
Determinants of alveolar Po2 and Pco2 |
|
|
Term
|
Definition
Gases diffuse down pressure gradients->high to low pressure
In gas mixtures, gases diffuse down pressure gradients->high partial pressure to low partial pressure
A particular gas diffuses down its own partial pressure gradient
Pressure of other gases irrelevant |
|
|
Term
| Rate of diffusion in lungs |
|
Definition
Diffusion between alveoli and blood is rapid
Small diffusion barrier
Large surface area |
|
|
Term
|
Definition
Increased ventilation due to increased demand
Minimal changes to arterial Po2 and Pco2 |
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Term
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Definition
Ventilation does not meet demands
Arterial Po2 decreases
Arterial Pco2 increases |
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Term
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Definition
Ventilation exceeds demands
Arterial Po2 increases
Arterial Pco2 decreases |
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Term
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Definition
| Labored or difficult breathing |
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Term
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Definition
| Temporary ceasation of breathing |
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Term
| Oxygen transport in blood |
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Definition
1. Oxygen transport by hemoglobin
2. The hemoglobin-oxygen dissociation curve
3. Other factors affecting affinity of hemoglobin for O2
Oxygen not very soluble in plasma
Thus only 3.0mL/200mL arterial blood oxygen dissolved in plasma(1.5%)
Other 197mL arterial blood oxygen transported by hemoglobin |
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Term
| Oxygen binding to hemoglobin |
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Definition
Hb+O2<-->Hb*O2
Hb=deoxyhemoglobin
Hb*O2=oxyhemoglobin |
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Term
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Definition
Hemoglobin can bind up to 4 oxygen molecules
Binding of oxygen to hemoglobin follows law of mass action
More oxygen->more binds to hemoglobin
Non-linear relationship
Positive cooperativity
Sickle cells may only carry 1 or 2 oxygens |
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Term
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Definition
A measure of how much oxygen is bound to hemoglobin
100% saturation-->all 4 binding sites on hemoglobin have oxygen bound to them |
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Term
| Oxygen-carrying capacity of blood |
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Definition
When 100% saturated, 1 gram hemoglobin carries 1.34mL oxygen
Normal blood hemoglobin levels=12-17gm/dL
Oxygen-carrying capacity of hemoglobin in blood=200mL oxygen per liter blood |
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Term
| Effects of O2 affinity changes |
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Definition
Shift right-->less loading of O2 and less unloading
Shift left-->more loading of O2 and less unloading |
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Term
| Temperature effects:O2 saturation |
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Definition
| Higher temperature:active tissues, shift right, more O2 unloading in tissues, more O2 delivered to tissues |
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Term
| pH effects: O2 saturation |
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Definition
Bohr effect:Lower pH increases O2 unloading
Active tissues->produce more acid pH decreases in tissues
Decreased pH causes shift right in saturation curve
More O2 is unloaded to tissues |
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