Term
| List the three parts of the cardiovascular system. |
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Definition
1) Heart
2) Blood
3) Vasculature |
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Term
Explain pulmonary circulation.
Explain systemic circulation; also describe the 3 circulation beds. |
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Definition
Pulmonary circulation - Concerning the blood flow to, within, and from the lungs
Systemic circulation - concerning blood flow to and from the remainder of the body and consists of specific circulation beds - transfer of nutrients! 1)Renal 2)Hepatic 3)Skeletal muscle |
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Term
Define the following terms:
1)Cardiac cycle
2)Diastole
3)Systole
4)End Diastolic Volume
5)Ejection Fraction
6)Preload
7)Afterload
8)Frank-Starling Law
9)Contractility
10)Stroke Volume
11)Cardiac Output |
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Definition
1)Cardiac Cycle - The cycle of blood flow and related electrical ad mechanical events as blood is received and ejected by the heart.
2)Diastole - The period of relaxation of the myocardium
3)Systole - The period of contraction of the myocardium
4)End Diastolic Volume - The volume of blood in the ventricles at the end of diastole
5)Ejection Fraction - The fraction of EDV that is ejected with each cardiac cycle
6) Preload - The stretch on the ventricular myocardium at EDV.
7)Afterload - The pressure that must be overcome by the ventricles prior to ejection.
8)Frank-Starling Law - Concerns the increase in the velocity/power of myocardial contraction with increasing stretch caused by EDV.
9)Contractility - Measure of the velocity/power of the myocardial contraction.
10)Stroke Volume - The volume of blood ejected from the ventricles per beat
11)Cardiac Output - The volume of blood pumped by the heart over a specified period of time: SV x HR = CO or Q |
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Term
| Starting at the right atrium, list the path way of blood throughout the body. |
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Definition
| Right Atrium -> Tricuspid Valve -> Right Ventricle -> Pulmonary Valve -> Pulmonary Arteries -> Lungs -> Pulmonary Veins -> Left Atrium -> Mitral Valve -> Left Ventricle -> Aortic Valve -> Systemic Circulation |
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Term
| In regards to conductance of the heart, where does the initiation of the action potential take place? Where does it follow after this? |
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Definition
1)Sinoatrial (SA) node - initiation of action potential
2)Atrioventicular (AV) node - delays impulse
3)Bundle Branches - right and left
4)Purkinjie Fibers |
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Term
| How is heart rate regulated? |
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Definition
The sinoatrial node (the pacemaker) consists of nervous tissue containing:
1) Slow Sodium channels
2) Fast Sodium channels
The slow sodium channels are leaky which means that they are constantly allowing sodium in causeing regular depolarization. |
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Term
| Alone, the SA node sets a HR of __-__ bpm. |
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Definition
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Term
| List 4 fun facts regarding cardiac muscle anatomy. |
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Definition
1) Very similar to skeletal muscle
2) Sarcomeres - actin - myosin
3) Calcium-regulated contraction
4) Fibers are anchored to intercalated disc |
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Term
| How do muscle fibers communicate with each other? Explain this. |
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Definition
Through gap junctions at the intercalated disc. Can exchange molecules, elements, and action potentials.
There is a brief delay in action potential when traveling through the gap junction. |
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Term
| Explain the synchronization of the cardiac contraction through the gap junctions. |
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Definition
1) "filtering" of the action potential through the Gap Junctions causes the atria to contract from the bottom up.
2) Delay of action potential at the AV node causes the ventricle to contract after atrial contraction.
3)There is non conducting fibrous tissue between atria and ventricles. |
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Term
| List the 2 broad mechanisms that control cardiac performance. |
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Definition
1) Extrinsic Control - hormonal, neural
2) Intrinsic - Sarcomere length. |
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Term
| Extrinsic control is governed by what? |
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Definition
Autonomic Nervous System
-Inotropic (contractility)
-Chronotropic (heart rate)
1) Sympathetic System - Norepinephrine increases contractility and heart rate
2) Parasympathetic System - Acetylcholine decreases contractility and heart rate. |
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Term
| What is the inotropic aspect (how do Norepinephrine and acetylcholine increase/decrease contractility)? |
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Definition
1) In the sympathetic system, when norepinephrine is released, this increases calcium influx into the myocardium
2) In the parasympathetic system, acetylocholine is released which decreases calcium influx into the myocardium. |
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Term
| What is the chronotropic aspect (how does NE/ACh increase/decrease heart rate)? |
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Definition
1) Sympathetic - Increases Heart Rate. NE increases the slow sodium leak channel.
2) Parasympathetic - decreases heart rate. ACh decreases the slow sodium leak channel and also decreases the resting potential. |
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Term
During rest, ___________ control predominates and keeps HR low.
What are the two responses to heart rate during exercise? |
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Definition
parasympatheitic
Exercise heart rate response -
1)Initial rise in HR occurs due to a removal of parasympathetic control.
2)Increased sympathetic influence results in most of the increase in heart rate. |
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Term
| What is major influence on the inotropic aspect (contractility)? |
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Definition
Frank-Starling Law of the Heart
-Increased contractile strength in response to preload stress (stretching of the myocardium increases contractile strength)
-Increasing EDV increases myocardial stretch and contractility. |
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Term
| What are the three mechanisms involved with the Frank Starling Law of the Heart? |
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Definition
1) Degree of overlap between actin and myosin
2) Increased calcium sensitivity
3) Stretch induced calcium influx |
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Term
| Even though Frank-Starling occurs in the absence of neural or hormonal influence, extrinsic mechanisms can still influence Frank Starling. How? |
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Definition
| Sympathetic Activity -> Norepinephrine -> Peripheral Vasoconstriction -> Increased Venous return -> Increased EDV |
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Term
| How is intrinsic control extrinsically influenced? |
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Definition
| Inotropic (contractility) via increased afterload! This increases the force the myocardium must overcome to eject blood volume. |
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Term
| What are three causes of increased afterload? |
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Definition
1) Hypertension
2) Atherosclerosis
3) High blood viscosity |
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Term
Cardiac output =
SV will plateau or even decrease as one reaches maximal exercise/maximal heart rate. Why? |
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Definition
Cardiac Output = SV * HR
SV plataus during maximal exercise because there is an increase in diastole which causes less blood fill in the heart. |
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Term
| What effect does dehydration have on exercising heart rate? |
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Definition
| dehydrating causes an increase in heart rate because the blood is thicker. This causes the flow rate to be lower and the heart has to work harder to pump it through the veins. |
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Term
| Heart rates are typically higher in runners than in cyclists or swimmers working at the same intensity. Why? |
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Definition
Swimmers are lying down so blood does not have to work against gravity
Cyclist are usually hunched over so blood still doesn't have to work as hard against gravity as for runners. |
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Term
Describe arteries. What are the specialized cells they possess?
Describe arterioles. |
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Definition
Arteries - transport large volumes of blood from the heart. Heavily reinforced with smooth muscle. Note endothelium, these are specialized cells that line the inside of all vessels.
Arterioles - Small branches of arteries, heavily muscled and high nervous innervation. Act to regulate blood pressure and blood flow to vascular beds - also contain endothelial cells. |
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Term
Describe capillaries.
Describe venules.
Describe veins. |
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Definition
Capillaries
1)Very thin-walled with no smooth muscle.
2)Pores (fenestrae) allow for exchange of material betrween blood and tissue
Venules
1)No smooth muscle or nervous innervation
2) Collect blood from vascular beds.
Veins
1)Some smooth muscle, sometimes innervated
2)Transport blood back to the heart
3)Veins below heart have one-way valves to prevent back flow |
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Term
| How is blood flow maintained during exercise? |
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Definition
Contracting skeletal muscle influences venous return!
When our muscles contract, valves are opening and closing.
Remember we have valves in our veins!! |
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Term
Fluids flow from areas of ____ pressure to areas of ____ pressure.
Blood flow rate (F) is going to depend on ____________ ___________ and the ________ ________ (delta P) along the _______ of a vessel. |
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Definition
high, low
Blood flow rate (F) is going to depend on vascular resistance (R) and the pressure gradient (delta P) along the length of a vessel. |
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Term
So blood flow is going to depend on what two opposing factors?
What are the typical vessel pressures in the: aorta, Skeletal muscle capillaries, pulmonary capillaries, and the vena cava? |
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Definition
1) Pressure gradient
2) Vascular resistance
Aorta = 100 torr
Skeletal Muscle Capillaries = 35-10 torr
Pulmonary Capillaries = 16-7 torr
Venae Cavae = 0 torr |
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Term
The resistance to blood flow is going to be related to the _________ of the blood, the ______ of the blood vessel, and the _____-_________ ____ of the vessel.
What factor has the largest impact on resistance? |
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Definition
viscosity, length, and the cross-sectional area.
Radius has the largest impact on resistance. |
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Term
An increase in viscosity = an ________ in resistance
An increase in vessel length (longer) = an ________ in resistance. |
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Definition
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Term
Which blood vessel has the largest cross sectional area? Which has the smallest?
Why is this important in both cases? |
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Definition
Largest = Capillaries - makes since considering we need the pressure to be low for diffusing of O2 and CO2 - also this causes the velocity of the blood to be very low.
Smallest = Aorta - makes since considering we need high pressure to force the blood throughout the body. This causes the velocity of the blood to be very high. |
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Term
| Despite the small radii of capillaries, resistance _________ because of the large total vascular area in the capillary beds. What does this allow for? What does this prevent? |
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Definition
resistance decreases.
This low resistance allows blood flow to occur within the capillary beds at low pressure and only small pressure gradients.
This also prevents the capillaries from being damaged and keeps the plasma from being squeezed out (prevents edema). |
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Term
| List the three variables we can change as a result of acute exercise and/or chronic training. |
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Definition
1) Change in pressure (delta P)
2) Cross-sectional area of the vessel
3) Viscosity of the blood. |
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Term
What two things can the viscosity be affected by?
What three things can the change in pressure be affected by? |
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Definition
Viscosity can be affected by
1) hydration
2) red blood cell volume
The change in pressure can be affected by
1) Heart contractility
2) Vasodilation/Constriction
3) Vascularity |
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Term
What is vascular tone a result of?
What surrounds arteries and arterioles and what does this do?
What lines the inside of the vessel and what do these do? |
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Definition
Vascular tone is a result of interaction of vasoconstrictive and vasodilatory factors
-VSM and Endothelial cells communicate via gap junctions.
Vascular Smooth muscle surrounds arteries and arterioles controlling the diameter of the vessel.
Endothelial cells line the insideof the vessel and secrete vasodilatory and vasoconstrictive factors. |
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Term
What is the primary sympathetic influence on coronary and vascular beds of organs?
List the four hormones and constrictive agents that we use. |
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Definition
Primarily Vasoconstriction
1)Circulating catecholamines
- Norepinephrine
- Epinephrine - can cause vasoconstriction in peripheral VSM, vasodilation in others (coronary arteries)
2)Angiotensin II
3)Vasopressin
4)Endothelin - released by the endothelial cell of the vessels in response to vessel damage. |
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Term
| What are the two mechanisms that cause VSM relaxation? |
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Definition
1) Removal of Vasoconstriction Stimulation
2) Introduction of Vasodilators |
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Term
| What are the two vasodilators which are released from the endothelial cells? |
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Definition
1) Prostacyclin (PGI2)
2) Nitric Oxide (Endothelium Derived Relaxing Factor - EDRF) |
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Term
Nitric Oxide is produced quickly by conversion of ________ (an amino acid) in response to what?
How long does Nitric Oxide last? |
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Definition
arginine in response to increased stress on the vessel wall and hypoxia (low blood oxygen) - also relieves sheer stress on artery walls.
-Very short half life (< 10 sec) acts locally. |
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Term
| List five other metabolic vasodilators. |
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Definition
1) Hypoxia (low oxygen) - inhibits calcium influx to VSM. Stimulates NO production. Causes relaxation/dilation.
2)K+
3)H+
4)Lactate
5)CO2
All of these possess vasodilator properties. |
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Term
| How is blood flow to the working muscle controlled? |
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Definition
-Strenuous exercise can increase blood flow requirements by 20-30x resting level.
-Cardiac output increases by only about 7-8x resting level
-Blood flow is shunted from other tissues to working muscle
-Control is at the arteriole level via "precapillary sphincter" |
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Term
| What else happens to blood flow during exercise? |
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Definition
Fight or flight response
-Initial reaction to exercise results in an increased autonomic (sympathetic response)
-Autonomic and hormonal responses cause widespread vasoconstriction of extremities to preserve blood supply for the central system.
-Local regulation of blood flow via locally produced vasodilators overrides autonomic response at working muscle.
-Autonomic effects remain in non-working muscle, gut, etc. |
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Term
| Neural/Hormonal Control - NE = Constirction(contraction) = Periphery system |
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Definition
| Local Control - Endothelial cells which release NO (vasodilation) = Relaxation (dilation) = central system |
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Term
| List the four main parts involved in lung function. |
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Definition
1) Trachea
2) Bronchi
3) Bronchioles
4) Alveoli |
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Term
Define the following:
1) Total Lung Capacity (TLC):
2) Residual Volume (RV):
3) Vital Capacity (VC):
4) Inspiratory volume:
5) Tidal Volume: |
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Definition
1) Total Lung Capacity (TLC): The total volume of the lungs after a maximal inspiration = about 6 L
2) Residual Volume (RV): The amount of air left in the lungs after a maximal expiration = about 1 L
3) Vital Capacity (VC): TLC - RV. The maximum amount of air a person can inhale after a maximal expiration = about 5 L
4) Inspiratory volume: The volume of air in a single inspiration = about 0.5 - 5 L
5) Tidal Volume: The volume of a normal resting inspiration or exhalation = about 0.5 L |
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Term
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Definition
The movement of air between the atmosphere and the lungs. Determined by pressure gradients and airway resistance.
-The ideal gas law states that pressure in a system is inversely related to volume. Thus, as volume of the system increases, pressure decreases. |
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Term
In regards to pressure and volume of air in the lungs, air flows in when:
air flows out when: |
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Definition
Air flows in when volume of air increases and pressure decreases.
Air flows out when volume of air decreases and pressure increases. |
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Term
Under resting conditions, (at the end of an expiration), the pressure within the chest cavity and atmostphere is what?
By expanding the size (volume) of the chest cavity during inspiration, the pressure in the cavity drops, allowing air to flow where? |
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Definition
EQUAL!
From the atmosphere into the lungs |
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Term
| In regards to the diaphragm, what happens during contraction and relaxation. |
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Definition
Contraction draws the diaphragm down and promotes inspiration
Relaxation returns the diaphragm to its resting position and decreases the volume of the chest cavity forcing expiration. |
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Term
| What happens within the respiratory musculature during exercise? |
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Definition
1) Expansion of the rib cage further increases the volume of the chest cavity during inspiration
2) Contraction of the rib cage during expiration assists in lowering the volume
3) Rectus abdominus forces abdominal organs upward assisting the diaphragm |
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Term
| The sum result of the physiological processes of respiration is to change the volume of the thoracic cavity by doing what two things? |
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Definition
1) Reduce thoracic pressure to promote inspiration
2) Increase thoracic pressure to promote expiration
It is important to remember that air flows from areas of high pressure to areas of low pressure. |
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Term
| What role does altitude play in breathing (remember pressure)? |
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Definition
| Higher altitude = a lower pressure which makes it harder to breath. |
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Term
| What is on the alveoli that provides assistance in respiration? |
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Definition
Assistance is provided by surfactants on the alveoli. The alveoli are bathed in a water based fluid. Surface tension places external collapsing force on the alveoli. However, surfactant reduces this surface tension of water which reduces the collapsing force.
When the alveoli expand, the surfactant disperses and are less effective. |
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Term
When alveolar size is small, surface tension is ___, assisting in _________.
When alveolar size is large, surface tension is ___, assisting in ________. |
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Definition
When alveolar size is small, surface tension is low, assisting in expansion.
When alveolar size is large, surface tension is higher, assisting in collapse. |
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Term
In the alveoli, the pressure is ____ and the resistance is ____.
In the lungs, where is the lowest resistance found? |
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Definition
low, low
Lowest resistance is found in the terminal bronchioles because of their enormous area compared to larger airways. |
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Term
| List the two factors affecting airway area (resistance). |
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Definition
1) Bronchial smooth muscle tone - airways contain a layer of smooth muscle which contracts in response to a vairety of stimulie a) Pollution b) Allergens and c) Cold air
2) Airway obstructions - a)Mucus - bronchitits, asthma, and dry air.
and b)Collapsed airway - emphysema. |
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Term
What is the purpose of ventilation?
What is hyperventilation?
Hypoventilation?
Hyperpnea?
Hypopnea? |
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Definition
The purpose of ventilation is to provide oxygen to, and remove carbon dioxide from, the living system. Blood CO2 level is a primary driving force behind ventilation.
Hyperventilation - When alveolar ventilation is greater than necessary to remove metabolic CO2
Hypoventilation - When alveolar ventilation is less than adequate to remove metabolic CO2.
Hyperpnea - an increase in ventilation
Hypopnea - a decease in ventilation |
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Term
| List the two types of ventilation rate measurements: |
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Definition
1) Total ventilation - inspiratory volume x breathing rate
2)Alveolar ventilation - (inspiratory volume - dead space) x breathing rate. |
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Term
| What is dead space? and what are the two types? |
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Definition
1)Anatomical dead space (trachea, bronchioles, and alveoli) - the portion of the conducting airways that do not participate in gas exchange
2)Physiological Dead Space = Anatomical Dead Space + ventilated alveoli receiving inadequate or no blood supply so that gas exchange with the blood does not occur. |
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Term
| How is gas exchanged between the lung and the blood? |
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Definition
| The alveoli have extremely thin walls. Extensive profusion - relatively low blood velocity. This is the sit of gas exchange between the lungs and the blood. Gas exchange is accomplished by pressure gradients! |
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Term
| The atmosphere is composed of many gases. The mass of these gases combine to place pressure on all entities in the atmosphere. Combined, these gases exert a total pressure at sea level of about ____ torr. |
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Definition
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Term
| What is the partial pressure? |
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Definition
| A partial pressure is the portion of the total pressure that is exerted by any one particular gas. Partial pressure is the product of the total pressure multiplied by the fraction of the gas that is in question. |
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Term
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Definition
| Barametric pressure * Fraction of gas. |
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Term
| Regarding Pulmonary Gas Exchange, What is the first step in Oxygen delivery from the atmosphere to the alveoli? Also what is the equation for PIO2? |
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Definition
The partial pressure of inspired oxygen (PIO2) is dependent on the barometric pressure (PB) and the fraction of oxygen in the inspired gas (FIO2) which = 20.93% and a third term (PH2O) which is the vapor pressure of water and = 47 torr.
PIO2 = (PB - PH2O) * FIO2 = (760 - 47) * 0.2093 = 149 torr. |
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Term
At rest, actual averate alveolar pressure is going to be about ___% less at rest, because not all of the air in the lungs is recycled with each breath.
How would hyperventilation or exercise effect actual PAO2? |
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Definition
25%
It would increase it because more air is participating in gas exchange with the atmosphere. |
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Term
| Going to altitude environments will reduce __ and reduce ____. |
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Definition
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Term
What is the second step of oxygen delivery from the alveoli to the pulmonary capillary blood.?
What two variables can change in regards to this? |
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Definition
Movement of gases between the alveoli and blood are governed by Fick's Law of Diffusion. The alveolar capillary unit is structurally predisposed to gas diffusion because of its large surface area and very thin diffusion barrier.
1) Pressure: BP and Partial Pressure
2) Thickness of the membrane |
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Term
| Like gas transport from the atmosphere to the lungs, gas flow through the cardio-pulmonary cardiovascular system relies on ________ _________. Exercise will cause _________ in O2 and _________ in CO2 pressure at the working muscle and in the venous blood |
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Definition
pressure gradients
decreases on O2
increases in CO2 |
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Term
Why is it so hard to breath on Mt. Everest?
What two things help breathing on Everest? |
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Definition
Arterial blood in the lung has a partial pressure of about 40 torr at rest (drops significantly during exercise). PAO2, at best, on Everest is about 43 torr (3 torr! thats Nothing! almost no pressure gradient!). So there is not much of a driving force behind oxygen diffusion!
1) Hyperventilation helps increase PAO2
2) Supplemental O2 is used |
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Term
What are the two primary constituents of blood?
What does hemoglobin do? |
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Definition
1) Plasma - water based fluid
2) Red blood cells - comprise 35-50% of blood volume and contain the molecule hemoglobin
Hemoglobin transports O2 in the blood. |
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Term
98% of the oxygen carried by the blood is bound by __________.
1.5% of the oxygen carried by the blood is what? |
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Definition
hemoglobin
dissolved in the plasma |
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Term
| What happens to the affinity between oxygen and hemoglobin as the hemoglobin enters environments with low oxygen pressure? |
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Definition
| The affinity decreases. A drop from 100 torr at alveoli to 40 torr or lower (about 15 torr at max exercise) at working muscle promotes the unloading of oxygen. |
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Term
| If O2 is no longer binding to hemoblobin for transport, how does O2 get to the working muscle once the O2 pressure has decreased? |
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Definition
At the working muscle, myoglobin (a muscle counterpart to hemoglobin) has an attachment point for oxygen (Fe) and facilitates storage and transfer from the blood to the muscle and into the mitochondria.
Myoglobin maintains a high affinity for O2 even at low O2 levels. So when O2 leaves Hb, it can be transported by myoblobin instead! |
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Term
| What is the oxyhemoglobin dissociation curve representing? |
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Definition
| The % saturation of hemoglobin at any given O2 pressure. When running blood through the lungs, Hb can take all of the O2 from the lungs. When O2 pressure drops (from 90-100 torr to 15-40 torr, hemoglobin doesn't want to hold on to O2 anymore so myoglobin takes over. |
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Term
In regards to the oxyhemoglobin Association-Dissociation curve, what 4 factors assist in offloading of O2 at the working muscle?
What 4 factors assist in promoting onloading of O2 at the lung? |
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Definition
Offloading:
1) Decrease in PO2
2) Increase in PCO2
3) Increase in Temperature
4) Decrease in pH
Onloading:
1) Increase in pH
2) Decrease in Temperature
3) Decrease in PCO2
4) Increase in PO2 |
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Term
| What are the three forms in which CO2 is carried. There is a special equation that you need to know for one of these forms of transport, what is it? |
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Definition
1) Dissolved in the plasma - about 10% of the total CO2 is carried as dissolved gas
2) Bicarbonate - about 60 - 70%:
H+ + HCO3 <--> CO2 + H20
3) Carbamino - Hemoglobin - bound to terminal amine group of Hb = about 20-30%. |
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Term
| As hemoglobin becomes deoxygenated at the muscle, how does this affect CO2? What about when hemoglobin is oxygenated at the lung? |
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Definition
| As hemoglobin becomes deoxygenated at the muscle, CO2 uptake is enhanced. As hemoglobin is oxygenated at the lung CO2 is offloaded. |
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Term
| List the two respiratory centers and where they are located. |
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Definition
1) Central respiratory center located in the lower brain
2) Peripheral RC located in the wall of the aortic arch |
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Term
List and describe the two mechanisms which control respiration.
Which mechanism predominates in early exercise? |
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Definition
1) Motoneural - utilized proprioceptors (nerve receptors) (primary stimulus to increase breathing). When joints start moving around axis, this stimulates breathing.
2) Chemoneural - influenced by chemicals (3). CO2 control, O2 control, and pH (H+) control.
Motoneural predominates early in exercise - limb movements excite joint proprioceptors that transmit excitatory impulses to the respiratory center located in the brain stem and lower brain. |
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Term
| How is CO2 controlled at the central system? |
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Definition
| It is stimulated by CO2 diffusing across the blood brain barrier and H+ produced by the CO2. Not stimulated by blood-borne H+! Responsible for about 80% of CO2 influenced steady state control. |
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Term
| How is CO2 controlled at the peripheral system? |
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Definition
-Respond directly to blood CO2 levels
-Transmit signal to the CNS
-Responsible for remaining 20% of CO2 influenced control. |
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Term
| How is O2 controlled during respiration? |
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Definition
-receptors located in the peripheral respiratory center
-blood hypoxia (low oxygen) elicits an increase in the firing rate of these receptors
-increases in blood CO2 levels increase sensitivity of these receptors to hypoxia.
So hypoxia + CO2 levels = bigger response |
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Term
| How is pH controlled during respiration? |
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Definition
1)Low pH (acidosis) stimulates chemoreceptors.
2)Increased respiration results in CO2 removal and increases pH (decreasing acidosis)
Remember reaction!
H+ + HCO3 <--> CO2 + H20. When CO2 decreases, reaction runs to the right and more H+ are given off increasing the pH and decreasing acidosis! |
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Term
| Prior to high-intensity, intermediate-length efforts, athletes will frequently practice hyperventilation. Why? |
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Definition
| When you hyperventilate, you are breathing more than necessary which in turns gets rid of more CO2. So with CO2 levels decreasing, this causes the reaction to run to the righ so we rid more protons (H+) and pH increases from the blood preventing acidosis longer. |
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Term
| Why do men tend to have higher VO2 max's then women (2 reasons): |
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Definition
1) A greater percentage of their body mass is composed of muscle
2) Higher hemoglobin levels in males. |
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Term
2 sources of CO2 production include:
During exercise at progressively higher work rates, CO2 production and ventilation exhibits a ______ rise.
Accumulation of H+ results in extra CO2 production and an exponential rise in ventilation commonly known as the "__________ _________." |
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Definition
1) Metabolic
2) H+ buffering
linear
"ventilatory threshold" |
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Term
What is the respiratory exchange ratio (RER)?
What is the range of values?e
Low RER's suggest what?
High RER's suggest what?
What affect does acidosis have on RER? |
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Definition
Ratio of CO2 produce:O2 consumed.
-RER values range from 0.71 to > 1.00. RER is commonly used to predict substrate utilization.
-Low RERs suggest high fat catabolism - fat requires more O2 per ATP regeneration.
-High RERs reflect higher CHO metabolism
Acidosis - when buffering H+ ions, we produce lots of CO2 which means increase CO2 / O2. Then RER is possible to be greater than 1.00 (usually during a max test) |
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Term
An RER of 0.71 suggests what?
An RER of 1.00 suggests what? |
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Definition
0.71 suggest burning fat (takes more O2 to run)
1.00 suggests burning carbohydrates.
O2 = CO2 |
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Term
| In hematology, what are the five components of the blood? |
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Definition
1)Plasma - the liquid portion of blood and all of its non cellular components eg. water, transport protein, glucose, etc.
2)Hematocrit - All the solid cellular components.
3)Platelets - clotting factors
4)White cells - immune function
5)Red cells - contain hemoglobin and are involved in transport of O2 and CO2, acid base buffering |
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Term
| Red cells are produced where in response to what? |
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Definition
| Red cells are produced in the bone marrow in response to the hormone erythropoietin. |
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Term
| How can oxygen delivery be a limiting factor in exercise performance? |
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Definition
| The oxygen carrying capacity of the blood can be impacted by red blood cell and hemoglobin mass. |
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Term
Where is the main site of erythropoietin production?
When is EPO production enhanced? |
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Definition
specialized cells in the kidney.
EPO production is enhanced when blood flow to the kidney or blood oxygen levels are low
-Blood Hypoxia - altitude exposure or anemia
-Low renal blood flow - exercise. |
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Term
| What is our cardiac response to acute exercise? |
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Definition
Heart Rate
-Initial increase due to removal of parasympathetic control
-Subsequent increase in sympathetic input which causes a majority of the heart rate response |
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Term
| What are the two stimuli which increase heart rate? |
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Definition
1) Aerobic - increasing O2 demand
2) Resistance Training - Muscle contraction decreases vessel radius, reduce blood flow - totally different from aerobic - occludes blood vessels which decreases blood flow and makes heart work harder - also stroke volume decreases. |
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Term
| A maximum heart rate does not mean maximum performance and maximum performance does not always result in maximum heart rate. Why? |
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Definition
| In a max spring like the 100 meter race, there is not enough time for your heart rate to reach its maximum rate. In long distance biking, they can reach their max heart rate without going to max exercise. So we can't just go off of heart rate to determine how hard we are working. |
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Term
| Different responses are exhibited in response to endurance vs. resistance training. why? |
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Definition
A resistance trained heart there is increased hypertrophy of the heart muscle and there is an increased afterload.
In an endurance trained heart, there is a greater need for O2, so we need to increase stroke volume. Endurance is much better off in regards to heart disease. |
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Term
| List four acute vascular-blood responses to exercise. |
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Definition
1) Vasodilation of capillary beds of working muscle (NO, prostaglandin, shear stress, hypoxia, lactate, H+ ions)
2) Vasoconstriction of capillary beds of non-working organs - renal and gut - sympathetic control (NE/E).
3)Increased arteriovenous O2 difference - The vein that feeds muscle vs. the vein that drains it
4) Arterial desaturation - prolonged intense exercise especially at altitude (O2 pressure in the lungs decreases so we don't send as much O2 to the working muscle) |
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Term
| What are two vascular adaptations to endurance training? |
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Definition
1) Arteriogenesis - the enlargement of existing arterial vessels
2) Angiogenesis - formation of new capillaries from existing capillaries |
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Term
| List some blood responses to endurance training. |
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Definition
1) Increases in red cell and hemoglobin mass
2) Plasma volume expansion - due to increased blood protein levels -> 800 mL (about 20%). - Occurs early in training regimen. - Decreases viscosity, increases preload, decreases afterload -> increases stroke volume.
-Detraining effects can be partially reversed by artificial plasma volume expansion.
-Plasma volume decreases very quickly once training has ceased. |
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Term
| Are there any pulmonary adaptations? |
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Definition
| No true adaptations in pulmonary tissue to exercise training in healthy individuals. Training effect in respiratory muscles. |
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Term
| The big Question: Is cardiac output a limiting factor in endurance exercise performance? |
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Definition
| The answer is yes and no. It depends on the amount of muscle mass that is involved. A kayaker for instance is using a law percentage of his muscle mass so he is not as limited by cardiac output because he has plenty of blood and O2 to supply the working muscles. On the other hand, athletes like rowers or swimmers are limited by cardiac output because they are using a higher % of their muscle mass. |
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