KINES 350 Exam #2 Material Flashcards
Define: Pulmonary Ventilation
The process of moving and exchanging ambient air with air in the lungs
The lungs provide ______ exchange.
The “Gas Exchange”, surface for oxygen to transfer from alveolar air into alveolar capillary blood.
What does the alveolar air going into the alveolar capillary blood do/allow for?
Gas Exchange
- so we can get oxygen from air to alveoli into the blood
How much does the lungs usually weigh?
2.3 kg
Volume of the lungs?
4-6L (basketball)
TRUE OR FALSE:
The lungs are do not have a lot of vasculature.
FALSE:
* They are HIGHLY vascular
What percentage is the lungs is made up of air (airways) and blood (vasculature)?
90%
* 600 miles of capillaries in
lungs/chest cavity
* lots of blood supply to allow gas
exchange to occur
How much of the lungs is made up of solid tissue?
10%
TRUE OR FALSE: Lungs have a lot of surface area to allow more gas exchange?
True
* half a tennis court
What is INspiration?
Air movement INTO the lungs
What is the primary muscle that is responsible for inspiratory contraction?
Diaphragm
What is “aerobic metabolism”?
4x the number of mitochondria and aerobic enzymes
What are the 3 limiting factors for aerobic metabolism?
*Phosphocreatine
* Phosphagen
* Anerobic glycolysis
What factors/substrates contribute to the reason why we want to function under aerobic metabolism?
- Fatty acids
- Glucose
- Amino acids … to constantly fuel aerobic metabolism
What happens to the diaphragm and the ribs when we INhale, or breathe air in?
- Diaphragm: descends DOWN 10cm
- Ribs: rise due to the scalene, sternocleidomastoid, and external intercostal muscles
What 3 muscle’s move when our ribs move up and down?
- Scalene
- Sternocleidomastoid
- External Intercostal
What do the “Scalene” muscles do?
Elevates upper part of rib cage
What does the “Sternocleidomastoid” muscles do?
Raises sternum up
* allows air to get into lungs and help with expansion
70% of what occurs because of what?
Expansion, because the ribs are rising
The degree of filling and expansion depends on what?
- Inspiratory movement (how you
breath in)
TRUE OR FALSE: During workout out and increasing our exercise intensity,(light, moderate, vigorous), there is a higher contribution for the 3 muscles that help with inspiration, to increase thoracic cavity expansion to get air in lungs when exercising.
True
* allows for grater contraction to allow MORE air into the lungs
What “intra-pulmonic pressure” when inhaling?
When the atmospheric pressure decreases slightly below atmospheric pressure
* when inspiration and thoracic cavity expansion ends
What is EXpiration?
Air movement OUT of the lungs
What happens to the diaphragm and the ribs when we EXhale, or breathe air out?
Air movement OUT of the lungs
Knowledge Card! :)
At rest and light physical activity expiration happens at a natural recoil of stretched lung.
* Tissue sis very elastic
When we exhale all 3 muscles scalene, sternocleidomastoid, and external intercostal all do, what?
Relax
When we exhale and relax, what happens to the diaphragm and the ribs?
Diaphragm: moves UP
Ribs: go DOWN
The inspiratory muscles all contribute to what action to the lung tissue and causes what?
Presses on lung tissue and causes natural recoil to force air out of the lungs for expiration to occur
What is “Intra-pulmonic pressure” when exhaling?
Atmospheric pressure and when expiration ENDS
* when compressive force of muscles stops and when pulmonic pressure reaches atmospheric pressure
A decrease in chest volume does what to alveolar gas and causes what to happen?
Compresses alveolar gas to that air moves from the respiratory tract out into atmosphere.
During workout out and increasing our exercise intensity,(light, moderate, vigorous), what muscles help contract and pull the ribs down and decrease amount of expansion of lung capacity to take air in?
1) Internal muscles
2) Abdominal muscles
TRUE OR FALSE: Exhaling costs more energy due to contracting and the more contraction the more facilitated breathing.
True
What is “tidal volume”?
Volume inspired or expired per breath
* Females: 0.5L per breath/min
* Males: 0.6L
What is “minute ventilation”?
Breathing rate times tidal volume
What is the breathing rate at rest?
12 breaths/min
What is breathing rate during strenuous exercise?
35-45 breaths/min.
* as you increase activity level
* driving factor of increased ventilation as we exercise
What is “Total Lung Capacity”?
Volume in lungs after max. inspiration
* until you can no longer breathe in anymore
- Females: 3.2L
- Males: 4.8L
TRUE OR FALSE: As you work out, the amount of energy it costs you decreases.
False, it increases
Oxygen requirement of breathing and to make ATP is relatively small at/during _______. The is _____ difference in females and males.
A. rest
B exercise
C. A
D. no
A.
D.
During moderate intensity exercise (VE = 100L/min), what percentage of total oxygen consumption is needed of breathing?
3-5%
Knowledge card! :)
The metabolic demands of respiratory muscles during maximal intensity endurance = maximal effort is up to 15%.
* Causes competition for blood flow between respiratory VS. locomotor muscle
TRUE OR FALSE:
Endurance training has a little impact on the functional capacity of the pulmonary system.
False, has NO impact
Although there is no influence that endurance training has on functional capacity of the pulmonary system, what is one exception?
Swimming and scuba diving results in larger than normal tidal vol. and total lung capacity due to strengthening of inspirational muscles
- due to to work against extra resistance that is over their chest (thoracic) area making it harder to breathe, so the inspiratory muscles get stronger compared to a normal regular endurance trained athlete
Pulmonary ventilation DOES or DOES NOT limit max aerobic performance for most individuals despite feeling “winded.”
Does not
* Even if you run a marathon, the “can’t breathe” feeling isn’t the limiting factor of performance = healthy
Knowledge card! ;)
Females have consistently reduced lung volumes than males
- Produces greater use of ventilatory reserve and respiratory muscle work in females
- Expend more energy
TRUE OR FALSE:
Exercise training improves, ventilatory muscle endurance.
True
What does exercise training improve, and what is it caused by?
1) Improves the muscle you use to breathe
2) Caused by training induced increase in aerobic enzyme levels and oxidative capacity of the respiratory musculature
What are the benefits of exercise training and what it does to your pulmonary adaptations?
1) Less respiratory work by ventilatory muscles reduces overall energy demands
2) Less respiratory work by ventilatory muscles reduces overall energy demands
3)Ventilatory muscles more efficiently metabolize circulating lactate as metabolic yield exercise
How and why do we produce less lactate during intense exercise that causes less fatigue?
1) As we enhance aerobic capacity it allows less lactate to form
2) Instead of pyruvate going and becoming lactate, the pyruvate that is being formed by glycolysis, can enter the aerobic cycle instead
Where does the respiratory tree start?
Mouth or nose
As the air we breathe in enters our body, what happens within our bodies?
1) It will adjust to it internal body temperature
2) filter particles
3) humidify air we breathe in
What is the “trachea” and what does it do?
Cartilage tube connecting the pharynx and larynx to the lungs
What are the “bronchi” and what do they do?
Primary conduits into each of the L&R lungs
What are “bronchioles” or what do they do?
Conduct inspired (breathed in) to the alveolar ducts
What are “alveoli”, and what do they do?
Small, elastic, thin-walled membranous sacs made of simple squamous epithelial cells that allow for gas exchange between lung tissue and blood
Alveoli allow for 250 mL of ____ and 200 mL of ___________ per minute at rest by during exercise can increases carbon dioxide diffusion by 25x.
- oxygen
- carbon dioxide
We have around 600 million alveoli and surrounding each are what?
Pulmonary Capillaries
What do “Pulmonary Capillaries” do around our alveoli?
- They transport venous blood, carbon dioxide rich blood back to the alveoli
- CO2 from the blood to the alveoli
–> oxygen that has moved down respiratory tract to alveoli can then move into pulmonary capillaries
What is the “Conducting Zone”?
Anatomic dead space that occupies the largest portion of total lung volume
How much (%) of the “conducting zone” does it take up?
30%
What are the 5 functions of the “conducting zone?”
1) Air Transport
2) Humidification: moisture
3) Warming: close to body temperature
4) Particle filtration
5) Vocalization
—-> Helps with cold weather affects during physical activity
During cold weather physical activity, it causes your mouth to be dry or you to cough. What is happening to your conducting zone?
Overall water loss in conducting zone
What is the main point of the “Conducting Zone”?
Trying to warm area so heat is being lost form tissue
- losing warmth and water moisture you can use a face mask to help make and maintain moisture in your mouth
What is the “Respiratory Zone”, what does it do?
1) Epithelial enzymes make ‘surfactant’
2) Molecule Activation
3) Inactivation
4) Blood clotting regulation
5) Endocrine function
What does ‘surfactant” production cause?
Reduces surface tension at liquid air interface at alveoli (pulmonary capillaries)
What is in alveoli?
Air
What is in pulmonary capillaries?
Liquid
What is the “Respiratory Zone” made up of?
1) Respiratory bronchioles
2) Alveoli
What is “Partial Pressure?”
The pressure by an individual gas in a mixture
* the pressure the gas would exert if it was the only gas inside the container
What is “ambient air”?
Air we are breathing = 760 mm Mg (mercury)
- within Mg is…
1. Oxygen = 150 mm Mg (20.93%)
2.Nitrogen = 600 mm Mg (79.04%0
3.Carbon Dioxide = 0.2 mm Mg (0.03%)
What 2 ways is used to determine gas movement in humans?
1) Pressure Differential
2) Solubility of gas in fluid
What is “solubility”?
How well a particle will dissolve into a solution
In gas movement, solubility of the gas in the liquid ass 3 particles. Which of the 3 are best at dissolving and why?
A) Carbon Dioxide
B) Nitrogen
C) Oxygen
Carbon Dioxide
- Has a high solubility (ability to dissolve)
During “pressure differential” what is happening?
Gas will move from an area of high pressure to low pressure
What is the driving factor of “gas diffusion”?
Pressure Differential
TRUE OR FALSE:
At REST, oxygen moves from high to lower pressure.
True
What is “venous blood”?
Deoxygenated blood that flows from the body’s tissues into the heart through veins
What is “arterial blood”?
Oxygenated blood
TRUE OF FALSE:
During oxygen transportation to arterial blood, “partial pressure” changes from when it was in the alveoli and when in the arterial blood.
False, it is equal
- alveoli = 100 mm Mg
- arterial blood = 100 mm Mg
True or False:
During pulmonary ventilation, when oxygen leave the pulmonary capillaries (alveoli) and goes to the arterial blood, our bodies get rid of ALL of the CO2.
False, because it serves as a chemical basis for ventilatory control in the pons and medulla
- alveolar gas composition remains constant
TRUE or FALSE:
Small amount of O2 and CO2 dissolve in arterial and venous blood creating a partial pressure.
True
What are the 2 ways that oxygen is transported in the BLOOD?
1) dissolved in the fluid portion of the blood
2) in combination with hemoglobin
How is oxygen transported in the skeletal muscle?
In combination with myoglobin
What is the PRIMARY way that oxygen is transported in the blood?
Combine with myoglobin
One way that oxygen is transported in the blood is by being dissolved in fluid.
Does O2 have a high or low solubility? What happens?
Low solubility
* so only a small amount of O2 is dissolved
* 3mL of O2 dissolved per L in blood
* cannot sustain life (only for 3 seconds)
Can O2 dissolving in the blood sustain life?
No, only for 3 seconds
Even though desolation (dissolve) of O2 in the blood cannot sustain life, what is is actually important for?
1) establishes partial pressure of O2 in plasma
2) helps regulate breathing
3) determines oxygen loading of hemoglobin in the lungs & unloading from hemoglobin in tissues
—> the partial pressure of O2 dissolved in physical solution dictates the oxygenation of hemoglobin to oxyhemoglobin
The primary way that CO2 is transported in the blood is _______.
As a bicarbonate
What does CO2 and water make when mixed together?
Carbonic Acid
What helps speed up the process of CO2 and water mixing?
Carbon Anhydrase
With Pulmonary Ventilation, the need for different levels of respiration caries with what, state, of an individual?
Physiologic state
* sleep
* excitement
* exercise
* stress
What is the role of the respiratory system and what 3 things does it maintain?
1) O2 –> make sure enough O2 to meet metabolic demands of the tissues
2) CO2
3) H+ (acidity in arterial blood)
What happens when there is too much H+ ions?
Affects blood pH and stays constant
What is the “negative feedback system”?
When there is a change in O2, CO2, or H+ ions and triggers a response to reverse it back to its initial change and brings back to normal value
* changes in these variables in the blood cause compensatory changes in the level of ventilation
Pulmonary ventilation is controlled by what two parts of the brain?
1) Pons
2) Medulla
TRUE OR FALSE:
Breathing is an automatic process that is triggered in the brain stem.
True
How many respiratory centers do the medulla and pons have TOGETHER?
3
What does the “pons” do?
1) Controls the rate and pattern of breathing
2) Pontine group promotes inhalation by a constate stimulation of the neurons in the medulla
How many respiratory centers does the “pons” have and is the _____ group.
1
* Pontine group
What does the “Pontine group” do in in the pons as its only respiratory center?
Control rate and pattern of breathing and promotes inspiration by constantly stimulating neurons in the medulla
- Medulla stimulates normal respiratory cycle which is inspiration and expiration and there are inspiration and expiration neurons in the medulla that generate automatic inhale and exhale
What does the “medulla” do?
Governs the normal respiratory cycle
In the medulla, inspiration and expiration is controlled by inspiratory and expiration _____.
Neurons
What do “inspiratory neurons” do in the medulla?
* Activate what?
Active inspiration
What happens to “inspiratory neurons” when we exhale?
Turn off
Afferent nerves (moving away form the body) and away from CNS, they will activate the diaphragm and intercostal muscles, to trigger us to inhale.
The neurons will then deactivate because they will be inhibited by expiratory neurons
As exhalation occurs, the inspiratory neurons will slowing become less inhibited and then not inhibited at all eventually active again to trigger another cycle of inspiration.
What happens to “expiratory neurons” when we inhale?
Turn off
How many respiratory centers does the “medulla” have and what are the group(s) called?
2
* Dorsal Resp.
* Ventral Resp.
TRUE OR FALSE:
Automatic cycle of breathing can be modified or even temp. stopped, depending on the info. received by the respiratory control center.
True
For regulation of pulmonary ventilation, what are the two types of receptors?
1) Chemoreceptors
* Central
* Peripheral
2) Muscle and Lung receptors
* Muscle Spindles
* Mechanoreceptors
For pulmonary ventilation, and its Chemoreceptors, what are “Central Chemoreceptors”?
Neurons in the the medulla that are sensitive to the change in partial pressure of CO2 (pCO2) and pH, but not as much because H ions don’t cross the blood brain barrier so it take chemoreceptors longer to sense it
- Can sense change quickly
- b/c CO2 can diffuse through blood brain barrier in the cerebral spinal fluid
For pulmonary ventilation, and its Chemoreceptors, what are “Peripheral (Arterial) Chemoreceptors”?
Neuron bodies positioned in the carotid and aortic arteries that detect arterial hypoxia and trigger a ventilatory response in medulla
- sensitive to MOSTLY O2 as well as CO2 and -pH
- Tell medulla of how much O2 they detect in the blood
The carotid arteries positioned in a way that it can make sure there is enough _____ being pumped out from the heart.
A) CO2
B) O2
B) (O2) Oxygen
Where are the aortic arteries located? What does it do?
Where blood is being pumped from the heart to monitor oxygen going out into the body
* also regulate cardiac output
–> How much blood is being
ejected out from heart into
the body per minute
For pulmonary ventilation, and its Muscle and Lung Receptors, what are “Muscle spindles”?
They detect, respond, and modulate changes in the length of a muscle fiber when getting longer
- An in increase of motor discharge to the muscles to increase the amount of work during inspiratory
For pulmonary ventilation, and its Muscle and Lung Receptors, what are “Mechanoreceptors”?
Monitor the ….
1) expansion of the lung,
2) the size of the airway
3) the force of respiratory muscle contraction
4) extent of muscle shortening
TRUE or FALSE:
During exercise, no single mechanism entirely accounts for the increase in ventilation (hypernea) during exercise.
True
TRUE OR FALSE:
Instead of a single mechanism, there is combined and simultaneous effect of several chemical and neural stimuli instinct and modulate exercise ventilation broken into 3 phases.
True
What is “Phase 1” in regulation pulmonary ventilation during exercise? Controlled by what?
First 20 seconds of exercise
* central command
*neural input and feedback
What do the feedback proprioceptors in joints and active skeletal muscle do in “phase 1”?
Give proprioceptive input/feedback to central commands to regulate ventilation during exercise
TRUE OR FALSE:
Phase 1 does NOT continue all through exercise.
False, continues during all exercise
What is “Phase 2” in regulation pulmonary ventilation during exercise? Controlled/regulated by what?
Exponential rise in ventilation to achieve steady state based on metabolic gas exchange demands
- Central command input
- Feedback form respiratory neurons and chemoreceptors that sense carbon dioxide and O2 and acidity
- Feedback proprioceptors in joints and active skeletal muscle
What is “Phase 3” in regulation pulmonary ventilation during exercise? Controlled/regulated by what?
Fine tuning in steady state ventilation
*Central and reflex stimuli from CO2 and H+ concentrations
–> If alteration in these two feedback is going to be monitored and info will be sent back to the brain
During light to moderate intensity exercise during regulation of pulmonary ventilation, ventilation “increases” or “decreases” linearly with oxygen consumption and CO2 production?
Increases
After CO2 is produced during light to moderate exercise, it is transported as a __carbonate.
*What happens to the alveolar PO2 and PCO2?
Bicarbonate
*Remains near resting levels
(lactate production = lactate disappearance)
During Vigorous Exercise, pulmonary ventilation is no longer linked tightly to oxygen consumption, but …
Strenuous exercise results in increase ventilation
A small increase in the partial pressure of CO2 causes a large increase in what?
VE (minute ventilation)
What causes an increase of CO2 during vigorous exercise?
Acidosis
CO2 and H+ produced exceeding the capacity of hemoglobin accepting H+ ______ carbonic acid.
A) increases
B) decreases
A)
CO2 and H+ produced as byproduct of lactic acid being buffered by the sodium bicarbonate system
What limits VO2max in an elite, highly trained endurance athlete?
Pulmonary diffusing capacity
Why does “pulmonary diffusing capacity” limit elite endurance athletes? (short answer question)
Due to trained endurance athletes have high cardiac outputs because of their stronger hearts and how they can pump blood per minute.
- Exercise Induces Hypoxia
What is “Exercise - Induced Hypoxia?”
Decrease in partial pressure of arterial partial pressure of oxygen below 75 mmHg
Why does a decrease in partial pressure of arterial partial pressure oxygen to be below 77mmHg (exercise induced hypoxia), occur?
Pulmonary capillary blood flow transit time is too fast for diffusion to allow for adequate hemoglobin saturation
- Due to high cardiac output found in trained endurance athletes
What is “ventilatory threshold”?
The point where pulmonary
ventilation increases disproportionately relative to
increases in oxygen consumption
The _____ considered the threshold for anaerobic metabolism.
Ventilatory threshold
What is “hyperventilation”?
Result of carbon dioxide’s
production exceeding oxygen consumption (going above it)
- VCO2/VO2 >1.00
- Reduces alveolar and arterial PCO2
- Increases alveolar PO2 from resting level
TRUE OR FALSE:
When someone is hyperventilating during strenuous exercise, CO2 production is greater than O2 consumption.
True
The heart is a four chambered muscular organ. What is is composed of?
Myocardium
What is “myocardium”?
Striated muscle with high capillary density, numerous mitochondria, and single nucleus
- this is because heart relies on a lot of aerobic metabolism to make ATP
Heart weighs… males? females?
Males: 11 ounces
Females: 9 ounces
What are the 4 organs responsible for pumping and moving blood through the body, to and from the heart?
1) Right atrium
2) Right ventricle
3) Left ventricle
4) Left atrium
What does the “right atrium and ventricle” do?
Receive blood returning FROM body
- Pumps blood to lungs so oxygenation per CO2 can leave the blood for operation through pulmonary circulation
What does the “left atrium and ventricle” do?
Receive oxygenated blood from lungs/pulmonary system
- Pump blood and oxygen through aorta for distribution throughout systematic circulation
Coronary circulation/arteries provide oxygen and nutrient supply to the heart.
The left and right arteries come directly off of the _____.
Aorta
The right artery provides oxygen
nutrients to what side of the heart?
Right
* big in size
The left artery provides oxygen
nutrients to what side of the heart?
Left
Which artery eventually eventually splits into other capillaries?
A) Right
B) Left
C) Both
B) Left
How much oxygen does myocardium extract from blood in coronary vessels at REST?
70-80%
- other tissues only use about 1/4th of their oxygen delivered
- heart uses more oxygen at rest than other tissues
During exercise what is the only way to increase myocardial oxygen supply?
Increase blood flow
The heart uses Myocardial tissue that has a threefold higher oxidative capacity than skeletal muscle and has the greatest mitochondrial concentration of all tissues in the body = high amount of aerobic metabolism.
Are there similar patterns of myocardial metabolism exist in trained and untrained?
Yes
TRUE OR FALSE:
An endurance trained person has greater myocardial reliance on ______ catabolism in submaximal exercise = while preserving
Fat (greater use of the long chain fatty acids)
During moderate exercise, what is used mostly in a resting state?
A) Glucose
B) Glycogen
C) Both
C) Both
During intense exercise what is used more?
A) Lactate
B) Glucose
C) Both
A) Lactate
- anaerobic contribution for ATP production in working skeletal muscle and the byproduct being pyruvate and ultimately lactate
What is the “fate of lactate”?
Oxidizes by other tissues in the body and the heart being one
The heart uses what substrate as its PRIMARY to yield ATP because of its high oxidative capacities?
Lactate
______ are responsible for cardiac contractions.
Action potentials
What causes an action potential to happen?
Caused by time dependent changes in the permeability of the plasma membrane to potassium (K+), sodium (Na+), and calcium (Ca+) ions
Action potential arises spontaneously at the ______ and electrical signals spreads through the right and left atrium via gap junctions.
SA node
What is “atrial contraction”?
Ejection of the blood
What is “ventral relaxation”?
Filling of blood
What is the “relevance” of signal delaying at AV node?
When electrical signals are spreading though out the left and right atrium, that is when the atria is contracting
- this allows ejection from right atrium down through tricuspid valve to right ventricle or allows for blood to move from left atrium through mitral valve down to left ventricle
- this allows for ventricle to relax and fill with more blood
Why is the pause at the AV node, important?
If this doesn’t happen, the rest of the electrical signal will spread to the rest of the electrical parts of the heart very fast and cause the left and right atria’s to contract at the same time
- not producing an adequate amount of blood going from the atriums to the ventricles
What are “intercalated discs”?
Structural junctions, mechanical movement
*complex structural joints that couple mechanically 1 cardiac muscle cell to the other allowing for a quick continuous rhythmic contraction
What is the “SA node”?
A 3mm cluster of cells in the right atrium that generates spontaneous electrical impulses for contraction of the heart = heartbeat
- Automaticity = why it is known as the Pacemaker of the Heart
_________ occurs that will generate an AP in SA node and is responsible for cardiac contraction and for a heartbeat to happen = movement of sodium, calcium, and potassium ions make this possible
A) Depolarization
B) Repolarization
A) Depolarization
What are “gap junctions”?
Electrical linkages which spread signals in a pattern way from cardiac cell to cardiac cell
Neural inputs is the ______ nervous system that regulates/functions without thinking about it.
Autonomic
The sympathetic NS influence on extrinsic regulation of the heart, innervates the ventricle to , “increase” or “decrease” contractibility of the heart?
Increase
Sympathetic NS Influence –>
- Neurons innervate the atria and ventricles and come to the exact location of atria, close to SA node because wants to regulate pacemaker cells.
What does the sympathetic NS release?
1) Catecholamines
2) Epinephrine
3) Norepinephrine
The sympathetic NS’ releases catecholamines, epi, and norepi. and bind to what 3 receptors in the atria and ventricles?
1) Alpha 1
2) Alpha 2
3) Beta
The sympathetic NS’ releases catecholamines, epi, and norepi. and they all increase _____ node depolarization.
SA
- increase the rate that the SA node is firing causing Tachycardia HR>100bpm in atria
TRUE OR FALSE:
During exercise, in the SNS there is progressive stimulation with more intense exercise by reflex activity.
True
TRUE OR FALSE:
The SNS is responsible for regulating heart rate during intense exercise because of more release of catecholamines.
True
The ______ NS innervates the _____ to INCREASE contractibility of the heart.
A) Sympathetic
B) Parasympathetic
C) Ventricle
D) Atria
A)
C)
The ______ NS innervates the _____ to DECREASE contractibility of the heart.
A) Sympathetic
B) Parasympathetic
C) Ventricle
D) Atria
B)
D)
What does the parasympathetic NS release?
Acetylcholine
PNS neurons innervate ONLY to the _____.
Atria
SNS neurons innervate the ____ & _____.
Atria and Ventricles
The parasympathetic NS’ releases acetylcholine and bind to what receptors in the atria?
Muscarinic
What do “muscarinic receptors” do?
Decrease activity of the ions in the SA node and depolarization (slows the rate of depolarization) = heart rate is less than 100 bpm
- no effect on cardiac contractibility because not innervating the ventricles
During exercise in the PNS, central command inhibits parasympathetic stimulation at onset and during low to moderate intensity exercise
- Causes HR less than 60 bpm = bradycardia but not usual in resting state of healthy, exercised individuals
- PSN slowly is dropping input during exercise (brain inhibits PNS)
The ____ is the PRIMARY factor for controlling HR.
Brain
- central command
What is “anticipation HR”?
Tells us know that our brain is the primary factor of controlling HR
- Anticipation of exercise causes some neural outflow from the central command
What NS decreases and what NS increases, and causes an increase in HR before exercise starts?
1) Parasympathetic decreases
2) Sympathetic increases
Which anaerobic exercise is neural outflow, GREATER? or LOWER? than aerobic
Greater
Researchers found out that anticipation of exercise causes a greater increase in heart rate for ______ duration activates.
A) Shorter
B) Longer
Shorter
- Increases heart rate to get blood flow out of the heart before race begins basically revving the the body’s engine so they have what they need to run the race
In extrinsic regulation of the heart, with peripheral input, what are mechanoreceptors?
Specialized neurons that transmit mechanical information from the left ventricle, right atrium, and vein into electrical signals
What do “mechanoreceptors” do?
Modify inputs from parasympathetic and sympathetic outflow to initiate appropriate responses to intensity of exercise
What are “baroreceptors”?
Pressure sensitive neurons located in the aortic arch is where the aorta is and corroded arteries are arteries taking blood to brain
What will activate baroreceptors to slow heart rate and dilate peripheral vasculature (vasodilation)?
Too much of a stretch
Chemoreceptors have what 2 types?
1) Central
2) Peripheral
Where are “central chemoreceptors” and what are they sensitive to?
1) Medulla
2) CO2 mostly and blood pH
Where are “peripheral chemoreceptors” and what are they sensitive to?
1) Carotid Arteries
2) sense hypoxia and sensitive to changes in CO2
Local factors of peripheral extrinsic regulation of heart are byproducts of energy metabolism.
TRUE OR FALSE:
In the arterial system, no gas exchange can occur because the arteries are too thick.
True
The “outer” layer of arteries are made up of ______.
A) Collagen
B) Elastin
C) Smooth Muscle
D) Endothelial Cells
A) Collagen
What is “collagen”?
Main component found in connective muscle/tissue and provides support for all tissues
- is important so our blood vessels don’t rupture as blood pressure increases in arteries
- not stretchy (only 10% its resting length)
The “middle” layer of arteries are made up of some _____ but mostly ______. Also has ____.
A) Collagen
B) Elastin
C) Smooth Muscle
D) Endothelial Cells
1) Collagen
2) Elastin
3) Smooth muscle
What is “elastin”?
An extracellular protein and provides elasticity think rubber band
- stretches 200% past its resting state
What allows for arteries to dilate and constrict?
Elastin
What receptors do “smooth muscle” have?
Alpha
Beta
What does the peripheral release?
Acetylcholine
- Bind to the receptors to make an action and allow for vasoconstriction and vasodilation in the artery (changes in blood pressure)
What does the sympathetic release?
Epinephrine and Norepinephrine
- Bind to the receptors to make an action and allow for vasoconstriction and vasodilation in the artery (changes in blood pressure)
What is “vasoconstriction”?
Diameter of lumen is getting smaller = increase of BP caused by sympathetic NS
- epinephrine and norepinephrine
What is “vasodilation”?
Diameter of lumen to get bigger = decrease of BP caused by parasympathetic
- occurs more because of the decrease in sympathetic (less epinephrine and norepinephrine) and INCREASE in parasympathetic (acetylcholine)
The “inner” layer of arteries are made up of ______.
A) Collagen
B) Elastin
C) Smooth Muscle
D) Endothelial Cells
D) Endothelial cells
- make endothelial lipase which helps with the breakdown of certain proteins in our blood
What does “endothelial lipase” do?
Helps with the breakdown of certain proteins in our blood
______ muscle is innervated by sympathetic and parasympathetic nervous system.
Smooth
TRUE OR FALSE:
Constriction and dilation of smaller arterial blood vessels provide the crucial mechanism to regulate regional blood flow
True
What are “capillaries”?
Made up of single layer endothelial cells
- 2000 to 3000 per square millimeter of tissue in human body
Capillaries have what percentage of total blood volume?
6%
TRUE OR FALSE:
Capillaries are very small and narrow so only one blood cell can fit through.
True
How long does it take for a blood cell take to pass through?
1.5 seconds
- blood flow velocity relates inversely to cross-sectional area
Why is it beneficial that blood cells go through capillaries slow and one by one?
Enough time for gas exchange, substrates/ nutrients to leave the plasma into any other skeletal muscle/tissue that needs it
The more training activity the more capillary activity and capillary density.
What are “precapillary sphincters”?
Control blood flow into a specific capillary to meet metabolic requirements and only receiving the amount that it NEEDs
- don’t want to over do it and waste blood flow
What are “precapillary sphincters controlled” by? What system?
SNS, and innervates sphincters to decrease and cause vasocontraction
At rest one of every 30 to 40 capillaries in skeletal muscle remains open.
What factors cause relaxation of precapillary sphincters? Increase in?
1) BP
2) neural control factors
production of local metabolites produced during exercise
- increase in acidity
- increase in CO2
- increase in temperature
TRUEOR FALSE:
The venous system contains “smaller” veins compared to capillaries.
False, larger compared to capillaries
Systemic venous vessels serve as blood reservoirs as they contain ___ of total blood volume at rest.
65%
What does the “venous system” do?
Return mixed venous blood back to the right atrium (as you go through vascular network, bp decreases (120/80)) so since get here you have little to no blood pressure at all
Blood pressure _______ in direct proportion to the resistance encounters in the vascular circuit so the need of something other than bp is needed to move blood.
A) Increase
B) Decrease
B) Decrease
Venous return to the heart is therefore only possible because of what two factors?
1) Valves
2) Skeletal Muscle Pump
What does a “valve” do once blood moves up it?
It closes
- makes sure the blood does not move back down (gravity)
What does the “skeletal muscle pump” do?
Rhythmic action of muscular activity and consequent compression (squeezing) of thin veins contributes to venous return
- veins are all throughout our skeletal muscle but not as strong as arteries and are easily compressed
What is “active recovery cooling down”?
Facilitates blood flow via skeletal muscle constriction throughout the venous system back to the heart
Without, valves and the skeletal muscle pump, would would happen?
Blood would pool in our lower extremities because of gravity
- if someone stands for too long a period of time the blood starts to pool at the body of legs and people pass out risking venous blood return to the heart
What is “cardiac output”?
The amount go blood pumped by the heart in a 1-minute period
How do you determine Cardiac Output?
Heart rate (beats/minute) x stroke volume (L/beat)
What is “stroke volume”?
The quantity of blood ejected with each stroke or contraction of the heart
TRUE OR FALSE:
At rest, Cardiac output is about 5 L/min, and training status DOES affect this and NOT the size of the individual or heart.
False, doesn’t and DOES depend on the size of the individual and heart
What is the diving factor that affects the cardiac output at rest?
Individual’s size
- females have lower
What happens to cardiac output when exercising?
Increases rapidly at the onset of exercise to meet the demands needed for specific activities
When cardiac output reaches the needs of an activity, what happens after?
Plateaus, when steady state is achieved because blood flow is met
Cardiac output increases due to increased….
1) HR –> because of increased SNS and decreased PNS input
2) Stroke volume –> 2 mechanisms
What are the two mechanisms that cause an increase in stroke volume increasing Cardiac output?
1) Enhance Cardiac Filling in diastole
What is “diastole”?
Relaxation of ventricles and when they fill up it increases diastolic volume.
- When exercising, we have more blood returning to the heart (65% of blood of our venous system = due to skeletal muscle to enter into circulation enhancing cardiac filling
When we are exercising, we have more or less blood returning to the heart?
More
*due to skeletal muscle to enter into circulation enhancing cardiac filling
