Exercise Physiology

_______ ______: process by which ambient air is moved into and exchanges air in the lungs. Different from oxygen consumption.

_______: diaphragm descends, ribs are raised, volume increases, intrapulmonic pressure decreases, air rushes in. (external intercostals, scm, scalenes, spinal extensors)

_________: diaphragm relaxes, ribs lower, volume decreases, intrapulmonic pressure increases, air rushes out. (rectus abdominus, internal intercostals, posterior inferior serratus)

_____ _____: governs gas diffusion through alveoli. It's rate is directly proportional to the tissue area, a diffusion constant (solubility, molecular wt), and the pressure differential on either side of the membrane.

True or False: Co2 diffuses about 10 times faster than O2 because of higher solubility.
True False

____ ____: maximal inspiration at end of tidal inspiration

____ ____: maximal expiration at end of tidal expiration.

____ ____: maximal volume expired after maximal inspiration.

_____ ____ ____: air volume remaining in lungs after maximal expiration.
____ ______ ____: volume in lungs after tidal expiration.
_____ _____ _____: volume in lungs after maximal inspiration.

FEV/____- normal or increased for restrictive lung disease (80% or greater)
___/ FVC- <70% indicates obstructive lung disease
___: only 40% of normal in obstructive lung disease

True or False: Dynamic Lung Volumes provide no information about aerobic fitness. There is no difference between healthy and olympic athletes.
True False

True or False: Dynamic Lung Volumes does not provide indication of health risk for "at risk" exercisers.
True False

_____ _____: Increases intrathoracic pressure that occurs when exhalation is forced against closed glottis. Results in collapse of veins in thoracic region, impaired venous return, acute drop in arterial blood pressure, decreased blood supply to brain, and "spots before the eyes".

True or False: Valsalva Maneuver causes acute rise in blood pressure with resistance training.
True False

____ ____: driving force for pulmonary blood and alveolar gas exchane.

____ ____: the rate of gas diffusion into a liquid depends on pressure differential between the gas above the fluid and gas dissolved in the fluid and solubility of the gas in the fluid.

PO2 ___ mm Hg: regulates breathing and 02 loading of Hb.

PCO2- __ mmHg: chemical basis for ventilatory control via respiratory center.

In the Medulla
___ neurons activate diaphragm and intercostals.

___ neurons activated by passive recoil of lungs.

True or False: P02 has most important respiratory stimulus to medulla at rest.
True False

Describe the phases of Ventilatory Response During Exercise:

_____ ____: ratio of minute ventilation to oxygen consumption. 25=light exercise/35-40=intense exercise

_____ ____: imbalance between lactate formation and clearance. Describe 4 Ways:

Describe 3 functions lof measuring Lactate Threshold levels:

____ ____: point of disproportionate increase in Ve with increased VO2.
True or False: increase not linked to increased 02 demand but increased C02.

Lactate+ NaHC03 yields NaLactate + H2C03 --> H20 + C02

____ _____ ____: inability to fully aerate blood in pulmonary capillaries. Caused by Rapid Blood Flow, Bypass Of Diffusion Area, and ANF (pulmonary capillary vasodilators affected.

___ muscle in arterioles constricts or relaxes to regulate blood flow to periphery. Vessel diameter is critical to blood flow.

BP= ____ (Q)x ___ _____

___ BP: during left ventricular contraction the highest pressure generated (120)
__ BP: relaxation phase of the cardiac cycle (80)

Peripheral Resistance = ___/ __

____ ____ Mechanism: reduced renal blood flow causes kidneys to release renin. Renin stimulates function of angiotensin1 that converts rapidly to angiotensin 2. Angiotensin 2 constricts arterial blood vessels and stimulates adrenal cortex to release aldosterone, which causes sodium and salt retention by kidneys.

____ blockers: adrenergic inhibitors that slow heart rate and reduce myocardial contractility.
___ blockers: adrenergic inhibitors that induce dilation of arterial blood vessels.
___ ___ blockers: induce dilation of arterial blood vessels.
______: cause renal excretion of electrolytes and water to reduce plasma volume.
_____ inhibitors: induce dilation of arterial blood vessels by inhibiting kidney's production of vasoconstricting hormone angiotensin. Causes retension of sodium and water which expands blood volume.

At rest, myocardium can extract __-__% of 02 in blood of coronary vessels. Other tissues __%.

___ ___ node: "pacemaker" located within posterior wall of R atrium.

____ Effect: increases HR (SA node) resulting in tachycardia.
____ Effect: increases myocardial contractility.

Sympathetic nervous system releases _____ which accelerates HR.
Parasympathetic nervous system releases ____ which slows HR.
_____: slowing of heart due to vagus nerve stimulation.

______ Law: Pressure= Gradient X vessel radius4 / Vessel Length X viscocity

Decrease radius by half, flow decreases by __
Increase radius by 2, flow increases by __

_____ _____: key signal molecule in dilation of blood vessels and decreasing vascular resistance.

____ ____: amount of blood pumped by the heart in 1 minute.

Describe the 2 things we measure to calculate cardiac output.

Cardiac output at rest:
5l/min for 70 kg _____
4 l/min for 56 kg _____

Describe 2 factors that affect cardiac output at rest.

Cardiac output increases __ fold during exercise for untrained individuals.

Cardiac output increases __ fold during exercise for trained individuals.

Describe the 3 mechanisms that increases SV during exercise.

___-___ mechanism: contractile force increases as resting lenght of cardiac fibers increases.

____ ____: increase in HR and decrease in SV during exercise due to plasma volume shift, decreased preload, and reduced SV.

What adaptations allow expansion of a-v 02 difference:

____ Hypertrophy: endurance training; 25% larger heart volume and volume overload with training- increased plasma volume ("preload")

____ Hypertrophy- resistance training: thicker intraventricular septum, ventricular wall thickness, and increased "afterload"- heart is constantly pumping against resistance to blood flow

______: dense CT surrounding entire muscle- joins to stron CT of the tendons at the muscle tendon junction.
______: CT layer surrounding bundles of muscle fibers (up to 150-fasciculus)- major pathway for blood vessels and nerves.
______: fine layer of CT separates each muscle fiber- role in force transmission to tendon.

____ ____: terminal cisternae, ca2+ storage site.

____ ____: direct electrical impulse into muscle.

_____ : produce ATP in vicinity of contractile apparatus.

____: wind around each other in double helical arrangement.
____: bundles contain globular heads.

______: functional unit of the muscle fiber (contractile apparatus of the fiber.

Three substances that play an essential role in muscle contraction:

_____: released from motor nerve axon causes depolarization of muscle fiber- action potential travels along muscle fiber, down into t-tubule, causing __ release from sarcoplasmic reticulum.

__ binds to troponin allowing actin and myosin to bind.

Actin and myosin binding cause myosin ATPase to hydrolyze ___ to ADP causing myosin crossbridge movement.
Ca2+ is taken up by the _____ _____ as muscle activation ceases, restoring Troponin-Tropomyosin inhibition with actin and myosin in relaxed state.

_____: fibers run parallel to muscle's long axis, a fiber's force generation transmits directly to the tendon.
_____: pennation angle, some of the force is Not transmitted to the tendon, but allows for more sarcomeres to contribute to force production.

Afferent neurons enter cord through ____ ____ and transmit sensory information from periphery.
Afferent neurons synapse through _______ that relay information to various levels of cord.

____ ____: consists of the motor neuron and all the muscle fibers it innervates. May innervate many muscles but each muscle fiber is innervatied my only one neuron.

The ____ _____ is the information sender and the _____ _____ is the information recipient. However, most neurons function as both.

At an excitatory synapse, ___ binds to postsynaptic neuron and causes _____ channels to open. The influx of ____ increases the voltage across the membrane and an action potential is generated if reaches approximately ___.

______: describes changes in membrane potential that helps trigger an action potential.
______: describes change in membrane potential that inhibits an action potential.

At an inhibitory synapse the binding of neurotransmitter ____ to postsynaptic neuron causes ___ channels to open. Influx of ____ decreases the voltage across the membrane and an action potential is not generated.

_____ _____: one of the factors that contributes to increases in strength prior to hypertrophy of the muscle.

___ ____ motor units innervate Type IIb muscle fibers.
____ ____ motor units innervate Type IIa muscle fibers.
_____ motor units innervate Type I muscle fibers.

______ or ______ ______: either the neuron receives enough input to initiate an action potential or it does not.

Describe the 2 methods to improve force gradation of muscle.

_____ _____: motor units with the small axons are recruited first, while motor units with larger axons are recruited last.

_____ _____: Tap stretches muscle, muscle spindle detects stretch , sensory fibers send signal to cord. Alpha motor neuron contracts muscle and extends leg.

_____ ______: inhibition of motor neurons controlling the antagonist muscles.

____ _____ ____: causes muscle relaxation and lengthening in response to contraction.

____ ____ ____: rapidly progressing fatal disease attacking the upper motor neurons and lower motor neurons due to neurotoxicity.

____ _____: no communication between nerve and muscle . Less junctional folding and fewer ACh receptors. Inhibition of existing ACh receptors by antibodies. Widened synaptic cleft. End plate potentials diminished. Corticosteroids and Immunosupressive drugs may help.

_____ _____: slow or delayed relaxation of muscle after a contraction. Continuous muscle activity in absence of input from motor neuron.

_____: South American Indian arrowhead poison binds to ACh receptor. Asphyxiation occurs when respiratory muscles are involved.

_____: singnal by nerve at muscle does not cause depolarization thus muscles do not respond due to blockage of Sodium channels.