KNES 210 Final

BP response to resistance exercise

- compresses vessels -Peripheral resistance increases -Blood pressure increases temporaily

Role of Ca2+

- needs to be present for contraction to happen - released into cytosol when nerve impulse travels to muscle

3 factors that determine resistance

1. Blood thickness (viscosity) 2. Length of conducting tube 3. Blood vessel radius

3 physiologic classificans of motor units

1: fatigability 2: tension characteristics 3: twitch characteristics

4 components of strength

1: increased electrical activity (IEMG) 2: Increased motor unit firing rate 3: recruitment of high-threshold motor units 4: Motor unit coordination

NaK pump

3 Na+ in , 2 K+ out

Muscles' Chemical Composition

75% water, 20% protein, 5% salts and other

motor unit

A motor neuron and all of the muscle fibers it innervates

Titin

A series elastic component protein responsible for allowing the sarcomere to stretch and recoil

Golgi Tendon Organ (GTO)

A specialized sensory receptor located at the point where skeletal muscle fibers insert into the tendons of skeletal muscle (prevents torn tendons)

Facilitation

ACh release excites postsynaptic membrane of its connecting neuron (or muscle)

Tension Characteristics

ALL or NONE principle (stimulus is strong enough or not to create an action potential)

inspiratory reserve volume

Amount of air that can be forcefully inhaled after a normal tidal volume inhalation

Valsalva maneuver

Closing glottis following a full inspiration while maximally activating expiratory muscles, creating compressive forces that increase intrathoracic pressure above atmospheric pressure (lifting)

Diaphragm and rib action during inspiration

Diaphragm: descends Ribs: rise

Diaphragm and rib action during expiration

Diaphragm: raises Ribs: lower

slow twitch fibers (type I)

Generate energy for ATP resynthesis through aerobic system of energy transfer (high fatigue resistant)

Repolarization

Na+ channels close and K+ channel open and negative charge restored

action potentials

Nerve impulses or signal sent the length of a cell

Pressures in pulmonary venous blood (between lungs and heart)

O2 = 100mm CO2 = 40mm

Pressures in systemic arterial blood (between heart and tissues)

O2 = 100mm CO2 = 40mm

pressures in lungs (at rest)

O2 = 100mm CO2 = 40mm

Pressures in pulmonary arterial blood (between heart and lungs)

O2 = 40mm CO2 = 46mm

Pressures in systemic venous blood (between tissues and heart)

O2 = 40mm CO2 = 46mm

Pressure in tissues (at rest)

O2 = 46mm CO2 = 40mm

ECG phases

P wave (atrial depolarization); QRS complex (ventricular depolarization); T wave (ventricular repolarization)

Heart's Electrical Activity Order

SA node, AV node, bundle of HIS, purkinje fibers

sequence of events in muscular contraction

SLIDE 49-52!!

Diastolic Blood Pressure (DBP)

The pressure in arteries and other blood vessels when heart is at rest or between beats (bottom #)

Systolic Blood Pressure (SBP)

The pressure in arteries and other blood vessels when the heart is contracting (top #)

When does EPSP occur?

When sodium channels open in response to a stimulus

excitatory postsynaptic potential (EPSP)

a slight depolarization of a postsynaptic cell, bringing the membrane potential of that cell closer to the threshold for an action potential

muscle proteins

actin and myosin (contractile elements

What does hydrolysis do?

activates myosin's two heads, placing them in an optimal orientation to bind actin's active sites

chronic exercise

adaptation

Anatomic dead space

air in each breath that does not enter alveoli and participate in gas exchange with blood

tidal volume

air moved during each inspiration or expiration cycle

Motor neuron pool

all the motor neurons that innervate an entire muscle

residual lung volume (RLV)

amount of air remaining in the lungs after a complete and total forced exhale

inhibitory postsynaptic potential (IPSP)

an inhibitory hyperpolarization of the postsynaptic membrane of a synapse

order of arteries (and viens)

arteries, arterioles, metarterioles, capillaries

what does the transitional zone consist of?

bronchioles, alveolar ducts, and alveoli

Enhanced facilitation (disinhibition)

causes full muscle activation during all-out effort

Sarcoplasm

contains nuclei that house genes, mitochondria, and other specialized organelles

How does O2 bind to hemoglobin (Hb)?

cooperative binding

Where does fatigue occur?

disruption in the chain of events between CNS and the muscle fiber

aerobic exercise

endurance (needs lots of oxygen)

Type 2x

fast glycolytic (recruited last)

Type 2a

fast oxidative/intermediate

Pennate

fibers lie at oblique angle (high# of fibers)

Fusiform

fibers run parallel (rapid muscle shortening = speed and ROM)

Current (movement of ions)

flow of electricity/ voltage from one point to another

Hyperpolarization

further efflux of potassium and redistribution of ions and resting potential restored

Mechanical action of crossbridges

globular head of myosin crossbridge provides mechanical power stroke for actin and myosin to slide past each other

hypertention

high blood pressure

hypertrophy

increase in cell size (all are capable, but mainly ype II)

Hyperplasia

increase in number of cells (occurs in utero)

anaerobic exercise

intense short bursts of activity (produce energy without oxygen)

Large SV =

low HR (common in endurance athletes)

What is the point of ventilation?

maintain the concentration gradient of CO2 and oxygen in the alveoli and surrounding blood vessels

Voltage (membrane potential)

measure of potential energy generated by separated charge

Intrinsic regulation of the heart

mechanisms contained within the heart that control CO (SA node)

resting potential

more sodium outside the cell and more potassium inside the cell

sliding filament model

muscle shortens or lengthens because thick and thin filaments slide past each other without changing length

Heart Rate (HR)

number of heart beats per minute

Resistance (cell membrane)

opposition to the movement

expiration

passive process during rest and light exercise air moves out of lungs (natural recoil of stretched out lung tissue and relaxation of inspiratory muscles)

Ejection Fraction (EF)

percent of ventricle emptying

elastic component

potential source of "free" energy stored somewhere in MTU

Surfactant

proteins, phospholipids, and calcium ions produced by alveolar epithelial cells to reduce surface tension

sarcoplasmic reticulum

provides structural integrity

Pacinian corpuscles

respond to deep pressure and vibration

Depolarization

sodium goes into the cell, voltage-gated channels open, action potential

Twitch characteristics

speed of propagation and recovery (ie: high force = fast fatigue)

acute exercise

stress

Perimysium

surrounds bundles of muscle fibers (fasciculus)

Sarcolemma

surrounds each muscle fiber and encloses fiber's cellular contents

Epimysium

surrounds entire muscle (forms tendons)

Blood pressure ranges

systolic: moves in 20s diastolic: moves in 10s (120/80 = healthy)

Effects of exercise on RVL

temporarily increases from an acute bout of either short-term or prolonged exercise

expirtory reserve volume

the additional amount of air that can be expired from the lungs by determined effort after normal expiration

ambient air

the air immediately around us

Stroke Volume (SV)

the amount of blood that comes out of the heart for each beat

forced vital capacity

the maximum amount of air that can be removed from the lungs during forced expiration

myosin filament

thick filament (myosin head)

actin filament

thin filament (contains troponin, tropomyosin)

wave summation

this occurs when a second stimulus is received before the muscle fiber has relaxed, creating a second contraction that is stronger than the first

Cardiac Output (CO) or (Q)

total volume out per minute

what does the conducting zone consist of?

trachea to terminal bronchioles (deadspace)

fast twitch fibers (type II)

type IIx: fast-glycolytic fibers type IIa: fast-oxidative-glycolytic

unfused tetanus (incomplete)

type of wave summation with partial relaxation observed between twitches

Component that veins have and arteries do not?

valves to prevent backflow

ventilation vs respiration

vent: mechanically moving air resp: gas exchange across a membrane

When does IPSP occur?

when an inhibitory presynaptic cell fires an action potential

fused tetanus (complete)

when stimulus frequency is so high that no muscle relaxation takes place between stimuli

Endomysium

wraps individual muscle fibers

gradation of force

The force of muscle action varies from slight to maximal based on: - Number of motor units recruited - Frequency of motor unit discharge

"three" factors produce neuronal facilitation

1. Decreased sensitivity of the motor neuron to inhibitory neurotransmitters 2. Reduced quantity of inhibitory neurotransmitter substance transported to the motor neuron 3. Combined effect of both mechanisms

3 components of stretch reflex

1. Muscle spindle: responds to stretch 2. Afferent nerve fiber: carries sensory impulse from spindle to spinal cord 3. Efferent spinal cord motor neuron: activates stretched muscle fibers

Type 1

Slow oxidative ( recruited first)