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)