Exs Phys test 1

What is skeletal muscle

voluntary and straited, make up the Musculoskeletal system

what is cardiac muscle

involuntary and striated and only found in the heart

what is smooth muscle

involuntary, non-striated, found in walls of blood vessels and internal organs

what is a function of smooth muscle

contraction, relaxation, regulate blood flow

what is epimysium

tissue surrounding the entire muscle

what is endomysium

tissue surrounding the muscle fiber

what is perimysium

tissue surrounding the fascicle

what are sarcomeres

smallest functional muscle cells

what is a sarcoplasm

fluid part of muscle fiber containing dissolved proteins, minerals, glycogen and fats

what are transverse tubules

extensions of the plasmalemma and pass laterally through the muscle fiber

How are nerve impulses transmitted to individual myofibrils

t tubules being interconnected as they pass through myofibrils

what is a function of the sarcoplasmic reticulum

storage site for calcium, essential for muscle contraction

what are myofibrils

long strands of sarcomeres each muscle has thousands of them

what are dark regions of sarcomeres

A bands

what are light regions of sarcomeres

I bands

what is the lighter region in the A band known as

H zone only visible when relaxed

what is the dark line in the middle of the H zone called

M line

In the I band what are the dark stripes called

Z disk

what are the proteins found in the sarcomere

Actin, Myosin, thin/thick filaments

What is found in the A band

both thick and thin filaments

What is found in the I band

Only thin filaments

What is found in the H zone

thick filaments

what is found on the M line

proteins that serve as attachment site for thick filaments

functions of myosin

2 strands twisted together forming globular head which protrude from thick filament to form cross bridge that interact during muscle contraction

what is titin

stabilizes myosin filaments along their axis, Z disk to M line

what are the 3 different proteins in thin fillaments

actin, tropomyosin, troponin

what is nebulin

anchoring protein for actin that regulated actin/myosin interactions

function of tropomyosin and troponin

work together with calcium to maintain contraction and relaxation of myofibril

what are the 3 functions of titin

stabilizing sarcomeres and centers myosin, increase force production, prevents overstretching

what happens when calcium is released and binds to titin

changing titin’s stiffness which allows for more force to be generated when stretched

what is a motor neuron

nerve cell that connects with and innervates many muscle fibers

what is a motor unit

a single motor neuron and all the muscle fibers it innervates

what is included in the neuromuscular junction

synapse between motor neuron and muscle fiber, this is where communication between nervous system and muscular system occur

what is the excitation contraction coupling

excitation of a motor nerve and results in contraction of muscle fibers

what is the first step of excitation contraction coupling

action potential starts in nervous system

what is the second step of excitation contraction coupling

AP arrives at axon terminal and releases ACh

what is the third step of excitation contraction coupling

Ach crosses synapse and binds to Ach receptors on plasmalemma

what is the fourth step of excitation contraction coupling

AP travels across sarcolemma down t tubules

what is the fifth step of excitation contraction coupling

Triggers Ca release from sarcoplasmic reticulum

what is the sixth step of excitation contraction coupling

Ca enables actin and myosin contraction

what is the role of calcium (actin) in a cross bridge cycling

the excitation triggers release of calcium from SR, Ca binds to troponin causing a conformational change, pulls tropomyosin off binding site on actin which allow myosin heads to attach

what is the role of ATP (myosin) in cross bridge cycling

myosin attaches to actin, ATP binds to myosin head releasing it from the actin, ATPase breaks ATP into ADP +P, myosin heads get cocked, head attaches to new actin binding site which creates power stroke (pull)

what is the order of cross bridge cycling

Attach, power stroke, release, cock

characteristics of Type 1 fibers

slow contractile speed, high oxidative capacity, low glycolytic activity, high fatigue resistance, low motor unit strength, low power

characteristics of type IIa fibers

moderate high oxidative capacity, high glycolytic activity, fast contractile speed, moderate fatigue resistance, high motor unit strength, high power

characteristics of type IIx fibers

low oxidative capacity, highest glycolytic activity, fast contractile speed, low fatigue resistance, high motor unit strength, highest power

what are fiber type determinants

genetic factors, training factors, aging

what is the recruitment order for muscle fibers

type I, type IIa, type IIx

what is a static contraction

isometric, no movement

what is a dynamic contraction

movement, concentric shortening, eccentric lengthening

generation of force 4 methods

motor unit recruitment, frequency of stimulation, length tension relationship, muscle memory

what is motor unit recruitment

more force is generated when more motor units are activated

what is frequency of stimulation

rate coding, twitch 1, summation 3, tetanus multiple, withstand

what is length tension relationship

muscles force output determined by its starting length

what is muscle memory

body’s ability to retain physical activity after resting long periods of time

what is the speed force relationship

concentric contractions are slower with greater force and eccentric are quicker with greater force

what is muscle soreness

soreness caused by exhaustive high intense workouts or when you first start

what are types of muscle soreness

acute soreness, delayed onset muscle soreness

what is acute muscle soreness

soreness that occurs during or immediately after exercise

characteristics of muscle soreness

accumulation of metabolic byproducts H ions, tissue edema,

what is delayed onset muscle soreness

occurs 1-2 days after exercise, basically grade 1 strain, major cause is eccentric contractions

what is structural damage

indicated by muscle enzymes in blood, z disk disruption, precipitates muscle hypertrophy

what is inflammatory reaction

inflammation and soreness are connected, released substances initiate inflammation

What effects does DOMS have on performance

decrease ability to produce force, loss of strength

what are the 3 factors that contribute to loss of strength

physical disruption of muscle, failure of excitation contraction coupling, loss of contractile protein

what are the 3 strategies of reducing DOMS

minimize eccentric work early in training, start with low intense and work up, start with high intensity to be less soreness later

What is apart of the efferent nervous system

Autonomic and somatic

what is apart of the autonomic nervous system

sympathetic and parasympathetic

what is sensory division

transmits information from periphery to the brain

what are the major families of sensory receptors

mechanocreptors, thermoreceptors, nucleoreceptors, photoreceptors, chemoreceptors

what are the special families of sensory receptors

joint kinesthetic receptors, they are sensitive to joint angles and rate of change

what are the 2 built in safety mechanics that prevent injury

Muscle spindles, Golgi tendon organs

what are muscle spindles

sense stretch, sensitive to muscle length and tells the muscle to shorten to prevent damage

What are the Golgi Tendon Organs

sense tension, tells the muscle to shut down to prevent damage, sense strength of contraction

what is motor division

transmits information from CNS to PNS and stimulates muscle activity

what is sensory motor intergration

process set of communication and interaction between sensory and motor systems

what is step 1 in sensory motor integration

stimulus is sensed by sensory receptors

what is step 2 in sensory motor integration

sensory info is sent to CNS via sensory neurons

what is step 3 in sensory motor integration

CNS interprets sensory information and sends out response

what is step 4 in sensory motor integration

Motor AP sent out on a motor neuron

what is step 5 in sensory motor integration

Motor AP arrives at skeletal muscle, response occurs

what is the autonomic ns

controls involuntary internal functions such as HR, BP

what is the sympathetic ns

prepares body for action, sympathetic stimulation

what are characteristics of sympathetic regulation

increase HR, increase BP, increase blood flow to muscles, increase airway diameter, increase metabolic rate, increase glucose levels

what is parasympathetic ns

active at rest and opposes sympathetic effects

what are characteristics of parasympathetic regulation

increase digestion and urination, conservation of energy, decrease HR, decrease diameter in blood vessels and airways

what is a part of the cell body

the nucleus

what is the function of dendrites

receives and carries impulse toward the cell body

what is the function of an axon

sends information starts in axon hillock, end branches axon terminals neurotransmitters

what factors determine the speed of action potential propagation down an axon

myelination

what characteristics are apart of myelination

Schwan cells, nodes of Ranvier, salutary conduction, multiple sclerosis

what makes up a Schwan cell

fatty sheets around axon

what is a characteristic of nodes of ranvier

not continuous

what is saltatory conduction

hopping from node to node

what is multiple sclerosis

degeneration of myelin