A&P 1: Chapter #10 - Muscle Tissue

Belly of skeletal muscle

(8)

Smooth

Percytes are what kind of muscle cells

Sarcolemma

Plasma membrane of a myocyte cell (S)

Replenishing CP stores Convert lactate into pyruvate Reload O2 into myoglobin

The oxygen debt consists of (3)

length; sarcomeres

The force of a muscle contraction depends on the _____ of the ______________ prior to the contraction

somatic motor neuron; innervates

A motor unit consists of a ___________ ___________ ________ and the muscle fibers it _________

calcium

At the neuromuscular junction, voltage gated channels open resulting to an influx of _____________

10

Between 30-50 ears of age, about ____% of our muscle tissue is replaced by fibrous connective tissue and adipose tissue

40

Between 50-80 year of age another ___% of our muscle is replaced

Sarcoplasm

Cytosol of the myocyte cell (R)

Muscle tone

Even when at rest, a skeletal muscle exhibits a small amount of tension, called this

Somite

From what structures do muscles originate from in the embryo

Hyperplasia

Growth in cell number

Heart

Location of cardiac muscle

Various organs like GI tract

Location of smooth muscle

Dense bodies

Smooth muscle have __________ ________ instead of Z discs

Visceral (single unit) Multiunit

Smooth muscle innervation can be (2)

Unfused tetanus

Tetanus resulting from multiple action potentials at a lower frequency

structural

Thanks to ___________ proteins, there is a transmission of force throughout the entire muscle, resulting in whole muscle contraction

extensibility

The ability of muscle to stretch without being damaged is called

Sarcoplasmic reticulum

The depolarization of the muscle cell via influx of Na+ results in Ca+ being released from ____________ ______________

many

The strength of contraction depends on how ____ motor units are activated

Muscle filament

The structures of the myocyte that perform contraction (T)

Excitation-Contraction coupling

This concept connects the events of a muscle action potential with the sliding filament mechanism

Skeletal

Which of the types of muscle cells are voluntary?

Sarcomere

Z discs move toward each other and ____________ shortens

Myomesin

structural protein of the M line which holds the thick filaments to the center of the sarcomere

Dystrophin

thin filaments attach to z discs by this structural protein; related to muscular dystophy

One nucleas Striated Intercalated discs

Appearance of cardiac muscle

multi-nucleated striated

Appearance of skeletal muscle

One nucleus No striations

Appearance of smooth muscle

Neurotransmitter

Calcium in the synaptic end bulb triggers exocytosis of _________________ into the synaptic cleft

Muscle strength and flexibility decreases Reflexes slow Slow oxidative fiber number increase

Consequences of loss of muscle tissue are

Myosin Actin

Contractile muscle proteins

1. Myosin heads hydrolize ATP and become reoriented and energized 2. Myosin heads bind to actin, forming cross-bridges 3. Myosin cross-bridges rotate toward center of sarcomere (power stroke) 4. As myosin heads bind ATP, the cross-bridges detach from actin

Contraction cycle (4)

A band

Dark, middle part of the sarcomere that extends entire length of thick filaments and includes those parts of thin filaments that overlap thick filaments

Myoblasts

Each myocyte arises from the fusion of 100+ _________________

pump blood

Function of cardiac muscle

produce movement stabilize body positions regulate organ volume move substances within the body produce heat

Function of skeletal muscle

Vasodilation/constriction

Function of smooth muscle

Creatine phosphate Anaerobic cellular respiration (glycolysis) Aerobic cellular respiration

How does the skeletal muscle produce ATP?

Tendon

Identify

Not available

If O2 is ____________, pyruvic acid is converted into lactic acid

available

If oxygen is ___________, pyruvic acid is transported to the mitochondria to be broken down to generate ATP

Concentric Eccentric

Isotonic contraction includes two types

I band

Lighter, less dense area of sarcomere that contains remainder of thin filamnts but no thick filaments. A Z disc passes through the centre of each I band

skeleton

Location of skeletal muscle

Muscle fiber (myocyte)

Long, tubular cells that develop from myoblasts to form muscles (13)

mitosis

Mature skeletal muscle fibers cannot undergo _______

alternately

Motor units contract ___________ to sustain contractions for longer periods of time

tetanus

Muscle contraction resulting from multiple action potentials

1. Inadequate release of Ca+ from SR 2. Depletion of CP, oxygen + nutrients 3. Build up of lactic acid and ADP 4. Insufficient release of ACh at NMJ 5. CNS fatigue

Muscle fatigue occurs due to

Contraction

Muscle tone is due to weak, involuntary _______ of motor units

Myogenesis

Muscles form by ___________ ; which is the process in which myoblasts form into myocyte

thin filaments

Myosin pulls on actin, causing __________ ____________ to slide inward

H zone

Narrow region in center of each A band that contains thick filaments but no thin filaments

Ligand-gated Na+ ; sarcoplasm

Neurotransmitter in the neuromuscular junction binds to _________ channels on the motor end plate which cause an influx of Na into the _________

Size

No matter how strong a contraction, thick and thin filaments of a sarcomere do not change in ________

Satellite cell

Precursor cell to myoblasts

Troponin Tropomyosin

Regulatory muscle proteins

Latent period Contraction period Relaxation period

Twitch contraction periods

Unfused Fused

Types of tetanus

Stronger

Wave summation results in a ___________ contraction

Skeletal Cardiac Smooth

What are the 3 types of muscle cells?

Weakest; stronger

_________ motor units are recruited first followed by _______ motor units

Fascicle

a bundle of skeletal muscle fibers surrounded by perimysium (11)

Duchenne muscular dystrophy

a genetic disoder characterized by progressive muscle degeneration and weakness

Epimysium

a sheath of fibrous elastic connective tissue surrounding an entire muscle (10)

Myofibril

basic rod-like organelle of a muscle cell responsible for contraction (14)

Sarcomere

basic unit of striated muscle tissue

Twitch contraction

brief contraction of all muscle fibers in a motor unit in response to a single action potential

Pericytes

contractile cells that wrap around the endothelial cells of capillaries and venules throughout the body

Myosin

contractile protein of the thick filaments which binds with actin on thin filaments

Actin

contractile protein of thin filaments that binds with myosin on the thick filament

Isotonic contraction

contraction in which tension is constant while muscle length changes

Dermatome

embryonic cells that give rise to inguinal system

Large fiber diameter

fast twitch; pale in color, less blood supply,

Skeletal muscle

form of multinucleated, voluntary, striated muscle functioning in moving bones

Strength training

generates hypertrophy in muscle fibers

Hypertrophy

growth of muscle size; addition of myofilaments to myofibril

Thick filament

larger of the two types of protein filaments that, together form cylindrical structures called myofibrils; occupy the A band, M line, and H zone

Endomysium

layer of areolar connective tisssue that ensheaths each individual myocyte (L)

Stretching

lengthens muscle fibers

Isometric contraction

muscle contracts but does not change length

Muscle striations

muscle tissue featuring a striped pattern from repeating functional units called sarcomeres (Q)

Smooth muscle

muscle which contractions start more slowly and last longer; can shorten and stretch to a greater extent; spindle shaped

Cardiac muscle

muscle which has the same arrangement as skeletal muscle, but also has intercalated discs

Z disc

narrow, plate-shaped regions of dense material that seperate one sarcomere from the next

Wave summation

occurs in muscle when a second action potential triggers muscle contraction before the first has finished

Eccentric contraction

occurs when muscle lengthens while contracted

Concentric contraction

occurs when muscle shortens while in contraction

Motor unit recruitment

process in which the number of active motor units increases

Alpha-actin

protein involved in th

Tropomyosin

protein on thin filament which blocks actin's binding sites during resting

Troponin

protein which moves tropomyosin off of the binding sites of a thin filament when bound to Calcium

Slow oxidative (SO) Fast oxidative

red fiber(s)

M line

region in center of H zone that contains myomesin proteins that hold thick filaments together at the center of the sarcomere

Perimysium

sheath of connetive tissue surrounding a bundle of muscle fibers (9)

Small fiber diameter

slow twitch;

Muscle fatigue

The inability to maintain force of contraction after prolonged activity

Thin filament

smaller of the two types of protein filaments that, together form cylindrical structures called myofibrils;

Sarcoplasmic reticulum

smooth endoplasmic reticulum of muscle cell that stores calcium, regulating blood calcium levels and utilized during contractionf

Titan

structural protein which plays an important role in elasticity of the sarcomere by anchoring the ends of the thick filaments to the Z discs

Fused tetanus

tetanus resulting from multiple action potentials at a higher frequency

Nucleus

the 'brain' of the cell that houses the (P)

Oxygen debt

the amount of oxygen needed to recover after activity

neuromuscular junction

the events at the __________ _____________ produce a muscle action potential

Transverse tubule

tubes of the sarcolemma which allow depolarization of the membrane to quickly penetrate into the interior of the cell

Smooth muscle

which kind of muscle cell has the greatest ability to regenerate?

Fast glycolytic (FG)

white fiber

Slow oxidative Fast oxidative Fast glycolytic

Skeletal muscle fiber types

Motor end plate

Section of the sarcolemma where the neuromuscular junction exist

Titan Nebulin Alpha-actin Myomesin Dystrophin

Structural muscle proteins