ch 10 vocab

A&P1 - dr tenneson

fiber

each cell of an organ is called a _____

myosin & actin

2 types of filaments of myofibrils

sarcolemma

muscle cell membrane

sarcoplasm

cytoplasm

sarcoplasmic reticulum

_____ _____ is a network membrane enclosed by tubules that form a sleeve around each myofibril (like ER)

t-tubules

run transverse through muscle fiber. internal extensions of the sarcolemma

fascia

superficial connective tissue

• subQ

• loose connective tissue & fat underlying skin

deep fascia

dense irregular connective tissue around & within muscle tissue

epimysium

connective tissue surrounding whole muscle/group of muscles (= fascia)

perimysium

connective tissue surrounds bundles of 10-100 muscle cells

endomysium

connective tissue that separates individual muscle cells

tendon

connective tissue layers extend beyond the muscle belly to form the _____

fascia lata

enveloping the entire group of quadriceps & hamstring muscles

tendon

cord of dense connective tissue that attaches a muscle to the periosteum of a bone

aponeurosis

a tendon. a thick fascia that connects 2 muscle bellies. extends as a broad, flat layer

epicranial aponeurosis

connects the muscle bellies of the occipitalis & the frontalis to form “one” muscle: the occipitofrontalis

occipitofrontalis

epicranial aponeurosis: connects the muscle bellies of the occipitalis & the frontalis to form “one” muscle: the ________

neuromuscular junction

each motor neuron supplies multiple muscle cells: _____ _____

terminal

each muscle cell is supplied by 1 motor neuron _____ branch & is in contact with 1-2 capillaries

filaments

thick & thin _____ overlap each other in a pattern that creates striations

I

the ___ band region contains only thin filaments

sarcomeres

filaments are arranged in compartments called _____, separated by Z discs

Z discs

filaments are arranged in compartments called sarcomeres, separated by …..

I band

type of striation: actin filaments (light)

A band

myosin filaments (dark) & overlapping actin fibers

H band

portion of myosin not overlapping actin

Z band

in the middle of I band, & are the units of contraction

myosin

thick filaments are composed of _____

M line proteins

myosin is held in place by ….

Z lines

thin filaments are held in place by ….

sarcomere

from one Z line to the next is a _____

structural

_____ proteins keep thick & thin filaments in the proper alignment

titin

____ helps a sarcomere return to its resting length

myomesin

_____ forms the M line

nebulin

_____ helps maintain alignment of thin filaments in the sarcomere

dystrophin

_____ reinforces the sarcolemma

actin

the thin filaments

sliding filament mechanism

_____ _____ _____: thick & thin filaments slide on one another & the sarcomere is shortened

:)

• neuromuscular junction

• axon terminal

• motor end plate

• neurotransmitter

• sarcolemma

• ATP

• muscle proteins

• answer: :)

synaptic end bulbs

_____ _____ _____ are swellings of axon terminals

contraction

_____ cycle:

1. ATP hydrolysis (myosin head energized)

2. myosin attaches actin to form crossbridges

3. power stroke, myosin head pivots, moving myosin past actin

4. ATP binds to myosin, detaches cross bridge

cycle repeats as long as there’s ATP & high levels of Ca2+

EC coupling

____ _____ involves events at the junction between a motor neuron & a skeletal fiber (neuromuscular junction)

presynaptic

_____ membrane: the neuron

postsynaptic

_____ membrane: motor end plate on the muscle cell

motor end plate

rich in chemical (ligand) - gated sodium channels that respond to AcCh

muscle action potential

propagated over the surface of the muscle cell membrane (sarcolemma) via voltage (electrical)-gated Na+ & K+ channels

botulinum

_____ toxin: bacteria found in improperly canned food

curare

plant poison

neostigmine

anticholinesterase agent. blocks removal of AcCh from receptors so strengthens weak muscle contractions

ATP

muscle uses ____ at a great rate when active

sarcoplasmic ATP

______ ____ only lasts for a few seconds during muscle metabolism

creatinine phosphate

_____ _____ system:

• anaerobic, produces few ATP molecules

• can power maximal muscle contraction for about 15 seconds

• used for maximal short bursts of energy

• unique to muscle fibers

glycogen/lactic acid

_____/_____ _____ system:

• anaerobic

• produces a small amount of ATP

• can provide enough energy for about 30-40 seconds of maximal muscle activity

• involves fermentation

aerobic

_____ system:

• used when molecular activity lasts more than 30 seconds

• provides 90% of ATP energy if activity lasts more than 10 minutes

• involves complete oxidation of glucose via cellular respiration

• endurance muscles

oxygen debt / Excess Post-Exercise Oxygen Consumption (EPOC)

the amount of O2 repayment required after exercise in skeletal muscle

muscle fatigue

loss of muscle strength

muscle tension

contractile force produced by muscles

active muscle tension

muscle filament contractions

passive muscle tension

stretching of elastic muscle components

motor unit

one somatic motor neuron & all the skeletal muscle cells it stimulates

twitch contraction

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

myogram

record/graph of a muscle contraction

refractory period

the time when a muscle has temporarily lost excitability

latent

_____ period: Ca2+ released from SR. slack is removed from elastic components

contraction

_____ period: 10-100 msec. filaments slide past e/o

relaxation

_____ period: 10-100 msec. active transport of Ca2+ into SR

wave summation

increased strength of a contraction, resulting from the application of a second stimulus before the muscle has completely relaxed after previous stimulus

incomplete/unfused tetanus

sustained muscle contraction. permits partial relaxation between stimuli

complete/fused tetanus

sustained contraction. lacks even partial relaxation between stimuli.

recruitment

process of increasing the number of active motor units. aka multiple motor unit summation

treppe - staircase effect

athletic warmup. inactive muscle experiences series of twitches

muscle tone

involuntary contraction of a small number of motor units. alternatively active & inactive in a constantly shifting pattern, keeps muscles firm even though relaxed. does not produce movement

isotonic

_____ contractions: a load is moved

concentric

_____ contraction: a muscle shortens to produce force & movement

eccentric

_____ contraction: a muscle lengthens while maintaining force & movement

isometric

_____ contraction: no movement occurs

slow oxidative

SO:

• slow twitch

• small diameter

• red

• prolonged contractions

oxidative glycolytic (FOG)

• hybrid of FG & SO fibers

• fast twitch A

• medium diameter

• red

• split ATP at very fast rate

• used for walking/sprinting

fast glycolytic (FG)

• fast twitch B

• white

• anaerobic movements of short duration

• used for weight lifting

anabolic steroids

similar to testosterone. increase muscle size, strength, & endurance

visceral

_____ smooth muscle: found in the walls of hollow viscera & small bv’s. the fibers are arranged in a network & function as a “single unit”

multiunit

_____ smooth muscle: found in large bv’s, large airways, iris of the eye.

sarcoplasm

contains thick & thin filaments. not organized into sarcomeres

smooth

____ muscle:

• tapering ends

• single, oval, centrally-located nucleus

helix

muscle fiber contracts & twists into a _____ as it shortens

calmodulin

protein that binds calcium ions in the cytosol

peripheral arteriole dilation

smooth muscle action to release heat

peripheral arteriole constriction

smooth muscle action to conserve heat

panting/fanning

skeletal muscle action to release heat

shivering

skeletal muscle action to conserve heat

fibrosis

scar formation

hypertrophy

cells grow in size

hyperplasia

some cells can divide

stem

new fibers can form from _____ cells in bv walls

myofibrosis

replacement of muscle fibers by excessive amounts of connective tissues

myosclerosis

hardening of the muscle caused by calcification

fibromyalgia

widespread musculoskeletal pain & fatigue

myasthenia gravis

most common primary disorder of neuromuscular transmission. autoimmine disorder. blacks ACh receptors

muscular dystrophies

group of inherited diseases that destroys muscles

Tic

involuntary twitching of muscles normally under voluntary control