Ch 9 Flashcards
What are the three types of muscle tissue?
skeletal, cardiac, smooth
What are the five functions of muscles?
- move bones
- open sphincters
- generate heat
- maintain posture
- stabilize joints
Which muscle type do we have voluntary control of?
skeletal
This type of muscle tissue is striated, voluntary; usually attached to skeleton (except sphincters)
Skeletal Muscle
This type of muslce tissue is: striated, involuntary, intercalated disks connect cytoplasm of cells; found in heart
Cardiac Muscle
not striated, involuntary; found in walls of hollow organs (visceral organs)
Smooth Muscle
What two types of muscles are striated?
Skeletal and Cardiac
What type of muslce tissue is multinucleated?
Skeletal
What two types of muscle tissue has a single nucelus?
Smooth and Cardiac
What do muscles do when they are stimulated?
contract
When a muscle is said to be excited this a responce to?
a stimulius or envronmental change
If a muscle is stretched passivly this is called?
extend
This is when muscles return to their resting length after being shortened?
elastic
Muscle movement is a result of muslce?
contraction
red pigment - stores oxygen in muscle (as opposed to hemoglobin in blood)
myoglobin
stored glucose (energy) in muscle
glycogen
Glucose and oxygen combine to make?
ATP
skeletal muscle is considered an
organ
This surrounds each muscle fiber ?
endomysium
This surrounds a fascicle (bundle of muscle fibers)?
perimysium
fibrous connective tissue that surrounds entire muscle
epimysium
coarse fibrous tissue that organizes muscle into functional groups; gives rise to tendons
fascia
Muscles have two types of attachmetns to fascia?
Indirect and direct
Tendons and aponeurosis are two ways to that muscle can attach to the fascia. These are know as____ attachments?
indirect
A _______ is where the epimysium is fused to the periosteum (bone) or to the perichondrium (cartilage)
direct attachment
What attaches to less movable part of the bone
orgin
What attaches to a more movable part of the bone?
Insertion
A muscle fiber is also know as a ?
muscle cell
cell membrane of muscle cell?
Sarcolemma
cytoplasm of muscle cell is called?
Sarcoplasm
What are the bundles of proteins in a muscle cell called?
myofibrils
repeating sections of myofibrils are called?
sarcomeres
Each sarcomere contains thick and thin?
filaments
Thick filaments in sarcomeres are called?
myosin
Thin filaments in sarcomeres are called?
actin
Elastic filaments in sarcomeres are called?
titin
Thick filaments slide past thin filaments during_____?
Contraction
Myosin filaments ______ form cross- bridges to attach to actin , so that ________ can occur
heads, contraction
protein that blocks active sites of actin, preventing cross-bridging
tropomyosin
When the actin and myosin can attach this is called?
actin-myosin cross-bridging
when Ca2+ attaches to______, it moves tropomyosin out of the way
troponin
system of tubules around each myofibril, regulates Ca2+ levels
sarcoplasmic reticulum (SR)
invaginations of the sarcolemma that go deeply into the myofibrils
Transverse or T-tubules
activation of myosin cross bridges, shortens the muscle fiber
Contraction
inactivation of the cross bridges and tension
declines (muscle fiber returns passively to longer shape)
Relaxation
thin filaments are pulled past thick filaments by cross-bridges
Sliding Filament Theory
What molecule prevents attachment of myosin heads to actin?
tropomyosin
Which muscle filament changes length during contraction?
actin nor myosin
neither actin nor myosin
Nerve impulse moving down a motor neuron is called?
action potential
What is the location where neuron stimulates the muscle cell (site between nerve cell & muscle cell!)
Neuromuscular junction
When an impulse moves down a neuron, Na rushes into neuron, and K+ rushes out. This is called?
depolarization
What causes synaptic vesicles (containing ACh neurotransmitter) to fuse with axon membrane, releasing the ACh
Ca2+
What is the response by a single muscle fiber to a stimulus that is at least at threshold level (7-100msec) called?
Muscle Twitch
Period between stimulation and excitation (2msec): preparing to contract (ions moving!)
latent period
period: cross bridging, tension peaks
contraction
Ca2+ goes back into SR; muscle tension decreases what period is this?
relaxation period
What are the four functional characteristics of muslces?
contract
excited
extend
elastic
With a nerve impules Na rushes in and K rushes out. This is called?
Depolarization
Name for weak muscle disease due to shortage of ACh receptors, probable autoimmune disease
Myasthenia Gravis
A stimlus is not dependent on the strength of the stimulus. Rather, if the stimlus reaches the threshold, a muscle fiber will give a complte responce. This is called.
All of none law
one motor neuron and all muscle fibers (cells) it innervates is called?
Motor Unit
: minimal force to cause the first contraction
a threshold stimulus
strongest stimulus that produces increased force, all motor units are firing
maximal stimulus
