Edition Welsh Test Bank chapters 1-15 with
questions and verified answers latest update
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Muscles are organs composed of specialized cells that generate forces, allow the types
of... - ANSWER>>- Walking
- Speaking
- Breathing
- Pumping Blood
- Moving food through the digestive tract
3 types of muscle tissue - ANSWER>>- Skeletal
- Smooth
- Cardiac
Structure of a skeletal muscle - ANSWER>>Skeletal muscles are composed primarily of
muscle fibers with connective tissue, blood vessels, and nerves
Connective Tissue Coverings - ANSWER>>endomysium, perimysium, epimysium,
fascia
Endomysium - ANSWER>>- Surrounds each muscle fiber
- Provide the chemical environment for the exchange of ions for nervous stimulation
Perimysium - ANSWER>>Surrounds fascicles within the muscle
Epimysium - ANSWER>>Surround the entire muscle
Fascia - ANSWER>>- Most superficial layer
,- Continuous with the epimysium
- Separates individual muscles
Tendon - ANSWER>>- Cordlike
- Fibers may intertwine with those in the periosteum, attaching the muscle to the bone
Aponeurosis - ANSWER>>- Broad fibrous sheet
- May attach to bone, to skin, or to the connective tissues of adjacent muscles
Compartment - ANSWER>>The space that contains a group of muscles, blood vessels,
and nerves, all tightly enclosed by fascia
Complex Network of Fascia - ANSWER>>- Deep fascia
- Subcutaneous fascia
- Subserous fascia
Skeletal Muscle FIbers - ANSWER>>Each skeletal muscle fiber is a single muscle cell
Muscle fibers are... - ANSWER>>multinucleated, elongated, cylindrical cells
The cytoplasm (sarcoplasm) contains - ANSWER>>- Many small, oval nuclei
- Mitochondria
- Myofibrils
Myofibrils - ANSWER>>- Myosin: Thick filaments
- Actin: Thin filaments
Produces the striations characteristic of... - ANSWER>>skeletal muscle fibers
The striations result from a rewearing patter of units called... - ANSWER>>Sacromeres
,The striation patter has 2 main parts - ANSWER>>1. I bands (light bands)
2. A bands (dark bands)
I bands - ANSWER>>thin actin filaments held together by direct attachments to Z lines
A bands - ANSWER>>thick myosin filaments overlapping thin actin filaments
H Zone: only thick filaments
M Line: proteins
thick filaments - ANSWER>>Composed of myosin
Thin Filaments - ANSWER>>Consists of a double strand of actin twisted into a helix
Each actin molecule has a binding site to which the head of a... - ANSWER>>myosin
molecule can attach
Associated with... - ANSWER>>troponin and topomyosin
At rest, the troponin-tropomyosin complexes block the binding site on... -
ANSWER>>actin molecules preventing the formation of linkages with myosin
Sarcoplasmic Reticulum - ANSWER>>A network of membranous channels that
surrounds each myofibril and runs parallel to it
Transverse Tubules (T tubules) - ANSWER>>A set of membranous channels that
extends into the sarcoplasm and contains extracellular fluid
Each one lies between... - ANSWER>>2 cisternae
, The 2 cisternae and transverse tubule form a... - ANSWER>>triad near the region
where the actin and myosin filaments overlap
Skeletal Muscle Contraction - ANSWER>>Muscle fiber contraction results the
movement of actin and myosin filaments in which they slide past one another,
shortening the sarcomeres
neuromuscular junction - ANSWER>>the synapse where a motor neuron axon and a
skeletal muscle fiber meet
The muscle fiber membrane is specialized to form a... - ANSWER>>motor end plate
where nuclei and mitochondria are abundant and the sarcolemma is extensively folded
Synaptic Cleft - ANSWER>>Separates the membrane of the neuron and the membrane
of the muscle fiber
The cytoplasm at the distal end of the axon contains... - ANSWER>>many tiny vesicles
that sore neurotransmitters
Neurotransmitters are... - ANSWER>>chemicals released at a synapse
Stimulus for Contraction - ANSWER>>Acetylcholine is the neurotransmitter that motor
neurons use to control skeletal muscle contraction
When an actin potential reaches the end of the axon synaptic vesicles release... -
ANSWER>>acetylcholine into the synaptic cleft
Diffusion across... - ANSWER>>the cleft
Binds to receptors in the... - ANSWER>>muscle fiber membrane