Chapter 6 Flashcards
Exam 3
3 Types of Muscle Tissue
Skeletal, Cardiac, Smooth
Structure of a skeletal muscle
What
3 Functions of Muscular System
1) Movement of organism
2) Movement of materials within
3) Temperature Regulation
Cells of Muscles are called
Muscle Fibers
Type of Muscle Fiber, Uninucleated, Not striated, pointed cylinders, parralel forming sheets
Smooth Muscle Fiber
Muscle Contraction in Smooth Muscle is
Involuntary
Type of Muscle Fiber, uninucleated, striated, tubular
Cardiac Muscle Fiber
Type of muscle that has branched muscle fibers and incarcerated disks
Cardiac
Type of Muscle Fiber, multinucleated, striated, tubular
Skeletal Muscle Fiber
Skeletal Muscle Contraction is
voluntary
Cardiac muscle contraction is
Involuntary
Skeletal Muscles are attached to the skeleton, and their contraction causes movement on bones at their
joints
Functions of Skeletal Muscles
1) Support
2) Movement
3)Temp regulation
4) Protection of internal organs
5)Stabilize Joints
Function of Cardiac Muscles
Heart beat, circulation of blood
Bundle of skeletal muscle fiber
Fascicle
Connective tissue that covers muscles and extends to become its tendon
Fascia
Attachment site to the stationary bone
Origin (of a muscle)
The attachment on the bone that moves
Insertion (of a muscle)
The muscle that does most of the work
Agonist (prime mover)
Assists the agonist
Synergist
The muscle that acts opposite to the prime mover
Antagonist
If the antagonist and the agonist contract at the same time
NO movement
Rectus means
straight
What is used to name skeletal muscles
Size, Shape, Location, Direction of muscle fibers, Attachment location or number
Transverse means
across
oblique means
diagonal
Muscle contractile unit
Sacromere
Park of sarcomere, forms thick filaments
Myosin
Part of sarcomere, forms thin filaments
Actin
Process of contraction (4 steps)
1) Muscle activated by nerve
2) Nerve activation increases calcium ions near contractile proteins
3) Presence of Calcium permits contraction
4) When nerve stimulation stops, contraction stops
Principle source of energy
ATP
Required for muscle contraction and relaxation
ATP
Anaerobic or Aerobic metabolism of glucose produces more ATP
Aerobic
Anaerobic
Without Oxygen
Aerobic
With Oxygen
A type of nervous system cell that stimulates muscle fibers to contract
Motor nuron
Group of neurons
Nerve
The part of a neuron that stimulates a muscle fiber or several
Axon
Where an axon terminal comes near the sarcolemma
Neuromuscular junction
end of an axon
axon terminal
thin tissue layer over muscle cell
sarcolemma
the space that separates axon terminal and sarcolemma
synaptic cleft
ACh (Acetylcholine)
Axon terminals contain these
Synaptic Vesicles
Synaptic Vesicles are filled with this neurotransmitter
Acetylcholine
When nerve signals traveling down axon arrive at an axon terminal,
synaptic vesicles release Ach into synaptic cleft
Disease in which muscles contract forcefully, caused by a bacteria-producing toxin, death by respiratory failure
Tetanus
Botulism toxins, deadliest, bind neurons and prevent muscle contractions
Clostridium botulinum
Small, fluid-filled sacs found between tendons and bones, acts as cushion and lubricant
bursae
Why is tetanus so bad ( how does it happen)
blocks release of inhibitory neurotransmitter, muscles cant stop contracting
How does botulism happen
blocks release of Acetylcholine, muscles cant contract
Which of the three main types of muscles has intercalated disks in its cells?
Cardiac
Cardiac muscle differs from skeletal muscle in that
it is involuntary
A muscle is arranged in bundles of muscle fibers, called
faciscles
The principle, recyclable, short-term energy molecule used by all human cells is
ATP
Muscle fibers are mainly comprised of which organic macromolecule?
protein
Which of the three muscle types do you find in the walls of blood vessels and the intestine?
Smooth
What structure connects muscle to bone?
Tendons
Which of the three muscles types has multiple nuclei per cell?
Skeletal
Name the connective tissue that covers whole muscles.
Fascia
Connection of Actin and Myosin
Z line
Once a muscle cell has depleted its small supply of ready-made ATP, what will it use next for energy?
Creatine Phosphate
Skeletal muscle groups that work together to create the same movement are referred to as
Synergistic
The primary energy source used by muscle cells to generate ATP is
Glucose
Which sequence lists the structures from largest, most inclusive, to smallest?
a.muscle fiber-myofibril-muscle-fascicle-thick filament
b.muscle-thick filament-fascicle-muscle fiber-myofibril
c.thick filament-fascicle-myofibril-muscle-muscle fiber
d.muscle-fascicle-muscle fiber-myofibril-thick filament
e.fascicle-muscle-myofibril-muscle fiber-thick filament
d
Myofibril
Neurotransmitter that has an excitatory effect on skeletal muscle, causing it to contract.
Acetylcholine
We are unable to exert any conscious control over the contraction
Involuntary, smooth or cardiac muscle.
How does botulism toxin keep skeletal muscles from contracting?
Botulism toxin blocks nerve functions, and nerves are required for a muscle to contract. When a muscle is contracting, it is because vesicles with acetylcholine have traveled into the receptors of the muscle cells, causing the units to contract. Botulism toxin blocks the receptors so that the acetylcholine cannot go into the receptors and activate the muscle.
How does tetanus toxin keep skeletal muscles in a constant state of contraction?
Tetanus toxin blocks the release of neurotransmitter that would stop the contraction so it just keeps on contracting.
Single muscle cell
Myofibril
Test, electrodes stimulate nerve and record nerve response
Nerve conduction test
Test, stimulates muscle, or stimulates nerve and records muscle response
Electromyography test
Drug that blocks Cholinestrerase form breaking down acetylcholine in the muscles
Edrophonium
Immune system attacks cells that they dont recognize as their own
Autoimmune disease
Autoimmune disease that stops that breakdown of acetylcholine in the muscle
Myasthenia gravis
Allows muscles to contract
acetylcholine
