Week 12 Flashcards
Muscular system
What type of muscle is multinucleate?
skeletal muscle
Are skeletal muscles controlled
by hormones?
No
What is the specialized plasma membrane of skeletal muscles?
sarcolemma
What are long organelles inside muscle cell?
myofibrils
What bands give the muscle its striped appearance?
Light (I) bands and dark (A) bands
What type of muscle is fusiformed?
smooth muscle
What are the (3) layers of connective tissue of skeletal muscles?
- epimysium
- perimysium (surrounds fascicles)
- endomysium
What layer does the cardiac and smooth muscle both have in common and only that?
endomysium
a bundle of skeletal muscle cells is called?
A fascicle
Muscle fiber is AKA?
Skeletal muscle cell
What is the contractile unit of a
muscle fiber?
Sarcomere
Is I band light or dark bands?
Light bands
Is A band light or dark bands?
Dark bands
Which banding pattern contains only thin filaments?
Light bands / (I) bands
Which banding pattern contains only the entire length of the thick filaments?
Dark bands / (A) bands
thin filaments are AKA?
Actin
thick filaments are AKA?
Myosin
What is a support beam of the actin bridge (a midline interupption)?
Z disc
What is a support beam of the myosin bridge (a midline interruption)?
M line
The region between two Z discs is where sarcomeres are present, true or false?
True
What zone is a lighter central area?
H zone
M line is in center of what?
H zone
What myofilaments in the sarcomere are composed of the contractile protein
actin?
Thin filaments
When myosin heads link thick and
thin filaments during contraction, this is referred to as?
Cross bridges
Does myosin or actin contain ATPase?
myosin
What specialized smooth endoplasmic reticulum stores and releases calcium in the skeletal muscle?
Sarcoplasmic reticulum (SR)
What does Sarcoplasmic reticulum (SR) surround?
Myofiber
Irritability is AKA?
responsiveness
The ability for the cell to receive and respond to a stimulus is referred to as?
irritability
The ability for the cell to shorten when an adequate stimulus is received is called?
Contractility
The ability of muscle cells to be stretched is called?
extensibility
The ability for the cell to recoil and resume resting length after stretching is called?
Elasticity
In order for skeletal muscles to contract, it must be stimulated by what type of cell?
a motor neuron (nerve cell)
When one motor neuron and all the skeletal muscle cells stimulated by that neuron, this is known as?
Motor unit
The association site of axon terminal of the motor neuron and sarcolemma of a muscle is called?
Neuromuscular junction
What neurotransmitter stimulates skeletal muscle?
Acetylcholine (ACh)
What is the gap between nerve
and muscle that is filled with interstitial fluid?
Synaptic cleft
Is muscle fiber contraction is “all or none” or gradual?
All or none
different degrees of skeletal
muscle shortening is AKA?
Graded responses
What immediate source of energy for muscle contraction do we need?
ATP
(3) Three ways to generate ATP?
- Direct phosphorylation of ADP by creatine phosphate
- Aerobic respiration
- Anaerobic glycolysis and lactic acid formation
What type of acid produces muscle fatigue and needs a huge amount of glucose?
Lactic acid
Anaerobic glycolysis reaction that breaks
down glucose without?
Oxygen
In anaerobic glycolysis, glucose is first broken down to pyruvic acid and then it is converted to?
Lactic acid
The temporary shortage of oxygen in the body’s cells that occurs during the beginning of strenuous exercise is called?
oxygen deficit
If muscle activity is strenuous and
prolonged, muscle fatigue occurs because of what (3) things?
▪ Ionic imbalances occur
▪ Lactic acid accumulates in the muscle
▪ Energy (ATP) supply decreases
What are (2) type of Muscle Contractions?
- Isotonic contractions
- Isometric contractions
When myofilaments are able to slide past each other during contractions, what kind of muscle contraction is this?
Isotonic contraction
What type of contraction causes the muscle to shorten and movement will occur?
Isotonic contraction
What type of contraction causes the muscle to unable to shorten or produce
movement?
Isometric contraction
The result of a staggered series of nerve impulses delivered to different cells within the muscle is referred to as?
Muscle tone
If the nerve supply to the muscle is destroyed, what happens?
Muscle atrophy and/or paralysis
