Skeletal and Smooth Muscle Flashcards
What are the 3 types of joints?
- Fibrous
- Cartilaginous
- Synovial
What type of cartilage is a symphyses joint made of?
Fibrocartilage
What type of cartilage is a synchondrosis joint made of?
Hyaline cartilage
What are thin filaments made of?
- G-actin
2. F-actin
fetal structure which gives rise to the pulmonary trunk
conus arteriosis
Legamentum arteriosum is a remnant of the ____ ____
ductus arteriosus
Extrafusal fibers are _____ motor neurons
alpha
Intrafusal fibers are ____ motor neurons
gamma
What two types of sensors are within the muscle spindle?
- nuclear chain fibers
2. nuclear bag fibers
What do muscle spindles do?
sense rate of stretch in the deep tendon reflex
What are Type I fibers?
Slow twitch muscles. Endurance. Small diameter. Aerobic respiration. Resist fatigue. Low stores of glycogen.
What are Type IIa fibers?
Intermediate twitch muscles
What are Type IIb fibers?
Fast twitch fibers.
Type I fibers are red due to _______
high amount of myoglobin
Type IIb fibers are white due to ______
lack of myoglobin content
Reflex circuitry is located ______
exclusively in the spinal cord
Actin and myosin overlap in smooth muscle, giving rise to a ______ _______
Dense Body
What are the two noncontractile intermediate filaments located in smooth muscle?
Desmin and Vimentin
How many calcium molecules bind to calmodulin in contraction?
4
Define extensibility
Ability of a muscle to stretch to its normal resting length and beyond
Elasticity
ability of a muscle to recoil back to its original length after being stretched
What are satellite cells?
stem cells under skeletal muscle basement membrane
Darker bands in a muscle are __ bands. The lighter bands are __ bands.
Dark - A bands
Light - I bands
What is the largest protein known?
Titin
What binds to the Z and M lines of a muscle?
Titin
Where is Dystrophin found?
Just inside the sarcolmma
Dystrophin transfers force from the contractile system to the outside of the cells via membrane-spanning proteins called _______
Integrins
How do muscle shorten during contraction?
Actin slides over myosin
Troponin-tropomyosin complex regulates contraction in response to ____
calcium
Thin filaments are composed of ____, _____, and _____
actin, troponin, and tropomyosin
How is the myosin head dislodged from actin after the power stroke?
ATP
Why does rigor mortis occur?
the muscles are unable to relax due to lack of ATP following death
When can optimal force from a muscle can be produced?
From rest
High levels of troponin in the blood can indicate what? (2 things)
- heart attack
2. recent exercise
What is a motor endplate?
Where a motor neuron synapses on the sarcolemma
The infoldings of a motor endplate are lined with ______
ACh receptors
What is the purpose of T-Tubules?
to bring stimulation/signal from a motor unit deep inside a muscle cell so all sarcomeres can be contracted
Depolarization wave goes all the way down the T-tubles to the _______ channels
L-Type Ca2+ channels
L-Type Ca2+ channels are mechanically coupled to _____ channels, which release Ca2+ from the sarcoplasmic reticulum to the cytoplasm
Ryanodine channels
Ca2+ binds to subunit on _____, hich reveals the binding site for myosin
troponin
Botulinum toxin interferes with _____ release
ACh
How does Curare cause paralysis?
binds/blocks ACh receptors
What is Myasthenia gravis?
Paralysis from antibodies blocking ACh from reaching muscle fibers
What is a possible treatment for Myasthenia gravis?
Eserine
Does the heart undergo temporal summation of twitches from individual action potentials?
FUCK NO! only skeletal muscle does that shit
What is Tetanus?
a sustained contraction in skeletal muscle
What is the difference between Isometric and Isotonic contraction?
Isometric - muscle is stimulated but doesn’t move
Isotonic - muscle shortens with stimulation
What is creatine phosphate?
Energy source/protein present in muscle
Once creatine phosphate is drained, how does the muscle use energy?
- Anaerobic respiration - buildup of lactic acid
2. Aerobic respiration - needs oxygen. Produces more ATP than anaerobic
What is the difference between visceral and multiunit smooth muscle?
visceral - functional unit that works through gap junctions
multiunit - individual nerve endings to individual muscle fibers
Smooth muscle cell margins contain _____
caveolae
Smooth muscle has small indentations of _____ _____ instead of receptor mediated endocytosis
pinocytotic vesicles
Contraction is mediated by _____ ______ _____
Myosin Filmanet Proteins
Relaxation is mediated by ____ _____ ______
Myosin Light Chain Phosphatase
