Muscle Anatomy + Sliding Filament Theory Flashcards
What are the muscle pairs?
Agonistic and Antagonistic
Muscle contracts
Agonistic
Muscle relaxes or lengthens
Antagonistic
Muscles that bend a limb
Flexor
Muscles that straighten a limb
Extensors
Muscles that cause movement in opposite directions
Antagonist
Muscle to Bone
Tendons
Bone to Bone
Ligaments
What are the 3 types of Muscle Cells?
Cardiac, Skeletal, and Smooth
Which Muscle cell is this?
-Only found in the heart (covers the walls)
-Tubular, striped, branched
Cardiac Muscle
Which Muscle cell is this?
-Lines blood vessels, tubes, and walls of internal organs (ex. esophagus, stomach)
-Non-striped and spindle-shaped
Smooth Muscle
Which Muscle cell is this?
-All over the body;attached to bones.
-Many nuclei
-Tubular and striped
-Very long
-Supports the body
Skeletal Muscle
What is the Order of Components in the skeletal muscles? (Largest to Smallest)
Muscle > Muscle Fiber Bundle > Muscle Fiber > Myofibril > Myofilaments
Muscles are made up of bundles of muscle fibres, which are made up of..
Myofibrils
The membrane that encloses the muscle fibers.
Sarcolemma
Within the Muscle Fibers are tiny ____________ bundled together.
Myofilaments
Threadlike structures of contractile proteins found within the muscle.
Myofilaments
Thin Myofilaments are composed of..
Actin
Thick Myofilaments are composed of..
Myosin
The functional/contractile unit/Basic, repeating unit of a muscle cell
Sarcomere
The length of the Muscle Fibre that anchors the Actin Fibres.
One to One = 1 Sarcomere
Z Line
Full length of the thick Myosin Filaments, including the part that is overlapped with Actin Filaments (aka dark band)
A Band
Thin Actin Filaments (aka light band)
i / I Band
In middle of A Band where only thick Filaments are found
H Zone
Center of H Zone where thick Filaments are bound in the center
M Line
Spaces where thick and thin overlap and attach to each other
~Myosin Heads attach onto Actin Filaments
Cross-Bridges
Cytoplasm of Muscle Fibre
Sarcoplasm
Storage sites for Calcium; surrounds Myofibrils
Sarcoplasmic Reticulum
What are the components of Actin Filament?
Tropomyosin, and Troponin
Long protein filament that blocks or exposes the binding sites for Myosin Heads.
~Bands that run along the length of the Actin Filament
Tropomyosin
A protein attached to Tropomyosin.
~Attachment site for Ca2+ ions (which are necessary for muscle contractions).
~IS LIKE GLUE
Troponin
The Sliding Filament Theory is how muscle ____________ occur
contractions
(True or False) Z-lines move closer together during the Sliding Filament Theory (muscle contraction).
True
(True or False) Sarcomeres shorten during the Sliding Filament Theory (muscle contraction).
True
(True or False) Actin Filaments slide over Myosin Filaments during the Sliding Filament Theory (muscle contraction).
True
(True or False) Actin and Myosin Filaments change length during the Sliding Filament Theory (muscle contraction).
FALSE!!!!! THEY DO NOT CHANGE LENGTHS!!!!
(True or False) The energy for muscle contraction comes from ATP.
True
The state when the Myosin head is not contacting the Actin, Calcium is absent, and the Tropomyosin is blocking the Myosin-binding sites on Actin.
Relaxed State
During Cross Bridge, _______ ions are released from the Sarcolemma upon stimulation.
Calcium Ions
What happens to the Troponin (glue) when Calcium binds to it during Cross Bridge?
The Troponin becomes unsticky, changing its shape and moves the Tropomyosin away from the Myosin-binding site on the Actin.
After Calcium binds to the Troponin during Cross Bridge and moves the Tropomyosin away, what happens to the Myosin heads?
The Myosin heads attach to the exposed binding sites on the Actin Filaments.
What happens during Power Stroke? (Step 2 of the Sliding Filament Theory)
The Myosin head pulls back and moves the Actin with it.
What step of the Sliding Filament Theory is Cross Bridge?
Step 1!!
What happens during Detachment? (Step 3 of the Sliding Filament Theory)
ATP binds to the Myosin heads causing the Myosin to let go of the Actin.
What is the fourth and last step of the Sliding Filament Theory?
Hydrolysis
a reaction in which a water molecule is used during the breakdown.
Hydrolysis
When it binds to the Myosin, ATP breaks down into ADP, Pi, and energy.
Hydrolysis
During Hydrolysis, Calcium detaches from Troponin and is __________.
Reabsorbed
During Hydrolysis (The last step in the Sliding Filament Theory), what happens to the Tropomyosin?
The Tropomyosin moves back to its original position and blocks the Myosin binding site again.
During Hydrolysis, creatine Phosphate regenerates ___.
ATP
means ‘No Oxygen’
Anaerobic
means ‘With Oxygen’
Aerobic
What are the 3 ways energy is made for Muscle Contraction?
- Breakdown of creatine phosphate (anaerobic)
- Aerobic Cellular Respiration
- Lactic Acid Fermentation (anaerobic)
-High-energy compound that builds up when muscle is resting.
-The fastest way to make ATP available to muscles
Creatine Phosphate
-Provides enough energy for about 8 seconds of intense activity, and then it is spent.
-Supplies a Phosphate to ADP
Creatine Phosphate
Creatine Phosphate is a way to get ATP before O2 enters the..
Mitochondria
-Takes place in the Mitochondria
-Provides MOST of the muscle’s ATP
Aerobic Cellular Respiration
During this, Glycogen and Fats are stored in muscle cells to be used as fuel to produce ATP when oxygen is available.
Aerobic Cellular Respiration
During Aerobic Cellular Respiration, Myoglobin in muscle cells stores ______ to use during muscle contractions.
Oxygen
During Aerobic Cellular Respiration, CO2, Water, and Heat are produced as..
Wastes!!!
-Supplies ATP in the Absence of Oxygen.
-Produces Lactate which makes the Sarcoplasm more acidic.
-Results in Oxygen deficit
Lactic Acid Fermentation
During Lactic Acid Fermentation, the accumulation of Lactate for longer than two minutes causes..
Cramping and Fatigue
When energy demand exceeds ATP supply, and lactic acid accumulates.
Oxygen Debt
Cramping results from the lack of..
ATP
One reason why ATP is needed is to pump Calcium ions back into the Sarcoplasmic _________.
Reticulum
Another reason why ATP is needed is to break the linkages between Actin and Myosin so the Muscle Fibres can..
Relax
What does replenishing an oxygen deficit require?
Replenishing Creatine Phosphate supplies, and disposing of Lactate.
When ATP production is gone and skeletal muscle becomes fixed (body stiff as a board).
~Moments up to 60 hrs after death
~Cross-Bridges fail to detach
Rigor Mortis
Rapid breathing after exercise is designed to repay..
Oxygen Debt