Exam 3 Lecture 6 Flashcards
What % of body weight and volume is Muscle
40%
Sarcomere Anatomy: Microscope
- I band [actin only - either side of Z disc]
- H band [Myosin only]
- Mitochondria
- Transverse Tubule
- Z-Disc
What is a Z-Disc
the 2 ends of each sarcomere [between 2 I bands]
Soleus Muscle Contraction
Slow onset but long,sustained force
CBC: What happens after the Myosin Head pulls the Sarcomeres together/
It loses the ADP molecule and is now stuck b/c no energy to pull it off of the F-site [makes muscles stiff]
Describe Myosin color and thick or thin
Red and Thick
L-T Relationship: New A Fiber
Understretched = Little force produced
Where is glycogen stored
Liver, Skeletal Muscle
What is Tropomyosin in Actin Filaments
Blocks the view of the myosin head trying to bind to the Actin F-sites; must be moved out the way via Ca++ binding to Troponin C
How Achilles Tear is Handled
Cadaver or take 2 ends and overlap/connect them; makes for weaker muscle overall
Type 2 Skeletal Muscle
*Color [and why]
*Speed and duration of contraction
*Myoglobin and Mitochondria
White, b/c lack of myoglobin
fast onset and short contraction
little myoglobin and mitochondria
CBC: By adding Ca++ to “ready to go state”, what happens next
*What happens to a Phosphate during this
Tropomyosin moves out of the way , allowing for the myosin head to attach to the F-sites on Actin Filament
*Phosphate is released
L-T Relationship: C Fiber Stretch
*Length of Sarcomere?
Best case scenario for our muscles; 2 micrometers; best stretch and force combo
How do motor neurons get proteins far away from the nucleus?
They have a railroad track type system to send proteins down the axon
Where is the Achilles attached
Soleus/Gastroc to Calcaneus Bone
Individual Muscle Cell Name
Muscle Fiber
Contraction of Myofibril: What happens to the H band
The H band disappears
What is the basic functional unit of a skeletal muscle
Sarcomere
What is Titin
the elastic connective tissue that anchors actin and myosin together; allows for stretch
Contraction of Myofibril: Does the A band change
No, it stays the same
CBC: What happens after Myosin head is attached to F-site?
Tension in head is used as energy and pulls at F-site to bring Z-discs closer together and slide actin filament to the right [contraction]
Sarcomere Anatomy: Microscope Pt.2
- Z-Disc
- I Band [actin only]
- A band [actin + myosin]
- H band
- Z-Disc
What is Passive Tension?
Applying pressure to tendons to stretch muscle out
Gastrocnemius Muscle Contraction
Right in the middle between Ocular Muscle and Soleus [most muscles fall into this range]
What is a H band
Only Myosin
What is a Myofibril
*how many makes up a muscle fiber
*Less or more for fine motor movement muscles
Contain actin and myosin; 200 or more per muscle fiber; less for more fine motor movement muscles
What is Rigor Mortis, per lecture?
Stiff muscles from no ATP [myosin heads stuck on F-sites]
What is Active Tension?
*Shape on graph
Tension from contracting muscle with AP
*upside U or V shape
Contraction of Myofibril: What happens to the I band
I band shrinks; the part where no overlap of actin and myosin is the part where the muscle shrinks during contraction
How do skeletal muscles get proteins down the muscle for rebuilding?
Skeletal muscles are one of the only muscles that are multi-nucleated, allowing for proteins to be produced throughout the muscle
Ocular Muscle Muscle Contraction
short lived, but rapid start [less myoglobin and mitochondria]
What does a ligament connect
*3 examples
Bone to Bone [patellar, ACL, MCL]
L-T Relationship: D Fiber Stretching
Overstretched = no force produced
What is an I band
Band of only Actin
What is Myoglobin
*how does it help mitochondria
*affinity for O2
Protein that contains iron and helps O2 unload from blood to muscle
*helps by giving O2 so mitochondria can use it as energy to create ATP
*high affinity for O2
What is the Troponin Complex?
*3 Parts with Function
3 proteins stuck together to help with binding of F-site and myosin head
* Trop I - Actin
*Trop T - TropoMyosin
* Trop C - 4 binding sites for Ca++ to allow for rotate/unravel for F-sites to be seen/bound
Essential Light Chain vs Regulatory Light Chain
Essential - Gives Myosin head ATPase activity
Regulatory - helps with specific functions
7 things muscle does for the body
Locomotion
Expression
Communicate
Body temp
Store glycogen
Effectors from CNS
Stores ions, fluids, proteins
Large mu’s
*Reason
*which order are they activated and are they easy or hard to activate
Larger motor movements
*Activated 2nd, harder to excite
L-T Relationship: Original A fiber
Cardiac Ventricle; Frank Starling; little understretched to allow for big stretch and push blood out
CBC: How does the Myosin Head look in the “ready to go” state
Cocked in perpendicular angle with ADP and Pi attached
How many Myosin Molecules per Myosin Filament
200
What is a motor unit
1 or more collection of muscle fibers that is controlled by a single motor neuron
What do Tendons Connect
*Which tendon connects muscle to muscle
Muscle to bone
*Intermediate tendons connect muscle to muscle
Example of Type 1 and Type 2 Skeletal Muscles
Type 1: Duck and Goose breast; dark meat
Type 2: Chicken breast; white meat
Sarcomere Anatomy
- Z-Disc
- I Band [actin only]
- A Band [actin + myosin]
- H Band [myosin only]
- Titin
- Z-Disc
Skeletal Muscle Histology
- Nuclei
- Striation from Actin and Myosin
Muscle Cell Wall name
Sarcolemna
Type 1 Skeletal Muscle
*Color [and why]
*Speed and duration of contraction
*Myoglobin and Mitochondria
Red, b/c of the iron found in myoglobin
*Slow onset but long, sustained contraction
*Lots of Myoglobin and Mitochondria
Contraction of Myofibril: What happens to the Z discs
The Z-discs move closer together
More than 1 group of muscle cells
Fasciculus
CBC: How to get Myosin head unattached?
Has to come in contact with ATP
What is the F-Site in Actin
Binding sites for Myosin Head
What is an A band
Band of both actin and myosin [overlap of filaments = produce force]
Describe Actin color and thick or thin
White and thin
CBC: Last step before “recocking” myosin head back to ready state
ATP metabolized into ADP and Pi, allowing for Myosin to be reset and in the ready to go state
Muscle is made up of _
Many Fasciculi
Small mu’s
*Reason
*which order are they activated and are they easy or hard to activate
Fine motor control, less skeletal muscle cells
*activated 1st, easy
What is total tension?
Active + Passive Tension
How many chains does a Myosin Filament have?
6 total
*2 Heavy
*4 Light [essential, regulatory]
