Biology 20 - Muscles Flashcards
1
Q
What are the traits of a smooth muscle?
A
- Found in organs, blood vessels, intestines, and iris of the eye
- Long, tapered, one nucleus
- Involuntary
2
Q
What are the traits of a cardiac muscle?
A
- Found only in the heart
- Tubular and striated, one nucleus
- Branches, creating a net-like structure
- Involuntary
3
Q
What are the traits of a skeletal muscle?
A
- Found throughout our bodies
- Connected to bones with tendons
- Lies along the length of a bone
- Supports body, makes bones move, protects organs, stabilizes joints
- Tubular striated, very long, many nuclei
- Referred to as FIBERS rather than CELLS
- Voluntary
4
Q
How do skeletal muscles work?
A
- Work by contracting
- Only two actions - contraction and relaxation
5
Q
What is a skeletal muscle organization?
A
- The muscle is made up of many muscle fiber bundles which are surrounded by connective tissue and the whole muscle is surrounded by one connective tissue.
- Blood vessels and nerves run between the bundles to supply oxygen, nutrition, and signal for contraction.
- Inside the muscle fibers, are tons of microfilaments (actin and myosin) which are responsible for muscle contraction).
6
Q
What is actin fiber composition?
A
- 2 strands of protein wrapped around each other
7
Q
What is myosin fiber composition?
A
- 2 strands of protein wrapped around each other, 10 times longer and different shape
8
Q
Role of calcium?
A
- The troponin and tropomyosin on actin block myosin binding sites.
- Calcium ions bond to troponin which lets the tropomyosin get off the boding sites to allow myosin heads to bond.
9
Q
Energy for muscle contraction?
A
- ATP is used in contraction (it bonds to myosin heads)
- Lots of contractions use a lot of ATP
- More ATP is generated from stored creatine phosphate, aerobic cellular respiration, and fermentation
10
Q
Traits of stored creatine phosphate?
A
- Builds up when muscle is resting
- This regenerates ATP to use in muscle contraction
- Fastest way to make ATP
- Provides energy for 8 s of intense activity
11
Q
Traits of aerobic cellular respiration?
A
- Provides the most ATP
- Uses glucose and fatty acids as fuel to produce ATP
12
Q
Traits of fermentation?
A
- Can result in oxygen deficit
13
Q
Training effects on muscles
A
- Muscles can run oxygen deficits
- The # of mitochondria and muscle tissue increases
- Fermentation can be avoided resulting in less lactate produced so oxygen deficit is less
- Replenishing oxygen deficit requires replenishing creatine phosphate supplies + disposing of lactate
- Exhaustion after a long race is due to using glycogen stored in muscles
- A high-carb diet can replace oxygen stores
14
Q
What is muscle atrophy?
A
- Reduction of muscle size due to lack of use
15
Q
What are muscle growth traits?
A
- An increase in muscle mass is called hypertrophy
- Caused by an increase in muscle fiber size
- Increased muscle mass has + active enzymes and + mitochondria
- Increased blood and stores of glycogen
