Biology 20 - Muscles

Question 1

What are the traits of a smooth muscle?

Answer 1

• Found in organs, blood vessels, intestines, and iris of the eye
• Long, tapered, one nucleus
• Involuntary

Question 2

What are the traits of a cardiac muscle?

Answer 2

• Found only in the heart
• Tubular and striated, one nucleus
• Branches, creating a net-like structure
• Involuntary

Question 3

What are the traits of a skeletal muscle?

Answer 3

• 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

Question 4

How do skeletal muscles work?

Answer 4

• Work by contracting
• Only two actions - contraction and relaxation

Question 5

What is a skeletal muscle organization?

Answer 5

• 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).

Question 6

What is actin fiber composition?

Answer 6

• 2 strands of protein wrapped around each other

Question 7

What is myosin fiber composition?

Answer 7

• 2 strands of protein wrapped around each other, 10 times longer and different shape

Question 8

Role of calcium?

Answer 8

• 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.

Question 9

Energy for muscle contraction?

Answer 9

• 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

Question 10

Traits of stored creatine phosphate?

Answer 10

• 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

Question 11

Traits of aerobic cellular respiration?

Answer 11

• Provides the most ATP
• Uses glucose and fatty acids as fuel to produce ATP

Question 12

Traits of fermentation?

Answer 12

• Can result in oxygen deficit

Question 13

Training effects on muscles

Answer 13

• 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

Question 14

What is muscle atrophy?

Answer 14

• Reduction of muscle size due to lack of use

Question 15

What are muscle growth traits?

Answer 15

• 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

Question 16

What is muscular dystrophy?

Answer 16

• Skeletal muscle deteriorates, loses strength, and is replaced by tissue that impedes blood circulation

Question 17

What is botulism?

Answer 17

• Botox
• Made by a bacteria, if it’s in an anaerobic condition it can grow and reproduce

Question 18

What are cramps?

Answer 18

• Muscle contracts that wont stop

Question 19

What is contracture?

Answer 19

• Abnormal muscle shortening caused by nerve stimulation

Question 20

What is fibromyalgia?

Answer 20

• Chronic muscular pain and tenderness

Question 21

What is crush syndrome?

Answer 21

• Muscles get crushed, which releases potassium into your bloodstream, causing heart problems

Question 22

What is myositis?

Answer 22

• Muscle soreness, inflammation, and weakness from infection or autoimmune disease

Question 23

What are the traits of a slow twitch fiber?

Answer 23

• Contracts slowly to resist fatigue
• Contains a lot of myogloin
• Has lots of blood supply
• Substantial reserve in glycogen and fat

Question 24

What are the traits of a fast twitch A fiber?

Answer 24

• Meant for rapid generations of power
• Helpful in short bursts
• Rich in glycogen
• Very large amount of myoglobin
• Few mitochondria
• Vulnerable to lactate

Question 25

What are the traits of a fast twitch B fiber?

Answer 25

• Low myoglobin
• Few mitochondria
• Poor blood supply
• ATP from fermentation
• Fatigue easily