Muscle and Bone

Question 1

What are the two muscle classifications?

Answer 1

morphological
classification or a functional classification

Question 2

Morphological
classification muscles

Answer 2

1. Striated
2. Non striated or smooth

Question 3

Functional classification muscles

Answer 3

1. Voluntary
2. Involuntary

Question 4

What are the 3 muscle types?

Answer 4

1. Skeletal muscle: striated and voluntary.
2. Cardiac muscle: striated and involuntary.
3. Smooth muscle: non striated and involuntary.

Question 5

Describe muscle tissue

Answer 5

Cluster of specialized elongated cells, called myocytes with primary role of contraction

Question 6

The cytoplasm (sarcoplasm) of a muscle cell is filled with what?

(3)

Answer 6

1. Myofibrils, long protein cords composed of myofilaments.
2. Glycogen, provides energy to the cell with heightened exercise.
3. Myoglobin, the red pigment that stores oxygen until needed for muscular activity.

Question 7

What are the 2 myofilament types?

Answer 7

1. Thin filaments: primarily protein actin.
2. Thick filaments: primarily protein myosin I

Question 8

Describe the skeletal muscle fibers structure

Answer 8

long, multinucleated cells. The membrane is sarcolemma; the cytoplasm is sarcoplasm

Question 9

Describe the structure of Cardiac muscle fibers

Answer 9

Single nucleus, are branched, and joined together by intercalated discs that contain gap junctions for
depolarization between cells and desmosomes to hold the fibers together when the heart contracts

Question 10

Describe the structure of Smooth muscle fibers

Answer 10

Spindle-shaped (like a football) and have a single nucleus; Thousands of times shorter than skeletal muscle fibers

Question 11

What does each striated muscle fiber contain?

Answer 11

Myofibrils
* composed of long proteins including actin, myosin, and titin, and other proteins that hold them together which are organized into thick and thin filaments called myofilaments

Question 12

What are myofilaments?

Answer 12

very long chains of sarcomeres, the contractile units of the cell in both cardiac and skeletal muscle.

Question 13

What is the lenght of sacromeres?

Answer 13

Sarcomere length ranges from 1.5 to 3.5 µm.

Question 14

Where is this sample from?

Answer 14

the heart

Question 15

The number of myofibrils is variable and is regulated …..

Answer 15

….. regulated during the hypertrophy of muscle fibers that is associated with growth