Muscle

Question 1

What is special about cardiac muscle?

Answer 1

Highly specialised using elements from both muscle types

Question 2

What are muscles composed of?

Answer 2

Myofibrils (30cm long) units called sarcomeres. It contracts using sliding filaments sarcomeres are repeating units of micro fibrils

Question 3

What three types of sheathing are present in muscle fibre

Answer 3

EpiMYSEUM- whole muscle
PeriMYSEUM - divides into 10-100 fibre bundles
EndoMUSEUM - individual fibres

Question 4

Muscle cell- What is a sarcolenma?

Answer 4

Equivalent to the cell membrane

Question 5

Muscle cell- what is the sarcoplasmic reticulum?

Answer 5

Smooth er stores and transfers ions

Question 6

Muscle cell what is sarcoplasm

Answer 6

Cytoplasm equivalent contains contractile elements

Question 7

Why are muscles striated?

Answer 7

Overlapping fibres sliding filament hypothesis

Question 8

What are zdiscs?

Answer 8

Connecting proteins between actin filament bundles actions have heads which move from active sites each movement uses a molecule of ATP

Question 9

What are thick filaments made of?

Answer 9

Thick myosin

Question 10

What is myoglobin?

Answer 10

Relates to haemoglobin. Iron containing porphyrin contains 154 amino acids. It stores oxygen temporarily in muscles

Question 11

What are slow fibres?

Answer 11

Smaller in diamiter
Rich in myoglobin red colour
Prolonged sustained contraction
Aerobic
Ed solis muscle used in posture

Question 12

What are fast fibres

Answer 12

Fast ATP processing
Little myoglobin
Brief duration
Large diamiter
Fastest in anaerobic conditions but can be both aerobic and anaerobic 
Eg gastrocnemius muscle

Question 13

What are the two types of muscle?

Answer 13

Striated - will controlled fast/slow types.

Smooth- no definite structure to filaments usually beneath voluntary control