Lecture 14: Arthropods 1

Question 1

skeletal muscles

Answer 1

A) need a resistor to act against

B) work is antagonistic pairs (opposite directions)

Question 2

muscles

Answer 2

organ made of muscle tissue
muscle tissue is made of muscle fibre
muscle fibre is made of myofibrils
myofibrils are made of protein bundles

Question 3

sacromere

Answer 3

contractile unit of muscle fiber

Question 4

at low Ca concentration

Answer 4

myosin head cannot bind to actin because TROPOMYOSIN and TROPONIN work together to block myosin binding sites

Question 5

at high Ca concentration

Answer 5

myosin binding sites become exposed and myosin can bind to actin

Question 6

motor unit

Answer 6

• neuron + muscle fiber
• each muscle fibre is innervated by a single motor neuron
• hundreds of motor units in a single muscle

Question 7

an entire contractiom depends on

Answer 7

• the number of motor units activated

- the frequency at which they are firing

Question 8

Types of skeletal muscles

Answer 8

• striated
• cylindrical
• multicleated
• most are voluntary*

Question 9

striated

Answer 9

branched
can stand high pressure
have only one nucleus
have gap junctions between cells

Question 10

smooth muslces

Answer 10

blood vessels
digestive muscles
actin and myosin not regularly arranged
long spindle shaped with single nucleus