Muscle

Question 1

what makes up light band and dark bands

Answer 1

light - I band

dark - A band

Question 2

where does z line occur

Answer 2

runs through I -band

Question 3

where is sarcomere and significance

Answer 3

between 2 I-lines - where muscle shortens

Question 4

3 feature of skel. muscle fibers

Answer 4

1. long and straight
2. multinucleatied - peripheral
3. no cell-cell junctions

Question 5

4 features of cardiac cells

Answer 5

1. short
2. often branch
3. one or two central nuclei
4. have intercalcated disc between - at ends

Question 6

what is contained in intercalcated discs (3)

Answer 6

1. demosomes
2. fascia adherents - anchor
3. gap junctions - communicate

Question 7

define myofibrils and myofilaments

Answer 7

myofibrils - cylindrical cells that are striated

myofilaments - what create the striations

Question 8

2 types of myofilments

Answer 8

thick and thin

Question 9

attachement of thin myofilaments

Answer 9

to z-discs and into sarcomere

Question 10

arrangement of myfilaments

Answer 10

1 thick with numerous thin filaments surrounding it

Question 11

2 different types of contractions

Answer 11

1. isotonic - flexion occurs - myofilaments slide deeper

2. isometric - no movement

Question 12

special attachement to T-tubule in skeletal muscle vs. cardiac

Answer 12

terminal cisternae - stores Ca and released if triggers

- cardiac must get Ca from outside

Question 13

what is different about cardiac ultrastructure (3)

Answer 13

1. less distinct myofibrils
2. less dev. sarcoplasmic reticulum
3. wider T-tubules

Question 14

Features of a motor unit

Answer 14

1. can innervate multiple muscles

2. all or nothing signal

Question 15

synaptic muscle cell order of things

Answer 15

1. voltage gates Ca channel opens
2. Ca in
3. releases vesicles of ACTH
4. ACTH bind w. receptors
5. Na channel opens
6. muscle contracts

Question 16

3 different muscle wrapping and what they surrounds

Answer 16

1. endomysium - CT around muscle fiber
2. perimysium - surround group - fascicle
3. epimysium - surrounds whole muscle

Question 17

general shape of smooth muscle cells

Answer 17

• long and fusiform (tapered)

- connected by gap JCTs

Question 18

how to diff. smooth muscle from fibroblast

Answer 18

• nucleus in cytoplasm in smooth muscle

Question 19

what is smooth muscle missing

Answer 19

myofibrils

Question 20

what covers binding myosin sites on actin

Answer 20

tropomysin

Question 21

what are the binding sites on actin

Answer 21

myosin

Question 22

what are the Ca binding proteins associated with actin

Answer 22

troponin