lecture 17

Question 1

skeletal muscles are critical for most

Answer 1

behaviors including breathing, moving, and talking VOLUNTARY MOVEMENTS and REFLEXES

Question 2

skeletal muscles are very

Answer 2

organized

Question 3

what is the contractile unit of a skeletal muscle

Answer 3

sarcomere

Question 4

what is the level of organization for skeletal muscles

Answer 4

muscle -> muscle cell/fiber -> myofibril -> sarcomere

Question 5

what tissues do muscles have

Answer 5

muscle tissue, connective tissue, nervous tissue

Question 6

where do skeletal muscles connect to

Answer 6

to the bone or either side of a joint

Question 7

muscles can only what kind of movement

Answer 7

contract and relax

Question 8

muscles work in what kind of pairs

Answer 8

opposing pairs

Question 9

what do muscles need to do to create bidirectional movement

Answer 9

there needs to be a coordinated relaxation/contraction around joint

Question 10

the skeletal muscles are in control by the what

Answer 10

somatic nervous system

Question 11

what do skeletal muscles and cardiac muscles have in common

Answer 11

they are striated

Question 12

the cardiac muscle is controlled by the

Answer 12

autonomic nervous system

Question 13

how do skeletal and cardiac muscles differ

Answer 13

skeletal: multiple nucleus and somatic NS cardiac: one nucleus and autonomic NS

Question 14

what are cardiac myocytes

Answer 14

cardiac muscle cells

Question 15

what are the four specializations that cardiac cells do

Answer 15

intercalated discs, gap junctions, pacemaker cells, long action potential

Question 16

intercalated discs

Answer 16

mechanically connect adjacent cells

Question 17

gap junctions

Answer 17

allows AP’s to move between adjacent cells

Question 18

pacemaker cells

Answer 18

endogenously generate contraction signal AP

Question 19

long action potential

Answer 19

ensures muscles have time to relax before next AP

Question 20

what type of cells initiate heart contractions

Answer 20

pacemaker and conducting cells

Question 21

the heartbeat is

Answer 21

myogenic

Question 22

myogenic

Answer 22

regulated by the muscle

Question 23

what can the ANS alter in cardiac muscle cells

Answer 23

the ANS can alter the rate of contraction but it is not necessary for their function

Question 24

sinoatrial node

Answer 24

specialized muscle fibers located in the right atrium of the heart initiates the heartbeat

Question 25

where is the smooth muscle located and what does it do

Answer 25

it lines many hallow organs and generate long sustained contractions or waves of contractions (gut, uterus, blood vessels)

Question 26

many smooth muscles are connected by (same as cardiac cells)

Answer 26

gap junctions

Question 27

smooth muscles do what to blood vessels

Answer 27

vasocontraction and vasodilatation

Question 28

smooth muscles are different from skeletal and cardiac because

Answer 28

they are not striated and contract in all directions

Question 29

smooth muscles can contract for long periods of time while

Answer 29

conserving ATP

Question 30

smooth muscles have no

Answer 30

sarcomere