6. Muscle, Bone and Skin

Question 1

functions of muscle

Answer 1

body movement

stabilization of body movement

movement of substances through the body

generating heat

Question 2

tendon

Answer 2

connects muscle to bone

Question 3

ligament

Answer 3

connects bone to bone

Question 4

sarcomere

Answer 4

contractile apparatus

Question 5

thick filaments are made of…

Answer 5

myosin

Question 6

thin filaments are made of…

Answer 6

actin

Question 7

Z line

Answer 7

separates sarcomeres
where actin attaches

Question 8

I band

Answer 8

contains actin only

Question 9

H zone

Answer 9

myosin only

Question 10

A band

Answer 10

where actin overlaps myosin

Question 11

M line

Answer 11

midline of myosin fibers

Question 12

T tubule

Answer 12

infoldings of the sarcolemma that transport the AP

Question 13

structure of skeletal muscle

Answer 13

muscle
muscle fascicle
muscle fiber
myofibril
sarcomeres

Question 14

steps of skeletal muscle contraction

Answer 14

1. tropomyosin covers binding site of actin
2. Ca2+ binds to troponin causing tropomyosin to expose the binding site, myosin binds actin
3. myosin kicks out phosphate and ADP (low energy position)
4. ATP binds myosin, actin and myosin unbind
5. ATP splits to ADP and phosphate on myosin (high-energy position)

Question 15

sarcoplasmic reticulum

Answer 15

when permeable during AP, releases Ca2+ around the sarcomere which allows myosin and actin to slide

Question 16

role of Ca2+ in muscle contraction

Answer 16

binds troponin causing tropomyosin to reveal the binding site

Question 17

which motor units are activated first?

Answer 17

smaller ones

Question 18

oxygen debt

Answer 18

the need for increased oxygen after exercise in order to metabolize lactic acid

Question 19

type I muscle fibers

Answer 19

slow twitch
slow
low force
high resistance to fatigue
aerobic
red (a lot of myoglobin)

Question 20

type II A muscle fibers

Answer 20

fast twitch
fast
high force
medium resistance to fatigue
long-term anaerobic
red

Question 21

type II B muscle fibers

Answer 21

fast glycolytic twitch
very fast
very high force
low resistance to fatigue
short-term anaerobic
white (low myoglobin)

Question 22

is cardiac muscle striated?

Answer 22

yes

Question 23

how many nuclei in cardiac muscle?

Answer 23

one

Question 24

sympathetic innervation _____ heart rate

Answer 24

increases

Question 25

parasympathetic innervation _____ heart rate

Answer 25

decreases

Question 26

what is different about APs in the heart?

Answer 26

a plateau is created by slow voltage-gated sodium channels to allow the heart to fill with blood

Question 27

role of calcium in cardiac AP

Answer 27

enters the membrane to maintain positivity and maintaining depolarization for longer

Question 28

does smooth muscle have sarcomeres?

Answer 28

no

Question 29

osteoblasts

Answer 29

secrete collagen and things to form bone differentiate into osteocytes

Question 30

osteocytes

Answer 30

incapable of mitosis exchange nutrients and waste with blood

Question 31

osteoclasts

Answer 31

resorb bone matrix

Question 32

spongy bone

Answer 32

contains red bone marrow where RBCs develop

Question 33

compact (cortical bone)

Answer 33

surrounds the medullary cavity which holds yellow bone marrow (adipose cells)

Question 34

cartilage

Answer 34

composed of collagen no blood vessels or nerves

Question 35

fibrous joints

Answer 35

no movement fibrous connective tissue teeth and mandible

Question 36

cartilaginous joints

Answer 36

slight flexibility, no movement connected by cartilage ribs and sternum

Question 37

synovial joints

Answer 37

have synovial fluid knee

Question 38

is the epidermis vascular?

Answer 38

no

Question 39

cells of epidermis

Answer 39

keratinocytes melanocytes langerhans (immune) Merkel (sensory)