Lesson 1

Question 1

what are the 3 types of muscle

Answer 1

skeletal
smooth
cardiac

Question 2

T or F: smooth muscle is striated

Answer 2

F: skeletal and cardiac muscle are due to the organization of the sarcomeres

Question 3

T or F: skeletal muscle only has one nucleus per cell

Answer 3

F: multinucleated. Cardiac has one or two nuclei, smooth has one nuclei per cell

Question 4

What are some unique structural characteristics of cardiac muscle

Answer 4

intercalated disk
desmosomes
gap junctions

Question 5

What type of muscle can we voluntary control? What is the exception to that?

Answer 5

skeletal
diaphragm

Question 6

desmosomes connect what to what? hemidesmosomes?

Answer 6

desmosomes: cell to cell
hemid: cell to basement membrane

Question 7

what do gap junctions allow for in cardiac muscle cells?

Answer 7

rapid communication of the electrical impulse between cells

Question 8

smooth muscle has ________ control, contractions produce ________, and they are organized in__________

Answer 8

involuntary
constriction
multidirectional contractile units

Question 9

_________ surrounds muscle, __________- surrounds fasicles, _________- surrounds a fiber

Answer 9

epimysium
perimysium
endomysium

Question 10

Give examples of muscles for the following muscle types
fusiform
parallel
convergent
unipennate
bipennate
multipennate
circular

Answer 10

biceps brachii
rectus abdominis
pec major
palmar interossei
rectus femoris
deltoid
orbicularis occuli

Question 11

What are some other types of cells found in skeletal muscle?

Answer 11

• mature myofibers
• adipocytes
• fibroblasts
• circulatory system cells
• satellite cells
• nervous system cells

Question 12

What are the 2 types of mature myofibers?

Answer 12

extrafusal: normal contractile
intrafusal: maintain tension of muscle spindles

Question 13

what are the 3 types of adipocytes

Answer 13

white, beige, brown

Question 14

what are the jobs of fibroblasts

Answer 14

• make/organize connective tissue
• maintain signaling niches
• wound healing
• progenitor cells

Question 15

which cells in the muscle tissue support neurons and promote regenerative growth

Answer 15

satellite glial cells (not muscle satellite cells)

Question 16

which cells line axons in PNS

Answer 16

schwann cells

Question 17

Which cell covers the schwann cell at the NMJ and cement axon to the muscle

Answer 17

kranocyte

Question 18

_________ respond to changes in length and are located in the muscle fibers, _________ respond to changes in force and are located at the myotendon junction

Answer 18

muscle spindles
golgi tendon organ

Question 19

what are 2 joint kinesthetic receptors

Answer 19

ruffini and pacinian corpuscles

Question 20

_____________ found in joint capsule and respond to pressure, __________ found in connective tissue around the joint and respond to accel/decell of joints

Answer 20

ruffini corpuscles
pacinian corpuscles

Question 21

T or F: fiber type % and cross sectional area of muscles are the same between sexes

Answer 21

F: cross sectional area is different but not fiber type %

Question 22

what is the purpose of a T-tubule

Answer 22

allow AP to penetrate nearer to the internal structures of the fiber

Question 23

what makes up a triad

Answer 23

T-tubule + 2 flanking terminal cisternae

Question 24

what is the contractile unit

Answer 24

myofibril

Question 25

T or F: a sarcomere is M line to M line

Answer 25

F: Z disc to Z disc

Question 26

T or F: actin is stationary and pulls myosin during a muscle contraction

Answer 26

F: actin is what moves during a contraction, myosin pulls actin

Question 27

What do we need to know about myosin heavy chain purpose? myosin light chain?

Answer 27

heavy - they don’t all contract at the same speed
light - controls how close the myosin head is to actin

Question 28

Myosin is an ________

Answer 28

ENZYME

Question 29

Titin’s purpose?

Answer 29

acts as a spring and holds actin to the z disc
*largest know protein
*provides passive tension

Question 30

Nebulin’s purpose?

Answer 30

is in the center of actin and keeps it organized
*large protein (not bigger than titin)
*“molecular ruler”

Question 31

what are the different populations of mitochrondria?

Answer 31

1 - subsarcolemmal (cluster at nucleus and neuromuscular junction)
2 - intermyofibrillar

Question 32

What type of tissue has the most mitochondria?

Answer 32

cardiac

Question 33

list the types of skeletal muscle from most mitochondria to least

Answer 33

type 1>2a>2x>2b

Question 34

T or F: smooth muscle has more mitochondria than skeletal

Answer 34

F: smooth is really variable so it depends

Question 35

_______ connects the sarcolemma to the basil lamina

Answer 35

Laminin