Muscle

Question 1

muscle tissue is composed of

Answer 1

• muscle cells (myocytes, myofibers)
• stem cells (satelite cells)
• nerve supply
  
  • somatic motor (voluntary)
  • visceral motor (involuntary)
• exciteable plasma membranes
• connective tissue
• blood vessel, lymphatics

Question 2

non-muscle contractile tissue

Answer 2

• myoepithelial cells (gladular)

- myofibroblasts (wound healing)

Question 3

skeletal muscle

Answer 3

• striated
• voluntary
• skeletal movement

Question 4

visceral

Answer 4

• striated
• voluntary visceral muscle
• tongue

Question 5

cardiac

Answer 5

• striated
• under autonomic control
• sympathetic and parasympathetic

Question 6

smooth

Answer 6

• nonstriated
• wide distribution
• gut, bronshioles, blood vessels, ureter, gall bladder
• autonomic via parasympathetic and sympathetic NS

Question 7

myo, sarc, mysium

Answer 7

-having to do with muscle

Question 8

sarcolemma

Answer 8

-plasma membrane + external lamina

Question 9

sarcoplasm

Answer 9

-cytoplasm

Question 10

sarcoplasmic reticulum

Answer 10

-sER

Question 11

myofiber

Answer 11

-myocyte = muscle cell

Question 12

skeletal muscle layers

Answer 12

-epimysium, perimysium, endomysium

Question 13

characteristics of skeletal muscle

Answer 13

striated

• multinucleated
• voluntary
• long unbranched fibers
• continuous external lamina
• no gap junction
• rich CT investment: surrounds entire muscle, surrounds fascicles, surrounds fibers
• multinucleated, a true syncytium
• nuscleus is eccentric
• each cell is full of myofibrils which are full of myofilaments

Question 14

where are organelles contained in muscle fibers

Answer 14

-in the gaps between myofribrils

Question 15

I band

Answer 15

• Z line is found in the middle of this

- this is where you only find myosin, no actin

Question 16

A band

Answer 16

-where myosin and actin overlap

Question 17

H band

Answer 17

-where you only see actin

Question 18

M line

Answer 18

-where the actin is anchored

Question 19

Z line

Answer 19

-where the myosin is anchored

Question 20

during contraction what happens to the bands

Answer 20

• z lines come together
• a band does not change
• h band narrows
• i band narrows

Question 21

t tubules

Answer 21

-run transversely through the myofibrils, carrying a membrane potential which triggers the sarcoplasmic reticulum to release calcium

Question 22

what links contractile proteins to the ECM

Answer 22

• dystrophin

- a mutation in this protein causes muscular dystrophy

Question 23

red muscle fibers

Answer 23

• many mitochondria, myoglobin dn oxydative enzymes

- aerobic

Question 24

white muscle fibers

Answer 24

• fewer mitochondria and oxidative enzymes
• anaerobic, quick to fatigue
• strong

Question 25

sensory perception

Answer 25

-muscle spindle provides proprioception and stretch sensation

Question 26

golgi tendon organ

Answer 26

-proprioception and inhibition reflew

Question 27

cardiac muscle

Answer 27

- involuntary - striated - long, branched fibers - discontinuous external lamina - many gap junctions - cells often binucleate - intrinsic capability to beat

Question 28

fascia adherin

Answer 28

the end to end junction of cardiac muscle | -desmosomes

Question 29

cardiac t tubule

Answer 29

- less efficient than skeletal muscle but cell-autonomous contractility and a functional syncitium compensate - does not completely surround the miofibril

Question 30

endocrine myocardial cells

Answer 30

- release ANF, a vasodilator - released in response to high BP, high NA+, and angiotensin 2 - predominantly in the aorta

Question 31

purkinje fibers

Answer 31

- specialized conducting cells - rich in glycogen - conduct impulses

Question 32

excitation contraction coupling of smooth muscle

Answer 32

1. electrical via Ca gated channels, slow excitation, NT released through varicosities. also done via caveolae which is a faster process 2. mechanical via stretching simulating mechanosensitive ion channels (myogenic) 3. hormonal - oxytocin stimulating uterine contraction

Question 33

leiomyomas

Answer 33

- uterine fibroids | - bundles of smooth muscle

Question 34

repairing skeletal

Answer 34

- satellite cell activation | - disease or trauma

Question 35

cardiac repair

Answer 35

- some satellite cell activation but not much - limited mitosis is possible - most repair though is fibrotic

Question 36

smooth repair

Answer 36

-actively proliferates in response to damage and physiological need