msk histology formatives

Question 1

main features of cardiac muscle?

Answer 1

branching fibres
central nuclei
intercalated discs

Question 2

main features of smooth muscle?

Answer 2

spindled cells
single central nuclei
no striations

Question 3

main features of skeletal muscle

Answer 3

multinucleated muscle fibres

striated cytoplasm

Question 4

why is skeletal muscle striated

Answer 4

bc the myofibrils are in register

Question 5

what is a myofibril

Answer 5

arrangement of contractile proteins within a muscle fibre

Question 6

which ions are released into the sarcoplasm via t tubules?

Answer 6

calcium ions (play vital role in contraction of muscle)

Question 7

what is the diff btwn endomysium, perimysium and epimysium?

Answer 7

endomysium = sticks adjacent muscle fibres to each other

perimysium = binds groups of muscle fibres together to form fascicles

epimysium = binds fascicles together to form anatomically defined muscles

Question 8

what is the sarcolemma

Answer 8

cell membrane of muscle cells

Question 9

does exercise change the proportion of t1/t2 muscle fibres

Answer 9

no

exercise incr size of muscle fibres

Question 10

what is diff btwn t1/t2 muscle fibres

Answer 10

t1 = slow twitch
t2 = fast twitch

Question 11

release of ______ at motor end plates stimulates contraction of skeletal muscle

Answer 11

ACh

Question 12

are skeletal muscles vascular

Answer 12

yes bc contraction is energy dependant

Question 13

what do muscle spindles sense

Answer 13

stretch n tension in muscle

Question 14

do skeletal muscles contain pain receptors

Answer 14

no

Question 15

what are sharpey’s fibres made of

Answer 15

type 1 collagen

Question 16

what are sharper’s fibres

Answer 16

bundles of strongly minded t1 collagen connecting periosteum to bone, merging w the bone’s collagen fibres

Question 17

what is a t tubule

Answer 17

invagination of sarcolemma - conduct charge when cell is depolarised

Question 18

what may protect tendons from frictional injury

Answer 18

they may lie in a fibrocollagenous tendon sheath

Question 19

what do tendons comprise of

Answer 19

dense reg fibrous connective tissue

Question 20

ligaments/tendons: which contains elastin

Answer 20

lig. may contain elastin (not normally found in tendons?

Question 21

ligaments/tendons: which contains fibroblasts

Answer 21

both

Question 22

ligaments/tendons: which contain myocytes

Answer 22

none

Question 23

what do osteoblasts secrte

Answer 23

osteoid

Question 24

what type of collagen is osteoid rich in

Answer 24

1

Question 25

are osteoclasts mono or multinucleated

Answer 25

multi

Question 26

are osteocytes dead cells

Answer 26

no - they dormant but living

Question 27

which has more ER: osteoblasts or cytes

Answer 27

osteoblasts

Question 28

are osteocytes in contact w 1 another n how

Answer 28

yes: thin cytoplasmic processes running through canaliculi

Question 29

what are Haversian canals

Answer 29

run in centre of osteons and convey blood vessels through bone

Question 30

what is sig about urothelium?

Answer 30

water/urine-proof: umbrella cells that are not in contact w basement membrane

Question 31

where is urothelium found

Answer 31

renal pelvis
ureters
urinary bladder
urethra

Question 32

how do the diff parts of the colon differ in their histolofy

Answer 32

they don’t - all same

Question 33

which 2 autonomic nerve plexuses innervate GI tract

Answer 33

meissner’s plexus: submucosa

Auerbach’s plexus: btwn layers of muscular proprietary

Question 34

what are the 4 main layers of gi tract

Answer 34

(innermost)

• mucosa (epithelium, lamina propria, muscularis mucosa)
• submucosa
• muscularis propria
• adventitia

Question 35

what is the colon’s muscularis propria like

Answer 35

double-layered: inner circular, outer longitudinal

Question 36

what is a prominent brush border a feature of

Answer 36

s intestine NOT colon

Question 37

what is epimysium

Answer 37

thick layer of connective tissue surrounding muscle

Question 38

what is tropomyosin

Answer 38

long protein that runs along the actin filament, blocking the myosin head binding sites

Question 39

what is troponin

Answer 39

small protein that binds the tropomyosin to the actin

3 types: I, T, C

Question 40

what is the diff btwn troponin I/T/C

Answer 40

i - binds to the actin filament.
t - binds to tropomyosin
c - binds to calcium ions.

Question 41

briefly describe myosin

Answer 41

myosin filaments have many heads that can bind to sites on actin filament