Physiology Exam 2 Lecture 15

Front 1

smooth muscle consists of spindle shaped muscle cells with a ____ nucleus

Back 1

single

Front 2

do smooth muscles jhave the capacity to divid throughout life

Back 2

no

Front 3

smooth muscle is under the control of the _____ division of the NS

Back 3

autonomic

Front 4

does smooth muscle utilize cross bridge movemnt between actin and muyosin to gneerate force

Back 4

surpirsingly yes

Front 5

is tropomyosin present in thin filaments of smooth muscle

Back 5

yes

Front 6

is troponin present in thin filaments of smooth muscle

Back 6

no

Front 7

thin filaments are anchored to either the plasma membrane or cytoplasmic structures known an _____ _____

Back 7

dense bodies

Front 8

in smooth muscle does contraction occur by a sliding filament mech

Back 8

yes

Front 9

in smooth muscle what does calcium bind to

Back 9

calmodulin

Front 10

are there T tubules in smooth muscle

Back 10

no

Front 11

is SR less abundant and not arranged in a pattern of thick and thin filaments

Back 11

yes

Front 12

what are five inputs influencing smooth muscle contractile acitivity

Back 12

spontaneous electrical activity in the plasma membrane of the muscle clel\neurotrans released by autonomic nuerons
homrones
locally incduced changes in the chemical composition of the exttracell fluid is paracrine agents acidity and oxygen
stretch oopens mechanosensitve ion channels

Front 13

definition. no constant resting potential as in smooth muscle

Back 13

spontaneous electrical activity

Front 14

definition. the membrane potential change occurrin during the spontaneous depolarization to threshold

Back 14

pacemaker potntial

Front 15

this procues a rhythmis state of contractile activity

Back 15

pacemaker potential

Front 16

definition. period fluctuations (dirifes) in the membrane porential

Back 16

slow waves

Front 17

_____ _____ is food in the GI tract slow waves are depolarized above threshold

Back 17

excitatory stimuli

Front 18

innervatoin of smooth muscle by a post ganglionic autonomic neuron can be ______ or _______

Back 18

excitatory or inhibitory

Front 19

what are the two types of smooth muscle

Back 19

single unit smooth and multi unit smooth

Front 20

single or multi unit smooth. undergo synchronized electrical and mechanical activity

Back 20

single

Front 21

single or multi unit smooth due to gap junctions between cells which allow action potentials to propagate from cell to cell

Back 21

single

Front 22

single or multi unit smooth have no gap junctions

Back 22

multi

Front 23

single or multi unit smooth are influenced by nerves hormones local factor and stretchin

Back 23

single

Front 24

single or multi unit smooth heavily innervated by the autonomic ns

Back 24

multi

Front 25

single or multi unit smooth do not response to stretching

Back 25

multi

Front 26

single or multi unit smooth examples are smooth muscles of the lung airway sand large arteries

Back 26

multi

Front 27

single or multi unit smooth examples ar esmooth muscles of the GI tract, uterus, and small diameter blood vessels

Back 27

single

Front 28

cardiac muscle combines the properties of both ______ and ____ muscle

Back 28

skeletal and smooth

Front 29

how is cardiac muscle like skeletal

Back 29

striated
topo and topo
T tubules associated with sarcoplasmic reticulum

Front 30

how is cardiac msucle like smooth

Back 30

individual cells are relatively small and generally a single nucleus
gap junctions between cells
cells arrange in layers and surround hollow cavities

Front 31

definiton. structuresthat join adjacent cardiac muscle cells end to end

Back 31

intercalated disks

Front 32

whtin the intercalated disks are _____ tha thold th ecells together and attach to _____; also within these disks are _____ ______

Back 32

desmosomes
myofibrils
gap junctions

Front 33

depolarization during cardiac action potentials is partly due to influx of extracellular calcium via voltage gated channels known as _______ ____ ____

Back 33

Ltype calcium channels

Front 34

______ receptors in the cardiac SR are opened by the binding of calcium... however, this mechanism is slightly different than that of skeletal muscle

Back 34

ryanodine

Front 35

what happens after cytosolic calcium is elevated in cardiac muscle?

Back 35

thin filament activation
cross bridge cycling
force generation

just like skeletal muscle

Front 36

what does the L in Ltype stand for

Back 36

long lassting current

Front 37

can cardiac muscle undergo tetanic contractions

Back 37

NO!

Front 38

in cardiac muscle the action potential and twitch are both prolonged du to the _____ ______ ______ _____

Back 38

long lasting calcium current

Front 39

why are the L type and lack of tetanic contractions important

Back 39

the heart is an oscillating pump