Muscle Module 7

Question 1

Smooth muscle is _______________

Answer 1

not as specialized as skeletal muscle

Question 2

3 key feature of smooth muscle cells

Answer 2

• there is a SR Membrane in smooth muscle
• No T tubules
• No neuromuscular junction

Question 3

Why dont we need T tubules in smooth muscle cells

Answer 3

T tubules conduct depolarization in action potential deep in the cell but smooth muscle cells are small

Question 4

Without neuromuscular junctions what happens to the path of neurotransmitters in cell

Answer 4

neurotransmitters have a larger distance to travel and thus the smooth muscle has a slower response to stimulus

Question 5

Where does the sarcoplasmic reticulum lay in smooth muscle

Answer 5

no myofibrils so it lays at the membrane

Question 6

Skeletal muscle from a teleological perspective.

Answer 6

Designed go produce large force rapidly thus

• contractile units are parallel to each other
• neurtransmitter have a short area of diffusion

Question 7

____________ explains a phenomena in terms of the purpose it serves

Answer 7

teleology

Question 8

Smooth muscle from a teleologic al perspective although the contraction relies on CA2+ cross bridges too contract;

Answer 8

however, the physiological design is very varied to acomidate for various functions

Question 9

Smooth muscle filaments

Answer 9

smooth muscle has thin and thick filaments variable in length

Question 10

________________ is more varied in smooth muscle than skeletal muscle

Answer 10

length and organization of filaments

Question 11

sarcoplasmic reticulum lays at the membrane because

Answer 11

smooth muscle has no myofibrils

Question 12

adjacent demosomes allow the cells to

Answer 12

mechanically connect

Question 13

____________ are specialized structures at the cell membrane that thin filaments attach to. Their function is to allow thin filaments to attach to cell membrane

Answer 13

demosomes

Question 14

dense bodies connect __________________

Answer 14

adjacent thin filaments.

Question 15

dense bodies have a composition similar to _________

Answer 15

Z disks

Question 16

__________ site where two cells are in chemical continuity with one another so small molecules can pass from one smooth muscle cell to another.

Answer 16

Gap junction

Question 17

Gap junctions allow smooth muscle cells to be in

Answer 17

electrochemical continuity

Question 18

Where are smooth muscles typically located

Answer 18

walls of hallow organs, blood vessels, airways, GI system

Question 19

what is the side of an organ that is lined with hallow muscle called

Answer 19

lumen

Question 20

What is the connective tissue laying between the lumen and smooth muscle called

Answer 20

endothelium

Question 21

What are the cl;assifications of smooth muscle based on contraction

Answer 21

• phasic

- tonic

Question 22

______________ are the relatively break and synchronous contractions including the beginning of esophagus

Answer 22

phasic

Question 23

__________ are the relatively slow and prolonged contractions

Answer 23

tonic

Question 24

what are some of the causes for the variability in smooth muscle contraction

Answer 24

• variability in neurotransmitters (stimulatory or inhibitory)
• variability in proximity of neuron
• variability in distribution of receptors for NT
• contractility in endocrine regulated (ex hormones)
• variability in density of voltage gated channels
• variabilty ion cell communications

Question 25

skeletal muscle only has ______________

Answer 25

excitatory neurotransmitters

Question 26

what is one way that makes smooth muscle cell communications unique

Answer 26

Gap Junctions which sharer electrochemical information

Question 27

What is the classification of smooth muscle by organization

Answer 27

1. multiunit | 2. single unit

Question 28

______________ is characterized by - fine control and over contraction - prolongued contraction

Answer 28

multiunit

Question 29

_______________ is characterized by - rythmic contraction - uniform contraction

Answer 29

single unit

Question 30

example multiunit smooth muscle

Answer 30

blood vessels, airways

Question 31

example multiunit smooth muscle

Answer 31

blood vessels, airways | -very fine control of controlling the muscles

Question 32

example single smooth muscle

Answer 32

uterus, intestine | -0rythmic centurion necessisarry to deliver a baby

Question 33

Examples of tonic muscles

Answer 33

- esopophagus sphincter, arteries - maintain finetuning - 0tend to be multiunit

Question 34

examples of phasic muscles

Answer 34

- intestine, uterus - rhythmic, rapid - teend to be single unit

Question 35

________ graded response, no action potential

Answer 35

multiunit smooth muscle allows this to happen

Question 36

why are phasic muscles typically single unit

Answer 36

gap junctions and action potentials

Question 37

_____________ are receptors for neurotransmitter and are less than in skeletal muscle cells

Answer 37

ligand gated channels

Question 38

________________ for circular factors. CLosser to blood vessels where blood is released

Answer 38

ligand gated channel for circulating factors

Question 39

__________ are low in number and some are calcium channels for contraction

Answer 39

voltage gated channels

Question 40

Why aren't action potentials produced by multiunit smooth muscle

Answer 40

low number of voltage gated Ca2++ ions

Question 41

What kind of response are produced by multiunit smooth muscle

Answer 41

a little bit of contraction for a relatively brief period of time in a select # of cells operating independently. Because each cell is independent, we can either get a little contraction or ra lot of contraction

Question 42

Are action potentials produced by single unit smooth muscle

Answer 42

yes because more voltage gated ion channels

Question 43

do single unit smooth m muscle cells have gap junctions

Answer 43

yes gap junctions

Question 44

explain the response of single unit smooth muscle

Answer 44

all or none response. Rapid synchronous, depolarized and contraction