Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Muscles > Smooth muscle > Flashcards

Smooth muscle Flashcards

1
Q

What is muscular tissue derived from

A

Mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is muscular tissue composed of

A

Cells (multinucleate syncytia) whose cytoplasm contains filaments made of proteins (actin, myosin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

DO smooth muscles have striations

A

no

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is smooth muscle supported by and contains?

A

Connective tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is smooth muscle structurally organized as

A

sheets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Examples of single sheeted muscles

A

Arterioles and airways

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are single sheeted muscles orientated like

-what does it do

A

Circularly orientated

  • tonically maintains vessel diameter and pressure
  • vary diameter and so control flow and pressure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Examples of multiple sheeted muscles

A

Ileum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are multiple sheeted muscles orientated like?

  • What do they do
  • Why do they have two layers
A

Two sheets perpendicular to each other

  • longitudinal and circular layers
  • vary diameter and length (peristalsis)
  • Have two layers so they can move things along
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Difference between smooth muscle and skm

A

SM often associated with other tissue types e.g. secretory epithelia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the types of smooth muscle

A

Single unit

Multi unit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are single unit muscles like

A

All cells are ‘touching’ as they have gap junctions to allow action potentials to travel between cells so all the muscle works as a single unit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What do varicosities do

A

Interact with cells as they release neurotransmitters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are multiunit muscles like

A

Cells don’t communicate with each other (allows for finer control)
-Each unit has to be stimulated separately

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What do single unit smooth muscle behave as

A

Functional syncitium (have gap junctions)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Difference between Multiunit muscles and single unit

A

Single unit- myogenic

Multi unit- neurogenic

17
Q

Why is smooth muscle needed instead of skeletal muscle sometimes

A

There is a stretch-relaxation response of single-unit smooth muscle.
-SMOOTH MUSCLE HAS CONNECTIVE TISSUE WHICH PREVENTS OVER-STRETCHING UNLIKE SKELETAL MUSCLE WHICH IS ELASTIC

18
Q

What is unique to smooth muscle

A

Stretch-relaxation response (e.g. in bladder)

19
Q

Which inorganic ion is responsible for the contraction of smooth muscle?
-How does it come into cell

A

Ca2+

-via voltage gated ca2+ channels

20
Q

What does noradrenaline bind to and where is this found?

A

Alpha1 adrenoceptors on vascular smooth muscle contraction

21
Q

What does acetylcholine bind to and where is this found?

A

Muscarinic receptors found on bladder smooth muscle contraction

22
Q

What happens when noradrenaline binds to adrenoceptor

A

1) Increase in activity of G protein
2) Release of inositol triphosphate (IP3)
3) Interacts with receptor in sarcoplasmic reticulum which releases Ca2+

23
Q

What happens when acetylcholine binds to muscarinic receptor

A

1) Increase in activity of G protein
2) Release of inositol triphosphate (IP3)
3) Interacts with receptor in sarcoplasmic reticulum which releases Ca2+

24
Q

What causes the increase in activity of G protein

A

Binding of acetylcholine/noradrenaline to metabotropic receptors

25
Q

What does Ca2+ bind to in smooth muscle

A

calmodulin

26
Q

What is the contraction by sliding filament theory in smooth muscle

A

1) Ca2+ binds to calmodulin
2) Ca2+-calmodulin activates enzyme Myosin Light Chain Kinase (MLCK)
3) MLCK phosphorylates Myosin Light Chain (MLC)
4) Actin then binds (MLC must be phosphorylated for actin ti bind)

27
Q

What causes a rise in intracellular calcium in smooth muscle

A
  • depolarisation of membrane potential and open voltage sensitive ca2+ channels
  • Release of intracellular calcium
28
Q

What does actin binding to phosphorylated MLC cause

A

contraction

29
Q

How is smooth muscle relaxed

A

Decrease in conc of calcium ions leads to dissociation of Cal from MLCK which means that it is now inactive and incapable of phosphorylating MLC

30
Q

What does Noradrenaline bind to to reduce Ca2+

A

beta-adrenoceptors on bronchial smooth muscle to reduce Ca2+

Muscles (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions