Brainscape's Knowledge GenomeTM

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


See full index

Medicine Year 1 - Semester 2 - Part 1 > Structure of Skeletal, Cardiac and Smooth Muscle > Flashcards

Structure of Skeletal, Cardiac and Smooth Muscle Flashcards

1
Q

What enables body movement ?

A

Skeletal muscle contraction

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

What enables body posture ?

A

Continual adjustments of skeletal muscles

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

What enables support and protection ?

A

Skeletal muscles

e.g. surrounding joints and within the abdominal wall

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

What enables sphincter control ?

A

Skeletal and Smooth muscle - cardiac sphincter in stomach; bladder; anus

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

What enables movement of food along the GIT ?

A

Smooth muscle generates peristalsis

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

What enables regulation of blood flow ?

A

Cardiac muscle pumps blood
Smooth muscle in vessel walls regulate blood flow

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

What enables temperature regulation ?

A

Skeletal muscle - shivering
Smooth muscle - erection of hairs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Name the 4 characteristics of ALL muscle

A

Excitability
Contractility
Extensibility
Elasticity

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

What is meant by excitability ?

A

Responsive to stimuli

i.e. a chemical signal such as a neurotransmitter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is meant by contractility ?

A

Ability to shorten forcibly when adequately stimulated

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

Concentric contraction

A

Muscle shortens

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

Eccentric contraction

A

Muscle is stretched

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

Isometric contraction

A

Muscle contracts but does not shorten

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

What is meant by extensibility ?

A

Can extend beyond their resting/relaxed length

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

What is meant by elasticity ?

A

Recoil and resume its resting length after stretching

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

State the common features of all muscle

A

Actin and myosin
Use of ATP
Calcium ions
Stimulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Function of actin and myosin

A

Generate force for contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How is ATP generated ?

A

generated via respiration

  • Aerobic oxidative respiration
  • Anaerobic glycolytic respiration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Function of calcium ions

A

Needed for activation of contraction

20
Q

Function of stimulation

A

Need an action potential from a neuron

21
Q

What % of muscle protein does actin and myosin make up ?

A

around 90%

22
Q

What are actin and myosin ?

A

They are both enzymes :

ATPases - hydrolyse ATP –> ADP + Pi

23
Q

Describe some muscle cell components

A

Cell membrane - sacrolemma
Cytoplasm - sacroplasm
Nuclei, organelles …

Full of myofibrils - actin/myosin

Many mitochondria
Extensive sarcoplasmic reticulum

24
Q

Function of transverse T tubules

A

Brings action potentials into interior of muscle fibre

25
Q

Briefly describe skeletal muscle

A

640 muscles : 40% of body mass

Attached to the skeleton via tendons

Voluntary and reflexive control
Sporadic and continual contraction

26
Q

Describe skeletal muscle cells

A

Large multinucleate cells (100micrometres - 60mm)

27
Q

State the 3 layers that form the tendons

A

Epimysium - outer
Perimysium - middle
Endomysium - innermost

28
Q

What in the function of the 3 layers ?

A

They are connective tissue which covers and supports muscle.

Maintains structural integrity

29
Q

Myocyte

A

A single muscle cell, containing myofilaments

30
Q

Myofilament

A

Contractile units called SARCOMERES

31
Q

What are myofilaments composed of ?

A

Actin and Myosin

32
Q

Fasicle

A

Grouping of elongated bundles of muscle fibres (cells)

33
Q

Endomysium

A

Separates the muscle fibres

34
Q

Perimysium

A

Loose collagenous connective tissue that surrounds fascicles

35
Q

Epimysium

A

Dense collagenous sheath that surrounds gross muscle.

36
Q

Briefly describe cardiac muscle

A

Can contract without stimulation - auto-rhythmic

Involuntary muscle : ANS

Branched cells

37
Q

Describe cardiomyocytes

A
  • Striated
  • Small
  • Uni or Bi-nucleated
  • Large number of mitochondria (25-30% of cell volume)
  • Aerobic respiration : can use multiple fuel sources
  • Intercalated discs : gap junctions / desmosomes
38
Q

What are GAP junctions ?

A

They are formed by connexions - 6 subunits/channel

Sites of low electrical resistance

They electrically connect cells

39
Q

Function of GAP junctions in cardiac muscle

A

Electrically links cardiomyocytes - allows diffusion of ions

Cells of the myocardium contract as a unit (ALL or nothing)

40
Q

State the 7 places where smooth muscle is found

A

Blood vessels
Digestive tract
Bladder wall / urinary tract
Respiratory tract
Reproductive tract
Eyes
Skin

41
Q

Briefly describe smooth muscle cells

A

Small - 100-200 micrometers in length

Spindle shaped cells arranged into sheets
Less regularly organised

NO striations
Single nucleus

Involuntary - ANS, hormones and stretch

42
Q

Describe the structural organisation of smooth muscle

A

Longitudinal and Circular layer

43
Q

Difference between smooth muscle and cardiac/ skeletal muscle

A

Smooth muscle has a slower contraction rate and a longer duration than cardiac or skeletal muscle.

44
Q

Describe actin and myosin in smooth muscle

A

Actin and myosin anchored via dense bodies throughout the sarcoplasm.

Focal adhesions structurally connect cells

45
Q

Summary of skeletal muscle

A

Size - LARGE ( up to 60cm)
Shape - Regular parallel myofibres
Striations - Yes
Nuclear content - Multinucleated
Intercalated discs - NO
Gap junctions - NO
Control - Voluntary (via motor neurons and reflexive)
Metabolism - Aerobic and anaerobic

46
Q

Summary of cardiac muscle

A

Size - Small (50-100 micrometers)
Shape - Branched
Striations - Yes
Nuclear content - 1/2 nuclei
Intercalated discs - Yes
Gap junctions - Yes
Control - Involuntary (via AND hormones and stretch)
Metabolism - Aerobic

47
Q

Summary of smooth muscle

A

Size - Small (30-200 micrometers)
Shape - Spindle
Striations - No
Nuclear content - single nuclei
Intercalated discs - No
Gap junctions - Yes
Control - Involuntary (via AND hormones, local chemicals and stretch)
Metabolism - Mainly aerobic

Medicine Year 1 - Semester 2 - Part 1 (51 decks)

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