Slide Set 5 Flashcards

1
Q

3 types of muscles

A
  • skeletal
  • cardiac
  • smooth
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2
Q

Which muscles do we have voluntary control over?

A

Skeletal

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3
Q

Structure of skeletal muscle

A

multinucleated
striations
large muscle fibers

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4
Q

a flexor-extensor pair of muscle is called:

A

antagonist muscle group

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5
Q

Which tissue is present in skeletal muscles

A

connective tissue

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6
Q

Connective tissue components

A
  • epimysium : covers the muscle as a whole
  • perimysium : binds fascicles together and is wrapped around it
  • endomysium : covers skeletal muscle fibers
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7
Q

Unique structure of skeletal muscle cell is due to :

A
  • T tubules : allow electrical signals traveling along sarcolemma to move deeper in cell
  • The triad : formed from a triplet of tubules, made of the sarcoplasmic reticulum, allows signal traveling along T tubule
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8
Q

What is the contractile unit of muscle fibres

A

the sarcomere

= segment of myofibril between 2 successive Z lines

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9
Q

what gives skeletal muscle its striations?

A

The A and Z bands of the sarcomere

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10
Q

Muscle fibers -> __ -> myofilaments

A

myofibrils

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11
Q

Myofilaments are made up of 4 different proteins

A

Myosin : thick filaments
Actin
Tropomyosin
Troponin

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12
Q

Thin filaments attach to

A

both Z lines of a sarcomere

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13
Q

What are the regulatory proteins

A
  • nebulin : helps align actin

- titin : provide elasticity, stabilise mysosin

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14
Q

Globular protein that forms 2 fibrous strands that twist around each other to form bulk of thin filament is

A

actin

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15
Q

What are 2 phases leading to muscle fibre contraction

A

Phase 1 : motor neuron stimulates muscle fiber

Phase 2 : excitation-contraction coupling occurs

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16
Q

In neuromuscular junctions, motor neurons connect to sarcolemma at __

A

motor endplate

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17
Q

Neuromuscular junction

A

= synapse where neurotransmitter molecules transmits signals, motor neuron is in contact with muscle fiber

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18
Q

Which neurotransmitter is released by a motor neuron when it binds with receptors of muscle fiber

A

acetylcholine

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19
Q

Mechanism of contraction

A
  • fiber stimulated by motor neuron releasing ACH
  • electrical impulse travels from sarcolemma down the T tubule where voltage change triggers opening of the voltage gated calcium channels
  • allows passive diffusion of calcium out of the SR -> triggers contraction process
20
Q

What initiates a muscle action potential?

A

The net entry of SODIUM through ACH receptor-channel

21
Q

Can muscles store ATP?

A

very little

22
Q

Muscles store __ used to make ATP on __

A

phosphate

creatine

23
Q

A sprinter would have which kind of fibres?

A

Fast-twitch glycolytic fibres (work anaerobically)

24
Q

what are the types of skeletal muscle fibres?

A

Slow-twitch

Fast twitch : oxidative-glycolytic fibres and glycolytic fibres

25
Q

Why are slow twitch fibres darker?

A

due to myoglobin

26
Q

Cardiac muscle fibers are different to skeletal muscle fibres in that :

A
  • they have intercalated disks
  • branched fibres
  • retain calcium in the SR longer, longer contraction
27
Q

Smooth muscle

A
  • small, tapered cells, single nuclei
  • no T tubules
  • loosely organized SR
  • calcium finds to CALMODULIN
  • no stations (still has thick & thin filaments)
28
Q

Types of smooth muscle tissue

A
  • single unit

- multiunit

29
Q

Difference between the types of smooth muscle

A

single unit : have gap junctions, many cells contract as a unit
multi unit : doesn’t act as a single unit, each fiber responds to 1 nervous input

30
Q

Each cell is individually enervated

A

= multi unit smooth muscle tissue

31
Q

Smooth muscle contraction is

A

slower and longer

32
Q

6 groups with smooth muscle

A
vascular
gastrointestinal
urinary
respiratory
reproductive
eye
33
Q

What controls smooth muscle

A
  • hormones
  • paracrines
  • neurotransmitters
34
Q

Where is the heart found?

A

in mediastinum

35
Q

2 circuits in heart

A

pulmonary (low pressure, low resistance)

systemic (high pressure, high resistance)

36
Q

Veins

A

carry blood to heart

37
Q

Arteries

A

carry blood away

38
Q

Heart is composed mostly of

A

myocardium

39
Q

Which 2 factors influence arterial blood pressure by peripheral resistance ?

A
  • blood viscosity

- diameter of arterioles

40
Q

What are the 4 different valves

A
  • 2 AV valves= atrioventricular valves (R&L)

- pulmonary and artery semilunar valves

41
Q

Which valves prevent back flow from left and right atria

A

AV valves

thanks to chord tendinae

42
Q

Which valves prevents back flow of blood

A

semilunar valves

43
Q

__ cells receive signal from __ cells in the hear

A

Contractile; autorhythmic

44
Q

5 major structures compose the conduction system of the heart

A
  • Sinoatrial node
  • Atrioventricular node
  • AV bundle (bundle of HIs)
  • Right & Left bundle branches
  • Purkinje system
45
Q

What is the heart’s pacemaker?

A

the SA node

46
Q

what can be overexcited due to lack of sleep, caffeine, excess nicotine? This causes a higher depolarisation

A

Purkinje fibers

-> ectopic focus

47
Q

What is an indicator of heart damage

A

cardiac troponins