Brainscape's Knowledge GenomeTM

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


See full index

Prosthesis > Chapter 3: Neuromuscular System Function > Flashcards

Chapter 3: Neuromuscular System Function Flashcards

1
Q

What is a motor unit?

A
  • A motor unit is what transmits nerve impulses to make muscle fibres contract or shorten
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

“They conduct impulses from the brain and the spinal cord to the effectors which are the muscles”. What are we talking about?

A

Motor units

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

Motor units are constituted by:

A
  • Postsynaptic motor neuron button at the neuromuscular junction (motor endplate)
  • All extrafusal fibres to which it stimulates
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The smaller the group of muscle fibres innervated, the _____ _____ will the movement be

A

More accurate

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

What is the function of the motor unit?

A

Muscle contraction or shortening by depolarisation of muscle fibres

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

What are muscles formed of?

A
  • Hundreds of thousands of motor units
  • Vessels
    Nerves
  • Joined by a bundle of connective tissue and fascia that surrounds them
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Our muscle spindles control our ______ , so they control our ______

A

VDR; Reflexes

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

What happens during the isotonic contraction?

A
  • The fibres are shortened, and the length may vary
  • The same muscle tone is maintained
  • There is contraction under a constant load
  • Physiological contraction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Example of an isotonic contraction

A

Masseter during mastication

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

What is an isometric contraction?

A
  • It is a muscle contraction without shortening
  • It maintains the same length, but the tone is increased
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Does the isometric contraction have a positive effect on the muscle?

A

No, this contraction is not good for the muscle because it produces an accumulation of catabolites

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

Example of an isometric contraction

A

Masseter when clenching, like in bruxism

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

What is the controlled relaxation?

A

It is a stop of nerve stimulation in the muscle. The muscle is in its resting tone and has its normal length.

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

All muscles have some type of innervation, it can be either sensitive or motor. True or False

A

True

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

Motor afferent neurons detect pain. True or False

A

False, sensitive afferent neurons detect pain

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

What teeth have a lot of proprioception and oversee lateral movements?

A

Canines

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

The CNS receives and processes information and generates a motor response. True or False

A

True

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

Reflexes have to go through the CNS. True or False

A

False, reflexes does not go through the CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Match the letters with the numbers:

A. Sensitive afferent neurons
B. Motor efferent neurons

  1. CNS –> Muscle
  2. Muscle –> CNS
  3. Muscle tone, pain, proprioceptive information
A
  1. B
  2. A
  3. A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does the trigeminal motor nucleus supply?

A

The masticatory muscles and the accessory muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the sensitive receptors?

A

They are neurologic structures situated in the tissues that provide information to the CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Examples of sensitive receptors

A
  1. Nociceptors
  2. Proprioceptors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What do proprioceptors report to the CNS?

A

Position and jaw movements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the function of the nociceptors?

A

To detect pain, nociceptors are specific to discomfort or pain at any injury (mechanical, thermal etc)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Nociceptors can detect changes in occlusal morphology. True or False

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Types of proprioceptors

A
  1. Muscle spindles
  2. Golgi tendon organs
  3. Periodontal mechanoreceptors
  4. Pacini corpuscles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

How many receptors do our teeth have?

A

2 receptors: proprioceptors and nociceptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

An example where both the proprioceptors and nociceptors are activated

A

Biting on something hard (both receptors make us stop the biting)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What type of receptors would we be pressuring if we push back hard on our mandible?

A

Our proprioceptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Where can we find muscle spindles?

A

Inside the muscle belly, embedded in extrafusal muscle fibres

31
Q

Muscle spindles are composed of _____ muscle fibres

A

Intrafusal

32
Q

What sensitive receptors detect changes in muscle length?

A

Muscle spindles

33
Q

Where does the order of motor response come from?

A

The trigeminal motor nucleus

34
Q

“Muscle spindles participate in the myotatic reflex”. What myotatic reflex specifically?

A

The maintenance of muscle tone

35
Q

What type of proprioceptors can we find in the tendons of skeletal muscles?

A

Golgi tendon organs

36
Q

What are Golgi tendon organs?

A

They are compounds of tendon fibres surrounded by lymphatic spaces wrapped in a fibrous layer

37
Q

What do Golgi tendon organs report?

A

Changes in pressure

38
Q

What happens when we stimulate the Golgi tendon organs?

A

They stretch tendon/muscle contraction

39
Q

What sensitive receptors have an inhibitory response of muscle contraction being a protective character and avoiding muscle strain?

A

Golgi tendon organs

40
Q

Role of periodontal mechanoreceptors

A
  • They respond to occlusal forces that occur during teeth contacts
  • They influence the dynamics of mandibular control
  • They can detect changes in the occlusal morphology
  • They cause reflexes arc adaptation to avoid undesirable contacts (in occlusion)
  • Useful to avoid craniomandibular dysfunction
41
Q

Masticatory forces are controlled because of which sensitive receptors?

A

Periodontal mechanoreceptors

42
Q

Where are the pacini corpuscles?

A

In the TMJ

43
Q

What sensitive receptors have a connective tissue capsule and a core which contains a nerve fibre termination in their centre?

A

Pacini corpuscles

44
Q

Role of pacini corpuscles

A
  • They respond to rapid vibrations and deep mechanical pressure
  • They are responsible for the perception of joint movement and intense pressure
45
Q

Do reflexes receive influence from the cortex or the stem?

A

No

46
Q

Pathway of a response to a stimulus:

A

Neuron A –> Dorsal nerve root/cranial equivalent (trigeminus) –> Neuron E –> Skeletal muscle

47
Q

What is the myotatic reflex triggered by?

A

A muscle passive stretch

48
Q

What kind of sensitive receptor does the myotatic reflex stimulate?

A

The muscle spindles

49
Q

What is a myotatic reflex?

A

It is a reflex action that protects from a sudden stretch

50
Q

What via does the myotatic reflex uses?

A

The monosynaptic via

51
Q

Role of the myotatic reflexes

A
  • It prevents luxation (dislocation)
  • It is responsible for the state of small permanent contraction in the elevator muscles to counteract the force of gravity
52
Q

“Teeth’s non-contact protection against hard objects” What are we talking about?

A

The nociceptive reflex

53
Q

Role of nociceptive reflex

A
  • It relaxes elevator muscles
  • Contraction of depressors muscles
  • It opens the mouth and avoids teeth contact by protective reflex
54
Q

Periodontal receptors perceive a painful stimulus during the nociceptive reflex. True or False

A

True

55
Q

What kind of receptors are activated during the tactile reflex?

A

Periodontal and muscle receptors

56
Q

What happened during the tactile reflex?

A

The CNS recognises the force that will be applied to chewing different types of food (hard or soft)

57
Q

What are the phases of mastication

A
  1. Opening
  2. Closing:
    a. Flattening
    b. Trituration
58
Q

“Mandible up to a 15-18mm distance from maximum intercuspation” What phase of mastication are we talking about?

A

Opening

59
Q

What happens during trituration?

A
  • Few contacts –> fragmentation of alimentary bolus –> increase of contacts
  • Side movements (inclined cusp planes)
  • Simple MI position
60
Q

What happens during flattening?

A
  • Mandible 3mm from MI
  • Lateral movement displacements of 3-4 mm
61
Q

What is deglutition?

A

It is a series of muscular contractions that move the bolus from the oral cavity to the stomach

62
Q

What happens during deglutition?

A
  • Closed lips and teeth at MI
  • Condyles are in CR
  • Alimentary bolus at the back of the tongue
63
Q

Phases of deglutition

A
  1. Voluntary
  2. Pharyngeal
  3. Reflex or Somatic
64
Q

Match the letter with the number:

A. Voluntary
B. Pharyngeal
C. Reflex or Somatic

  1. Pharynx –> Oesophagus
  2. Cardia is opened –> Stomach
  3. Tongue –> Pharynx
A

A. 3
B. 1
C. 2

65
Q

What happens during the voluntary phase?

A

Bolus formation

66
Q

What happens during the pharyngeal phase?

A
  • The soft palate closes the nasal fossa
  • The epiglottis closes the trachea and occludes the oropharyngeal airway
67
Q

What happens during the somatic phase?

A
  • The cardia is opened
  • The bolus enters the stomach
68
Q

What happens in the somatic phase if the patient does not have teeth?

A

No teeth –> visceral –> tongue moves forward to seal

69
Q

What happens during phonation?

A
  • Contraction/Relaxation of vocal cords creating sounds
  • Form adopted by the mouth –> resonance and articulation
70
Q

Pathway of phonation

A

Air –> lungs –> diaphragm

71
Q

Match the letters with the numbers:

  1. Lips
  2. Teeth
  3. Tongue and palate
  4. Tongue and upper incisor
  5. Lower lip and upper incisor
  6. Tongue and soft palate

A. F and V
B. Z
C. S
D. M, B, P
E. K and G
F. D

A
  1. D
  2. C
  3. F
  4. B
  5. A
  6. E
72
Q

When we are speaking there is no teeth contact. True or False

A

True

73
Q

What happens when there is teeth malposition (regarding the articulation of sounds)?

A

Sensitive stimuli –> CNS –> Alteration in patterns of phonation

A new pattern is created –> Unconsciously –> Learnt reflex

Prosthesis (9 decks)

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