Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

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
Nociceptors can detect changes in occlusal morphology. True or False
True
26
Types of proprioceptors
1. Muscle spindles 2. Golgi tendon organs 3. Periodontal mechanoreceptors 4. Pacini corpuscles
27
How many receptors do our teeth have?
2 receptors: proprioceptors and nociceptors
28
An example where both the proprioceptors and nociceptors are activated
Biting on something hard (both receptors make us stop the biting)
29
What type of receptors would we be pressuring if we push back hard on our mandible?
Our proprioceptors
30
Where can we find muscle spindles?
Inside the muscle belly, embedded in extrafusal muscle fibres
31
Muscle spindles are composed of _____ muscle fibres
Intrafusal
32
What sensitive receptors detect changes in muscle length?
Muscle spindles
33
Where does the order of motor response come from?
The trigeminal motor nucleus
34
"Muscle spindles participate in the myotatic reflex". What myotatic reflex specifically?
The maintenance of muscle tone
35
What type of proprioceptors can we find in the tendons of skeletal muscles?
Golgi tendon organs
36
What are Golgi tendon organs?
They are compounds of tendon fibres surrounded by lymphatic spaces wrapped in a fibrous layer
37
What do Golgi tendon organs report?
Changes in pressure
38
What happens when we stimulate the Golgi tendon organs?
They stretch tendon/muscle contraction
39
What sensitive receptors have an inhibitory response of muscle contraction being a protective character and avoiding muscle strain?
Golgi tendon organs
40
Role of periodontal mechanoreceptors
- 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
Masticatory forces are controlled because of which sensitive receptors?
Periodontal mechanoreceptors
42
Where are the pacini corpuscles?
In the TMJ
43
What sensitive receptors have a connective tissue capsule and a core which contains a nerve fibre termination in their centre?
Pacini corpuscles
44
Role of pacini corpuscles
- They respond to rapid vibrations and deep mechanical pressure - They are responsible for the perception of joint movement and intense pressure
45
Do reflexes receive influence from the cortex or the stem?
No
46
Pathway of a response to a stimulus:
Neuron A --> Dorsal nerve root/cranial equivalent (trigeminus) --> Neuron E --> Skeletal muscle
47
What is the myotatic reflex triggered by?
A muscle passive stretch
48
What kind of sensitive receptor does the myotatic reflex stimulate?
The muscle spindles
49
What is a myotatic reflex?
It is a reflex action that protects from a sudden stretch
50
What via does the myotatic reflex uses?
The monosynaptic via
51
Role of the myotatic reflexes
- 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
"Teeth's non-contact protection against hard objects" What are we talking about?
The nociceptive reflex
53
Role of nociceptive reflex
- It relaxes elevator muscles - Contraction of depressors muscles - It opens the mouth and avoids teeth contact by protective reflex
54
Periodontal receptors perceive a painful stimulus during the nociceptive reflex. True or False
True
55
What kind of receptors are activated during the tactile reflex?
Periodontal and muscle receptors
56
What happened during the tactile reflex?
The CNS recognises the force that will be applied to chewing different types of food (hard or soft)
57
What are the phases of mastication
1. Opening 2. Closing: a. Flattening b. Trituration
58
"Mandible up to a 15-18mm distance from maximum intercuspation" What phase of mastication are we talking about?
Opening
59
What happens during trituration?
- Few contacts --> fragmentation of alimentary bolus --> increase of contacts - Side movements (inclined cusp planes) - Simple MI position
60
What happens during flattening?
- Mandible 3mm from MI - Lateral movement displacements of 3-4 mm
61
What is deglutition?
It is a series of muscular contractions that move the bolus from the oral cavity to the stomach
62
What happens during deglutition?
- Closed lips and teeth at MI - Condyles are in CR - Alimentary bolus at the back of the tongue
63
Phases of deglutition
1. Voluntary 2. Pharyngeal 3. Reflex or Somatic
64
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. 3 B. 1 C. 2
65
What happens during the voluntary phase?
Bolus formation
66
What happens during the pharyngeal phase?
- The soft palate closes the nasal fossa - The epiglottis closes the trachea and occludes the oropharyngeal airway
67
What happens during the somatic phase?
- The cardia is opened - The bolus enters the stomach
68
What happens in the somatic phase if the patient does not have teeth?
No teeth --> visceral --> tongue moves forward to seal
69
What happens during phonation?
- Contraction/Relaxation of vocal cords creating sounds - Form adopted by the mouth --> resonance and articulation
70
Pathway of phonation
Air --> lungs --> diaphragm
71
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
1. D 2. C 3. F 4. B 5. A 6. E
72
When we are speaking there is no teeth contact. True or False
True
73
What happens when there is teeth malposition (regarding the articulation of sounds)?
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.
© 2025 Bold Learning Solutions. Terms and Conditions