Term
At the myoneural junction, what kind of neurotransmitter is released? What kind of receptor is on the muscle? |
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Definition
Ach Nicotinic (cholinergic) |
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Term
| What are the types of muscle spindles? |
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Definition
1. Static -Measures length (static proprioceptors) 2. Dynamic -Measures rate (dynamic proprioceptors) |
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Term
What are the power producing fibers in muscle? What are the sensory fibers in muscles? |
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Definition
The EXTRAfusal fibers produce the power The INTRAfusal fibers are sensory in muscle spindles |
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Term
| What are the two types of intrafusal muscle fibers? |
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Definition
Intrafusal = sensory muscle fibers Gamma motor neurons (alpha motor for extrafusal m. fibers) Type IA- Nuclear Bag fibers (Nuclei all over) -Have type I sensory neurons Type II- Nuclear chain fiber (Nuclei arranged in row) -Type II sensory neuruons |
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Term
| What types of innervation do intrafusal muscles fibers have? |
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Definition
They have both afferent and efferent innervation. Efferent gamma motor neurons Afferent Nuclear Chain-Type II sensory neurons (Static-Muscle Length) Nuclear bag fibers- Type IA sensory neurons (Dynamic-Velocity of Contraction) |
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Term
| What do Type Ia nuclear bag intrafusal muscle fibers sense? |
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Definition
Type Ia nuclear bag fibers sense velocity of contraction They are DYNAMIC Word association : They are first (I), and dynamic like A1 sauce which you put in a bag. |
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Term
| What do Type II intrafusal muscle fibers sense? |
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Definition
Type II intrafusal muscle fibers sense muscle length. They are a nuclear chain. Word association: Chain gang-slow static (locked down) come in second (II) |
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Term
What is the purpose of gamma motor innervation (gamma bias)? |
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Definition
Gamma motor neurons exist so the muscle spindle fibers can function at ALL muscle lengths. In other words contraction of gamma neurons offset the contraction of alpha neurons...so there is always tension on the Type Ia receptors. In other words, the type Ia receptors never go limp. |
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Term
| How do intrafusal muscle fibers send signals? |
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Definition
intrafusal muscle fibers are (stretch sensitive) mechanoreceptors -They have deformable sodium channels When they are stretched, the sodium channels deform, allowing cations into flux in causing depolarization of the nerve cells. |
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Term
| What is the function of the golgi tendon organ and where is it located? |
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Definition
The GTO senses tension (Force) placed on a muscle. It is located on the tendon between the muscle and the bone. Responsible for the inverse myotatic reflex (stretch reflex) -It is a protective reflex, when something is far too heavy, it protects your muscles from tearing. -Heavy box, biceps and delts are inhibited and triceps are activated...throw box down |
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Term
| What are some types of nociceptors? |
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Definition
Temperature Pain Force/Load Know: Pacinian Corpuscles, free/naked nerve endings, GTOs, muscle fibers, |
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Term
| Explain the nociceptive reflex. |
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Definition
It is a withdrawal reflex 1. Ipsilateral side- flexors are activated and extensors are inhibited 2. Contralateral side- extensors are activated and flexors are inhibited. Example is you step on a tack. -Pain is recieved in foot, leg on that side has withdrawal of ipsilateral leg and stabalization of contralateral leg. |
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Term
| Explain nociceptor reflex in mastication. |
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Definition
When an unexpected danger is presented (hard object) the jaw immidiately stops from closing to prevent damage to teeth. Area rich in PCs Inhibitory signals (IPSPs) sent to muscles of mastication and activating signals sent to digastric for quick opening. |
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Term
| What signals does the brainstem send to alpha motor neurons? |
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Definition
Cordinating signals from cerebellum -pattern movements -writing movements Spinal cord- locomotive control center -basic locomotion is spinal reflex purposeful movement is brainstem/cerebellum -the ability to do what we need to do and when we need to do it is a higher brain function (corticle control). |
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Term
| What is the function of the supplementary motor area? |
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Definition
Mental rehearsal -You are THINKING of moving your finger -Subject is thinking about moving finger but not actually moving finger. Moving finger results in lighting up pre and post central gyri. |
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Term
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Definition
Normal muscle activity resulting from resistance to stretch. -Include contractile activity- modulated Tissue Elasticity |
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Term
| How does stress affect mandibular rest position (freeway space)? |
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Definition
The freeway space is decreased with excess stress! Normally 1.5-3mm (dynamic-changing) |
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Term
| Typically, how many muscle fibers does a single alpha neuron innervate? |
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Definition
Many! In the quadriceps=1000's Index finger=100's Eye=10's |
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Term
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Definition
| Motor neuron and all the muscle fibers it innervates |
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Term
| What are the three muscle fiber types and their advantages/disadvantages? |
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Definition
1. SO- Slow Oxidative (slow twitch) high oxidative capacity, low glycolytic capacity -Long distance muscles 2. FG- Fast Glycolytic (Fast Twitch) -high glycolytic capacity, Low oxidative capacity -Spinter muscles= burn out quick 3. FOG- Fast oxidative glycolytic moderate oxidative cap. & high glycolytic capacity -Hybrid (Super fiber) sprinter and long distance |
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