Exam 2 Flashcards
Name the five general senses
Seeing, hearing, smelling, tasting, touching
What is the feedforward control system?
Type of control system that anticipates and compensates for disturbances affecting the system
What is the feedback control system?
A control mechanism that uses information from measurements to manipulate a variable to achieve the desired result
What is the Theory of Feedback Control?
When sensory signals detect deviation from the desired state during movement, feedback control comes into play.
What are the six steps to optimal feedback control?
- Brain sends out command, 2. Movement, 3. Detect error (sensory feedback), 4. compared to original ‘out’ signal, 5. Make changes in position, velocity, or force, and 6. Repat task with improved performance
Sensory information from the trunk and limbs is relayed through where?
the spinal cord
From the spinal cord, where does sensory information go to?
the brain or back to muscle
Specifically, what part of the spinal cord receives sensory information?
the dorsal horns of the spinal cord
Specifically, what part of the spinal cord outputs motor information?
the ventral horn of the spinal cord
What are the parts of the Short-Latency Reflex (SLR)?
Limb (muscle), spinal cord, and the limb (muscle)
What are the parts of the Long-Latency Reflex (LLR)?
Limb (muscle), spinal cord, brain, spinal cord, and limb (muscle)
What makes a reflex complex?
It is voluntary and decision-based, it occurs 50-100 ms after event, and persistently mutable
What makes a reflex simple?
It is faster, 20-50 ms after event, and somewhat mutable
What does decussation in the spinal cord mean?
It signifies crossing over. Most tracts decussate in the spinal cord just before they synapse with lower motor neurons.
What sensations travel through the medial lemniscal tract?
Fine touch and proprioception
What sensations travel through the anterolateral tract?
Coarse touch, pain, and temperature
What sensation travels through the gracile nucleus?
touch and proprioception for the lower body
What sensation travels through the cuneate nucleus?
touch and proprioception for the upper body
Sensory information is relayed through the _______ to the _____________ cortex.
thalamus, somatosensory
What are the four maps in the somatosensory cortex?
area 1- texture, area 2- size and shape, area 3a- proprioceptive, and area 3b- touch
Why do the index finger and face occupy such large portions of the sensory map?
they have a higher sensitivity due to denser concentration of sensory receptors
What is a dorsal root ganglion neuron?
these neurons play a crucial role in transmitting sensory impulses from the peripheral nervous system to the central nervous system
How many different muscle nerves are there?
four
Describe muscle nerve type Ia
large receptor: primary spindle endings, sensitive to: muscle length and rate of change of length
Describe muscle nerve type Ib
large receptor: golgi tendon organs, sensitive to: muscle tension
Describe muscle nerve type II secondary spindle endings
medium receptor, sensitive to muscle length with little rate sensitivity
Describe muscle nerve type II nonspindle endings
medium receptor, sensitive to deep pressure
Describe muscle nerve type III
small receptor: free nerve endings, sensitive to: pain, chemical stimuli, and temperature
Describe muscle nerve type IV
small UNMYELINATED receptor: free nerve endings, sensitive to: pain, chemical stimuli, and temperature
What are the largest sensory afferent in the body?
Ia afferents
Group Ia and II afferent carry information from where?
Muscle spindles
Muscle spindles detect what?
Changes in muscle length (stretch reflexes)
How does muscle spindles lie with extrafusal muscle fibers?
In-parallel
What fibers detect dynamic changes in length?
Dynamic nuclear bag fibers (Ia)
What fibers detect sustained stretch?
Static nuclear bag fiber (Ia, II), and nuclear chain fiber (Ia, II)
What kind of connection do Ia and II afferents make in the spinal cord?
monosynaptic
Describe a monosynaptic connection and give an example of an afferent receptor that uses it
The sensory neuron directly synapses directly onto the motor neuron in the spinal cord. Ia and II afferents use it.
How does an alpha motor neuron differ from a gamma motor neuron?
Alpha motor neurons innervate skeletal muscles as the largest neurons in the CNS. Gamma motor neurons innervate spindle organs of the muscle.
Define proprioception
Status of the body internally, or where various parts are in space and in relation to one another
What is joint position sense?
The ability of a person to perceive a presented joint angle, and then after the limb is moved, actively or passively move the joint to reproduce the same angle