Chapter 13 Flashcards
Neural Pathways
What are the 4 ways to classify neural pathways?
- By the efferent division that controls the response (somatic v. autonomic)
- By the CNS location where the reflex is integrated (spinal v. cranial reflexes)
- Innate or learned (conditioned) reflex
- By the number of neurons in the reflex pathway (monosynaptic or polysynaptic
What is monosynaptic?
2 neurons with 1 Ganglia (i think this is what it is??)
(one sensory and one motor neuron)
What is polysynaptic?
3 neurons with 2 ganglia (i think this is what it is??)
- ALL cranial reflexes are polysynaptic (the three levels of neurons in the brain)
Figure 13.1c
What are autonomic reflexes? What is another name for them?
- AKA visceral reflexes
- Some are spinal reflexes with brain modulation
- Some are integrated in the brain
- Polysynaptic
Figure 13.1a
What are muscle spindles?
- stretch receptors
- encode signals about muscle length and changes in muscle length
What are sensory receptors in the skeletal muscle reflexes called? Where are they located?
- called proprioceptors
- located in skeletal muscle, joint capsules, and ligaments
Where do proprioceptors send signals to?
Input signals from proprioceptors go to t he CNS through sensory neurons
Look at slide 13 for the skeletal muscle reflex
What are the effectors in the skeletal muscle reflex?
contractile skeletal muscle fibers
- AKA extrafusal muscle fibers
What is the stretch reflex?
a contraction response to the muscle stretch
What is the muscle stretch reflex?
- load added to muscle
- muscle and muscle spindles stretch as arm extends (muscle spindle afferent fire more frequently)
- Reflex contraction initiated by muscle stretch restores arm position and prevents damage from over-stretching
figure 13.5
What is a myotatic unit?What type and describe its stretch reflex?
- collection of pathways controlling a single joint
- Monosynaptic stretch reflex involves only 2 neurons (seonsry neuron from spindle somatic motor neuron to muscle — patellar tendon reflex)
What is reciprical inhibition?
antagonist ic muscles must relax as the prime mover muscles contract (polysynaptic)
What does the flexion reflex accomplish?
- pulls limbs away from painful stimuli (nociceptors)
- polysynaptic
- associated with crossed extensor reflexes
Figure 13.6
What is the role of the spinal cord?
spinal reflexes, locomotor pattern generators
What is the role of the brain stem?
posture, hand and eye mvoements
What is the role of the motor areas of the cerebral cortex?
planning and coordinating complex movement
What is the role of the cerebellum?
Monitors output signals from motor areas and adjusts movements
What is the role thalamus?
Contains relay nuclei that modulate and pass messages to cerebral cortex
What is the role of the basal anglia?
motor planning
figure 13.7
What are the 3 levels of nervous system control?
- spinal cord (integrates spinal reflexes, contains central pattern generators)
- Brain stem and cerebellum (postural reflexes and eye/hand movements)
- Cerebral cortex and basal ganglia (voluntary movements)
What is the corticospinal tract?
neurons from motor cortex to spinal cord
What does smooth and cardiac muscle control movement?
hormones or autonomic division of nervous system
