Lecture 3 Flashcards
(30 cards)
What are the main divisions of the nervous system?
- Central Nervous System (CNS)
- Peripheral Nervous System (PNS)
What does the CNS comprise of?
Brain and spinal cord
Describe:
The Peripheral Nervous System
- Divided in autonomic division and somatic division
- Somatic division carries information to the CNS from proprioceptive structures and from the CNS to muscles
What neurons are involved in somatic nervous system?
Alpha motor neurons
Gamma motor neurons
What relays information to subcortical structure?
Cerebral cortex
What structures relays information to the brain stem?
Subcortical structures
Describe:
The contemporary pathway of information flow
- Cerebral cortex to subcortical structure
- Subcortical structure to brain stem
- Brain stem to spinal cord
True or False:
The cerebral cortex can directly send information to the spinal cord
True, called the latereal corticospinal tract
True or False:
The subcortical structures cannot send information by itself
False, the subcortical structures can also send information by itself without information from cerebral cortex
True or False:
The spinal cord cannot control movement on its own
False, the spinal cord can control movement on its own (e.x. walking, wagging tail)
What was the original concept of movement in the body? Who provided a new concept? How?
- Original concept: Fluids in our body moved and allowed us to move
- Luigi Galvani’s frog leg experiment showed how bioelectrical signals (very small amounts of electricity) controls movements
Define:
Multipolar neurons
A neuron with multiple axon terminals (e.x. Alpha motor neurons)
Define:
Myelin sheath
Insulation of fat that cover the neuron, allows rapid information delivery
What disease results in the degeneration of myelin sheaths?
Multiple Sclerosis (MS)
What are glial cells?
They are the insulation and holds everything together in the brain; however, they are difficult to study
List:
The main functions of glial cells
- Surround and secure neurons in place
- Supply nutrients and oxygen to neurons
- Insulate neurons from one another
- Destroy pathogens
List:
2 types of neurons
- Motor (efferent) neurons
- Sensory (afferent) neurons
Describe:
The function of motor neurons
- Efferent neurons
- Transmits information relating to a movement
- Typically an alpha motor neuron (for sure an efferent neuron)
- Cortical motor neuron (synapses with alpha motor neuron)
Describe:
The function of sensory neurons
- Afferent neurons
- Conveys information from muscle to central nervous sytem (CNS)
What does efferent and afferent mean?
Efferent: Outward, away from CNS
Afferent: Inward, towards CNS
Define:
A motor unit
An alpha motor neuron and all the muscle fibres that it innervates
Describe:
The function of extrafusal muscle fibres
Produces force, cause muscle fiber contracts
Describe:
The function of intrafusal muscle fibres
Monitors for stretch
Relies on proprioception (We know where out limbs are due to this)
What are extrafusal and intrafusal muscle fibres innervated by?
Extrafusal muscle fibres: Alpha motor neurons
Intrafusal muscle fibres: Gamma motor neurons
