Neurophysiology Flashcards
Name the nervous systems
- Central nervous system and peripheral nervous system
- Somatic nervous system and autonomic nervous system
- Sympathetic nervous system and parasympathetic nervous system
What are the specialized cells of the nervous system and what do they do?
Neurons
- rapid transmissions of action potentials
- made up of dendrites, cell body, axon, synaptic terminals
Neuroglial / glial cells:
- form a syncytium (unified cytoplasm of each glial cell)
- cells act as one
- gap junctions provide cell communication
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What are the types of glial cells and what nervous system do the belong to?
CNS: microglia, astrocyte, oligodendrocyte
PNS: Satellite cell. Schwann cell
Which part of a neuron conducts action potentials from the cell body to the intended target?
Axon
What is the purpose of myelin sheaths?
To insulate axons and increase conduction velocity of action potentials
Which division of the autonomic nervous system generally has short preganglionic neurons and long postganglionic neurons?
Both parasympathetic and sympathetic systems have the same neuron length
What is the purpose of the autonomic nervous sytem?
Control involuntary functions of organs and tissues
The pineal gland is located in the:
Epithalamus
Explain dendrites, axon and the cell body
Dendrites:
- PNS function: receive info. and transfer it within neuron
- CNS function: send signals back and forth with other neurons
Cell body: Has nucleus and organelles
Axon: transmit outgoing electrical signal
- convey chemical and electrical signals
What are the nodes of Ranvier?
enable action potentials to jump between nodes which increase saltation
What does the cell body propagate?
Propagates action potential when threshold is reached thanks to the Ca2+ stores
What is axonal transport?
When proteins moved in vesicles down axon. These protein are synthesized in rER in cell body
Explain action potentials
Will only be generated once threshold voltage is reached.
Depolarize the RMP of post synaptic membrane which depolarizes the membrane to -50mV
Explain the refractory period and its two types
Absolute refractory period: voltage gated Na channels are inactive
Relative refractory period: Na channels are close and active and replenishing of Ca2+ storage
What is compound action potential?
Peripheral nerves are generally bundles of nerve axons
Sum of all electrical activity happening in each axons in nerve bundle
What does the central nervous system consist of?
Brain and spinal cord
Afferent sensory information (info. from senses) and providing efferent response (signal/response command)
What is the brain composed of?
Brainstem, cerebellum, diencephalon and cerebrum
Describe the parts of the brainstem
Medulla oblongata: runs continuous with spinal cord
- motor and sensory nuclei for throat, mouth, neck (sensory nuclei: respiratory and cardiovascular control)
The pons: continuous with medulla and contains nuclei responsible for respiratory system
Midbrain: continuous with pons below and diencephalon above
Explain the cerebellum
Attached to brainstem and concerned with rate, range and direction of movement
What is the diencephalon comprised of?
Thalamus:
-relay afferent info. to ipsilateral cerebral cortex
- sleep and wakefulness
Subthalamus
Hypothalamus: regulates autonomic functions
- blood pressure
- heart rate
- body temp.
- control hormone from hypophysis (pituitary)
- regulate intake of food
What is the cerebrum?
Contains specialized areas: motor cortex, somatosensory cortex, visual cortex, auditory cortex
What is the spinal cord composed of?
Dorsal and ventral roots protruding from both sides
Dorsal roots carry afferent signals; ventral roots carry efferent signals
What are the most important cranial nerves?
IX: glossopharyngeal
X: Vagus
Explain the peripheral nervous system
Sensory pathways start with receptors.
Transduction process leads to an electrical response in the primary afferent called receptor potential
What is the receptor potential?
Triggers action potential: contain information about sensory stimulus conveyed to the CNS via primary afferent
Explain the somatic nervous system
Contains all peripheral pathways which control skeletal muscle and responsible for communicating with the environment
What are types of fibers and their explanations?
Fibers type a: motor neuron - large myelinated sheath
Fiber type b: small, no myelination - pain
What is the autonomic nervous system?
Involuntary control of vast majority of organs with exception of motor control of skeletal muscle
What are the two sub types to the autonomic nervous system?
Sympathetic nervous system
Parasympathetic nervous system
Which are the main characteristics of sympathetic and parasympathetic nervous systems?
Sympathetic:
- generally has short preganglionic neurons and long postganglionic neurons
Parasympathetic:
- possess long preganglionic neurons and short postganglionic neurons
Briefly explain the enteric nervous system
Consists of autonomic neurons of the gi ttact from oesophagus to anus
Cells not influenced by CNS
What is proprioception?
Experience and understand our position and the position of any part of our body in a 3D space, movement and force.
Where are the most relevant proprioceptor found?
Capsule of joints, muscles and tendons
- golgi tendon organ
- muscle spindle
- joint receptor
