Neuro Function Flashcards
What is the function of the nervous system?
Receives and reacts to environment stimuli on a physiologic and cognitive level
What are the three components of the nervous system?
- Brain
- Spinal cord
- Nerves
Which parts of the nervous system are a part of the CNS (central nervous system)?
Brain and spinal cord
Which part of the nervous system is part of the PNS (peripheral nervous system)?
Nerves
What are the membranes that encase the CNS
Meninges
This is the outer and toughest layer of meninges
Dura mater
This is the middle layer of meninges and has a spider web-like vascular system
Arachnoid layer
This is the innermost layer of the meninges
Pia mater
Plasma-like liquid that fills the space between the arachnoid and the pia mater layers to provide additional cushion and support
Cerebrospinal fluid
Interconnected, hollow areas of the brain where CSF is produced, fills, and flows
Ventricles
Which cells provide support in the brain
Neuroglia cells
What is the function of neuroglia cells
They scaffold neural tissue, isolate, and protect neuron cell membranes, regulate interstitial fluid, defend the neuron against pathogens, and assist with neural repair
These cells:
- Generate and transmit bioelectrical impulses
- Do not have the ability to divide
- Losses due to aging or injury cannot be replaced
- Not all cell death results in loss of functioning
- Undamaged cells in the brain will assume functions of damaged cells
- Severed peripheral nerves can regenerate to a point to reestablish connections
Neurons
What do severed spinal cord nerves result in?
Paralysis and loss of sensation below the area of damage
These cells require a constant oxygen and glucose supply, making them vulnerable to hypoxia and hypoglycemia
Neurons
Projections that transmit impulses away from the cell body
Axons
Projections that transmit impulses toward the cell body
Dendrites
Tiny bulges at the end of the axon that communicate with neurons, muscle fibers, or glands
Terminal boutons
Surrounds some axons and increases the rate of impulse transmission
Myelin
Produce the myelin sheaths
Schwann cells
Sites of nutrition exchange where myelin is not present
Nodes of Ranvier
Bundles of myelinated nerves
White matter
The gap between the neurons
Synapse
Space between the neurons in the synapse
Synaptic cleft
Opposite end to the presynaptic terminal
Postsynaptic cell membrane
What are neural impulses generated by?
Small ionic changes
The ability to create a charge
Action potential
Charging at rest
Resting potential
Why does the plasma side of the neuron membrane have a slight charge at rest, or resting potential
Because of the sodium ions concentrated on the outside of the cell
What is it called when protein gates open and sodium flows into the cell, increasing the charge
Depolarization
This is the largest region of the brain and controls the higher thought processes
Cerebrum
Folds that increase the surface area
Gyri
Grooves between the gyri
Sulci
This lobe facilitates voluntary motor activity and plays a role in personality traits
Frontal lobe
This lobe receives and interprets sensory input with the exception of smell, hearing, and vision
Parietal lobe
This lobe processes visual information
Occipital lobe
This lobe is essential for hearing and memory
Temporal lobe
This area within and across the lobes stimulates muscle activity
Motor
This area within and across the lobes receives sensory information
Sensory
This area within and across the lobes integrates information and initiates coordinated responses
Association
Receives and relays most of the sensory input, affects mood, and initiates body movements
Thalamus
Functions of this in the diencephalon are unclear
Epithalamus
The most inferior portion of the diencephalon and regulates many bodily functions
Hypothalamus
This collaborates with the hypothalamus to regulate vital activities
Brain stem
This area of the brain contains nerves that regulate sleep and breathing
Pons
This is the smallest region of the brain and acts as a relay station for auditory and visual information and controls the visual and auditory systems as well as eye movement
Midbrain
This area of the brain is a conduction pathway for ascending and descending nerve tracts that coordinates heart rate, peripheral vascular resistance, breathing, swallowing, vomiting, coughing, and sneezing
Medulla
Lies deep within the cerebrum, diencephalon, and midbrain and plays a pivotal role in coordination, motor movement, and posture
Basal ganglia
This system includes portions of the cerebrum and diencephalon and works in conjunction with the hypothalamus to influence instinctive behavior, emotions, motivation, mood, pain, and pleasure
Limbic system
Where does the spinal cord exit from the skull?
Foramen magnum
At L2, the spinal cord transitions into individual nerve roots called what?
Cauda equina
How many pairs of spinal nerves branch off at regular intervals in the spinal cord?
31 pairs
Which fibers in the spinal cord carry sensory information in the form of action potentials from the periphery back to the brain
Ascending fibers, or afferent tracts
Which fibers in the spinal cord carry motor impulses in the form of action potentials from the brain to the fibers of the PNS
Descending fibers or efferent tracts
Process within the spinal cord that creates an unconscious response to stimuli
Spinal reflex arcs
Withdrawal reflex in response to touching an unpleasant stimulus; causes the muscles of a limb to withdraw the limb from the source of the stimulus without any conscious action
Flexor reflex
Several nerves intersecting to form an organized collaboration
Plexus
This controls smooth muscles and the unconscious response that affects such activities as heart rate, blood pressure, and intestinal motility
Autonomic Nervous System
Which two subdivisions of the autonomic nervous system have an antagonistic effect with each other to aid in maintaining homeostasis
Sympathetic and parasympathetic nervous systems
This system is responsible for the fight or flight response and is augmented by secretions of the adrenal medulla; stimulates the adrenergic receptors
Sympathetic nervous system
This system is responsible for the rest and digest response; stimulates the cholinergic receptors
Parasympathetic nervous system
This is caused by localized conditions such as trauma, compression, or infections that affect a single spinal nerve, plexus, or peripheral nerve trunk
For example: fractured bones may lacerate or compress nerves; Excessively tight tourniquets; infections such as herpes zoster may affect a single segmental afferent nerve distribution
Mononeuropathy
This involves demyelination or axonal degeneration of multiple peripheral nerves that leads to symmetric sensory, motor, or mixed sensorimotor deficits.
Typically, the longest axons are involved first - symptoms begin in the distal part of the extremities
Polyneuropathy
- Common condition of excess CSF accumulation within the skull
- Ventricles dilate and the brain and blood vessels become compressed
- Pressure thins the cortex, causing severe brain damage
Hydrocephalus
This cause of hydrocephalus is due to CSF flow disruption
Non-communicating or an obstructive hydrocephalus