Nervous System Flashcards
Peripheral nervous system
Carries messages to and from the central nervous system
Sensory division of PNS
Receptors to stimuli; sensory neurons send signals to CNS
Motor division
Contains motor neurons which carry signals from CNS to effectors
Somatic nervous system
Allows voluntary movement
Autonomic nervous system
Regulates involuntary, subconscious activities
Cerebrum
Complex portion of brain consisting of two hemispheres
Cerebral cortex
Thin outer layer (gray matter); billions of unmyelinated nerve cells and neuroglial cells
Cerebral white matter
Nerve cells with myelinated axons; communicates between neurons in the brain and between the brain and the rest of the body
Areas of cerebrum
Frontal lobe
Parietal lobe
Temporal lobe
Occipital lobe
Frontal lobe
Motor function, personality, speech
Parietal lobe
Sensory functions (e.g. Taste)
Temporal lobe
Auditory and olfaction (smell)
Occipital lobe
Visual cortex
Cerebrum functions
- voluntary movement
- interpreting sensations
- language
- decision making
- self-awareness
- creativity
- memories
Midbrain
Relays and integrates signals
Pons
Bridge between higher and lower brains
Medulla oblongata
Autonomic centers for respiration, heart rate, and digestion
Cerebellum
- Coordinates voluntary, sensory-motor movements
- stores memory of “learned motor patterns”
Thalamus
Processes sensory signals and relays information to appropriate centers
Hypothalamus
Responsible for homeostasis; controls heart rate, blood pressure, breathing rate, body temperature, and hunger
Limbic system
Complex set of structures responsible for emotions and formation of memories
Acquired brain injury
Cerebrovascular accident; death of neurons from interruption of blood flow to a region of the brain
Causes of cerebrovascular accidents
Stroke, aneurysm, heart attack, meningitis, substance abuse
Meningitis
Infections of meninges (membranes surrounding brain and spinal cord)
Traumatic brain injury
Damage to neurons or nerve connections from force (trauma)
Causes of traumatic brain injury
Automobile accident, slip and fall, sports injury, gun shot, explosion (war)
Spinal cord functions
Transmits signals to/from brain
Reflex center
Reflex arc
Circuit or neurons in spinal cord prewired to respond to stimuli
Reflex arc components
- receptor
- sensory neuron
- interneuron
- motor neuron
- effector
Parasympathetic nervous system
Adjusts bodily function so that energy is conserved during non-stressful times; “resting and digesting”
Sympathetic nervous system
In charge during stressful or emergency conditions; “fight or flight”
Effects of sympathetic nervous system
- pupils dilate
- decreased salivation
- increased breathing rate
- narrowed blood vessels
- slowed digestion
- epinephrine and norepinephrine stimulated
- salt and water retained
- bladder relaxed
- defecation inhibits
Spinal cord injury
Damage to neurons or nerve connections from force (trauma); causes loss or impaired sensation or motor control and permanent or intermittent pain.
Central nervous system
Brain and spinal cord; integrates and coordinates all nervous functions
