Chapter 49: The Nervous System Flashcards
Brain matter
Gray matter consists of neuronal cell bodies, dendrites, and unmyelinated axons
White matter consists of bundles of myelinated axons
- Located on the exterior of the spinal cord
- Located on the interior of the brain
Enteric nervous system
Seperate division of the autonomic nervous system
A distinct network of neurons that exerts direct and partially independent control over the digestive tract, pancreas, and gallbladder
ANS ganglions
Preganglionic neurons connect the central nervous system to the ganglia
- Have cell bodies in the CNS
- Release acetylcholine
Postganglionic neurons connect the ganglion to the effector organ
- Those of the parasympathetic nervous system release acetylcholine
- Those of the sympathetic nervous system release norepinephrine
Glia
Nourish, support, and regulate the functioning of neurons
Major brain regions
Forebrain- processing of olfactory input, regulation of sleep, learning, and any complex processing
Midbrain- coordinates routing of sensory input
Hindbrain- controls involuntary activities and coordinates motor activities
Brain development
Forebrain
Telencephalon
- Cerebral cortex
- Basal nuclei
Diencephalon
- Thalmus
- Hypothalmus, Epithalmus
Midbrain
Mesencephalon
- Midbrain
Hindbrain
Metencephalon
- Pons
- Cerebellum
Myelencephalon
- Medulla oblongata
The cerebrum
The cerebellum
The diencephalon
The brainstem
Arousal and sleep
Controlled by the brainstem and cerebrum
Controlled in part by the reticular formation at the core of the brainstem formed by neurons in the midbrain and pons
- These neurons control the timing of sleep periods characterized by rapid eye movements (REMs) and by vivid dreams
Sleep is also regulated by the biological clock and regions of the forebrain that regulate intensity and duration
Biological clock regulation
Circadian rhythms are coordinated by a group of neurons in the hypothalamus called the suprachiasmatic nucleus (SCN)
The SCN acts as a pacemaker, synchronizing the biological clock
Emotions
Generation and experience of emotions involve the limbic system comprised of the:
- Amygdala
- Hippocampus
- Parts of the thalamus
Generating and experiencing emotion often require interactions between different parts of the brain
The structure most important to the storage of emotion in the memory is the amygdala, a mass of nuclei near the base of the cerebrum
Frontal lobe functions
Motor cortex- control of skeletal muscles
Prefrontal cortex- decision-making and planning
Broca’s area- forming speech
Parietal lobe functions
Somatosensory cortex- sense of touch
Sensory association cortex- integration of sensory information
Temporal lobe
Auditory cortex- hearing
Wernicke’s area- comprehending language
Occipital lobe
Visual association cortex- combining images and object recognition
Visual cortex- processing visual stimuli and pattern recognition
Information processing
Cerebral cortex receives input from sensory organs and somatosensory receptors
The thalamus directs different types of input to distinct locations
Integrated sensory information passes to the prefrontal cortex which helps plan actions and movements
In the somatosensory and motor cortex
neurons are arranged according to the part of the body that generates input or receives commands
Brain lateralization
The left hemisphere is more adept at language, math, logic, and processing of serial sequences
The right hemisphere is stronger at facial and pattern recognition, spatial relations, and nonverbal thinking
Memory and learning
Short-term memory is accessed via temporary links formed in the hippocampus
Long-term memory occurs when links in the hippocampus are replaced by connections in the cerebral cortex itself
Schizophrenia
Affects neuronal pathways that use dopamine as a neurotransmitter
Parkinson’s disease
Caused by death of dopamine-secreting neurons in the midbrain
Alzheimer’s disease
Caused by the formation of neurofibrillary tangles and amyloid plaques
