Chapter 5: The Central Nervous System Flashcards
Central Nervous System (CNS)
- brain and spinal cord
Peripheral Nervous System (PNS)
- nerve fibers
- afferent and efferent divisions
Enteric Nervous System (ENS)
- nerves network of the digestive tract
Divisions of the Efferent Nervous System
Somatic Nervous System
- fibers of the motor neurons that supply the skeletal muscles
Autonomic Nervous System
- fibers that innervate smooth muscle, cardiac muscle, and glands
- is further divided into the sympathetic and parasympathetic nervous system
Neurons Functional Classes
- the functional classes
Afferent
Efferent
Interneurons
Glial Cells of Neruons
- support interneurons physically, metabolically, and functionally
- astrocytes, oligodendrocytes, microglia, and ependymal cells
Protection and Nourishment of the Brain
- major features protect the CNS from injury
- cranium and vertebral column
- meninges
- cerebrospinal fluid
- blood-brain barrier
Three Meningeal Membranes
- wrap, protect, and nourish the CNS
Dura Mater
Arachnoid Mater
Pia Mater
Fluids of the Brain
- brain floats in its own special cerebrospinal fluid
- surrounds and cushions the brain and spinal cord
- highly selective blood-brain barrier regulates exchanges between the blood and brain
- shields from harmful changes
Nourishment of the Brain
- brain depends on constant delivery of oxygen and glucose by the blood
- cannot produce ATP without O2
- brain damages results if deprived of O2
Components of the Brain
- brain stem
- cerebellum
- forebrain
- diencephalon
- hypothalamus
- thalamus
- cerebrum
- basal nuclei
- cerebral cortex
Cerebral Cortex
- divided into right and left cerebral hemispheres
- connected by the corpus collosum
- is an outer shell of gray matter covering an inner core of white matter
Gray Matter: CNS computers
White Matter: wires that connect the computers
Cerebral cortex and Neural Networks
- neurons in different regions of the cerebral cortex may fire in rhythmic synchrony
- neural network or assembly
- cerebral cortex is organized into layer and functional columns
- functional differences result from different layering patterns and different input-output connections
Lobes of the Cerebral Cortex
- occipital
- temporal
- parietal
- frontal
Parietal Lobe
- somatosensory processing
- sensations from the surface of the body, such as touch, pressure, heat, cold, and pain
Frontal Lobe
- primary motor cortex which controls the skeletal muscles
- stimulation of different areas of the primary motor cortex brings about movement in different regions of the body
Cerebral Cortex and Motor Control
- higher motor areas are also important in motor control
- supplementary motor area
- premotor cortex
- posterior parietal cortex - somatotopic maps vary slightly between individuals and are dynamic, not static
- use-dependent competition
Plasticity and Language in the Cortex
- brain can be remodeled in response to varying demands
Plasticity: ability to change or be functionally remodeled in response to demands - different regions of the cortex control different aspects of language
- Broca’s area (speaking) and Wernicke’s area (comprehension)
- language disorders
- aphasias, speech impediments, and dyslexia