Nervous System Key Terms and Brain Anatomy

• Key terms and definitions related to the nervous system are presented

Meninges and Cerebrospinal Fluid

• Meninges are the three protective membranes covering the brain and spinal cord
• The three layers of the meninges, listed from innermost to outermost, are the pia mater, arachnoid mater, and dura mater
• Cerebrospinal fluid cushions the brain and spinal cord

Brain Lobes and Functions

• The frontal lobe controls motor functions and decision-making
• The occipital lobe is responsible for processing visual information
• The temporal lobe is involved in auditory processing and memory formation
• The parietal lobe handles spatial awareness and sensory perception
• The insular lobe is involved in emotional awareness and taste perception

Brain Imaging Techniques

• A CT scan utilizes X-rays to create brain images
• An MRI uses radio waves and magnetic fields for imaging
• A PET scan uses radioactive tracers to measure brain activity
• A SPECT scan measures blood flow in the brain

Aphasia Types

• Broca's aphasia results in difficulty with speech production but intact comprehension
• Wernicke's aphasia results in an inability to comprehend spoken and written language
• Conduction aphasia is caused by damage to the arcuate fasciculus

Brain Activity and Function

• Gamma rays are emitted by radioactive tracers in PET scans
• SPECT scans measure blood flow evaluation in the brain
• The frontal lobe is involved in speech comprehension
• CT scans provide better spatial resolution than MRI for soft tissues
• The cerebral cortex is responsible for higher cognitive functions like reasoning and memory
• The insular lobe is involved in emotions, perception, and consciousness
• The frontal lobe is responsible for impulse control and decision-making
• MRI scans are best for detecting acute hemorrhages
• Aphasia affects both speech production and comprehension

Cell Transport Mechanisms

• Simple diffusion involves the passive movement of molecules across membranes
• Active transport requires ATP to move substances against concentration gradients
• A hypertonic increases solution causes cells to shrink due to water loss
• The sodium-potassium pump moves 3 Na+ ions out of the cell and 2 K+ ions into the cell
• Osmolarity refers to the total concentration of solutes in a solution
• Facilitated diffusion is passive transport via protein channels
• Osmosis is the diffusion of water through a selectively permeable membrane
• Isotonic solutions have equal osmolarity to the intracellular environment
• Ion channels facilitate ion movement across cell membranes
• Osmolality measures solute concentration per liter of solution
• A hypotonic solution causes cells to swell from water influx
• Vesicular transport is the process of moving substances in vesicles

Solutions and Cellular Effects

• A 5% saline solution is hypertonic compared to human cells
• Dehydration increases blood osmolarity due to fluid loss
• Impairment of the sodium-potassium pump leads to increased extracellular sodium concentration
• Impairment of the sodium-potassium pump leads to decreased intracellular potassium concentration
• Consequences of sodium-potassium pump failure include potential cell death and muscle contraction issues
• Oral rehydration is recommended as a treatment for dehydration

Nervous System Divisions

• The autonomic nervous system regulates involuntary body functions
• The somatic nervous system controls voluntary muscle movements
• The sympathetic nervous system prepares the body for the 'fight or flight' response
• The parasympathetic nervous system promotes 'rest and digest' activities
• The motor division activates effectors in response to stimuli
• The blood-brain barrier (BBB) regulates substance exchange between blood and brain

Neural Cells and Structures

• Glial cells provide support within the nervous system
• A neuron is the basic unit of the nervous system that transmits signals
• Dendrites receive signals and transmit them to the soma
• The axon transmits electrical impulses away from the soma
• The soma is the cell body of a neuron
• The myelin sheath insulates axons to speed up impulses
• Sensory neurons transmit signals from sensory receptors to the CNS
• Interneurons connect sensory and motor neurons within the CNS

Neuron Function

• The resting membrane potential is typically -70 mV in neurons
• The depolarization phase is caused by the influx of sodium ions
• The repolarization phase is primarily caused by the efflux of potassium ions
• The absolute refractory period occurs when sodium channels are inactivated
• Stimulus intensity is encoded by the frequency of action potentials
• Synaptic transmission depends on neurotransmitter release at the synapse

Neurotransmitters

• Glutamate is the primary excitatory neurotransmitter in the CNS
• Oligodendrocytes provide myelination in the central nervous system
• GABA is the primary inhibitory neurotransmitter in the CNS
• Glycine inhibitory neurotransmitter in the spinal cord
• Serotonin a neurotransmitter linked to regulating mood
• Acetylcholine is the neurotransmitter at the neuromuscular junction
• Dopamine is the neurotransmitter associated with pleasure and reward
• Calcium promotes neurotransmitter release from synaptic vesicles

Synaptic Transmission

• The sodium-potassium pump maintains the resting membrane potential in neurons
• A chemical synapse is the site where neurotransmitters are released into the cleft
• Nicotinic receptors are where acetylcholine binds at the neuromuscular junction

Brain Protection and Waste Removal

• Cerebrospinal fluid removes metabolic waste from the brain
• The blood-brain barrier is a protective barrier that limits substance entry to the brain
• Meninges are protective layers surrounding the brain and spinal cord

Brain Regions

• The cerebellum coordinates voluntary muscle movements and balance
• The subarachnoid space is filled with cerebrospinal fluid
• The choroid plexus produces cerebrospinal fluid in the brain
• The central nervous system (CNS) comprises the brain and spinal cord
• The brainstem controls vital functions, such as breathing
• The cerebrum is responsible for higher cognitive functions
• The spinal cord transmits sensory and motor information
• The spinal cord is protected by the skull, cerebrospinal fluid, vertebrae, and meninges

Meningeal Layers and Spaces

• The dura mater is the outermost and toughest meningeal layer
• The subarachnoid space is located between the arachnoid mater and pia mater
• The choroid plexus in the brain produces cerebrospinal fluid
• Cerebrospinal fluid cushions and protects the brain

Blood-Brain Barrier (BBB)

• The blood-brain barrier protects the brain from harmful substances while allowing essential nutrients to pass through
• The BBB is characterized by tight junctions, selective permeability, and active transport
• Lipid-soluble molecules easily cross the blood-brain barrier
• Arachnoid villi reabsorb cerebrospinal fluid into the bloodstream

Neuron Physiology

• The sodium-potassium pump transports sodium out of the cell and potassium into the cell using ATP
• The resting membrane potential is typically -70 mV in neurons
• Fixed anions attract cations and maintain electrical neutrality inside the cell
• The potassium equilibrium potential is determined by both electrical and chemical gradients

Signaling Types

• Endocrine signaling involves hormone release into the bloodstream

Explore the nervous system's key terms, including the meninges and cerebrospinal fluid. Learn about the functions of the brain lobes: frontal, occipital, temporal, parietal, and insular. Discover brain imaging techniques like CT scans, MRIs, PET scans and SPECT scans.