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Izabella Gendorf - Nervous P:5 - Coggle Diagram
Izabella Gendorf - Nervous P:5
action potential/nerve impulse
Resting Potential: Negative charge inside the neuron.
Maintained by sodium-potassium pumps.
Depolarization: Sodium ions rush in, generating an impulse.
Repolarization: Potassium ions leave, restoring the charge.
Synapse: The junction where neurotransmitters transfer the signal.
Can be excitatory or inhibitory.
major divisions/subdivisions (cns and pns)
Central Nervous System (CNS): Brain and spinal cord.
Responsible for processing and decision-making.
Peripheral Nervous System (PNS): Nerves outside the CNS.
Subdivided into:
Somatic Nervous System (SNS): Voluntary control of skeletal muscles.
Autonomic Nervous System (ANS): Involuntary control of glands and smooth muscles.
Sympathetic Division: "Fight or flight," increases alertness.
Parasympathetic Division: "Rest and digest," conserves energy.
Enteric Nervous System: Regulates digestive tract functions.
classification of nuerons
Sensory (Afferent): Transmit signals to the CNS.
Examples: Pain receptors, photoreceptors.
Motor (Efferent): Send signals from CNS to muscles/glands.
Control voluntary and involuntary movements.
Interneurons: Connect neurons within the CNS.
Vital for reflex arcs and complex pathways.
major parts/functions of brain
Cerebrum: Higher cognitive functions, memory, voluntary movement.
Divided into lobes: frontal, parietal, occipital, temporal.
Cerebellum: Coordination, balance.
Also fine-tunes motor activity.
Brainstem: Basic life functions (heartbeat, breathing).
Includes midbrain, pons, and medulla oblongata.
major parts/functions of spinal cord
Dorsal Root: Sensory input to the CNS.
Ventral Root: Motor output from the CNS.
Gray Matter: Processes signals in interneurons.
White Matter: Transmits signals along pathways to/from the brain.
connective tissue coverings
Epineurium: Surrounds the entire nerve, providing protection.
Perineurium: Encases bundles of nerve fibers (fascicles).
Maintains the blood-nerve barrier.
Endoneurium: Surrounds individual nerve fibers, supports axons.
tissue (structure and functionof neurons/ganglia)
Neurons: Transmit electrical signals.
Types: Multipolar, bipolar, unipolar.
Can’t regenerate easily in the CNS.
Neuroglia: Supportive cells in the CNS and PNS.
Astrocytes: Regulate the blood-brain barrier.
Oligodendrocytes/Schwann Cells: Form myelin for insulation.
Major Functions
Sensory Input: Detects changes in the environment (internal and external).
Examples: Touch, temperature, pain.
Integration: Processes sensory information and makes decisions.
Happens in the brain and spinal cord.
Motor Output: Sends commands to muscles and glands to respond appropriately.
Includes voluntary and involuntary responses.
Cranial Nerves
12 pairs control motor, sensory, or mixed functions in the head and neck.
Example: Optic Nerve (II): Vision.
Vagus Nerve (X): Parasympathetic control of organs.
Neurotransmitters
Chemicals that transmit signals across synapses.
Example: Dopamine (reward), Acetylcholine (muscle control).
Others: Serotonin (mood), GABA (inhibitory).
Imbalances can lead to disorders like depression or Parkinson’s.
Spinal Nerve
31 pairs connect the spinal cord to the body.
Examples: Cervical, thoracic, lumbar nerves.
Each spinal nerve has sensory and motor functions.
Compare & Contrast ANS
Sympathetic: Increases heart rate, dilates pupils.
Prepares body for emergencies.
Parasympathetic: Decreases heart rate, promotes digestion.
Restores the body to a calm state.
Both systems work together to maintain homeostasis.
Reflex Arc
Sensory Receptor: Detects stimulus.
Examples: Touch or pain receptors.
Sensory Neuron: Sends signal to CNS.
Interneuron: Processes signal.
May bypass the brain for faster response.
Motor Neuron: Sends command to muscle/gland.
Effector: Carries out response.
Example: Pulling hand away from heat.
Disorder/Disease
Examples:
Multiple Sclerosis (MS): Damages myelin sheath, slows impulses.
Parkinson’s Disease: Affects movement, caused by dopamine deficiency.
Epilepsy: Seizures due to abnormal brain activity
Drugs/Abuse
Explores how drugs (e.g., cocaine, heroin) affect neurotransmitters.
Cocaine: Blocks dopamine reuptake, causing euphoria.
Alcohol: Enhances GABA, leading to sedation.
Long-term abuse can damage neurons and brain structure.