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Term 1: Central Nervous System (CNS)
Definition 1: Consists of the brain and spinal cord.
Term 2: Peripheral Nervous System (PNS)
Definition 2: All nerves outside the central nervous system (CNS).
Term 3: Sensory Division (Afferent)
Definition 3: Carries information to the CNS from receptors.
Term 4: Motor Division (Efferent)
Definition 4: Sends commands from the CNS to effectors like muscles and glands.
Term 5: Neurons
Definition 5: Nerve cells that send signals.
Term 6: Dendrites
Definition 6: Branch-like extensions of a neuron that receive signals from other neurons.
Term 7: Axon
Definition 7: The long, slender projection of a neuron that conducts electrical impulses away from the neuron's cell body.
Term 8: Glial Cells
Definition 8: Support and protect neurons.
Term 9: Myelin Sheath
Definition 9: Insulates axons and speeds up signal transmission.
Term 10: Nodes of Ranvier
Definition 10: Gaps in the myelin sheath that allow for saltatory conduction.
Term 11: Action Potential
Definition 11: Large, all-or-nothing electrical signal transmitted along an axon.
Term 12: Resting Potential
Definition 12: The membrane potential of a neuron at rest, typically about
-70mV.
Term 13: Threshold Potential
Definition 13: The critical level of membrane potential that must be reached to initiate an action potential, typically around -55mV.
Term 14: Synapse
Definition 14: The junction between two neurons for communication.
Term 15: Neurotransmitter
Definition 15: Chemical that transmits signals across the svnapse.
Term 16: Autonomic Nervous System (ANS)
Definition 16: Regulates involuntary functions and is divided into sympathetic and parasympathetic.
Term 17: Sympathetic Nervous System
Definition 17: Part of ANS that controls 'fight or flight' responses.
Term 18: Parasympathetic Nervous System
Definition 18: Part of ANS that controls 'rest and digest' functions.
Term 19: Reflex Arc
Definition 19: A neural pathway that controls a reflex action.
Term 20: Hippocampus
Definition 20: Brain structure involved in long-term memory formation.
Term 21: Cerebellum
Definition 21: Coordinates movement and balance; also helps with motor learning and fine-tuning movement.
Term 22: Motor Unit
Definition 22: A motor neuron and all the muscle fibers it controls. Small motor units provide fine control (e.g., in the eyes), while large motor units provide power (e.g., in the legs).
Term 23: Calcium lons (Ca~+)
Definition 23: Trigger contraction by exposing binding sites on actin.
Term 24: Brain Lateralization
Definition 24: The specialization of certain functions in either the left or right hemisphere of the brain.
Term 25: Left Hemisphere
Definition 25: Responsible for language, logic, math, and analytical thinking.
Term 26: Contraction of muscles step 1
Definition 26: Nerve Impulse:• Action potential travels down motor neuron.• Acetylcholine (ACh) is released into the neuromuscular junction. • ACh binds to receptors on the sarcolemma (muscle cell membrane)
→ triggers a new action potential in the muscle fiber.
Term 27: muscle contraction step two
Definition 27: Calcium Release: • The action potential travels down T-tubules → signals sarcoplasmic reticulum to release Ca* ions.
Term 28: Muscle contraction step three
Definition 28: Binding Sites Exposed:• Ca* binds to troponin, moving tropomyosin away from myosin-binding sites on actin.
Term 29: Muscle contraction step four
Definition 29: Cross-Bridge Cycling: • Myosin heads (on thick filaments) bind to actin (thin filaments). • ATP → ADP + Pi, powering the power stroke (myosin pulls actin). • New ATP binds → myosin detaches → cycle repeats.
Term 30: Muscle contraction step five
Definition 30: Relaxation: • When stimulation stops, Ca* is pumped back into
SR. • Tropomyosin covers binding sites again → muscle relaxes.
Term 31: Cerebrum/Cerebral Cortex
Definition 31: It is responsible for thinking, perception, movement, and memory.
Term 32: Frontal Lobe
Definition 32: Decision making, planning, movement (motor cortex), and language production (Broca's area.
Term 33: Prefrontal Cortex
Definition 33: As part of the frontal lobe, it is involved in personality, reasoning, and social behavior.
Term 34: Parietal Lobe
Definition 34: Processes touch, pressure, temperature, pain, and spatial awareness.
Term 35: Temporal Lobe
Definition 35: Hearing, language comprehension (Wernicke's area, and memory storage.
Term 36: Amygdala
Definition 36: Processes emotions like fear and anger.
Term 37: Thalamus
Definition 37: Acts as a relay station, sending sensory information to the correct part of the brain.
Term 38: Hypothalamus
Definition 38: Controls homeostasis (body temp, hunger, thirst) and links the nervous system to the endocrine system via the pituitary gland.
Term 39: Subcortical Nuclei (e.g., basal ganglia)
Definition 39: Clusters of neurons beneath the cortex that help regulate movement and emotions.
Term 40: Brain Stem
Definition 40: Controls basic life functions.
Term 41: Midbrain
Definition 41: Involved in eye movement and visual/auditory reflexes.
Term 42: Pons
Definition 42: Serves as a bridge between the cerebrum and cerebellum, and controls breathing and facial sensations.
Term 43: Medulla Oblongata
Definition 43: Heart rate, breathing, and blood pressure.
Term 44: Right Hemisphere
Definition 44: Creativity and spatial awareness.
Term 48: Alzheimer's disease
Definition 48: A neurological disorder characterized by the degeneration of neurons, leading to memory loss.
Term 49: Parkinson's disease
Definition 49: A neurological disorder caused by dopamine loss, resulting in tremors and movement issues.
Term 54: Somatic Nervous System (SNS)
Definition 54: Part of the motor division of the PNS that controls voluntary movements of skeletal muscles.
Term 55: Enteric Nervous System (ENS)
Definition 55: Sometimes called the 'second brain,' it controls the gastrointestinal system and can operate independently of the CNS while also communicating with it