Week 1 Goodnotes
Nervous System Overview
Divided into two main subdivisions:
Central Nervous System (CNS)
Comprised of the brain and spinal cord.
Responsible for processing information and controlling bodily functions.
Peripheral Nervous System (PNS)
Connects the CNS to the rest of the body.
Composed of thick bundles of axons, called nerves.
Carries messages to and from the CNS
Has two major subdivisions: Somatic Nervous System (SNS) and Autonomic Nervous System (ANS).
Communication in the Nervous System
Synapses
Tiny spaces between neurons where chemical transmitters are released.
Allow communication both electrically and chemically.
Types of Communication:
Signal Transmission: Enables transmission of signals from one neuron to another.
Information Processing: Plays a crucial role in how information is processed in the CNS.
Plasticity: Synapses can adapt and change, which is important for learning and memory.
Central vs. Peripheral Nervous System
CNS vs PNS
CNS is the brain and spinal cord; PNS consists of nerves and connects the CNS to the body.
PNS has two divisions: Sensory (afferent) and Motor (efferent) fibers.
Somatic and Autonomic Nervous Systems
Somatic Nervous System (SNS)
Controls voluntary or conscious activities.
Involves sensory perception and motor control.
Autonomic Nervous System (ANS)
Controls involuntary functions, such as internal organ regulation.
Divided into:
Sympathetic Division: Prepares the body for stress-related activities (fight or flight).
Parasympathetic Division: Calms the body and helps maintain routine operations.
Homeostasis: The body's state of equilibrium in which biological conditions are maintained at optimal levels.
Spinal Cord and Reflexes
Routes messages to and from the brain and contains reflexes that operate independently of the brain.
Organized into segmented sections, each connected to specific body parts through the PNS.
Reflex Action: Rapid response to stimuli, managed by spinal cord.
Neuroplasticity
Refers to the ability of the nervous system to change and adapt.
Involves:
Creation of new synapses.
Pruning unnecessary synapses.
Important for learning and memory retention.
Brain Structure
Cerebral Hemispheres: Divided into two halves by the longitudinal fissure; each hemisphere controls opposite sides of the body.
Brain Regions:
Cerebral cortex with folded structures (gyri and sulci) for various functions.
Function Processes: Including consciousness, thought, emotion, reasoning, language, and memory.
Lobes of the Brain
Frontal Lobe: Involved in reasoning, motor control, emotion, language. Contains Broca's area for language production.
Parietal Lobe: Processes sensory information and spatial awareness.
Temporal Lobe: Associated with hearing, memory, and emotional responses. Contains Wernicke’s area for language comprehension.
Occipital Lobe: Main area for processing visual information.
Internal Features of the Brain
Thalamus: Sensory relay center for all senses except smell.
Hippocampus: Critical for learning and memory.
Amygdala: Involved in emotions and memory processing.
Hypothalamus: Regulates homeostasis and links nervous and endocrine systems.
Brain Imaging Techniques
CT Scan: Uses X-rays to create images of brain structures.
PET Scan: Monitors brain activity using a radioactive tracer.
MRI/fMRI: Generates images of internal structures and tracks blood flow and oxygen levels for functional imaging.
Endocrine System Overview
Composed of glands that produce hormones, acting as chemical messengers in the bloodstream.
Hormones regulate bodily functions:
Pituitary Gland: Master gland controlling other glands.
Thyroid Hormones: Regulate metabolism and energy.
Adrenal Glands: Secret hormones for stress response (adrenaline).
Pancreas: Regulates blood sugar levels through insulin and glucagon.
Gonads: Produce sex hormones impacting reproduction and sexual behavior.
Dysregulation of Hormones
Can lead to disorders:
Hyperthyroidism: Excess thyroxine leads to agitation and weight loss.
Diabetes: Insufficient insulin production leads to high blood sugar.