F ANA 2 - nervous
Page 2: Introduction
The nervous system is a highly complex system in animals.
Main Functions:
Coordinates actions and sensory information.
Transmits signals to and from various body parts.
Page 3: Overview of Nervous System
Divisions:
Central Nervous System (CNS): Brain and Spinal Cord.
Peripheral Nervous System (PNS): Nerves.
Page 4: Nervous System Types
Central Nervous System:
Components: Brain and Spinal Cord.
Subdivisions:
Autonomic Nervous System: Controls involuntary functions (internal organs & glands).
Somatic Nervous System: Controls voluntary movements of skeletal muscles.
Autonomic Subdivisions:
Sympathetic (Arousing): Activates body in stressful situations.
Parasympathetic (Calming): Calms body after stress.
Page 5: Functions of Nervous System
1. Sensory Function
Sensory Receptors: Gather information and send it to the CNS.
2. Integrative Function
Uses sensory information to create:
Sensations
Memory
Thoughts
Decisions
3. Motor Function
Actions are carried out based on decisions.
Impulses sent to effectors (muscles or glands).
Page 6: Cells of the Nervous System
Neuron Structure and Functions
Dendrites: Receive signals from other cells.
Cell Body (Soma): Organizes functions of neuron.
Axon: Transfers signals to other cells/organs.
Myelin Sheath: Increases impulse speed.
Node of Ranvier: Allows ion diffusion.
Axon Terminals: Forms junctions with other cells.
Schwann Cell: Produces the myelin sheath.
Page 7: Neurons in the Nervous System
Sensory Neurons: ~10 million send information from the body to the brain.
Motor Neurons: ~500,000 control muscle and gland actions.
Page 8: Types of Neurons
Neuron Types:
Unipolar
Bipolar
Pseudounipolar
Multipolar
Page 9: Basic Neuron Types
Major types of neurons:
Multipolar: Motoneurons.
Bipolar: Interneurons.
Unipolar: Sensory neurons.
Page 10: Various Neuronal Structures
Different specialized cells in the nervous system:
Granule cell, Thalamic nucleus, Pyramidal cell, etc.
Page 11: Ganglia
Definition: Ovoid structures containing neuron cell bodies and glial cells.
Function: Serve as relay stations (nerve enters and exits).
Page 12: Neurotransmitters
Components:
Presynaptic neuron, Axon terminal, Synaptic vesicles.
Neurotransmitter receptors on postsynaptic neuron.
Page 13: Major Neurotransmitters
Acetylcholine: Source - CNS; action - excitatory (promotes parasympathetic effects).
Serotonin: Source - Brain; regulates mood, sleep, and inhibits pain pathways.
Dopamine: Source - Basal ganglia; modulates attention, emotions, fine movement.
Norepinephrine: Source - CNS; major role in sympathetic nervous activity.
GABA: Source - CNS; main inhibitory neurotransmitter.
Page 14: Neurotransmitter Imbalances
Schizophrenia: High dopamine levels.
Alzheimer's Disease: Low acetylcholine levels.
Depression: Low serotonin and norepinephrine levels.
Huntington's Disease: Low acetylcholine.
Anxiety: Low GABA; high serotonin/norepinephrine.
Page 15: Anatomy of the Brain
Main lobes of the brain:
Parietal, Frontal, Occipital, Temporal lobes.
Basal ganglia, Cerebellum, Brainstem.
Page 16: Brain Fissures and Lobes
Key Fissures:
Central fissure, Lateral fissure, Transverse fissure.
Lobes related to: Sensory and motor processing.
Page 17: Brain Weight and Structure
Average brain weight:
Young adult: ~1,400g
Elderly: ~1,200g.
Page 18: Brain Structures
Overview of specific brain structures: Corpus Callosum, Thalamus, Hypothalamus, etc.
Page 19: Corpus Callosum
Function: Connects left and right hemispheres; major communication pathway.
Page 20: Brain Functionality
Hemispheric Differences:
Left hemisphere: Verbal and analytical functions.
Right hemisphere: Spatial and creative tasks.
Page 21: Brain Anatomy - Gyri and Sulci
Gyri: Ridges on the brain surface.
Sulci: Grooves separating gyri.
Fissure: Deep grooves.
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Page 23: Gray Matter vs. White Matter
Gray Matter (40%): Contains neuronal cell bodies.
White Matter (60%): Composed of myelinated nerve fibers; facilitates communication between different brain areas.
Page 24: Brain Functions Segregated by Lobes
Frontal Lobe:
Motor Cortex, Premotor Cortex, Prefrontal Area, Broca's Area for speech.
Parietal Lobe:
Sensory processing, body orientation.
Occipital Lobe:
Visual processing.
Temporal Lobe:
Auditory processing, memory functions.
Page 25: Basal Ganglia Structure
Masses of nuclei located deep in the cerebral hemispheres.
Page 26: Basal Ganglia Functions
Control of:
Voluntary motor activity
Reflex muscular activity
Muscle tone
Role in arousal mechanism.
Page 27: Brain Structural Overview
Key components: Frontal lobe, Thalamus, Hypothalamus, Cerebellum.
Page 28: Thalamus Function
Acts as a relay station for sensations (except smell).
Handles memory, sensation, and pain impulses.
Page 29: Hypothalamus Location
Anterior and inferior to thalamus, controls various bodily functions.
Page 30: Hypothalamus Features
Includes optic chiasm and mammillary bodies, connected to pituitary gland.
Page 31: Hypothalamus Role in Endocrine Functions
Regulates pituitary gland hormones affecting metabolism, reproduction, stress response, etc.
Page 32: Hypothalamus: Homeostasis Regulation
Functions:
Fluid balance
Temperature regulation
Appetite control.
Page 33: Hypothalamus: Emotional Regulation
Regulates sleep-wake cycle, blood pressure, behavior, and emotional responses.
Page 34: Pituitary Gland
Key structures: Anterior and Posterior lobes, optic chiasm.
Page 35: Hypothalamus and Pituitary Gland Connection
Connection through stalk, involved in hormone secretion.
Page 36: Pituitary Hormones
Hormones produced by anterior and posterior pituitary glands: TSH, ACTH, LH, FSH, etc.
Page 37: Internal Capsule and CNS Connections
Nerve fibers converge in the internal capsule, pathways cross at pons and medulla.
Page 38: CNS Control Mapping
Maps the motor control of various body parts through the cortical trunk representation.
Page 39: Brain Stem Overview
Connects to the spinal cord and controls vital functions (breathing and heart rate).
Page 40: Midbrain Function
Connects pons and cerebellum, involved in sensory and motor pathways.Auditory and visual reflexes coordination.
Page 41: Pons Functionality
Encapsulates motor and sensory pathways; connects various brain regions.
Page 42: Medulla Oblongata Functions
Contains crossover of motor and sensory fibers; regulates vital functions.
Page 43: Fourth Ventricle and Cerebellar Connections
Plays a crucial role in coordination and communication with cerebellum.
Page 44: Cerebellum Functions
Coordinates movement, balance, fine motor skills, and sensory integration.
Page 45: Protective Structures of the Brain
The meninges cover and protect the brain and spinal cord.
Page 46: Meninges Layers
Layers:
Skull, Dura Mater, Arachnoid Mater, Pia Mater.
Page 47: Skull Bone Structure
Key bones: Parietal, Frontal, Occipital, Temporal, Sphenoid, etc.
Page 48: Major Skull Sutures
Sutures:
Sagittal, Coronal, Lambdoid, Squamous.
Page 49: Dura Mater
Tough outer layer, contains extensors like falx cerebri.
Page 50: Dural Extensions
Extensions include tentorium, falx cerebelli, and diaphragm sellae.
Page 51: Dural Pressure Issues
High pressure can cause herniation of tissue within cranial cavity.
Page 52: Arachnoid Features
Delicate, resembles spider web; houses choroid plexus for CSF production.
Page 53: Arachnoid Projections
Arachnoid villi absorb CSF; maintains balance of CSF production and absorption.
Page 54: Overview of Meninges
Layers: Dura Mater, Arachnoid, Pia Mater.
Page 55: Pia Mater Characteristics
Thin innermost layer closely adheres to brain surface; extends into folds.
Page 56: Cerebrospinal Fluid (CSF) Overview
Clear fluid, crucial for brain and spinal cord homeostasis.
Page 57: CSF Circulation Pathway
Pathway from lateral ventricles to the subarachnoid space for fluid movement.
Page 58: CSF Fluid Composition
Composition similar to blood plasma but differs in specific ion concentrations.
Page 59: CSF Analysis
Reports on color, protein count, white blood cell count; normal CSF is minimally cellular.
Page 60: Cerebral Circulation Overview
Receives 15% of cardiac output; high metabolic demand of the brain.
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Page 62: Circle of Willis Overview
Major arteries forming the Circle of Willis supply blood to the brain.
Page 63: Aneurysms of the Circle of Willis
Common sites for aneurysms include anterior and middle cerebral arteries.
Page 64: Cerebral Veins and Sinuses
Unique structure; no valves preventing backflow; relies on gravity.
Page 65: Blood-Brain Barrier (BBB)
Protects CNS; tight junctions between endothelial cells prevent unwanted substances from entering.
Page 66: BBB Alterations
Trauma affects integrity; influences selection of medications for treatment of CNS disorders.
Page 67: BBB Cellular Structure
Composition includes endothelial cells, astrocytes, and tight junctions.
Page 68: Brain Waves
Types:
Beta: 14-30 Hz; alertness and normal consciousness.
Alpha: 9-13 Hz; relaxed yet awake.
Delta: Below 4 Hz; deep sleep.
Theta: 4-8 Hz; light sleep, dreams.
Gamma: 30 Hz and above; heightened perception.
Page 69: Anatomy of Spinal Cord
Approximately 45 cm long; connects to brain at the foramen magnum.
Page 70: Structure of the Spinal Cord
Contains both gray and white matter organized in specific columns/horns.
Page 71: Ascending Tracts of Spinal Cord
Pathways carry sensory information to the brain; routes vary for different sensations.
Page 72: Descending Tracts
Motor pathways directing movement; includes tracts for skilled voluntary actions.
Page 73: Reflex Arc Structure
Components:
Sensory receptors, sensory neuron, relay neuron, motor neuron, effector organ.
Page 74: Vertebral Column Anatomy
Segments: Cervical, Thoracic, Lumbar, Sacral, and Coccygeal.
Page 75: Spine Structure
Components include vertebral body, spinous process, transverse process.
Page 76: Intervertebral Disks
Separates vertebrae and absorbs shock; key for spinal column flexibility.
Page 77: Peripheral Nervous System (PNS)
Includes cranial nerves, spinal nerves, and autonomic nervous system.
Page 78: PNS Functions
Connects CNS to limbs and organs; regulates involuntary body functions.
Page 79: Cranial Nerve Overview
Composed of sensory, motor, and mixed nerves with specific functions.
Page 80: Overview of Spinal Nerves
Includes cervical, thoracic, lumbar, sacral, and coccygeal nerves.
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Page 83: Sympathetic and Parasympathetic Functions
Mediated by norepinephrine and acetylcholine; controls fight or flight vs. rest and digest responses.
Page 84: Sympathetic Syndromes
Including pupil dilation, bowel paralysis, pulse rate variations due to neural damage.
Page 85: Motor Function Representation
Diagram illustrating motor control across body via the motor homunculus.
Page 86: Motor Neuron Types
Upper Motor Neuron: Initiates motor commands.
Lower Motor Neuron: Executes motor actions at muscles.
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Page 88: Coordination of Movement
Smooth and accurate movements are due to cerebellum and basal ganglia functions.
Page 89: Sensory System Function
Integrating Sensory Impulses
The thalamus is vital for processing sensory information (except smell).
Page 90: Receiving Sensory Impulses
Afferent pathways move impulses to the cerebral cortex for interpretation