Human Nervous System

Page 1: Human Nervous System

Page 2: Co-ordinating Systems

• Definition: Systems that facilitate communication between receptors and effectors in the body to produce correct responses to environmental changes (stimuli).

• Importance for Survival: All animals must respond to their environment to survive.

• Types of Co-ordinating Systems in Humans:

  • Nervous Co-ordinating System

  • Endocrine Co-ordinating System

• Functionality: Both systems work together to respond to environmental changes and maintain internal body conditions.

Page 3: Nervous Co-ordinating System

• Speed: It responds the fastest through nerve impulses.

Page 4: Endocrine Co-ordinating System

• Speed: Slower than the nervous system; operates through hormones carried in the bloodstream.

Page 5: Nervous System Overview

• Control and Communication Center: The nervous system allows continuous flow of information between the environment, brain, and various body parts.

• Functionality: Essential for effective body functioning and managing daily tasks.

Page 6: How Nervous System Functions

• Sensory Function: Sensory receptors detect changes in both external and internal environments.

• Integrative Function: Central nervous system (CNS) processes the information and determines responses needed.

• Motor Function: Effectors (muscles and glands) execute appropriate responses.

Page 7: Example of Nervous System Functioning

• Scenario: Riding a bike, noticing a red traffic light (sensory function), processing the information (integrative function leads to stopping the bike using brakes (motor function)).

Page 8: What are Stimuli?

• Definition: Physical or chemical changes that provoke a response in organisms.

• Examples: Light, temperature, sounds, atmospheric pressure, as well as internal conditions like blood pressure and pH.

Page 9: Human Nervous System Structure

• Main Components:

  • Central Nervous System (CNS): Brain and spinal cord

  • Peripheral Nervous System (PNS): Nerves throughout the body.

Page 10: Central Nervous System Overview

• Composition: Mass of interconnected neurons comprising the brain and spinal cord.

• Functions: Processes sensory information, maintains organ functions, controls movements, thoughts, and feelings.

Page 11: CNS Protection

• Protective Structures:

  • Meninges: Three connective tissue membranes

  • Cerebro-spinal Fluid: Cushions CNS against shocks, derived from blood plasma in the brain's ventricles.

  • Bony Cases: Cranium and vertebral column protect CNS.

Page 12: Cranium Protection

• Structure: Dome-shaped with 8 curved skull bones joined by sutures to shield the brain from mechanical injuries.

Page 13: Protective Layers of CNS

• Meninges Layers:

  • Pia Mater: Delicate inner layer

  • Arachnoid: Middle layer

  • Dura Mater: Tough outer layer

Page 14: Basic Protective Structures

• Illustration: Skull, Dura Mater, Arachnoid, Pia Mater, and brain tissue.

Page 15: Vertebral Column Protection

• Structure: Comprising 33 vertebrae that protect the spinal cord against mechanical injury, provides shock absorption through its curvature and inter-vertebral discs.

Page 16: Anatomy of the Lumbar Vertebrae

• Details: Includes spinal disc structure and transverse processes.

Page 17: Cross-Section of CNS

• Components: Skin, Dura Mater, Cranial Bone, Arachnoid, Pia Mater, nerve structures.

Page 18: Structure of the Brain

• Composition: Enlarged upper part of spinal cord within cranial protection; divided into sections including cerebrum, brain stem, and cerebellum.

Page 19: External View of Human Brain

• Components: gyrus, sulcus, cerebellum, cranial and spinal nerves.

Page 20: Internal Structure of the Brain

• Key Areas: Thalamus, hypothalamus, pituitary gland, and various brain regions illustrated with a focus on white and grey matter.

Page 21: Cerebrum Overview

• Functions: Controls voluntary and involuntary behaviors; composed of various lobes such as frontal, parietal, occipital, and temporal.

Page 22: Lobes of the Cerebrum

• Division: Central sulcus, parietal lobe, occipital lobe, temporal lobe, and connections illustrated across cerebral regions.

Page 23: Additional Brain Structure

• Components: Spinal cord, cerebellum, midbrain, etc.

Page 24: Cerebrum Components

• Characteristics: Largest part, divided into hemispheres linked by corpus callosum; features gyri and sulci for increased surface area.

Page 25: Cerebrum Ventricles

• Ventricles: Four cavities within brain filled with cerebro-spinal fluid; outer layer forms the cerebral cortex (grey matter) with underlying white matter.

Page 26: Surface Lobes of the Cerebrum

• Illustration of lobes: Frontal, parietal, occipital, and temporal lobes highlighted.

Page 27: Cerebral Cortex

• Definition: Outermost layer of grey matter that forms the cerebral surface.

Page 28: Grey Matter vs. White Matter

• Definitions:

  • Grey Matter: Neuron cell bodies

  • White Matter: Myelinated fibers

  • Structures: Neurons may organize into nuclei and tracts.

Page 29: Brain Ventricles

• Components: Lateral ventricles, third ventricle, fourth ventricle, and their pathways.

Page 30: Detailed Anatomy of the Brain

• Labeling: Identifying key features, emphasizing cerebro-spinal fluid.

Page 31 to 33: Functions of Cerebral Lobes

• Roles:

  • Frontal Lobe: Motor functions, reasoning, and personality control.

  • Parietal Lobe: Sensory perception and spatial orientation.

  • Occipital Lobe: Vision processing.

  • Temporal Lobe: Memory, language understanding, hearing.

Page 34: Brain's Lobes Overview

• Details: Functions related to decision-making, sensory processing, language comprehension, and attention.

Page 35: Cerebrum Functions Overview

• Areas: Motor area, sensory areas, and association cortex roles in integrating and processing information.

Page 36: Functional Areas of Cerebral Cortex

• Details: Specific roles of motor, sensory, and association areas illustrated.

Page 37 to 40: Cerebellum Structure and Functions

• Structure: Composed of two hemispheres with branches resembling a tree.

• Functions: Coordination of muscle movements, posture maintenance, and balance stability.

Page 41: Summary of Cerebellum

• Key Point: Position and composition emphasizing its role beneath the cerebrum.

Page 42-44: Hypothalamus Functionality

• Position: Below thalamus, above pituitary gland; regulates critical homeostasis functions.

• Functions: Influences autonomic system, emotional responses, and pituitary hormone control.

Page 45-46: Medulla Oblongata Overview

• Role: Serves as communication pathway for impulses; regulates vital reflex actions like breathing and heartbeat.

Page 47: Brain Structure Classification

• Components: Forebrain, midbrain, hindbrain categorization.

Page 48-50: Spinal Cord Structure and Functions

• Composition: Elongated nervous tissue with structured grey and white matter; protected by meninges and surrounded by vertebral column.

Page 51-53: Detailed Anatomy and Functions

• Gray Matter: Integration center for reflex actions; encasing structure aiding impulse pathways.

Page 54-56: Cross-Section of Spinal Cord

• Details: Visual representation of spinal structure emphasizing function and organization.

Page 57: Peripheral Nervous System Overview

• Definition: Consists of all nervous tissue outside CNS; links to receptors and effectors.

• Components: 12 pairs of cranial nerves and 31 pairs of spinal nerves.

Page 58: Structure of Nervous System

• Main Structures: Highlighting different nervous system components.

Page 59-60: Cranial and Spinal Nerves

• Cranial Nerves: Connect to brain, function in sensory or motor capacities.

• Spinal Nerves: Provide mixed sensory and motor neuron functions.

Page 61: Functions of PNS

• Roles: Collecting and transmitting information, combining sensory and motor functions.

Page 62: Motor Division Composition

• Divisions: Somatic and autonomic systems; controlling voluntary and involuntary movements, respectively.

Page 63-66: Autonomic Nervous System

• Functionality: Maintains homeostasis, controlling involuntary activities via sympathetic and parasympathetic responses.

Page 67-70: Comparison of Autonomic Functions

• Sympathetic vs. Parasympathetic: Effects on body organs during stress and rest, highlighting opposing reactions.

Page 71: Summary of Autonomic System Functions

• Stimulatory vs. Inhibitory: Functions categorized based on responses to stress and relaxation.

Page 72: Composition of Nervous Tissue

• Components: Neurons and supporting neuroglia cells.

Page 73-76: Neuron Structure and Types

• Structure: Main components including dendrites and axons enabling impulse conduction.

• Types: Sensory, connector, and motor neurons classified by functions.

Page 77: Neuron Functionality

• Dendrites: Collect information to pass to the cell body.

• Axons: Conduct impulses away from the cell body to effectors.

Page 78-81: Neuron Classifications

• Detailed Description of sensory, connector, and motor neurons; emphasizing functions within the CNS.

Page 82: Neuron Types Summary

• Visualization: Illustrates basic types of neurons and their distinctions.

Page 83-86: Motor Neuron Structure

• Functional Features: Describes layout and component roles for optimal impulse conductivity.

Page 87: Notes on Neurons

• Additional Notes: Key terminologies and features specific to the neuron structure and function.

Page 88-90: Nerve Structures

• Composition: Description of nerves comprising numerous neuron fibers, their connection and organization.

Page 91: Nerve Functions

• Roles: Key functions in transmitting impulses between CNS and body effectors.

Page 92-96: Synapses and Reflex Arcs

• Details on Synapses: Mechanism of impulse transfer across synaptic clefts, including neurotransmitter roles.

• Reflex Arcs: Identification of neural pathways that highlight reflex actions.

Page 97-100: Reflex Actions

• Description: Highlights importance of reflex actions, types of reflexes and their physiological significance.

Page 101-103: Reflex Arc Functionality

• Operation: Detailed description of impulse pathway upon stimulus triggering a reflex action.

Page 104-106: Revision Topics

• Future Directions: Suggestions for upcoming activities and areas of focus for review.