Skip to main content
Back

Study Guide: Nervous System Structure and Function

NotesPracticeVideo lessons

Study Guide - Smart Notes

Tailored notes based on your materials, expanded with key definitions, examples, and context.

Nervous System Overview

Central and Peripheral Nervous Systems

The nervous system is divided into two main parts: the Central Nervous System (CNS) and the Peripheral Nervous System (PNS).

  • Central Nervous System (CNS): Consists of the brain and spinal cord. It processes information and coordinates activity throughout the body.

  • Peripheral Nervous System (PNS): Includes all neural tissue outside the CNS. It connects the CNS to limbs and organs.

Major Brain Structures and Functions

  • Temporal lobe: Involved in auditory processing and memory.

  • Occipital lobe: Responsible for visual processing.

  • Cerebellum: Coordinates voluntary movements and balance.

  • Hypothalamus: Regulates homeostasis, including temperature, hunger, and hormone release.

  • Hippocampus: Essential for memory formation and spatial navigation.

  • Prefrontal cortex: Involved in decision-making, planning, and social behavior.

  • Limbic system: A group of structures involved in emotion, motivation, and memory.

Neuroanatomy Terms

Brain Surface Features

  • Gyrus (plural: gyri): A ridge on the cerebral cortex.

  • Sulcus (plural: sulci): A groove or furrow on the brain surface.

  • Fissure: A deep groove, often separating large regions of the brain.

Meninges

The meninges are protective membranes covering the brain and spinal cord:

  • Dura mater: The tough, outermost layer.

  • Arachnoid mater: The middle, web-like layer.

  • Pia mater: The delicate, innermost layer adhering to the brain and spinal cord.

Neural Function and Reflexes

Knee Jerk Reflex

The knee jerk reflex (patellar reflex) is a simple, monosynaptic reflex that helps maintain posture and balance.

  • When the patellar tendon is tapped, stretch receptors activate sensory neurons.

  • Sensory neurons synapse directly with motor neurons in the spinal cord, causing the quadriceps muscle to contract.

Reflex Arc Sequence

The correct sequence in a reflex arc is:

  1. Receptor

  2. Afferent neuron (sensory neuron)

  3. Integration center (usually the CNS)

  4. Efferent neuron (motor neuron)

  5. Effector

Other Key Terms

  • Coma: A state of deep unconsciousness.

  • Syncope: Temporary loss of consciousness (fainting) due to reduced blood flow to the brain.

  • Sciatica: Pain along the sciatic nerve, often caused by compression or irritation.

  • Nociceptors: Sensory receptors that detect pain.

  • REM sleep: Rapid Eye Movement sleep, associated with vivid dreams and brain activity similar to wakefulness.

  • Vagus nerve: A cranial nerve that controls parasympathetic output to many organs.

  • "Funny bone" nerve: The ulnar nerve is stimulated when you hit your "funny bone." It runs near the surface at the elbow.

Autonomic Nervous System

Sympathetic vs. Parasympathetic Nervous System

The autonomic nervous system (ANS) regulates involuntary body functions and is divided into:

  • Sympathetic Nervous System (SNS): Prepares the body for "fight or flight" responses.

  • Parasympathetic Nervous System (PNS): Promotes "rest and digest" activities.

Comparison Table: SNS vs. PNS Effects

Organ/System

Sympathetic Effect

Parasympathetic Effect

Heart

Increases heart rate

Decreases heart rate

Lungs

Bronchodilation (opens airways)

Bronchoconstriction (narrows airways)

Digestive system

Decreases activity

Increases activity

Pupils

Dilates pupils

Constricts pupils

Salivary glands

Decreases secretion

Increases secretion

Skeletal muscles

Increases blood flow

No significant effect

Blood pressure

Increases

Decreases

Parasympathetic Effects on Organs/Systems

  • Heart: Slows heart rate.

  • Lungs: Constricts bronchioles.

  • Brain: Promotes calm and restorative functions.

  • Digestive system: Stimulates digestion and peristalsis.

  • Salivary glands: Increases saliva production.

  • Pupils: Constricts pupils.

  • Skeletal muscles: Minimal direct effect.

  • Blood pressure: Lowers blood pressure.

Short Answer/Essay Concepts

Comparing SNS and PNS Effects

  • Fight or Flight (SNS): Increases heart rate, dilates pupils, inhibits digestion, increases blood flow to muscles, and raises blood pressure.

  • Rest and Digest (PNS): Decreases heart rate, constricts pupils, stimulates digestion, increases glandular secretion, and lowers blood pressure.

  • Example: Feeling "butterflies" in the stomach when nervous is due to SNS inhibition of digestive activity and increased adrenaline.

Study and Memory Strategies

  • Use mnemonics to remember anatomical terms.

  • Practice active recall and spaced repetition to enhance memory.

  • Relate new information to existing knowledge for better retention.

Key Definitions

  • Effector: A muscle or gland that responds to neural stimulation.

  • Receptor: A structure that detects stimuli.

  • Afferent neuron: Transmits sensory information to the CNS.

  • Efferent neuron: Carries motor commands from the CNS to effectors.

  • Integration center: Processes information and directs responses (usually in the CNS).

Additional info: Some explanations and examples were expanded for clarity and completeness based on standard Anatomy & Physiology curriculum.

Pearson Logo

Study Prep