Central Nervous System Quiz

Peripheral Nervous System (PNS)

• The PNS is the network of nerves outside the brain and spinal cord
• Acts as a communication bridge between the central nervous system and the body
• Consists of two major divisions: somatic and autonomic nervous systems
• Contains approximately 100 billion neurons

Nervous System Divisions

• The nervous system is divided into the Central Nervous System (CNS) and the Peripheral Nervous System (PNS)
• The PNS can be further divided into Afferent (Sensory) System and Efferent (Motor) System.
• The Efferent System is further divided into Somatic and Autonomic Systems.
• The Autonomic Nervous System is further divided into the Sympathetic and Parasympathetic divisions.

Somatic Nervous System

• Controls voluntary movements
• Connects the CNS to skeletal muscles and sense organs
• Responsible for conscious activities
• Uses motor and sensory neurons

Autonomic Nervous System (ANS)

• Controls involuntary functions of internal organs.
• Regulates internal organs.
• Has two main subdivisions:
• Sympathetic and Parasympathetic

Sympathetic Division

• "Fight or Flight" response
• Activates during stress
• Effects include: increased heart rate, dilated pupils, enhanced metabolism, decreased digestion
• Uses norepinephrine as the primary neurotransmitter

Parasympathetic Division

• "Rest and Digest" response.
• Active during calm states
• Effects include: decreased heart rate, constricted pupils, enhanced digestion, reduced blood pressure
• Uses acetylcholine as the primary neurotransmitter

Types of Neurons in PNS

• Sensory (Afferent) Neurons: transmit information from the body to the CNS
• Motor (Efferent) Neurons: transmit information from the CNS to the body
• Mixed Nerves: contain both sensory and motor neurons
• Interneurons: connect neurons within the CNS

Cranial Nerves

• 12 pairs of nerves that connect directly to the brain
• Control various functions like facial expressions, eye movements, hearing, taste, and smell

Spinal Nerves

• 31 pairs of nerves that connect to the spinal cord
• Organized by regions (cervical, thoracic, lumbar, sacral, coccygeal)

Neurotransmitters in PNS

• Chemical messengers
• Key types: acetylcholine, norepinephrine, epinephrine, substance P
• Different effects on target tissues

Central Nervous System (CNS)

• The control center of the body
• Consists of the brain and spinal cord
• Processes and coordinates all bodily functions
• Protected by bones and meninges (dura mater, arachnoid mater and pia mater)

CNS Structure

• Composed of myelinated (white matter) and unmyelinated (grey matter) neurons
• In the spinal cord, white matter is on the outer surface, and grey matter is in the center
• In the brain, grey matter is on the outer surface, and white matter is in the center

Protection of the CNS

• Skull (cranium) protects the brain
• Vertebral column protects the spinal cord
• Three layers of meninges: dura mater, arachnoid mater, and pia mater.
• Cerebrospinal fluid provides cushioning

Major Brain Regions

• Forebrain (cerebrum, thalamus, hypothalamus)
• Cerebellum
• Brain stem (pons, medulla oblongata)
• Regions work together in complex networks to perform functions

Cerebrum

• Largest part of the brain
• Divided into left and right hemispheres connected by the Corpus callosum
• Four lobes:
  • Frontal (movement, reasoning)
  • Parietal (sensation, spatial awareness)
  • Temporal (hearing, memory)
  • Occipital (vision)

Forebrain Includes

• Thalamus (sensory relay station)
• Hypothalamus (homeostasis control)
• Pineal gland (melatonin production)
• Pituitary gland (hormone control)

Cerebral Functions

• Controls higher-order thinking
• Manages voluntary movement (motor cortex)
• Processes sensory information (sensory cortex)
• Houses language centers
• Regulates emotional responses
• Stores memories

Cerebellum

• Located at the back of the brain
• Primary functions: Balance coordination, posture maintenance, fine motor control, movement timing
• Contains more neurons than the rest of the brain combined.

Brain Stem

• Three main parts: Midbrain, Pons, Medulla Oblongata
• Controls vital functions: breathing, heart rate, blood pressure, sleep cycles

Spinal Cord

• Extends from the brain stem to the lower back
• 31 pairs of spinal nerves
• Functions: Information highway to/from brain, reflex center, movement control

Spinal Cord Structure

• Grey matter (butterfly shape): Contains neuron cell bodies
• White matter: Contains axon tracts
• Central canal: Contains cerebrospinal fluid

CNS Disorders

• Common conditions affecting the CNS: Multiple sclerosis, Alzheimer's disease, Parkinson's disease, Epilepsy, Spinal cord injuries

Protecting CNS Health

• Regular exercise
• Proper nutrition
• Adequate sleep
• Mental stimulation
• Avoiding harmful substances
• Wearing protective gear during activities

Test your knowledge on the central nervous system with this quiz. Questions cover various aspects, including the brain stem, spinal nerves, and the functions of different nervous system divisions. Perfect for students studying neuroscience or related fields.