nervous system anatomy

Central Nervous System (CNS)

Brain and spinal cord; main control center of the body

Brain folds (gyri & sulci)

Increase surface area for more processing power

Brainstem

Controls survival functions such as breathing, heart rate, reflexes, pain, and temperature

Cerebellum

Coordinates movement, balance, and precision

Thalamus

Relay and sorting center for sensory information

Cerebrum

Responsible for higher processing like thinking, decision-making, and consciousness

Cerebral cortex

Outermost layer of the cerebrum; gray matter; site of complex processing

Frontal lobe

Planning, decision-making, personality, and motor control

Parietal lobe

Sensory processing, touch, spatial awareness, and navigation

Temporal lobe

Auditory processing and long-term memory

Occipital lobe

Visual processing

Corpus callosum

Connects the left and right hemispheres of the brain

Broca’s area

Speech production (left hemisphere)

Wernicke’s area

Language comprehension and word meaning (left hemisphere)

Limbic system

Controls emotions, memory, and self-gratifying behaviors

Hypothalamus

Maintains homeostasis and controls the endocrine system (hormones)

Hippocampus

Converts short-term memory into long-term memory

Amygdala

Processes emotions, especially fear, and triggers autonomic responses

Cingulate gyrus

Involved in decision-making and emotional regulation

Olfactory bulb

Responsible for the sense of smell

Spinal cord

Connects the brain to the peripheral nervous system and processes reflexes

Meninges

Protective coverings around the brain and spinal cord

Peripheral Nervous System (PNS)

All nerves outside the central nervous system

Somatic nervous system

Controls voluntary movement of muscles, skin, and tendons

Autonomic nervous system

Controls involuntary functions of organs and glands

Sympathetic nervous system

Responsible for fight-or-flight responses

Parasympathetic nervous system

Responsible for rest-and-digest and everyday maintenance