Central Nervous System

Cerebrum

Largest part of the brain responsible for conscious thought, memory, sensation, and voluntary movement

Cerebral hemispheres

Two halves of the cerebrum (left and right)

Cerebral cortex

Outer gray matter layer of the cerebrum involved in higher brain functions

Fissures

Deep grooves that separate major brain regions

Gyri

Raised ridges of the cerebral cortex

Sulci

Shallow grooves between gyri

Cerebellum

Coordinates balance, posture, and voluntary movements

Diencephalon

Brain region including the thalamus, hypothalamus, and epithalamus

Thalamus

Major sensory relay station to the cerebral cortex

Hypothalamus

Regulates homeostasis, hunger, thirst, temperature, and endocrine function

Brainstem

Connects brain to spinal cord

Midbrain

Part of brainstem involved in vision, hearing, and motor control

Pons

Brainstem structure involved in breathing and communication between brain regions

Medulla oblongata

Controls vital autonomic functions like heart rate and breathing

Ventricle

Fluid-filled cavities in the brain containing cerebrospinal fluid

Corpus callosum

Large fiber tract connecting the two cerebral hemispheres

Dura mater

Tough outermost meningeal layer

Arachnoid mater

Web-like middle meningeal layer

Pia mater

Thin innermost meningeal layer that adheres to brain tissue

Cranial meninges

Three protective membranes covering the brain

Cerebrospinal fluid

Fluid that cushions and protects the CNS

Choroid plexus

Produces cerebrospinal fluid

Reticular formation

Network controlling alertness and consciousness

Anterior lobe

Front portion of pituitary gland

Posterior lobe

Back portion of pituitary gland

Purkinje cells

Neurons in the cerebellum that regulate motor coordination

Ataxia

Loss of coordination due to cerebellar damage

Substantia nigra

Midbrain region involved in movement and dopamine production

Pineal gland

Secretes melatonin and regulates circadian rhythms

Limbic system

Group of structures involved in emotion, behavior, and memory

Nerve

Bundle of axons in the peripheral nervous system

Tract

Bundle of axons in the central nervous system

Amygdaloid

Structure involved in emotions, especially fear and aggression

Hippocampus

Involved in learning and memory formation

Basal nuclei

Regulate voluntary motor activity and muscle tone

Parietal lobe

Processes sensory information and spatial awareness

Frontal lobe

Involved in decision-making, personality, and voluntary movement

Occipital lobe

Visual processing center

Temporal lobe

Processes hearing, language, and memory

Precentral gyrus

Location of the primary motor cortex

Central sulcus

Separates frontal and parietal lobes

Postcentral gyrus

Location of the primary somatosensory cortex

Primary motor cortex

Controls voluntary muscle movements

Primary somatosensory cortex

Receives sensory input from the body

Primary visual cortex

Receives visual information from the eyes

Visual association area

Interprets visual information

Somatosensory association area

Interprets sensory information from the body

Premotor cortex

Plans and coordinates movements

Gustatory cortex

Processes taste sensations

Olfactory cortex

Processes smell

Primary auditory cortex

Receives sound information

Auditory association area

Interprets sound and speech

Integrative center

Processes information and makes decisions

Broca’s area

Controls speech production

Wernicke’s area

Controls language comprehension

Hemispheric lateralization

Functional differences between brain hemispheres

Electroencephalogram

Recording of electrical activity of the brain

Cranial nerves

Twelve pairs of nerves that arise from the brain

General senses

Touch, pain, temperature, pressure, and proprioception

Sensory pathways

Routes that carry sensory information to the brain

Sensation

Detection of a stimulus

Perception

Interpretation of sensory information

Receptive field

Area monitored by a sensory receptor

Nociceptors

Pain receptors

Thermoreceptors

Temperature receptors

Mechanoreceptors

Respond to touch, pressure, and movement

Chemoreceptors

Respond to chemical changes

Proprioceptors

Detect body position and movement

Baroreceptors

Detect blood pressure changes

Tactile receptors

Respond to touch sensations

Adaptation

Decreased response to constant stimulus

Anterior spinothalamic tracts

Carry crude touch and pressure sensations

Lateral spinothalamic tracts

Carry pain and temperature sensations

Spinocerebellar pathway

Carries proprioceptive information to cerebellum

Posterior column pathway

Carries fine touch and proprioception

Somatic nervous system

Controls voluntary skeletal muscle movement

Autonomic nervous system

Regulates involuntary visceral functions

Visceral effectors

Smooth muscle, cardiac muscle, and glands

Preganglionic neurons

Neurons that extend from CNS to autonomic ganglia

Ganglionic neurons

Neurons whose cell bodies are located in autonomic ganglia

Postganglionic neurons

Neurons that extend from ganglia to target organs

Autonomic ganglia

Sites where autonomic neurons synapse

Parasympathetic division

Anabolic, rest and digest division

Sympathetic division

Catabolic, fight or flight division

Enteric nervous system

Regulates digestive system activity

Visceral reflexes

Automatic responses of visceral organs

Short reflexes

Reflexes processed entirely within the enteric system

Long reflexes

Reflexes involving the CNS