The Central Nervous System (The Brain)

White Matter

• Myelinated bundles of axon of neurons

• Inner layer of brain

• Outer layer of spinal cord

Gray Matter

• Unmyelinated dendrites and cell bodies of neurons

• Outer layer of brain (cerebral cortex)

• Inner layer of spinal cord

The Brainstem

• Most inferior part of the brain

  • Midbrain

  • Pons

  • Medulla Oblongata

• Allows for conduction of impulses between the brain and spinal cord

• Control of heartbeat, respiration, and blood pressure

Medulla Oblongata

• Superior extension of the spinal cord

Diencephalon

• Hypothalamus

• Thalamus

Hypothalamus

• Controls automatic nervous system functions such as heart rate and digestive contractions

• Regulates body temperature, appetite, and sleep cycles

Thalamus

• Relays sensory information to different parts of the cerebrum

Cerebellum

• Produce smooth movements

• Maintain balance, coordination, and posture

Cerebrum

• Gyri

• Sulci

• Fissures

• Cerebral cortex

• Corpus callosum

• Lobes of the cerebrum

Gyri

• Ridges in the cerebrum

Sulci

• Grooves within the cerebrum

Fissures

• Deep sulcus that divides cerebrum into lobes

• Longitudinal fissure

  • Divides cerebrum into left and right halves/hemispheres

Cerebral Cortex

• Gray matter that runs along the surface of the cerebrum

• Made unmyelinated dendrites and cell bodies

Corpus Callosum

• Connects the 2 cerebral hemispheres

• Allows the two hemispheres to communicate

Lobes of the Cerebrum

• The cerebrum is divided by the longitudinal fissure along the midsagittal plane into left and right hemispheres

• Each hemisphere handles the opposite side of the body

  • Ex: left hand is controlled by the right hemisphere

• Each hemisphere has 4 lobes

Frontal Lobe

• Anterior lobe

• Functions

  • Reasoning and intelligence

  • Voluntary muscle control

  • Personality, behavior

  • Speech (Broca’s Area)

Parietal Lobe

• Middle, superior lobe

• Functions

  • Sensory perception such as pain, touch, and taste

Temporal Lobe

• Lateral lobe

• Functions

  • Hearing

  • Memory

  • Understanding language

Occipital Lobe

• Posterior lobe

• Visual interpretation