Brain Structures and Functions

Older Brain Structures

• Thalamus

  • Functions as a sensory switchboard.

  • Processes every sensory modality except for smell.

• Medulla

  • Responsible for controlling basic life functions such as heartbeat and breathing.

• Brainstem

  • Considered the oldest part of the brain.

  • Newer brain parts are built atop this structure.

  • Primarily manages automatic survival functions.

• Reticular Formation

  • Regulates arousal and alertness.

• Cerebellum

  • Coordinates voluntary movement and maintains balance.

Limbic System

• Amygdala

  • Involved in processing fear and aggression responses.

• Hippocampus

  • Critical for learning and memory consolidation.

• Hypothalamus

  • Acts as a reward center, motivating behaviors related to hunger, thirst, and sexual arousal.

• Pituitary Gland

  • Known as the master gland; it works in conjunction with the hypothalamus to regulate hormonal activities.

Cerebral Cortex

• Cerebral Cortex

  • The outer layer of the brain; it serves as the control and information-processing center.

• Cerebrum

  • The largest part of the brain, often referred to as the beefy portion.

• Brain Lobes

  • Frontal Lobe: Responsible for higher-order thinking, cognitive functions that define humanity.

  • Parietal Lobe: Associated with processing sensory input related to touch and body position.

  • Occipital Lobe: Primarily processes visual information.

  • Temporal Lobe: Primarily processes auditory information.

• Motor Cortex

  • The section in the left hemisphere controls movements on the right side of the body, while the right hemisphere controls movements on the left side.

• Sensory Cortex

  • Located at the front of the parietal lobe; it registers and processes sensory inputs.

• Association Areas

  • Areas of the cortex not involved in primary motor or sensory functions but engaged in higher mental functions.

  • Wernicke’s Area: Involved in language comprehension.

  • Broca’s Area: Controls speech production.

• Plasticity

  • Refers to the brain's remarkable ability to reorganize itself, particularly during younger years, to compensate for damage or loss of function.

Split Brain

• Corpus Callosum

  • A thick band of neural fibers connecting the left and right hemispheres of the brain.

  • Located in the middle section of the brain; the hemispheres are not connected until reaching the corpus callosum.

  • May be severed in individuals experiencing frequent seizures (such as those with epilepsy) to alleviate symptoms.

• Hemispheric Control

  • Each hemisphere controls the opposite side of the body:

  • Right Side/Right Visual Field: Managed by the left hemisphere.

  • Left Side/Left Visual Field: Managed by the right hemisphere.

Hemispheric Functions

• Left Hemisphere

  • Dominates analytical thoughts.

  • Associated with math and science abilities.

  • Facilitates language and speech functions.

  • Generally controls more crucial functions than the right hemisphere.

• Right Hemisphere

  • Associated with emotions and creative thinking.

  • Often referenced in relation to artistic abilities.