Comprehensive Notes on Brain Structure and Function

Overview of Brain Structure and Function

• Structure vs. Function: Anatomy (structure) and Physiology (function) are key concepts in understanding the brain.

Types of Organisms with Brains

• Brains are found in animals, which use nerves and muscles to move and organize their actions.
• Animals can be radially symmetrical (like a tire) or bilaterally symmetrical (like humans).

Simple Movement and Sensory Information

• Simple animals utilize a basic body plan to navigate and process sensory information.
• Sensory information is integrated in the brain to determine action through motor neurons.

Basic Brain Structure in Primitive Animals

• Primitive brains maintain a consistent structure with:
• Spinal Cord
• Hindbrain
• Midbrain
• Forebrain
• Functions become more complex as you move from the spinal cord (basic functions) to the forebrain (complex emotions, decision making).

Human Brain Development

• In embryos, the brain resembles primitive structures (spinal cord, hindbrain, midbrain, forebrain) but changes significantly during development, leading to larger forebrains for advanced functions.

Major Brain Structures to Know (17 Total)

1. Brainstem

• Composed of:
  • Medulla Oblongata: regulates breathing, circulation, digestion.
  • Pons: relays signals between the cerebrum and the cerebellum; involved in sleep.
  • Midbrain: processes visual and auditory data, initiates reflex actions.
• Functions:
  • Basic life functions (breathing, heart rate, digestion).
  • Routing and filtering sensory information.

1. Cerebellum

• Located at the back of the brain.
• Functions in motor control, coordination, and motor memory (like learning to ride a bike).

1. Thalamus

• A relay station sitting above the brainstem.
• Functions:
  • Sorts and directs sensory information to the correct areas of the brain.

1. Hypothalamus

• Located just above the roof of the mouth.
• Functions:
  • Regulates homeostasis (body temperature, hunger, thirst).
  • Influences circadian rhythms.

1. Pituitary Gland (part of the brain, posterior pituitary)

• Releases hormones (like antidiuretic hormone and oxytocin).

1. Cerebrum

• The dominant upper part of the brain responsible for higher functions.
• Integrates sensory data and coordinates voluntary movement.
• Composed of billions of neurons connected by synapses.

1. Corpus Callosum

• Connects the two hemispheres of the cerebrum.
• Facilitates communication between hemispheres.

1. Basal Ganglia

• A group of nuclei beneath the cerebral cortex.
• Involved in motor control; dysfunction relates to conditions like Parkinson's disease.

Cerebral Cortex and Its Lobes

• Comprises about 80% of the brain and is divided into four lobes:

1. Frontal Lobe
   • Functions:
   • Executive function, emotional control, decision-making.
2. Parietal Lobe
   • Functions:
   • Sensory perception, awareness of environment.
3. Occipital Lobe
   • Functions:
   • Responsible for vision.
4. Temporal Lobe
   • Functions:
   • Language processing, memory, hearing.

• Somatosensory Cortex: Located in the parietal lobe, processes sensory input.
• Motor Cortex: Sends out motor commands, located adjacent to the somatosensory cortex.

Brain Function Integration

• The brain integrates sensory inputs (like visual information) to respond appropriately.
• Recent imaging technology allows scientists to investigate brain activity more effectively, leading to better understanding of brain function and structure.

Conclusion

• Review the 17 brain structures and their functions frequently.
• Utilize tools such as flashcards for effective memorization of brain anatomy and functions.