Topic 6 - Nervous system (recorded section)

corpus callosum - a large bundle of myelinated neurons that connects the left and right hemisphere’s of the brain → allows for communication

each hemisphere is divided into 4 sections:

cerebral cortex / cerebrum

→ responsible for highest levels of thinking + memory + processing sensory information

• makes up the bulk of the brain

• has a large surface area due to its folds

 cerebral cortex is divided into 4 lobes:

    frontal lobe - responsible for a variety of functions such as concentration, problem-solving, planning/organizing, self-restraint, short-term memory, speech production

• broca’s area (in frontal lobe)

  • left hemisphere → speech production + articulation

  • right hemisphere → non-verbal communication (i.e. maintaining eye contact, processing sign language, interpreting gestures etc.)

    parietal lobe - responsible for integrating sensory information from various parts of the body (i.e. key component in speech comprehension + taste sensation) + knowledge of numbers and their relations (i.e. math) + reading

    occipital lobe - responsible for processing visual information (i.e. regulation + processing of sight)

    temporal lobe - responsible for processing auditory (hearing) information and interpreting smells

Cerebellum

• fist-sized structure located below the posterior of the cerebral cortex

• responsible for:

  • maintaining posture, balance and equilibrium

  • coordinating hand-eye movements for tasks like tracking + reaching

Diencephalon

• central part of brain - contains: thalamus, hypothalamus, pituitary gland + pineal gland

• responsible for:

  • relaying sensory signal to cerebral cortex

  • endocrine function → hypothalamus + pituitary gland regulates the release of hormones throughout the body

  • regulates circadian rhythm - body’s internal 24 hour clock

  • regulates homeostasis → i.e. maintain internal temperature, blood pressure, calcium + sodium levels

Brain stem

• located in the lowest part of the brain - most primitive of the four sections

  • developed early in evolutionary history to handle the fundamental + involuntary + autonomic functions necessary for survival

• contains 3 parts: midbrain, pons, medulla oblongata

• brain stem connects directly to spinal cord

• responsible for:

  • controls many of the body’s vital involuntary functions (i.e. respiration, heart rate, blood pressure and digestion)

limbic system - network of interconnected brain structures that controls emotions, decisions, motivations, and formation of memories

includes: hypothalamus, hippocampus, amygdala, thalamus, and olfactory bulb

hypothalamus

• monitors blood levels of glucose, salt, pressure and hormones

• controls + maintains body temperature

hippocampus (x2 structures)

• converts short term memories to long term memories

amygdala (x2 structures)

• involved in emotional responses - specifically in aggression + fear → helps attach emotional significance to memories

thalamus (x2 structures)

• responsible for the relay of different sensory signals to cerebral cortex

olfactory bulb (x2 structures)

• important for sense + smell