Thalamus
- Situated between the cerebral cortex and midbrain.
- Main function is relaying and processing sensory and motor signals to the cerebral cortex
- Regulates consciousness, sleep, activity, and alertness.
- Every sensory system includes a thalamic nucleus that receives sensory signals and sends them to cortical areas.
- Surrounds the third ventricle.
- Damage to the thalamus can lead to permanent coma.
Hypothalamus
- One of the most important functions is to link the nervous system to the endocrine system through the pituitary gland.
- Located below the thalamus and above the brain stem.
- Found in all vertebrate brains.
- Roughly the size of an almond in humans.
- Responsible for some metabolic processes and other activities of the autonomic nervous system.
- Controls body temperature, hunger, thirst, fatigue, sleep, and circadian cycles.
Hippocampus
- Part of the limbic system
- Plays important roles in the consolidation of information from short-term to long-term memory and spatial navigation.
- Humans have one in each side of the brain.
- The hippocampus is one of the first regions of the brain to suffer damage when diagnosed with Alzheimer's disease.
- Stores the explicit memory.
- Other damage includes oxygen starvation, temporal lobe epilepsy, or amnesia.
Cerebellum
- Located underneath the cerebral hemispheres and has the appearance of a separate structure.
- Plays an important role in motor control, cognitive functions, and regulating fear and pleasure responses.
- Does not initiate movement, but contributes to coordination, precision, and accurate timing.
- Receives input from sensory systems of the spinal cord and from other parts of the brain.
- Damage to the cerebellum does not cause paralysis, but produces disorders in fine movement, equilibrium, posture, and motor learning.
- Cerebellum is necessary for different types of motor learning, such as learning to adjust to changes in sensorimotor relationships.
Reticular Activating System
- Set of connected nuclei in the brains of vertebrates that is responsible for regulating arousal and sleep-wake transitions.
- During sleep, neurons in the RAS will have a much lower firing rate and a ligher level during the waking state.
- Helps meditate transitions from relaxed wakefulness to periods of high attention.
- Increased blood flow in the midbrain reticular formation during tasks that require increased alertness and attention.
Pons
- The structure located on the brain stem just above the medulla and below the midbrain.
- Includes tracts that conduct signals from the cerebrum down to the cerebellum and medulla.
- These tracts also carry the sensory signals up into the thalamus.
- Nuclei in the pons relay signals from the forebrain to the cerebellum.
- Other nuclei deal with: sleep, respiration, swallowing, bladder control, hearing, equilibrium, taste, eye movement, facial expressions, facial sensation, and posture.
- Also involved in sleep paralysis and generating dreams.
Medulla
- The Medulla is the lower half of the brainstem.
- Connects the higher levels of the brain to the spinal cord.
- Responsible for regulating several basic functions:
- Respiration, Cardiac center & reflex centers (vomiting, coughing, sneezing, swallowing)
- Deals with autonomic, involuntary functions such as breathing, heart rate, and blood pressure.
Spinal Cord
- The Spinal Cord is a long, thin, tubular bundle of nervous tissue and support cells that extends from the brain.
- Combined with the brain, the two make up the central nervous system.
- Functions in the transmission of neural signals between the brain and rest of the body.
- 3 Main Functions
- Channel for motor information.
- Channel for sensory information.
- Center for coordinating certain reflexes.
Corpus Callosum
- The Corpus Callosum connects the left and right brain and facilitates communication between the hemispheres.
- Transfers motor, sensory, and cognitive information between the hemispheres.
- Also involved in other functions: Tactile localization, eye movement, and maintaining the balance of arousal and attention.
Cerebrum
- With the assistance of the cerebellum, the cerebrum controls all voluntary actions in the body.
- Lies in front or on top of the brainstem and is the largest and best-developed of the five major divisions of the brain in humans.
- Directs the conscious motor functions of the body.
- Also is involved in memory along with other parts of the brain.
- Receives and processes visual, auditory, and other information.
- Synthesizes sensory information into our perceptions of the world around us.
- Damage to the cerebrum can result in loss of muscular power and precision.
Midbrain
- Portion of the central nervous system.
- Located below the cerebral cortex.
- Deals with vision, hearing, motor control, sleep/wake, arousal, and temperature regulation.
- Relays information for vision and hearing
- Smallest region in the brain