The Human Neural System:

• Complex network of specialized cells.

• Controls and coordinates bodily functions.

• Responds to various stimuli.

• Maintains internal balance.

The Midbrain:

• Part of the brainstem.

• Involved in sensory processing, especially visual and auditory.

• Role in motor control and regulation of sleep-wake cycles.

Reflex Action and the Reflex Arc:

• Rapid, involuntary responses to stimuli.

• Involves sensory receptor, sensory neuron, interneuron, motor neuron, and effector organ.

• Allows quick responses without conscious thought.

Peripheral Nervous System (PNS):

• Outside the central nervous system (CNS).

• Transmits sensory information to the CNS.

• Carries motor signals from the CNS to effectors.

• Communication network.

Autonomic Neural System (ANS):

• Involuntary physiological processes.

• Regulates heart rate, digestion, and more.

• Sympathetic and parasympathetic divisions for balance.

Central Neural System (CNS):

• Brain and spinal cord.

• Central control center.

• Processes sensory information.

• Initiates motor responses.

• Role in cognition, emotion, and consciousness.

Formation of the CNS:

• Originates from a neural tube during embryonic development.

• Complex folding and differentiation.

• Differentiation of neural stem cells into neurons and glial cells.

Protection of the Brain:

• Encased in the bony skull.

• Surrounded by cerebrospinal fluid (CSF) for cushioning.

• Meninges cover the brain and spinal cord.

Forebrain:

• Largest and most complex part of the brain.

• Includes thalamus, hypothalamus, and cerebral cortex.

• Responsible for higher cognitive functions, sensory processing, and physiological regulation.

The Thalamus:

• Acts as a relay station for sensory information.

• Directs signals to the cerebral cortex for processing.

• Important for consciousness and sensory perception.

The Cerebral Cortex:

• Outermost layer of the brain.

• Responsible for reasoning, language, memory, and voluntary muscle movement.

• Highly folded for increased surface area.