The Impact of Screen Time on Mental Health

General Overview

• The central nervous system (CNS) is comprised of the brain and spinal cord.
• The peripheral nervous system (PNS) comprises the nerves that connect the CNS to the rest of the body.
• The PNS is categorized into sensory (afferent) and motor (efferent) components.
• The motor component is further divided into somatic (voluntary) and autonomic (involuntary) parts.
• The autonomic nervous system (ANS) is further divided into sympathetic and parasympathetic components.

Cranial Nerves

• There are 12 pairs of cranial nerves.
• Cranial nerves I and II originate from the brain, while the remaining 10 originate from the brainstem.
• Some cranial nerves have both sensory and motor functions.

Spinal Nerves

• There are 31 pairs of spinal nerves.
• Each spinal nerve has a dorsal (sensory) root and a ventral (motor) root.
• Spinal nerves exit the vertebral column via intervertebral foramina.
• Spinal nerves are categorized into cervical, thoracic, lumbar, sacral, and coccygeal regions.
• Spinal nerves form plexuses which are networks of nerves within the body.

Organization & Function of the Brain

• Cerebrum:
  • Divided into lobes: frontal, parietal, temporal, occipital.
  • Important for higher-order functions like language.
  • Contains the primary motor cortex.
• Diencephalon:
  • Contains the thalamus and hypothalamus, which are key relay centers for sensory information and hormone regulation respectively.
• Brainstem:
  • Composed of the midbrain, pons, and medulla oblongata.
  • Crucial for regulating vital functions like breathing and heart rate.
• Cerebellum:
  • Located dorsal to the brainstem.
  • Responsible for motor coordination, balance, and posture.

Peripheral Nervous System (PNS)

• The PNS is comprised of the cranial nerves and spinal nerves.
• Somatic Nervous System: Controls voluntary movements.
• Autonomic Nervous System (ANS): Regulates involuntary functions such as heart rate, digestion, and temperature.
  • Sympathetic nervous system: Prepares the body for stress or “fight or flight”.
  • Parasympathetic nervous system: Calms the body and conserves energy.

Cranial Nerve Examples

• Olfactory nerve (I):
  • Sensory; responsible for the sense of smell.
• Optic nerve (II):
  • Sensory; responsible for vision.
• Oculomotor nerve (III):
  • Motor; controls most eye movements, including pupil constriction and lens accommodation.

Basic Circuitry

• Reflex arcs: Allow for rapid, involuntary responses to stimuli.
• Cranial and spinal nerve tracts and pathways: Carry signals between the CNS and PNS for motor and sensory information.

This quiz explores the various effects of excessive screen time, particularly focusing on mental health and productivity. It examines misconceptions about social media and offers strategies for balancing technology use with outdoor activities. Test your understanding of digital distraction and its implications for well-being.