Which structures form the diencephalon?

• A. Thalamus and hypothalamus
• B. Cerebral cortex and basal ganglia
• C. Midbrain and pons
• D. Cerebellum and medulla

Answer: (A)

The diencephalon comes from the forebrain and develops into structures that include the thalamus and hypothalamus (with the epithalamus often noted as part of it). The thalamus acts as the main relay station for sensory information to the cortex and helps integrate sensory and motor signals, while the hypothalamus regulates autonomic and endocrine functions, temperature, hunger, and circadian rhythms, among other roles. The cerebral cortex and basal ganglia are derived from the telencephalon, not the diencephalon. The midbrain and pons come from the mesencephalon and hindbrain regions, and the cerebellum and medulla are hindbrain structures. So the thalamus and hypothalamus are the correct pairing for the diencephalon.