Functional Anatomy of the Brain: The Thalamic Region and Brain Stem

This flashcard set covers the functional anatomy of the diencephalon, brain stem, reticular formation, and cerebellum as described in the lecture notes.

Diencephalon

Located near the midline of the brain above the midbrain, this region contains the thalamus, epithalamus, and hypothalamus.

Thalamus

Functions as a relay station or hub for all sensory impulses to the cerebral cortex, with the exception of smell.

Hypothalamus

A collection of neurochemically distinct nuclei below the thalamus that uses neurochemicals and hormones to maintain homeostasis and control the autonomic nervous system (ANS).

Brain Stem

The region superior but continuous with the spinal cord, consisting of the midbrain, pons, and medulla oblongata.

Medulla Oblongata

Extending from the pons to the spinal cord, it contains ascending/descending tracts and nuclei that regulate vital functions like heartbeat and breathing.

Cardiovascular centre

Nuclei in the medulla that control the rate and force of the heartbeat as well as the diameter of blood vessels.

Respiratory rhythmicity centre

Nuclei in the medulla responsible for controlling the rate and rhythm of breathing.

Decussation of pyramids

The crossing over of motor tract axons in the medulla, which results in each hemisphere of the brain controlling the opposite side of the body.

Pons

Located above the medulla and below the midbrain, it acts as a bridge connecting different parts of the brain and the spinal cord.

Pontine respiratory group

A group of neurons in the pons that acts as an off-on switch to regulate heavy breathing; it is inactive during quiet breathing.

Midbrain

Region extending from the pons to the diencephalon containing nuclei that express neurochemicals to control emotions, alertness, and cognition.

Substantia nigra

Midbrain nuclei containing dopamine-expressing neurons that help control subconscious muscle activities; loss of these neurons causes Parkinson’s disease.

Raphe nuclei

Nuclei within the midbrain characterized by serotonin-expressing neurons.

Locus coeruleus

Nuclei within the midbrain characterized by noradrenaline-expressing neurons.

Pedunculopontine

Nuclei within the midbrain characterized by acetylcholine-expressing neurons.

Reticular Formation

A netlike arrangement of neuronal cell bodies and small bundles of myelinated axons that relays sensory input from the spinal cord, ears, or eyes to the cerebrum.

Reticular Activating System (RAS)

The ascending portion of the reticular formation that maintains consciousness and alertness while filtering out insignificant sensory information.

Cerebellum

The second largest part of the brain, known as the 'little brain,' which is important for unconscious motor coordination, cognition, and emotion.

Purkinje neurons

Specific neurons located within the cerebellum.

Ataxia

A disease linked to the cerebellum, characterized by motor incoordination.