Nervous System QUESTIONS

Know the four main parts of the brain and their parts (parts of diencephalon and brainstem):

1. Cerebrum

Right and left hemispheres

Cortex (gray matter), white matter, basal nuclei

Lobes: frontal, parietal, temporal, occipital

2. Diencephalon

Thalamus → sensory relay station

Hypothalamus → main visceral control, hormone regulation, autonomic control

Epithalamus → pineal gland (melatonin), habenular nuclei (olfaction & emotions)

3. Brainstem

Midbrain → contains tracts, nuclei, cerebral aqueduct

Pons → relays signals, respiratory centers, cranial nerves V, VI, VII, VIII

Medulla oblongata → cardiovascular & respiratory centers, reflexes, cranial nerves VIII, IX, X, XI, XII

4. Cerebellum

Coordinates skilled movements, balance, posture

Lobes: anterior, posterior, flocculonodular

Structures: vermis (central), hemispheres (wings), arbor vitae (white matter), cerebellar nuclei

Gyrus vs. sulcus in cerebrum:

Gyrus → ridge/fold of the brain

Sulcus → shallow groove between gyri

Function: increases surface area of the cerebral cortex

Gray matter vs. white matter and locations of gray and white matter in parts of the brain and in the spinal cord:

Cerebrum:

Gray matter- Cortex, basal nuclei

White matter- Internal tracts (commissures, association, projection fibers)

Cerebellum

Gray matter: Cerebellar cortex, cerebellar nuclei

White matter: Arbor vitae (white matter tracts)

Spinal Cord

Gray matter: Central H-shaped region (horns)

White matter: Peripheral columns/funiculus

→ gray matter: neuron cell bodies, dendrites, glia, blood vessels

→ white matter: myelinated axons (communication between brain/spinal cord regions)

Types of cerebral white matter:

Commissural fibers → connect corresponding gray areas of both hemispheres (e.g., corpus callosum)

Association fibers → connect different parts of the same hemisphere

Projection fibers → connect cortex with lower brain centers and spinal cord

Central sulcus and the lobes it divides and the functions it divides:

Divides: frontal lobe (anterior) from parietal lobe (posterior)

Functions:

→ Frontal → motor functions, reasoning, personality

→ Parietal → somatosensory processing

Longitudinal fissure:

Deep groove separating the right and left cerebral hemispheres

Layers of the meninges and the spaces associated with them:

Dura matter

Tough, leather-like; two layers in brain

→ Subdural space (potential space; blood can accumulate → subdural hematoma)

Arachnoid Matter

Web-like middle layer

→ Subarachnoid space (contains CSF)

Pia Matter

Innermost, delicate layer

→ In direct contact with brain/spinal cord

Spinal Cord: dura mater single layer; epidural space (fat & vessels), subarachnoid space (CSF)

What part of the brain controls ANS?:

Hypothalamus → main visceral control center; regulates sympathetic & parasympathetic activity

Functions of the hypothalamus:

Controls autonomic nervous system (ANS)

Regulates:

→ Body temperature

→ Hunger and thirst

→ Circadian rhythms and states of consciousness

→ Emotional and behavioral patterns

→ Hormone production via pituitary gland (connected via infundibulum)

What part of the brain controls the heart and respiration?:

Medulla oblongata → cardiovascular center (heart rate & blood vessel diameter), respiratory rhythmicity

Pons → assists medulla in regulating breathing (pneumotaxic and apneustic areas)