N371 Introduction + Review

What are the three primary brain vesicles that form from the neural tube?

Forebrain (prosencephalon), midbrain (mesencephalon), and hindbrain (rhombencephalon).

What are the two main divisions of the PNS?

Sensory (afferent) and motor (efferent).

What does the prosencephalon become?

Telencephalon and diencephalon.

What does the mesencephalon become?

Stays as the midbrain.

What does the rhombencephalon become?

Metencephalon and myelencephalon.

What is the cephalic (mesencephalic) flexure?

The first major bend in the brain tube separating forebrain and hindbrain.

What structures develop from the telencephalon?

Cerebral cortex and basal ganglia.

What does the cingulate gyrus do?

Emotion regulation and error detection.

Function of hippocampus?

Memory consolidation and spatial navigation.

Function of entorhinal cortex?

Hub linking hippocampus and cortex for memory and association.

Function of orbitofrontal cortex?

Decision making, social behavior, reward/punishment evaluation.

What are the main subcortical limbic structures?

Amygdala, hypothalamus, septal nuclei, mammillary bodies, olfactory bulbs, fornix.

What does the amygdala do?

Fear, aggression, emotional memory.

What does the limbic system regulate?

Emotion, motivation, and memory.

What does the fornix do?

Connects hippocampus to other limbic areas — key for episodic memory.

What is the role of the basal ganglia?

Regulate voluntary movement and suppress unwanted movement.

What does the diencephalon form?

Thalamus, hypothalamus, epithalamus, and retina (optic cup).

Function of the thalamus?

Relay sensory input to cortex (except olfaction).

Function of the hypothalamus?

Homeostasis, autonomic control, endocrine link via pituitary.

Function of the epithalamus?

Pineal gland, circadian rhythm, melatonin release.

Main functions of the midbrain?

Motor control, eye movements, auditory and visual reflexes.

What cranial nerves arise from the midbrain?

CN III (oculomotor) and IV (trochlear).

What does the midbrain connect?

Forebrain to hindbrain.

What does the metencephalon form?

Pons and cerebellum.

What is the pons responsible for?

Balance, posture, breathing rhythm, relays signals to cerebellum.

What does the cerebellum do?

Coordinates voluntary movements, balance, and motor learning.

What does the myelencephalon form?

Medulla oblongata.

What are the main functions of the medulla?

Autonomic control (HR, BP, breathing) and reflexes (vomiting, coughing, sneezing).

What is the reticular formation?

Network across brainstem for sleep, arousal, muscle tone, pain modulation. Runs through both metencephalon and myelencephalon

How is gray/white matter arranged in spinal cord vs brain?

Reversed — spinal cord has gray inside, white outside.

How long is the spinal cord relative to the vertebral column?

Ends around L1–L2; shorter than the vertebral column.

How many spinal nerve pairs exist?

31 — 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal.

What are the main structural neuron types?

Multipolar, bipolar, unipolar (pseudounipolar), anaxonic.

What is a multipolar neuron?

One axon, many dendrites — most common.

What is a bipolar neuron?

One axon, one dendrite — found in sensory systems.

What is a unipolar neuron?

One process that splits into dendrite and axon

What is an anaxonic neuron?

No clear axon — mostly interneurons.

What are the main functional neuron types?

Motor (efferent), sensory (afferent), interneurons, cortical neurons.

What are the main glia of the PNS?

Schwann cells and satellite cells.

Function of Schwann cells?

Myelinate single axon segments, help regeneration.

Function of satellite cells?

Surround neuron cell bodies in ganglia; regulate environment and neurotransmitters.

What are the main glia of the CNS?

Oligodendrocytes, astrocytes, microglia, ependymal cells.

Function of oligodendrocytes?

Myelinate multiple axons in CNS.

Function of astrocytes?

Support neurons, regulate ions/NTs, form BBB, maintain metabolism.

Function of microglia?

Immune defense, phagocytosis, cytokine release.

Function of ependymal cells?

Line ventricles, produce and circulate CSF.

Function of nucleolus?

Produces rRNA for ribosomes.

Function of mitochondria?

Produces ATP.

Function of rough ER?

Protein synthesis (ribosome-studded).

Function of smooth ER?

Lipid synthesis and detoxification.

Function of Golgi apparatus?

Sorts, modifies, and packages proteins/lipids.

Translate mRNA into proteins.

Translate mRNA into proteins.

Function of microtubules?

Structural support and transport highways in axons.

What distinguishes motor neurons from cortical neurons?

Motor neurons synapse directly on effectors; cortical neurons process and integrate higher brain functions.

What is the main output tract of the hippocampus?

The fornix.

Which brain structure connects cerebrum and cerebellum?

The pons.

What part of the cerebellum controls trunk and proximal limb coordination?

The vermis.

What part of the cerebellum handles balance and eye reflexes?

The flocculonodular lobe.

What part of the cerebellum is responsible for distal limb coordination?

The intermediate zone.

What part of the cerebellum plans extremity movements?

The lateral hemispheres.

What are the two main parts of the rhombencephalon?

Metencephalon and myelencephalon.

Which cranial nerves originate from the pons?

Cranial nerves V, VI, VII, VIII. (facial sensation, hearing, facial movement)

Which cranial nerves originate from the medulla?

Cranial nerves IX–XII (Swalloing, speech, taste, parasympathetic functions)