CNS Anatomy, CSF, Neural Circuits & Brain Functions: Chapter 11

What does the Central Nervous System (CNS) consist of?

The brain and spinal cord.

What is the Peripheral Nervous System (PNS)?

Everything outside the CNS.

What are the four organizing principles of the CNS?

Hierarchy, Functional Organization, Topographical Organization, Neuroplasticity.

What is gray matter composed of?

Neuron cell bodies and nuclei; it is the site of processing.

What is white matter composed of?

Myelinated axons and nerve tracts that carry information between regions.

What are the three layers of meninges?

Dura Mater, Arachnoid Mater, Pia Mater.

What is the function of cerebrospinal fluid (CSF)?

Buoyancy/support, cushioning/protection, nutrient delivery, waste removal, ion and chemical homeostasis, immune buffering.

Where is CSF produced?

By the choroid plexus located in the ventricles.

What is the pathway of CSF flow?

Lateral Ventricles → Interventricular Foramina → Third Ventricle → Cerebral Aqueduct → Fourth Ventricle → Central Canal of Spinal Cord.

What is the function of the Blood-Brain Barrier (BBB)?

Protects the CNS from toxins, drugs, and pathogens while maintaining a stable environment.

What types of molecules can cross the BBB?

Lipid-soluble molecules, glucose, amino acids, hormones, and growth factors.

What are the major arteries supplying the CNS?

Internal Carotid Arteries and Vertebral Arteries.

What is an ischemic stroke?

A stroke caused by blocked blood flow.

What are the two main types of CNS neurons?

Multipolar neurons and pyramidal neurons.

What are the functions of astrocytes?

Neurotransmitter uptake/release, maintain BBB, regulate extracellular ions, store glycogen, provide glucose to neurons, repair tissue, stimulate myelination.

What is neurogenesis?

The formation of new neurons, occurring during development and limited in adults.

What is chemotaxis in the context of neuron growth?

Movement guided by attractive or repulsive chemical signals to find targets.

What is the principle of neuroplasticity?

"Neurons that fire together, wire together."

What are the components of a reflex arc?

Sensory neuron, interneuron (sometimes), motor neuron, and effector.

What is a dermatome?

An area of skin supplied by one spinal nerve.

What is the function of the medulla?

Controls heart rate, blood pressure, breathing, swallowing, vomiting, and coughing.

What is the role of the thalamus?

It is the major sensory relay station for most sensory information before it reaches the cortex.

What does the cerebellum control?

Balance, posture, eye movements, coordination, smooth movements, and motor learning.

What is the function of Broca's area?

Speech production.

What is the function of Wernicke's area?

Language comprehension.

What is the homunculus?

A map of the body on the sensory cortex, representing sensitivity rather than size.

What are the main functions of the limbic system?

Emotion, memory, motivation, reproduction, and nutrition.

What is long-term potentiation (LTP)?

A process that strengthens synapses, important for memory formation.

What is long-term depression (LTD)?

A process that weakens synapses.