Neuroanatomy & Neurophysiology Flashcards

What is the main function of the central nervous system?

Answer: Control voluntary and involuntary actions

The central nervous system (CNS), comprising the brain and spinal cord, acts as the primary control center for the entire body. It processes sensory information, initiates voluntary movements like walking and talking, and regulates essential involuntary functions such as breathing, heart rate, and digestion. Its comprehensive role makes it responsible for coordinating nearly all bodily activities and responses.

What is the function of myelin in the nervous system?

Answer: Increase the speed of nerve impulses

Myelin is a fatty substance that forms an insulating sheath around nerve fibers, or axons, in the nervous system. This myelin sheath acts like insulation on an electrical wire, allowing electrical nerve impulses to travel much faster along the axon. By preventing the dissipation of the electrical signal, myelin ensures rapid and efficient communication between neurons, which is vital for quick responses and complex cognitive functions.

Which part of the brain controls vital autonomic functions like heart rate and respiration?

Answer: The brainstem

The brainstem, located at the base of the brain and connecting to the spinal cord, is a vital control center for many basic life functions. It regulates critical autonomic processes that occur without conscious thought, such as heart rate, breathing, blood pressure, and sleep-wake cycles. Damage to the brainstem can therefore have severe, life-threatening consequences, highlighting its essential role in sustaining life.

What is the function of the hippocampus in the brain?

Answer: Forming new memories and learning

The hippocampus is a crucial brain structure located in the medial temporal lobe, playing a central role in memory formation and learning. Specifically, it is essential for converting short-term memories into long-term memories and for spatial navigation. Damage to the hippocampus can severely impair a person's ability to form new memories, a condition often seen in diseases like Alzheimer's.

What is the role of neurotransmitters in the nervous system?

Answer: Transmit signals between neurons

Neurotransmitters are chemical messengers that enable communication between neurons across a synapse, the small gap between nerve cells. When an electrical signal reaches the end of a neuron, it triggers the release of neurotransmitters, which then bind to receptors on the adjacent neuron, either exciting or inhibiting it. This process is fundamental for all brain functions, including thought, emotion, and movement.

What is the function of the sympathetic nervous system?

Answer: Managing stress responses

The sympathetic nervous system is a division of the autonomic nervous system primarily responsible for the 'fight or flight' response. It prepares the body to react to perceived threats or stress by increasing heart rate, dilating pupils, diverting blood flow to muscles, and releasing adrenaline. This system is crucial for survival, enabling rapid physiological adjustments to dangerous situations.

What is the role of the parietal lobe in the brain?

Answer: Processing sensory information

The parietal lobe, located at the top and back of the brain, is primarily responsible for processing sensory information from the body. This includes touch, temperature, pain, and pressure, as well as spatial awareness and navigation. It integrates sensory input from various sources to form a coherent understanding of the world around us and our position within it.

What happens when the blood-brain barrier is compromised?

Answer: Harmful substances can enter the brain, causing damage

The blood-brain barrier is a highly selective semipermeable membrane that separates circulating blood from the brain and extracellular fluid in the central nervous system. Its primary function is to protect the brain from pathogens, toxins, and harmful chemicals. When this barrier is compromised, it loses its protective integrity, allowing potentially damaging substances to enter the delicate brain tissue, which can lead to inflammation, infection, or neurological damage.

What is the significance of the blood-brain barrier in neurophysiology?

Answer: It protects the brain by controlling the flow of substances

The blood-brain barrier is a critical physiological mechanism that maintains the stable environment necessary for optimal brain function. It acts as a gatekeeper, carefully regulating which substances from the bloodstream can enter the brain tissue. This selective permeability is vital for shielding the brain from circulating toxins, pathogens, and fluctuations in blood composition, thereby preserving neuronal health and function.