Lecture 8 - Research Methods Flashcards
What are the three layers of the meninges that protect the CNS?
The dura mater (outermost), arachnoid membrane (middle), and pia mater (innermost).
What is the dura mater, and what is it made of?
The dura mater is the outermost layer of the meninges. It is made of tough, dense connective tissue that provides protection and support to the central nervous system (CNS).
What is the arachnoid membrane, and what is it made of?
The arachnoid membrane is the middle layer of the meninges. It acts as a cushioning layer and contains cerebrospinal fluid (CSF) in the subarachnoid space (area between this layer and the pia mater). It is made of a web-like structure of connective tissue.
What is the pia mater, and what is it made of?
The pia mater is the innermost layer of the meninges. It closely adheres to the surface of the brain and spinal cord, providing protection and nourishment. It is made of delicate connective tissue and contains blood vessels.
How is the CNS protected differently than the PNS?
The CNS is surrounded by bone and meninges, while the PNS is only surrounded by regular connective tissue.
What role does cerebrospinal fluid (CSF) play in the CNS?
It provides nutrients, removes waste, cushions the brain, and circulates immune system cells.
What are the four ventricles of the brain that contain cerebrospinal fluid?
The two lateral ventricles, the third ventricle, and the fourth ventricle.
Lateral Ventricles: Large, C-shaped cavities in the left and right hemispheres of the brain that produce cerebrospinal fluid.
Third Ventricle: Narrow cavity located beneath the lateral ventricles that connects to them and is surrounded by various brain structures.
Fourth Ventricle: Between the brainstem and cerebellum, connecting to the third ventricle and allowing cerebrospinal fluid to flow into the surrounding areas.
Where is cerebrospinal fluid (CSF) produced?
In the choroid plexus inside the brain’s ventricles.
What are the main functions of the basal ganglia?
The basal ganglia are brain structures that help control voluntary movements, manage motivation, and support reinforcement learning and habit formation. They coordinate our actions, making them purposeful and effective.
How does the basal ganglia receive input and send output?
It receives input from the forebrain, especially the frontal lobe, and sends output to the cerebral cortex and hindbrain.
What is the role of the hippocampus in the limbic system?
It is essential for forming long-term, explicit memories like facts and events.
What is the function of the amygdala?
It processes emotions, particularly fear.
What process marks the end of neurogenesis in humans?
Apoptosis, or programmed cell death, which occurs around the fifth month of development.
What is the neural tube and when does it form during brain development?
The neural tube is the initial structure from which the brain develops, and it forms during the first month of development.
What is the difference between symmetrical and asymmetrical cell division during brain development?
Symmetrical division produces two identical neural progenitor cells, while asymmetrical division results in one cell migrating away to become a neuron or glial cell.
What are CT scans used for in brain imaging?
To quickly create images of the brain and skull using X-rays, though they don’t provide high-resolution images of soft tissue.
How does functional MRI (fMRI) differ from traditional MRI?
fMRI measures changes in blood oxygen levels, providing both structural and functional information about brain activity.
What are MRI scans used for in brain imaging?
MRI (Magnetic Resonance Imaging) is used to obtain high-resolution images of the brain and soft tissues by using strong magnetic fields and radio waves. It primarily measures the magnetic properties of hydrogen atoms in water molecules.
What are fMRI scans used for in brain imaging?
fMRI (Functional Magnetic Resonance Imaging) measures brain activity by detecting changes in blood flow and oxygenation. It relies on the magnetic properties of hemoglobin in blood, showing regions of increased activity.
What are DTI scans used for in brain imaging?
DTI (Diffusion Tensor Imaging) is used to visualize white matter tracts in the brain by measuring the diffusion of water molecules along axonal pathways. It is a type of MRI that provides information about the directionality of water movement.
What are PET scans used for in brain imaging?
PET (Positron Emission Tomography) scans are used to observe metabolic processes in the brain by detecting radioactive tracers (usually glucose or other molecules) that emit positrons as they decay.
PET scans are used to track specific processes, such as neurotransmitter receptor activity, though they have been largely replaced by fMRI for most purposes.
What are EEGs used for in brain imaging?
EEG (Electroencephalography) measures electrical activity in the brain through electrodes placed on the scalp. It captures voltage fluctuations resulting from ionic current flows within the neurons.
What is an excitotoxic lesion?
An excitotoxic lesion is a brain lesion caused by the excessive stimulation of neurons through neurotransmitters like glutamate, leading to cell death.
What is the use of excitotoxic lesions in brain research?
Excitotoxic lesions are used to investigate the effects of neuronal damage on behavior and to model neurodegenerative diseases.
