GPT Neuro Notes Flashcards
(63 cards)
What are the four lobes of the cerebrum and their primary functions?
Frontal (motor cortex - executive function - speech production) - Parietal (somatosensory - spatial processing) - Temporal (auditory - language comprehension - memory) - Occipital (visual processing)
What type of fibers connect the two hemispheres of the brain?
Commissural fibers (e.g. corpus callosum)
Name the subcortical nuclei of the basal ganglia and their role.
Caudate - Putamen - Globus pallidus - Substantia nigra - Subthalamic nucleus - involved in initiation and inhibition of movement
What is the function of the thalamus in the CNS?
Acts as a relay station for sensory and motor signals to the cerebral cortex and is involved in consciousness and sleep
Which brain region controls homeostasis and autonomic function?
The hypothalamus
What are the three parts of the brainstem and their key functions?
Midbrain (eye movements - contains substantia nigra) - Pons (connects cerebellum and contains cranial nerve nuclei V–VIII) - Medulla oblongata (controls respiratory and cardiovascular centers - cranial nerves IX–XII)
What is the main role of the cerebellum?
Coordination of balance - posture - timing of muscle contractions
Where does the spinal cord end in adults?
At the level of L1-L2 vertebrae
Describe the organization of gray and white matter in the spinal cord.
Gray matter is butterfly-shaped with dorsal horns (sensory) and ventral horns (motor) - White matter surrounds gray matter and contains ascending and descending tracts
What is the difference between somatic and autonomic nervous systems?
Somatic controls voluntary skeletal muscles - Autonomic controls involuntary smooth muscle - cardiac muscle - glands
Where do sympathetic preganglionic neurons originate?
From the thoracolumbar spinal cord (T1-L2)
Where do parasympathetic preganglionic neurons originate?
From the craniosacral regions (cranial nerves III - VII - IX - X - and sacral spinal cord)
What cells form the myelin sheath in the CNS and PNS?
Oligodendrocytes in CNS - Schwann cells in PNS
Describe the resting membrane potential of a neuron.
Approximately -70 mV - Inside the neuron is negative relative to outside - Maintained by Na+/K+ ATPase and K+ leak channels
What ion movement causes depolarization during an action potential?
Influx of Na+ through voltage-gated sodium channels
What ion movement causes repolarization during an action potential?
Efflux of K+ through voltage-gated potassium channels
What is saltatory conduction?
Action potentials jump between Nodes of Ranvier along myelinated axons - increasing conduction speed
Name the main inhibitory and excitatory neurotransmitters in the CNS.
GABA (inhibitory) - Glutamate (excitatory)
What receptors does acetylcholine act on in the autonomic nervous system?
Nicotinic receptors at ganglia and neuromuscular junction - Muscarinic receptors at parasympathetic target organs
Name two major dopamine pathways and their functions.
Nigrostriatal (motor control) - Mesolimbic/mesocortical (reward - cognition)
Which sensory pathway carries fine touch and proprioception?
Dorsal column-medial lemniscal pathway
Which sensory pathway carries pain and temperature?
Spinothalamic tract
Where do corticospinal tract fibers decussate?
At the medullary pyramids
What is the difference between the lateral and anterior corticospinal tracts?
Lateral corticospinal tract controls limb muscles (crossed fibers) - Anterior corticospinal tract controls axial muscles (uncrossed fibers)
