Nervous System Overview Quiz

Nervous System Overview

• The nervous system is divided into the central nervous system (CNS) and the peripheral nervous system (PNS).
• The CNS contains the brain and spinal cord.
• The PNS contains cranial nerves and spinal nerves.
• Autonomic nerves are part of the PNS and control involuntary functions.

Neuron Structure

• Neurons are the functional units of the nervous system.
• A neuron has a cell body, dendrites, an axon, and terminal buttons.
• Afferent neurons carry information to the CNS from the body.
• Efferent neurons carry information from the CNS to the body.
• Interneurons connect neurons to each other within the CNS.

Glial Cells

• Glial cells are non-neuronal cells that provide support and protection to neurons.
• Types include Oligodendrocytes (CNS) and Schwann cells (PNS).
• These specialized glial cells form myelin sheaths that surround axons, aiding in electrical signal transmission.

White Matter

• White matter is composed mainly of axons and myelin.
• It's typically found in bundles (tracts, fasciculi, columns, etc.) that carry information throughout the CNS.
• A bundle of myelinated axons that travel together within the CNS.

Gray Matter

• Gray matter is primarily composed of neuron cell bodies.
• Ganglia are groups of neuron cell bodies in the PNS.
• Nuclei are groups of neuron cell bodies in the CNS.
• The cerebral cortex is a layer of gray matter on the surface of the brain.

Systems within the Nervous System

• Somatosensory system: transmits information from the skin and musculoskeletal system to the brain.
• Somatic motor system: transmits information from the brain to skeletal muscles.
• Autonomic system: transmits information between the brain and smooth muscle, cardiac muscle, and gland cells.
• Special sensory system: connects sensory structures (visual, auditory, vestibular, olfactory, gustatory) to the brain.

Brain Structure

• The brain is divided into the forebrain, midbrain, and hindbrain.
• The forebrain includes the cerebral hemispheres, diencephalon (thalamus, hypothalamus, epithalamus), and parts related to memory and emotions.
• The midbrain contains the superior and inferior colliculi, which are involved in visual and auditory processing, respectively.
• The hindbrain consists of the pons, cerebellum, and medulla oblongata. The cerebellum coordinates movement, while the pons and medulla oblongata have roles in vital functions such as breathing and regulating heart rate.

Brain Lobes and Function

• Prefrontal cortex: associated with intellectual functions, emotional processes, speech production.
• Frontal lobe: involved in voluntary movements, emotional aspects of language, processing of pain and vestibular functions
• Temporal lobe: involved in auditory perception, memory, and visual recognition.
• Parietal lobe: involved in somesthetic sensation, spatial awareness, taste sensation.
• Occipital lobe: involved in visual perception.
• Brain regions like the insula, and Wernicke's area, plays vital roles in integration and the interpretation of information and language.

Limbic System

• Limbic system involves hypothalamus, thalamus, cingulate gyrus, prefrontal cortex, septal area, amygdala, and hippocampus.
• Main Functions: short-term memory, emotional regulation, modulation of hypothalamic functions.
• Hippocampus: The formation of memories and learning are central tasks for the hippocampus.

Basal Ganglia

• Basal ganglia, a collection of gray matter within the brain, is critical for motor control and procedural learning.
• The basal ganglia play a vital role in controlling eye movements and routine behaviors.
• Dysfunction of the basal ganglia is linked to conditions like Parkinson's disease and obsessive-compulsive disorder.

Cerebellum

• The cerebellum is part of the hindbrain, is essential for coordinating voluntary movement (e.g., posture).
• Damage to the cerebellum can lead to loss of balance, ataxia, and problems with movement coordination.

Cranial Nerves

• Cranial nerves are part of the peripheral nervous system.
• They connect the brain to structures in the head, neck, and face.
• There are 12 pairs of cranial nerves, each with a specific function.
• Different cranial nerves are responsible for sensory, purely motor, or mixed functions (e.g., smell, vision, chewing, facial expression, hearing, etc.

Pineal Gland

• This gland produces melatonin, impacting the sleep-wake cycle.

Spinal Cord

• The spinal cord transmits information between the brain and the body.
• It's vital for reflexes and sensory-motor input and output.
• Spinal cord damage can result in paralysis and impaired sensory functions depending on the level of injury.

Other notable structures

• Major components of the brainstem such as pyramidal decussation, the medullary pyramids, the inferior olivary nucleus (involved in motor control), crossing over of fibers in the pyramids, roles in sensory/motor functions and autonomic regulation.