Nervous system 1 - divisions, neuroglia, neurons, hemisphere, and areas Flashcards
What are the main components of the Central Nervous System (CNS)?
The CNS includes the brain and spinal cord, responsible for integrating sensory information and responding accordingly.
What is the function of the Peripheral Nervous System (PNS)?
The PNS connects the CNS to the rest of the body, functioning as a communication network.
What are the two divisions of the PNS?
The Sensory division (transmits sensory information to the CNS) and the Motor division (transmits signals from the CNS to effector organs).
What are Neuroglia?
Supporting cells in the nervous system that provide protection, support, and maintenance for neurons.
What do Astrocytes do?
They maintain the blood-brain barrier, regulate electrical impulses, and clean excess neurotransmitters and potassium ions
What are the two divisions of the Autonomic nervous system?
The Sympathetic division (“fight or flight” response) and the Parasympathetic division (“rest and digest”).
What are the subcategories of the Motor division in the PNS?
The Somatic nervous system (voluntary control of skeletal muscles) and the Autonomic nervous system (involuntary regulation of visceral functions).
Name the types of Neuroglia in the CNS.
Astrocytes, Microglial cells, Ependymal cells, and Oligodendrocytes.
What is the role of Microglial cells?
They act as immune defenders in the CNS, transforming into macrophages to engulf pathogens and debris.
What is the function of Ependymal cells?
They line the ventricles of the brain and spinal cord, forming a barrier between cerebrospinal fluid and tissue fluid.
What do Oligodendrocytes do?
They produce the myelin sheath in the CNS, which insulates nerve fibers and speeds up signal transmission.
What are the key parts of a neuron?
Cell body, dendrites, axon, axon hillock, myelin sheath, node of Ranvier, terminal branches, and axonal terminals.
What is the role of Schwann cells?
Schwann cells form myelin sheaths around peripheral nerve axons and help with nerve regeneration.
What is the function of Satellite cells in the PNS?
Satellite cells surround neuron cell bodies in ganglia, regulating the external chemical environment.
What is the difference between a nucleus and a ganglion?
A nucleus is a collection of neuron cell bodies in the CNS, while a ganglion is in the PNS.
What are Neurons?
Neurons are excitable cells responsible for transmitting electrical signals throughout the body.
What is the difference between a tract and a nerve?
A tract is a bundle of axons in the CNS, while a nerve is a bundle of axons in the PNS.
What are the three types of neurons based on the number of processes?
Multipolar, Bipolar, and Unipolar neurons.
What is a Multipolar neuron?
A neuron with many processes extending from the cell body, common in the CNS.
What is a Bipolar neuron?
A neuron with two processes, found in some sensory organs like the eye and ear.
What are the three functional regions of a neuron?
Receptive region (receives stimuli), Conducting region (transmits action potential), and Secretory region (releases neurotransmitters).
What is a Unipolar (Pseudo-unipolar) neuron?
A neuron with a single process that splits into central and peripheral branches, commonly found in the PNS.
What are the three functional classifications of neurons?
Sensory neurons (carry impulses to the CNS), Motor neurons (carry impulses away from the CNS), and Interneurons (process information within the CNS).
What type of neurons are most motor neurons?
Motor neurons are typically multipolar.
What type of neuron is primarily involved in sensory functions?
Sensory neurons, which are typically unipolar or bipolar.
What is the most significant aspect of the brain’s complexity?
The intricate network of connections within the brain enables its vast array of functions, not just its size.
What are Interneurons?
Neurons that connect sensory and motor neurons, responsible for processing and integrating information in the CNS.
What are the major subdivisions of the brain?
- Cerebral Hemispheres
- Diencephalon
- Brain Stem
- Cerebellum
What functions are the cerebral hemispheres responsible for?
Thought, emotion, reason, touch, and vision.
What structures are part of the diencephalon and their functions?
- Thalamus: Relay station for information
- Hypothalamus: Hormone release, body temperature regulation
- Epithalamus: Pineal gland regulates circadian rhythms and melatonin production
What are the parts of the brain stem and their functions?
- Midbrain: Visual and auditory control, eye movement
- Pons: Relays signals, regulates sleep, respiration, etc.
- Medulla Oblongata: Controls autonomic functions like breathing and heart rate
What does the cerebellum regulate?
Movement, posture, and balance.
How is gray and white matter organized in the brain?
The cerebral hemispheres and cerebellum have an outer layer of gray matter (cortex). The brain stem contains gray matter (brain nuclei) within white matter.
How is the spinal cord organized?
It has a central cavity (spinal canal) surrounded by gray matter and then white matter. Gray matter contains neuron cell bodies, and white matter consists of myelinated axons.
What is the function of the brain’s ventricles?
They circulate cerebrospinal fluid (CSF), cushioning the brain. The ventricles are interconnected, and they communicate with the spinal cord.
What are the three basic regions of the cerebral cortex?
- Cerebral Cortex: Outer gray matter, responsible for processing information
- White Matter: Beneath the cortex, myelinated axons
- Basal Nuclei: Deep gray matter, involved in motor control and learning
What are the surface markings and lobes of the cerebral hemispheres?
- Gyri: Raised portions
- Sulci: Shallow grooves
- Fissures: Deep grooves
- Lobes: Frontal, Parietal, Occipital, Temporal, Insular
What are Brodmann areas?
A system of classification for regions of the cortex, associated with specific functions like motor, sensory, and cognitive functions.
What are the three main functional areas of the cerebral cortex?
- Motor Areas: Control voluntary movement
- Sensory Areas: Process sensory information
- Association Areas: Integrate information for complex behaviors
What is the primary motor cortex?
Located in the precentral gyrus, it controls skeletal muscles and is represented spatially (somatotopy) in the motor homunculus.
What does contralateral control mean?
Each hemisphere of the brain controls functions for the opposite side of the body.
What does the motor homunculus illustrate?
The proportional representation of the body in the motor cortex, with larger areas for parts requiring more precise control, like the hands and face.
What does Broca’s area do?
Directs the muscles involved in speech production and helps plan speech and motor activities.
What is the role of the premotor cortex?
It plans and coordinates movements by sequencing basic motor actions into more complex tasks.
What does the frontal eye field control?
Coordinates voluntary eye movements, ensuring both eyes move together.
What role does the Occipital Lobe play in sensory processing?
- Contains the primary visual cortex (processing visual information).
- The visual association area helps interpret visual stimuli.
What is the role of the Parietal Lobe in sensory processing?
- Contains the primary somatosensory cortex, which processes sensory input from the body.
- The somatosensory association cortex integrates sensory information for understanding spatial organization and texture.
What does the Insular Lobe do?
- Involved in somatic and visceral sensations, though not shown in the illustration.
What is the function of the Temporal Lobe’s sensory areas?
- Houses the primary auditory cortex (processing sound information).
- The auditory association area interprets sounds based on memory.
Where is the Primary Somatosensory Cortex located?
- In the postcentral gyrus of the parietal lobe, corresponding to Brodmann areas 1-3.
- Receives sensory input from the skin and proprioceptors.
What are the specialized sensory areas beyond the primary cortices?
- Vestibular Cortex: Sense of balance.
- Olfactory Cortex: Smell.
- Gustatory Cortex: Taste.
- Visceral Sensory Area: Internal sensations like fullness or heartbeat.
What does the Somatosensory Association Area do?
- Located posterior to the primary somatosensory cortex (Brodmann areas 5-7).
- Integrates sensory inputs like temperature and pressure, helping us recognize objects through touch.
What is the Motor Homunculus?
A map in the primary motor cortex showing how different regions control voluntary movements in the body.
What is the Sensory Homunculus?
A sensory map in the primary somatosensory cortex, showing how different body regions process sensory information.
What happens if the Primary Visual Cortex is damaged?
Can lead to cortical blindness, where the person loses visual perception in parts of the visual field despite having intact eyes.
What occurs if the Visual Association Area is damaged?
Can lead to visual agnosia (difficulty recognizing objects), prosopagnosia (difficulty recognizing faces), or motion perception issues.
What does the Auditory Association Area do?
Located near the primary auditory cortex, it interprets sounds, such as speech and music, using memory.
Where is the Vestibular Cortex located?
In the posterior part of the insula and adjacent parietal cortex, responsible for balance and head position awareness.
Where is the Olfactory Cortex and what does it do?
Located on the medial temporal lobe (uncus), it processes the conscious awareness of smells.
What is the Visceral Sensory Area’s function?
Located posterior to the gustatory cortex, it processes internal sensations like an upset stomach or fullness.
What is the Gustatory Cortex?
Located in the insula, it is involved in the perception of taste.
What is the Prefrontal Cortex’s role?
- It is essential for higher-order functions like abstract reasoning, judgment, memory recall, and personality.
- It matures gradually and is influenced by social feedback.
What are Multimodal Association Areas?
Areas that receive sensory input and integrate it to form a coherent perception of the environment. They include:
- Anterior Association Area (Prefrontal Cortex): Involved in planning, decision-making, and complex cognitive functions.
- Posterior Association Area: Important for spatial awareness, pattern and face recognition.
- Limbic Association Area: Plays a role in emotional responses and memory.
What happens if the Prefrontal Cortex is damaged?
Tumors or lesions can cause mood swings, loss of attentiveness, and altered social behavior.
What is the function of the Posterior Association Area?
Integrates sensory input, forming a cohesive understanding of the environment. It’s also involved in spatial awareness and recognizing patterns/faces.
What is the function of the Limbic Association Area?
Plays a crucial role in adding emotional significance to experiences and memories.
