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    From Nervous System

    Temporal Lobe
    Involved in auditory perception and memory.
    Cerebellar Hemispheres
    Lateral portions of the cerebellum.
    Thoracic Spinal Cord
    Middle portion of the spinal cord.
    Substantia Nigra
    Involved in movement and reward.
    Dura Mater
    Tough outer meningeal layer.
    Lumbar Plexus
    Nerve network for abdominal wall and thigh.
    Amygdala
    Involved in emotion and memory.
    Hypothalamus
    Regulates autonomic functions, hormones, and homeostasis.
    Filum Terminale
    Fibrous extension from conus to coccyx.
    Occipital Lobe
    Responsible for visual processing.
    Lateral Ventricles
    Paired brain cavities producing CSF.
    Pineal Gland
    Secretes melatonin to regulate sleep-wake cycles.
    Pia Mater
    Innermost layer of meninges.
    Falx Cerebri
    Dural fold between cerebral hemispheres.
    Foramina of Luschka
    Lateral apertures of fourth ventricle.
    Sacral Plexus
    Nerve network for pelvis and lower limb.
    Cerebrospinal Fluid (CSF)
    Protective fluid in brain and spinal cord.
    Arbor Vitae
    White matter of the cerebellum.
    Foramen of Magendie
    Median aperture of fourth ventricle.
    Diaphragma Sellae
    Covers the pituitary gland.
    Spinal Cord
    Transmits neural signals between brain and body.
    Fornix
    Fiber tract involved in memory.
    Fourth Ventricle
    Cavity between brainstem and cerebellum.
    Tectum
    Dorsal part of midbrain controlling visual and auditory reflexes.
    Corpus Callosum
    Connects the left and right cerebral hemispheres.

    Parietal Lobe

    Reviewed by our medical team

    Processes sensory information such as touch, temperature, and pain.

    1. Overview

    The parietal lobe is one of the four major lobes of the cerebral cortex and plays a key role in processing sensory information and integrating it with cognitive functions. It is involved in several functions, including spatial orientation, navigation, sensory perception, and the processing of touch, temperature, and pain sensations. The parietal lobe is critical for the ability to make sense of the world around us, helping us recognize objects, gauge distances, and navigate through our environment. Additionally, the parietal lobe is involved in higher-level functions like language comprehension, mathematical reasoning, and attention.

    2. Location

    The parietal lobe is located near the top and back of the brain, situated behind the frontal lobe and above the temporal lobe. It is bordered by the central sulcus in the front, the occipital lobe in the back, and the lateral sulcus (Sylvian fissure) to the sides. The parietal lobe extends from the lateral sulcus to the midline of the brain and plays a central role in integrating information from the sensory systems and the motor cortex. It is divided into two hemispheres, with each hemisphere processing sensory information from the opposite side of the body.

    3. Structure

    The parietal lobe is composed of several distinct regions that are responsible for different sensory and cognitive processes. The structure of the parietal lobe can be broken down into key components:

    • Somatosensory Cortex (Postcentral Gyrus): Located just behind the central sulcus, the somatosensory cortex is the primary region responsible for processing sensory input from the body. It receives information about touch, pain, temperature, and proprioception (sense of body position) and maps these sensations onto a "sensory homunculus," a visual representation of the body's sensory inputs.

    • Parietal Association Cortex: Surrounding the primary somatosensory cortex, the parietal association cortex integrates sensory information from multiple sources. It is involved in spatial processing, including the ability to understand the position of objects in space, movement, and orientation. It also helps in the coordination of attention and motor tasks.

    • Inferior Parietal Lobule: Located in the lower part of the parietal lobe, the inferior parietal lobule includes regions involved in higher cognitive functions such as mathematical reasoning, language comprehension, and the integration of sensory and motor information for goal-directed behavior. It contains structures such as the angular gyrus and supramarginal gyrus, which are critical for language processing and reading.

    • Posterior Parietal Cortex: The posterior parietal cortex is involved in spatial awareness and navigation, helping individuals recognize where they are in relation to their environment. This area also processes visual and tactile information to guide motor actions such as reaching, grasping, and pointing.

    4. Function

    The parietal lobe plays a significant role in various sensory, motor, and cognitive functions. Some of its key functions include:

    • Sensory perception: The parietal lobe is crucial for processing sensory information from the body. The somatosensory cortex, located in the postcentral gyrus, processes sensations of touch, pain, temperature, and proprioception. This information is essential for experiencing and interacting with the physical world.

    • Spatial awareness and navigation: The posterior parietal cortex is involved in spatial processing, including the recognition of body position and the ability to navigate in space. This area helps individuals perceive their surroundings and understand the location of objects, playing a critical role in tasks such as driving, reaching for objects, and spatial navigation.

    • Attention and coordination: The parietal lobe is responsible for attention, particularly the ability to focus on relevant stimuli and ignore distractions. The parietal association cortex integrates sensory information to coordinate attention, helping individuals prioritize tasks and respond to changes in their environment.

    • Motor coordination: The parietal lobe works closely with the motor cortex to plan and execute motor movements. It integrates sensory feedback from the body and surroundings to guide actions, such as reaching, grasping, and manipulating objects.

    • Language processing: The inferior parietal lobule, particularly the angular gyrus, is involved in language processing, including reading, writing, and comprehension. Damage to this area can lead to language disorders such as alexia (reading difficulties) or agraphia (writing difficulties).

    • Mathematical and cognitive functions: The parietal lobe, especially the inferior parietal lobule, is involved in mathematical reasoning, number processing, and abstract thinking. It plays a role in tasks such as calculating, estimating quantities, and solving problems that require numerical cognition.

    5. Physiological Role(s)

    The physiological roles of the parietal lobe are critical for the integration of sensory information, the regulation of attention, and the coordination of motor actions. These roles include:

    • Somatosensory processing: The parietal lobe helps process and interpret sensory inputs from the body. It allows individuals to feel touch, pain, temperature, and pressure, and it helps integrate this sensory information to guide physical actions, such as grasping an object or avoiding a hot surface.

    • Spatial orientation and navigation: The parietal lobe's involvement in spatial awareness allows the brain to create a mental map of the environment. It helps individuals orient themselves in space, navigate through unfamiliar areas, and understand spatial relationships between objects. This ability is essential for tasks such as walking, driving, and arranging objects in a room.

    • Body awareness: The parietal lobe is involved in proprioception, the sense of the body's position in space. It helps individuals perceive where their body parts are located in relation to each other and the surrounding environment. This is important for coordinated movement and balance.

    • Attention regulation: The parietal lobe contributes to the regulation of attention, enabling individuals to focus on relevant stimuli while filtering out distractions. It also plays a role in dividing attention between multiple tasks or stimuli, facilitating multitasking and efficient information processing.

    • Motor guidance: The parietal lobe works in coordination with the motor cortex to guide voluntary movement. It processes sensory feedback, helping the brain adjust motor commands and make fine-tuned adjustments to actions such as reaching for objects or maintaining balance.

    6. Clinical Significance

    The parietal lobe is clinically significant because damage to this region can result in a variety of neurological and cognitive deficits. Some key clinical conditions related to parietal lobe dysfunction include:

    • Hemispatial neglect: Damage to the right parietal lobe can lead to hemispatial neglect, a condition in which individuals fail to attend to or perceive stimuli on the opposite side of the body (usually the left side). This condition is often observed after a stroke or brain injury and can result in neglect of the left visual field, left arm, or left side of space.

    • Agnosia: Agnosia is a condition in which individuals are unable to recognize or interpret sensory stimuli, despite having normal sensory function. Parietal lobe damage can lead to specific types of agnosia, such as tactile agnosia (difficulty recognizing objects by touch) or visual agnosia (difficulty recognizing objects by sight).

    • Apraxia: Apraxia is a disorder characterized by the inability to perform purposeful motor activities, despite having intact motor and sensory function. Damage to the parietal lobe, particularly the posterior parietal cortex, can result in ideomotor apraxia, where individuals are unable to carry out learned motor tasks, such as brushing their teeth or buttoning a shirt.

    • Disorders of spatial awareness: Damage to the parietal lobe can lead to difficulties with spatial awareness and navigation. Individuals may have trouble recognizing the position of their body in space, leading to difficulties with tasks such as walking, reaching for objects, or navigating through crowded spaces.

    • Gerstmann syndrome: Gerstmann syndrome is a neurological disorder that can result from damage to the left parietal lobe. It is characterized by a combination of symptoms, including finger agnosia (difficulty identifying fingers), left-right disorientation, dysgraphia (difficulty writing), and dyscalculia (difficulty with mathematics).

    • Language deficits: Damage to the parietal lobe, especially the inferior parietal lobule, can result in language-related deficits, such as difficulty with reading (alexia) or writing (agraphia). In some cases, this can also include difficulties with speech comprehension and the integration of language with sensory information.

    The parietal lobe plays a crucial role in sensory integration, spatial awareness, and motor coordination. Damage to this region can result in significant cognitive and motor impairments that affect an individual's ability to interact with their environment. Early diagnosis and rehabilitation are essential for managing the effects of parietal lobe dysfunction and improving the quality of life for individuals affected by these conditions.

    Did you know? Neurons communicate with each other using electrical signals called action potentials.