U4 L8 L9 Parts Of The Brain Review PDF

A → Frontal Lobe B → Parietal Lobe C → Temporal Lobe D → Occiptal Lobe E → Cerebellum Frontal Lobe - vo...

A → Frontal Lobe B → Parietal Lobe C → Temporal Lobe D → Occiptal Lobe E → Cerebellum Frontal Lobe - voluntary movements (which are movements you control) of the opposite side of your body - sequencing of complex or multistep movements, such as getting dressed or making a cup of tea - speech and language production in the dominant frontal lobe (opposite your dominant hand) - attention and concentration - working memory, which involves processing recently acquired information reasoning, and judgment - organization and planning - problem-solving - regulation of emotions and mood, including reading the emotions of others - personality expression - motivation, including evaluating rewards, pleasure, and happiness impulse control - Controlling social behaviors Parietal Lobe → Essential for sensing and integrating taste, hearing, sight, touch, and smell, with more brain area dedicated to high-sensitivity body parts like fingers and hands. - Distinguishing between two points, even without visual input. - Localizing touch: When you touch any object with any part of your body, your parietal lobe enables you to feel the sensation at the site of the touch and not, say, in your brain or all over your body. - Integrating sensory information from most regions of the body. - Visuospatial navigation and reasoning: When you read a map, follow directions, or prevent yourself from tripping over an unexpected obstacle, your parietal lobe is involved. The parietal lobe is also vital for proprioception—the ability to determine where your body is in space, including in relationship to itself. For instance, touching your finger to your nose without the assistance of a mirror is a function of the parietal lobe. - Some visual functions, in conjunction with the occipital lobe. - Assessing numerical relationships, including the number of objects you see. - Assessing size, shape, and orientation in space of both visible stimuli and objects you remember encountering. - Mapping the visual world: a number of recent studies suggest that specific regions in the parietal lobe serve as maps to the visual world. - Coordinating hand, arm, and eye motions. - Processing language. - Coordinating attention. Occipital Lobe - The occipital lobe is the part of the brain that processes visual information. It's located at the back of the head and is the smallest lobe in the brain. - Visual perception: Processes color, shape, and movement - Spatial reasoning: Determines the size, distance, and depth of objects - Visual memory: Stores memories of objects, faces, and places - Language and reading: Helps with reading and writing The occipital lobe is primarily responsible for visual processing. It contains the primary visual cortex and the association visual cortex, which are crucial for: -​ Visuospatial processing -​ Distance and depth perception  -​ Color determination -​ Object and face recognition -​ Memory formation The primary visual cortex (also known as V1 or Brodmann area 17) processes visual information from the retina via the thalamus, while the secondary visual cortex (areas V2, V3, V4, and V5) further processes and integrates this visual information. Temporal Lobe - Auditory Processing: Responsible for listening and converting sounds into pictures. - Speech Perception: Enables communication and general speech perception. - Lexical-Semantic Processing: Dominant temporal lobe helps in recognizing words, finding lexemes to express thoughts, and understanding sensory stimulus. - Intonation and Facial Expression Recognition: Non-dominant lobe helps in recognizing intonation and determining facial expressions. - Olfactory Processing: Front and middle temporal compartments are responsible for odor recognition. - Memory Mechanisms: Involved in organizing complex mental processes, especially memory. - Emotional Control: Plays a role in emotion control and processing. - Sensory Integration: Integrates auditory stimuli, sensory linguistic, and visual information. - Spatial Orientation and Spatial Memory: Medial temporal regions are involved in spatial orientation and memory. - Complex Partial Seizures: Medial limbic-emotional part of the temporal lobe can cause seizures affecting emotions, cognition, and autonomic functions. - Personality Changes: Damage can result in personality changes, lack of sense of humor, philosophical religiosity, obsessiveness, and decreased libido in men. - Vision and Sensation: Involved in the analysis and synthesis of speech sounds, auditory, taste, and olfactory sensations. Cerebellum → Although the cerebellum constitutes only 10% of the total brain weight, it contains more than half of all the neurons in the brain - Maintenance of balance and posture. The cerebellum is important for making postural adjustments in order to maintain balance. Through its input from vestibular receptors and proprioceptors, it modulates commands to motor neurons to compensate for shifts in body position or changes in load upon muscles. Patients with cerebellar damage suffer from balance disorders, and they often develop stereotyped postural strategies to compensate for this problem (e.g., a wide-based stance). - Coordination of voluntary movements. Most movements are composed of a number of different muscle groups acting together in a temporally coordinated fashion. One major function of the cerebellum is to coordinate the timing and force of these different muscle groups to produce fluid limb or body movements. - Motor learning. The cerebellum ​ ​ ​ ​ Cranial Nerves 1-12 is important for motor learning. The cerebellum plays a major role in adapting and fine-tuning motor programs to make accurate movements through a trial-and-error process (e.g., learning to hit a baseball). - Cognitive functions. Although the cerebellum is most understood in terms of its contributions to motor control, it is also involved in certain cognitive functions, such as language. Thus, like the basal ganglia, the cerebellum is historically considered as part of the motor system, but its functions extend beyond motor control in ways that are not yet well understood. KEY TERMS Forebrain → The forebrain is located in the uppermost part of the brain. It extends from the top of the brainstem to the top of the head. It's the largest and most developed part of the brain, sitting above the midbrain and hindbrain. → divided into four major regions, cerebellum, thalamus, hypothalamus, and the limbic system Hindbrain → Located at the lower back part of the brain, connecting to the spinal cord. → consists of 3 main parts, cerebellum (voluntary movements, speech, balance), pons (bridge), medulla oblongata (involuntary functions) Midbrain → located just above the hindbrain and below the forebrain. → movement and motor control (substantia nigra) → sensory processing (superior colliculus (visual) and inferior colliculus (auditory)) → alertness and arousal (network of neurons manages sleep-wake cycle) Limbic System → emotion, behavior, and formation of memories Basal Ganglia A structure that processes choice (as in free will), regulates voluntary movement, and coordinates fine motions by working with the cerebellum. Hippocampus A part of the limbic system controls memory and learning (converts short-term to long-term memory) (spatial memory like how to get somewhere) (not a lot of growth of neurons occurs here) Amygdala A part of the limbic system controls emotional reactions, memory and decision- making. Social behavior and stress response (hormonal regulation) Cingulate Gyrus A part of the limbic system controls emotional processing, attention, focus, decision-making, pain and avoidance learning (learning to avoid things that harm us), empathy and social guidance Crocodile Brain → The first step/level of how the brain evolves (brain functioning) so this step is super simple, only completing functions that are necessary to keep you alive. It handles the most fundamental, life-sustaining functions. It's like the foundation of the brain's architecture, ensuring that the essential processes that keep us alive—like breathing, heart rate, and basic instincts—are maintained without conscious thought. → The next level would be the limbic system, for context, babies are born with almost a completely developed limbic system Cerebral Cortex → the outer layer that lies on top of your cerebrum → carries out essential functions of your brain, like memory, thinking, learning, reasoning, problem-solving, emotions, consciousness, and sensory functions Cerebellum → muscle control, balance, language processing and memory Blood-Brain Barrier → a protective barrier that separates the brain's blood vessels from the brain tissue. Its primary function is to regulate the movement of substances between the bloodstream and the brain, ensuring that the brain environment remains stable and protected from potentially harmful substances → The BBB is composed of endothelial cells that line the blood vessels in the brain. These cells are tightly packed together, forming tight junctions that prevent most substances from passing through. While the BBB blocks many substances, it allows essential nutrients like glucose and amino acids to pass through, supplying the brain with the necessary fuel and building blocks. It keeps out harmful substances like toxins, pathogens, and certain drugs, protecting the brain from infections and damage. Glial Cells → Maintains functioning and health of the nervous system → Glial = glue in greek because they were thought to simply hold neurons in place but actually do much more than that 1.​ Macroglia Astroglia (astrocytes) → star-shaped glial cells that provide nutrient support to neurons, helps repair damaged nervous system tissue, regulates communication between neurons, maintains blood brain barrier (keeps toxic substances from entering the brain) Oligodentroglia → responsible for covering neurons with isulatory material called meylin → they meylinate neurons in the CNS Ependymal → found within walls of ventricles where they produce cerebral spinal fluid which then circulates around the brain performing many functions including protecting the brain from injury and removing waste products 2. Microglia → primary immune defense system of CNS, they travel thorugh brain and spinal chord and remove damaged neurons, pathogens, and or foreign substances Meninges → The meninges are three protective layers of tissue that surround the brain and spinal cord, acting like a protective covering for the central nervous system. Dura mater → the outermost layer, and it's thick, tough, and durable → It provides a sturdy protective shield against external trauma and forms several important structures, including the falx cerebri and tentorium cerebelli. Arachnoid mater → The arachnoid mater is the middle layer, and it has a web-like appearance, hence the name "arachnoid," which means "spider-like." → It serves as a cushioning layer and contains the cerebrospinal fluid (CSF) within the subarachnoid space, which helps to protect the brain and spinal cord by absorbing shocks. Pia mater → The pia mater is the innermost layer, and it is thin and delicate. It closely adheres to the surface of the brain and spinal cord, following their contours. → It supplies blood to the brain and spinal cord through a network of blood vessels. It also helps in maintaining the health and nourishment of the nervous tissue. KEY STRUCTURES Pineal Gland → Produce melatonin (influenced by light, more light less melatonin), a hormone that regulates the sleep-wake cycle, also known as the circadian rhythm → By controlling melatonin levels, the pineal gland helps regulate various circadian rhythms → the melatonin release also helps protect cells from damage caused by free radicals Thalamus → receives sensory information from various sensory organs (such as the eyes, ears, and skin) and relays this information to the appropriate areas of the cerebral cortex for processing. This includes sensations of touch, pain, temperature, vision, and hearing. → relays motor signals from the cerebellum and basal ganglia to the motor cortex which helps control voluntary movements → attention, memory, learning, awareness, alertness, emotional processing Basal Ganglia → movement control and coordination → motor learning and the formation of habits → important for various cognitive functions including decision-making, attention, and working memory → emotional regulation Hippocampus → helps short-term memories become long-term memories, allows us to recall information → learning as well as spacial awareness, remembering the route to get certain places Amygdala → integral part of limbic system → role in processing emotions, particularly fear, anger, and pleasure. → emotional memory, behavioural repsonses incuding flight-or-fight → social behaviour like understanding others feelings → Fear and Threat Detection: One of the amygdala’s key roles is detecting potential threats and initiating appropriate responses. This is crucial for survival, as it helps us respond quickly to dangerous situations. Cingulate Gyrus → integral part of limbic system → emotional regulation, cognitive function, pain avoidance, social behaviour Pons → crucial part of brainstem, located between medulla oblongata and midbrain → transmitting signals between different parts of the brain, particularly between the cerebrum and the cerebellum. It helps in coordinating and integrating motor commands. → controls REM sleep, associated with dreaming → It helps regulate breathing patterns by interacting with the medulla oblongata, ensuring smooth and coordinated respiratory rhythms. → It plays a role in facial sensations, facial expressions, and eye movements. Medulla Oblongata → breathing, heart rate, and blood pressure → controls reflex actions, including coughing, sneezing, swallowing, and vomiting Corpus Callosum → connects two hemispheres of the brain and allows them to communicate with each other / transfer information between hemispheres → It helps coordinate functions that involve both hemispheres, such as motor coordination, sensory perception, and complex cognitive tasks like problem-solving and language processing Nucleus accumbens → key structure within the brain's reward system, playing a crucial role in the processing of pleasure, motivation, and reinforcement learning → The nucleus accumbens is involved in the experience of pleasure and the reinforcement of rewarding behaviors. It releases dopamine, a neurotransmitter associated with feelings of euphoria and pleasure, in response to rewarding stimuli. → It plays a role in motivating behavior, driving individuals to seek out rewarding activities and experiences. This includes behaviors related to food, social interactions, and other pleasurable activities. → Reinforcement Learning: The nucleus accumbens is essential for reinforcement learning, helping to strengthen behaviors that lead to positive outcomes. It allows individuals to learn from rewarding experiences and adapt their behavior accordingly.